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prehabilitation

Home fitness monitors versus CPET……do they compare?

The association of pre-operative home accelerometry with cardiopulmonary exercise variables

Anaesthesia. 2018;73(6):738-745. doi: 10.1111/anae.14181. 

Presented by: Dr Megan Burton

Background

This study looks at monitoring activity in patients before major surgery with the aim to identify patients at high-risk of peri-operative morbidity and mortality.

Cardio-pulmonary exercise testing (CPET) is used to access cardiac and pulmonary reserve and identify patients at high-risk of mobility and mortality. However CPET is restricted to particular hospitals and select patients.

This study’s aim is to try and use home-worn accelerometers as a cheaper and more accessible way of measuring pre-operative physical activity to predict adverse outcome in patient undergoing major surgery compared with cardio-pulmonary exercise testing.

Design & Setting

A UK based study comparing methods of measurement of pre- operative cardio-pulmonary fitness. Compares variables measured using a waterproof chest accelerometer which is fitted to the patient at their CPET and is worn continuously at home fore a 72 hour period.

These measurements are compared with Pre-operative cardio-pulmonary testing variables:

  • Peak power
  • Peak Oxygen consumption
  • Anaerobic threshold
  • Ventilatory equivalents for O2 and CO2
  • Predicted values for peak oxygen consumption.

Subjects were also asked to complete two self-reporting questionnaires to estimate physical activity and functional reserve:

  1. The Duke activity status index (DASI)
  2. The SF-12.

The accelerometer measures are compared to PRET measurements using persons correlation coefficient.

 

Subjects

Recruited participants were recruited from patients attending the pre- operative cardiopulmonary exercise clinic.

  • 50 recruited majority of whom were male (42).
  • 48 completed the 72 hours wearing the accelerometer.
  • Mean age 70,
  • Majority ASA 2’s and 3’s.
  • Mean DASI score = 37.6 and mean SF-12 = 44.4.

DASI is a subjective estimate of functional capacity. Maximum score is 58.2, and a score of 37.6 suggests pretty high functionality. i.e. able to walk up a hill, do yard work, climb a flight of stairs.

The SF-12 is a subjective measure of health and well being. the mean score for the US general population is 50.

Intervention

Participates had a waterproof accelerometer strapped to their chest for 72 hours. Accelerometer measures were collected and compared to cardio- pulmonary testing variables, which were collected from a standard CPET involving incremental exercise on a stationary bike whilst attached to ECG, pulse oximetry and gas analysis.This provided information on a number of variables: Peak power, Peak Oxygen consumption, anaerobic threshold, ventilator equivalents for O2 and CO2 and predicted values for peak oxygen consumption. They also asked participants to complete self reporting questionnaires: The Duke activity Status index and the SF-12 to look at baseline exercise capacity.

Outcomes

Primary outcome

Explore the associations between accelerometer variables measured at home with variables measured during cardiopulmonary exercise testing in patients scheduled for major surgery.

Secondary Outcome

Assess the acceptability and feasibility of using an accelerometer to determine the pre-operative activity level of patients.

Accelerometer frequency measures were categorised into activity levels (this categorisation has been previously documented and has shown to be 81–93% accurate compared to of videotape analyses)

Activity levels were categorised into Active, Stationary, and Lying, from accelerometer frequencies using an algorithm. These were compared with CPET variables: Peak power, Peak Oxygen consumption, anaerobic threshold, ventilator equivalents for O2 and CO2 and predicted values for peak oxygen consumption. These were compared using persons correlation coefficient to give an r value.

NB. Persons correlation coefficient is a measure of the linear correlation between two variables X and Y. It has a value between +1 and −1, where 1 is total positive linear correlation, 0 is no linear correlation, and −1 is total negative linear correlation.

Results

Accelerometer values:

  1. Lying 42.6% (12.6%) – No correlation with CPET variables
  2. stationary 53.0% (11.9%) – No correlation with CPET variables
  3. Active 4.7% (3.1%) – linearly correlated with: peak power, Peak O2 consumption, and anaerobic threshold ( r=0.5-0.7). Some correlation with ventilator equivalents for O2 and CO2 (r=<0.5). And no correlation with Predicted values for peak O2 consumption.

Conclusions

Pre-operative accelerometry is feasible and the study did find an association with fitness measured by cardiopulmonary exercise tests. But the accelerometer measurements only correlated when the participants were active, when they were inactive the measure’s did not correlate with CPET variables. There was a large amount of inactivity recorded; 95% were inactive for 24hrs of the day and sedentary for 99% of the time.

Overall the main conclusion they were able to produce was that pre-operative accelerometer is feasible and that its the duration of moderate intensity activity is likely to be the most useful measure of fitness.

 

Strengths

  1. Adequately powered study: The study calculated that a cohort of 47 participants would have 80% power to identify a Pearson’s correlation coefficient ≥ 0.4 at p ≤ 0.05 between an activity variable and either anaerobic threshold or peak oxygen consumption. They achieved 48 participants.
  2. The study was able to show correlation when active between the accelerometer readings and the CPET measurements with an r value of 0.5-0.7 which was the primary aim of the study.
  3. The secondary aim was the access the acceptability and feasibility of using an accelerometer to determine the pre-operative activity level of patients. Patients apparently reported that wearing an accelerometer at home for three consecutive days was acceptable (although 1/4 didn’t complete the 72hr period!).

Weaknesses

  1. Correlation coefficients are not robust so the r value can be misleading and although is widespread method in the analysis of comparing medical testing methods it is generally not considered a very good way.
  2. Chest accelerometers may not pick up activity where the chest is still but the legs are active- such as cycling. Considering patients underwent their CPET on a bicycle it seems unfortunate to miss potential data in this way.
  3. 72 hours is a snap shot of activity and doesn’t predict the potential for activity. Many did not complete the full 72 hour period so may miss some activity. And may not be a good predictor of cardio-respiratory reserve.
  4. One-quarter of the participants did not wear the accelerometer for 72 hrs, which might have limited how representative the results were for the total cohort.

Implications

I’m not convinced the chest accelerometer has the potential to replace CPET in predicting function reserve but perhaps there is a place for their use in the implementation in preoperative cardio-pulmonary exercise interventions. The study suggests that longitudinal methods of daily activity will be used to supplement formal cardiorespiratory fitness assessments but I don’t think theres enough evidence from this study to use it as a productive measure.

Potential for impact?

It may be useful as an activity measuring method in future research for the implementation of pre-operative exercise interventions.

Would an internet-based prehabilitation programme be effective?

Effectiveness of an internet-based perioperative care programme to enhance postoperative recovery in gynaecological patients: cluster controlled trial with randomised stepped-wedge implementation

BMJ Open 2018;8:e017781. doi:10.1136/ bmjopen-2017-017781

Presented by: Dr G Roberts

Background

Perioperative care is often a fragmented process between disciplines, patients, clinicians and hospitals.  A proof of concept trial had previously demonstrated in gynaecological care that an internet-based peri-operative care platform could potentially empower patients during this period; the aim to enhance post-operative recovery through appropriate self-management strategies, reduce inappropriate recovery behaviour and ultimately enable a quicker return to work.

Design & Setting

  • Three year (2011 to 2014) study sequentially across nine hospitals using a stepped-wedge cluster randomised trial (https://www.bmj.com/content/350/bmj.h391)
  • Eligible hospitals had to perform at least 100 hysterectomies or laparoscopic adnexal surgery. Hospitals served as the control group until the care programme was sequentially implemented.
  • Study design did not allow for blinding, but group allocation was concealed from patient until consent obtained. Data analysts blinded.

Subjects

Over 400 employed women aged between 18 – 65 scheduled for surgery of benign gynaecological disease.

Inclusion

  • Scheduled for hysterectomy (vaginal, laparoscopic or abdominal) and/or laparoscopic adnexal surgery.
  • Aged between 18 – 65.
  • Employed for at least eight hours a week.

Exclusion

  • Severe benign comorbidity or malignancy.
  • Pregnancy
  • Computer or internet illiterate.
  • Insufficient command of Dutch language.

Intervention

Internet-based care programme sequentially rolled out using a multifaceted implementation strategy. Patients were allocated to either the care programme (intervention) or usual care (control).  The care programme included an e-health intervention equipping patients with tailored personalised convalescence advice that had been designed by patients, gynaecologists, GPs and occupational physicians. Post-operatively, the web portal contained an interactive self-assessment tool to monitor recovery.

Outcomes

Primary

  • Sick leave duration until full sustainable return to work (defined as the resumption of own work or other work with equal earnings, for at least four weeks without recurrence of sick leave).

Secondary

  • Functional health status
  • Recovery
  • Self-efficacy
  • Coping
  • Pain

 Results

  • 433 participants recruited from potentially 1591.
  • Data for primary outcome obtained from 401 participants while data for secondary outcomes obtained from 334 participants.
  • 8% of participants in intervention group used the website programme as intended.
  • Median duration until full sustainable return to work was 49 days in intervention group and 62 days in control group.
  • No demonstrable difference in functional health status, self-efficacy and coping.

 Conclusions

The use of internet-based information technology to facilitate a gynaecology patient’s perioperative journey may result in a reduction in post-operative sick days.  It would be worth other surgical specialties adopting and evaluating this method, while identifying those patients who might benefit most from this approach.

Strengths

  • Assessment of both patient and organisation.
  • Intention-to-treat.
  • Sub-group analysis.

Weaknesses

  • Cluster design may have led to recruitment bias.
  • The online platform had a proof of concept but not necessarily validated.
  • Just under a third of eligible patients were recruited, the majority of whom either declined to participate or were not eligible.
  • Due to the eligibility criteria requiring employed women who were computer literate, a high proportion of participants were deemed highly educated – How can conclusions apply across the general population?
  • There was significantly more loss-to-follow up in the intervention group.

Implications

  • There is a potentially large positive bio-psycho-social impact if these results are proved to be reproducible.
  • Reduction in sick days would have a positive socio-economic effect.

 Potential for impact

With more focus and energy being applied to the process of perioperative care by many stakeholders and the increasing use of information technology, this approach may prove to empower patients during their perioperative journey and lead to better recovery profiles.  Care is needed however to ensure that there is more to recovery than simply ‘return to work’.

Personalised prehabilitation….the future?

Personalised Prehabilitation in High-risk Patients Undergoing Elective Major Abdominal Surgery. A Randomised Blinded Controlled Trial.

 Annals of Surgery 2018;267(1):50-56 doi:10.1097/SLA.0000000000002293

Presented by: Rebeca Harris ST4

Background

  • Major abdominal surgery is associated with a high rate of postoperative complications, particularly in elderly patients with multiple comorbidities.
  • Aerobic capacity determines postoperative functional reserve, which is negatively associated with postoperative morbidity and mortality.
  • Prehabilitation exercise programmes are postulated to improve aerobic capacity, and thereby reduce postoperative complications.
  • Previous studies have shown a bias towards low-risk patients, and lack of evidence on postoperative clinical outcomes.
  • Prehabilitation is defined as a preparatory intervention aiming to increase aerobic capacity. Methods include supervised endurance exercise training and the promotion of physical activity.

Design & Setting

  • Single centre: Hospital Clinic de Barcelona
  • Patients were blindly randomized
  • Collaborating anaesthetists and surgeons were blinded to patient’s allocation
  • Ethics approved
  • Sample size prospectively powered (as standard, accepting risks of: α 0.05 and β 0.2), based on:
    • the reduction rate of patients with postoperative complications as the main outcome
    • considering the local colorectal complication rate (30%), and
    • anticipating up to 20% drop out
    • Intention-to-treat analysis

Subjects

High risk patients for elective major abdominal surgery

Inclusion criteria:

  • Elective major abdominal surgery
  • High risk defined by all of the following:
    • Age > 70 and/or ASA III/IV
    • Duke Activity Status Index Score < 46
    • Preop schedule allowed at least 4 weeks for the prehabilitation intervention

Exclusion criteria:

  • Non-elective surgery
  • Unstable cardiorespiratory disease
  • Locomotor limitations precluding exercise training
  • Cognitive deterioration impeding adherence to the programme

Intervention

  • Baseline assessment within 1 week of preoperative assessment
  • Reassessment 1 week before surgery

Standard care:

  • Physical activity, nutritional and smoking cessation advice
  • IV iron if indicated for anaemia
  • Nutritional intervention if high-risk for malnutrition

Intervention:

  • Personalised prehabilitation programme based on health and social circumstances
  • Mostly community based
  • 3 major aspects
    • Motivational interview to assess adherence profile. Tailored physical activity programme then co-designed with the patient
    • Personalised daily physical activity programme
      • Pedometer to measure steps, then feedback and optimization
    • Supervised high intensity endurance exercise programme
      • 1-3 per week
      • Exercise bike interval training, tailored to increase intensity over time, based on work rate
      • Pulse oximetry and self-perceived exertion measured

Outcomes

Primary

  • Number of patients with a complication

Secondary

  • Number and severity of postoperative complications
  • Hospital and ICU length of stay

Other

  • Endurance time
  • Distance covered in 6 minute walking test
  • Physical activity (by validated patient survey)
  • Self perceived health status (by validated patient survey)
  • Psychological status (by HADS patient survey)
  • Pulmonary function tests
  • Cardiorespiratory exercise tests

 Results

Baseline characteristics

  • 209 assessed over 3 years – 144 eligible and randomised (> 70 per group, as per power analysis minimum)
  • Comparable patient characteristics between groups
  • 19 did not receive operation, so excluded mid-trial
  • Control: 1 unable to perform exercise testing, 6 abandoned
  • Intervention: 4 unable to perform exercise testing, 4 abandoned
  • 56 (Control) and 54 (Intervention) completed trial (< 70 per group, and > 20% dropout rate, thus underpowered)

 Control

  • No change in baseline characteristics at start vs 1 week pre-surgery

 Prehabilitation intervention

  • Mean duration 6 weeks + 12 supervised exercise session
  • PRMIARY OUTCOME
    • 50% reduction in number of patients with complications: 31% vs 62%, RR 0.5 (95% CI 0.3-0.8), p = 0.001
  • SECONDARY OUTCOMES:
    • Increasein Endurance Time (135%, p < 0.001)
    • Increasein Physical Activity Index (37 points, p< 0.001)
    • No significant difference in intraoperative parameters, but trend towards lower requirement of vasoactive drugs (p=0.053)
    • Lower mean number of complications per patient : Cardiovascular(p = 0.03, RR 0.1, 95% CI 0.1-1.0), Infection of uncertain source (p = 0.013, RR not possible), Paralytic ileus (p = 0.001, RR not possible)
    • In patients with complications, intervention reducedrisk of having more than one complication (RR 0.6, but 95% CI 0.3-1.1), but no effect on severity of complications.
    • Reduced length of ICU stay (3 vs 12 days, p = 0.046)

 Conclusions

  • High intensity endurance exercise training is feasible and safe in elderly and/or multimorbid candidates for major abdominal surgery
  • Prehabilitation enhanced clinical outcomes in high-risk candidates for elective major abdominal surgery, which can be explained by the increase in aerobic capacity
  1. Reduced complication rate
  2. Prevents > 1 complication
  3. Reduced ICU length of stay

Strengths

  • Randomised blinded controlled trial
  • High risk patient group selected, reflecting patient population
  • Initially adequately powered
  • Performed within realistic preoperative timeframe for urgent surgery
  • Highly personalised, patient-centred prehabilitation programme. Well detailed for reproducibility
  • Interesting secondary outcomes, validated tools used
  • Appropriate statistical analysis employed
  • Number of patients abandoning intervention arm < control, thus patient engagement good

Weaknesses

  • Single centre
  • Blinding of clinicians following interaction with patients may have been difficult
  • Underpowered following dropouts – still able to demonstrate statistically significant difference in primary outcome, however may have ‘missed’ other significant differences in secondary outcomes
  • ? Blinding of exercise tester
  • Primary outcome extremely broad – ‘any complications’ postoperatively. Not specific, and therefore clinical significance and importance of question reduced.
  • Survival and functional recovery not assessed
  • Underpowered to assess effect on specific and important post operative complications
  • Did not demonstrate a difference in the severity of postoperative complications
  • Claims significant reduction in CV complications and the number of patients having > 1 complication, but:
    • Reduction in CV complications 95% CI 0.1-1, wide and includes ‘no effect’
    • Reduction in number of patients having more than 1 complication 95% CI 0.3-1.1, wide and includes ‘no effect’
  • Endurance time rather than familiar, objective CPEX data e.g. Anabolic threshold, formed basis of measure of aerobic capacity
  • Intensive, highly tailored programme
    • ? Sustainability on larger scale
    • No cost analysis

Implications

  • Prehabilitation in elderly, multimorbid patients appears to be feasible, safe and ‘acceptable’ to patients
  • Prehabilitation can increase preoperative exercise endurance in high risk patients
  • Postoperative complication rates can be reduced by this strategy
  • However, larger trials are required to further characterise and assess the clinical significance of postoperative complication benefits, and to determine the effect on functional recovery and survival

Potential for impact

  • Important step towards assessing the potential benefits and characterising the design of prehabilitation exercise programmes in high risk patients undergoing high risk elective surgery
  • Important and exciting emerging field of research with potential for significantly improving patient outcomes

 

 

 

Herat rate monitors and prehabilitation. The future?

Evaluation of reliability of MYZONE MZ-3 Heart Rate Monitor: A study for the Future of Telephysiotherapy for Preoperative Prehabilitation in Cancer Patients.

TELEMEDICINE and e-HEALTH 2017;23(4):1-5 doi:10.1089/tmj.2016.0138

Presented by: Dr C Francis

Background

Pre-operative optimisation programs seek to implement a series of interventions to improve and enhance recovery after major surgery. An important aspect of this is the use of exercise programs. The Authors of this paper suggest a major barrier to successful completion of these programs could be inaccessibility of in-hospital supervised exercise programs. There is an increasing abundance of wearable technology, however the accuracy and reliability of commercially available Heart Rate monitors is variable.

Design & Setting

Small, prospective, pilot experiment at single centre in Australia. Small sample (n=7) of young, healthy volunteers without significant medical history and in normal sinus rhythm recruited. Asked to perform increasing intensity effort on exercise bike wearing the MYZONE MZ-3 Heart rate monitor and a clinical 3 lead ECG system. Paired HR measurements to be taken and compared statistically using a Bland Altman plot

Subjects

Seven young physically active, healthy individuals in normal sinus rhythm (mean age 29.7 years; 5 female, 2 male)

Intervention

Asked to complete an exercise on static bike of increasing intensity whilst wearing both clinical 3 lead ECG and MYZONE MZ-3 HR monitor.

Outcomes

1,983 data points collected. Of which 55 data points unpaired as loss of contact with MYZONE MZ-3 HR Monitor. Only paired data sets included. Significantly 5 of the 7 participants had their collected data received out of sync, reported as being due to a failure to manually synchronise time on both MYZONE MZ-3 HR and ECG monitors pre test. Authors included this data after retrospective correction of data by aligning out of sync data, moving the sample to the left by 20 seconds. The authors feel this adjustment of data unlikely to cause any clinically significant effects on results.

Results

Using a Bland-Altman plot able to demonstrate a bias of 0.4bpm, and adjusted 95% limits of agreement (95% LOA) to be -4.5 to +5.3 bpm. And a percentage error [95%LOA/mean HR] of 3.6%

Conclusions

MYZONE MZ-3 has an acceptable level of reliability for use in healthy volunteers performing exercise across a wide range of HR. Further studies using a similar methodology are required to validate the use in patients presenting for cancer surgery.

Strengths

  • Prospective study
  • Appropriate use of statistical analysis to assess reliability and precision of HR monitor.

Weaknesses

  • This study had a very small sample size, of healthy, young volunteers. Therefore, this cannot be extrapolated to those awaiting cancer surgery.
  • None of the participants were noted to have any features which may have produced inaccuracy such as arrythmias, obesity, tremor, pacemakers.
  • A static bike was used and so there was minimal movement artifact.
  • 55 data sets were not paired due to the loss of contact with HR monitor and are not included in reliability figures.
  • Perhaps most significantly there is retrospective alteration of the data collected from 5 out of the 7 participants. Whilst the authors claim this is unlikely to have caused significant effects to the results I fail to see how an experiment with aims of assessing precision and accuracy of a piece of equipment can be deemed safe when 5/7 of data sources have been altered retrospectively.
  •  In addition, there was no structured exercise protocol used and no examination of the cost benefit of the intervention.

Implications

  • Limited at present.
  • Could be deemed a starting point for a project requiring significant further examination.

Potential for impact

Increasing numbers of wearable technologies are available and being used in the community. There is much competition between devices and price points are changing dramatically as with most tech products. The use of these products could be of great use in prehabilitation of pre-operative patients. There is much scope for further investigation and cost benefit analysis of this and similar products.

Perioperative smoking cessation. What works?

A Perioperative Smoking Cessation Intervention with Varenicline, Counseling, and Fax Referral to a Telephone Quitline Versus a Brief Intervention: A Randomized Controlled Trial

Anesthesia & Analgesia 2017;125(2):571-579 doi:10.1213/ANE.0000000000001894

Presented by Dr T. Sheppard

Background

  • Smoking is addictive
  • High health burden with smoking-related diseases (but also high tax revenue)
  • Increased incidence of surgical complications associated with smoking
    • Wound
    • Pulmonary
    • Infection
  • Treatment with chemical & behavioural interventions is effective in reducing smoking in surgical patients – but has not been tested in a pre-op assessment clinic setting
  • Varenicline (Champix®) is effective in increasing abstinence in both surgical & non-surgical patients

Design & Setting

  • RCT
  • Open label
  • Prospective
  • Pre-op assessment clinic with 6 anaesthetists and 1 pharmacist delivering BOTH interventions

Subjects

  • Elective ambulatory and inpatient surgery
  • Preoperative surgical clinics: general surgery, orthopaedics, urology, plastic surgery, vascular surgery, otolaryngology, ophthalmology, and neurosurgery
  • Smokers of at least 10/day with no abstinence for 3 months in past year
  • Equal proportions based on “Stage of Change” i.e. readiness to quit smoking

Exclusions:

  • Patients with contraindications to varenicline (Champix®), pregnancy or breastfeeding, use of nicotine replacement therapy in last 3 months, use of tobacco products other than cigarettes

Intervention

Randomised to either;

A 10- to 15-minute structured preoperative counselling session

and

Pharmacotherapy with a free 3-month supply of varenicline

and

An educational pamphlet

and

A fax referral to a quitline for proactive telephone counselling and follow-up

or

Control group that received brief advice regarding smoking cessation and quitline                information for self-referral

Outcomes

Primary

  • 7-day point prevalence (PP) abstinence at 12 months after surgery

Secondary

  • Abstinence at 1, 3, and 6 months
  • Measurement of urinary cotinine (metabolite of nicotine) levels and expired-air carbon monoxide levels used to prove smoking cessation

Results

  • 18-month period
  • 296 patients randomised (8570 pts screened, 1024 smokers, 788 excluded)
  • Significant increase in smoking abstinence in intervention group vs control (42.4% vs 26.2% (RR, 1.62; 95% CI, 1.16–2.25; P = .003))
  • Significant increase in PP of secondary outcome measures;
    • 1 month: 45.7% vs 25.5% (RR, 1.79; 95% CI, 1.29–2.49; P < .001)
    • 3 months: 46.4% vs 26.9% (RR, 1.72; 95% CI, 1.25–2.37; P ≤ .001)
    • 6 months: 45.0% vs 26.2% (RR, 1.72; 95% CI, 1.24–2.38; P < .001)

Conclusions

  • Smoking abstinence significantly increased in intervention group and was also sustained for a longer period
  • Increased nausea reported in the intervention group, but other complications were no different
  • Significantly greater effect on in-patients than day-surgery

Strengths

  • Significant reduction in short-term and long-term smoking habits
  • Representative cohort of surgical patients

Weaknesses

  • Observer bias – advice given by anaesthetists & pharmacist as opposed to independent researcher
  • Details of surgery were not explored
    • Malignancy
    • Prolonged in-patient stay
    • ITU stay
  • Open label – significant reductions in smoking in both groups
  • Multiple interventions in the intervention group
  • Which part had the biggest impact?
  • Free prescription of Champix® – would otherwise have to be paid for

Implications

  • The smoking cessation methods on display in this trial were very effective
  • Unclear what the potential for long-term outcomes would be compared with a “control” population re: wound healing, pulmonary complications

Potential for impact

  • Some form of smoking cessation advice for surgical patients would likely lead to some reduction in smoking habits
  • With the move to day-of-surgery-admissions it is difficult to find an appropriate time for discussion about smoking cessation
  • Pre-op clinics themselves are extremely busy and with all the other important pieces of information, would smoking cessation be lost in a cloud of do’s and don’ts before surgery?

November 2017

Written by Dr C. Williams

Comparison of postoperative outcomes among patients treated by male and female surgeons: a population based matched cohort study. British Medical Journal 2017;359:j4366 doi:10.1136/bmj.j4366

This is a very interesting article published during a time when the argument about males vs females rages on. One only has to do a quick google search to see some of these arguments relating to the medical profession – from female medics have better outcomes to how the high number of female doctors are destroying the NHS.

This population based, retrospective, matched cohort study looked at patients who had surgery between 2007 and 2015. It looked at death rates, readmissions and complications based solely on the sex of the surgeon. The results suggest that patients treated by female surgeons were less likely to die within 30 days but there was no significant difference in readmission or complication rates. This difference in mortality was small and whether it makes any difference to long term survival is unclear. Interestingly no differences were found for patients who were operated on in emergency situations.

This study was done in Canada where, unlike the NHS, patients can freely choose their operating surgeon. The differences seen for elective surgery would suggest confounding factors play a role. The lack of difference in patients having emergency surgery would back this up. So, although an interesting study it would not suggest that one should pick a surgeon based on their sex alone.

Effect of various duration of smoking cessation on postoperative outcomes: A retrospective cohort analysis. Turn A, Koyuncu O, Egan C et al. European Journal of Anaesthesiology 2017 doi: 10.1097/EJA.0000000000000701 

There is now a solid evidence base that smoking is an independent risk factor for perioperative complications. Smokers are 1.4 times more likely to die after surgery than patients who have never smoked. Active smokers also have higher risks of respiratory, cardiovascular and neurological adverse events and are more likely to have problems with infections.

Preoperative smoking cessation would be expected to reduce postoperative smoking and it would be reasonable to expect that longer period of abstinence would correlate with stronger benefits. But the optimal period of preoperative smoking cessation remains controversial. Several randomised trials conclude that 3 to 8 weeks of preoperative cessation reduce wound complications but briefer periods do not seem to reduce respiratory complications. However, a meta-analysis published in 2011 suggested that each additional week of smoking cessation has a significant impact in the reduction in post-operative complications.

Prospective evaluation of the effects of smoking cessation on postoperative outcomes is not easy – a substantial number of patients do not want to stop smoking and even among those that attempt to stop the success rate is thought to be about 50% which makes it difficult to recruit patients in the context of a defined protocol. This paper was a retrospective cohort analysis of adult patients undergoing non-cardiac surgery with the main outcome easier being the relationship between smoking cessation and in-hospital morbidity/mortality.

The summary of the results is that smoking cessation is associated with reduced in-hospital morbidity and mortality – importantly this was shown to be independent of the cessation interval. From a clinical perspective, patients should be encouraged to stop smoking regardless of the time period before surgery.

Incidence of venous thromboembolic events in enhanced recovery after surgery for colon cancer: a retrospective, population-based cohort study. Moms MI, Vendler TA, Haidari JE et al for the Copenhagen cOmplete Mesocolic Excision Study group (COMES). Colorectal disease 2017 doi:10.1111/codi.13910

Abdominal surgery in patients with cancer is associated with an increased risk of venous thromboembolism (VTE). Both the Danish and NICE guidelines recommend prolonged thromboprophylaxis with low-molecular weight heparin for 28 days after executive surgery for colon cancer. The evidence behind these guidelines relies on randomised controlled trials that included both benign and malignant colorectal disorders or colorectal abdominal cancers pooled with other gastrointestinal tract, urinary tract and gynaecological malignancies including palliative surgery. None of these trials included enhanced recovery after surgery (ERAS) programmes.  This study aimed to investigate the risk of symptomatic VTE in patients undergoing elective resection of colon cancer following an ERAS without prolonged VTE prophylaxis.

This was a retrospective analysis of patient who underwent surgery between 2008 and 2013. The median length of stay was 4 days. Of the 1893 patients included, 4 (0.2%) had a non-fatal symptomatic VTE. All 4 of these patients had other postoperative complications prior to the VTE. The rate of VTE found in this study is much lower that the overall 14% risk quoted after major abdominal or pelvic surgery.

It would appear that the risk of symptomatic VTEs is negligible in patients having colon cancer resection following an ERAS programme with an uncomplicated post-operative recovery. It may be that the early mobilisation in an ERAS programme may contribute to the lower risk. The findings of this study suggest that there is a possibility that prolonged VTE prophylaxis may not be cost-effective in these patients.

However, before any changes are made or guidelines rewritten – this is a retrospective study. It does raise questions but further randomised trials are needed to investigate this further.

Randomised feasibility trial of high-intensity training before elective abdominal aortic aneurysm repair. New GA, Batterham K, Colling J et al. British Journal of Surgery 2017 doi:10.1002/bjs.10669

Abdominal aortic aneurysms (AAAs) are usually asymptomatic until they rupture which then carries an overall mortality rate in excess of 80%. Elective surgery, either open or endovascular, is the most effective treatment for preventing AAA-related rupture and death. Open aneurysm repair in particular is associated with neuroendocrine, metabolic and inflammatory changes that lead to an increase in global tissue oxygen uptake of up to 50%. Patients who have a low cardiorespiratory fitness levels are less able to meet these extra demands which can lead to tissue hypoxia and life-threatening complications. A study published in 2010 found that up to half of the patients presenting for intra-abdominal surgery did not have the fitness levels to be deemed at low risk of perioperative complications as quantified by cardiopulmonary exercise testing.

It seems intuitive that improving cardiorespiratory fitness would lead to reduced complications rates after surgery. The clinical effectiveness and cost effectiveness of preoperative exercise testing has not yet been established. It is unclear whether meaningful improvements in cardiorespiratory fitness can be achieved for patients with a large AAA in the limited window available before surgery (usually 4-6 weeks). This study aimed to look at the feasibility and acceptability of high-intensity training (HIT) for preoperative optimisation of patients with a large AAA. Patients were either randomised to usual care or preoperative HIT consisting of three exercise sessions a week for four weeks.

The preoperative HIT seemed to be feasible and acceptable to patients although twenty of the twenty-seven exercise participants had to have their exercise aims adjusted due to triggering safety criteria (such as a systolic blood pressure over 180mmHg). This may have contributed to the fact that measured cardiorespiratory fitness did not change substantially at group level. However, the results seem to point to a beneficial effect of the exercise programme on health status and physical function for up to 12 weeks after hospital discharge.

This feasibility study points to the fact that preoperative exercise and improving cardiorespiratory fitness could be beneficial. Large, multicentre trials that explore clinical and cost effectiveness are needed before recommendations can be safely made about preoperative exercise programmes.

Echocardiography and passive leg raising in the postoperative period: A prospective observational study. El Hadouti Y, Valencia L, Becerra A et al. European Journal of Anaesthesiology 2017;34(11):748-754 doi:10.1097/EJA.0000000000000679 

Perioperative fluid management is a controversial and challenging issue. Both over hydration and conservative fluid therapy can lead to postoperative complications. The difficulty is that many patients have signs that could suggest hypovolaemia (such as oliguria, tachycardia and hypotension) but not all these patients will respond to fluid administration.

Passive leg raising has been demonstrated to simulate preload increase and distinguish fluid responders from non-responders. Studies validating passive leg raising have been carried out most frequently on non-surgical patients. In this study patients in whom low cardiac output was suspected in the immediate postoperative period were included. A baseline echocardiogram was done then repeated 90 seconds after the patients legs had been elevated by 45 degrees. The measurements were repeated after legs had been lowered and finally repeated again after 500mls of fluid administered as a bolus. An increase in cardiac output of greater than 11% after passive leg raising predicted a volume response following fluid with 68% sensitivity and 100% specificity.

This study had a very low sample size and a note is made of difficulty in carrying out the echocardiogram as left lateral decubitus position is best for the echocardiogram but passive leg raising in this position is not really possible. Despite the positive results the potential benefits or clinical uses of using echocardiography and passive leg raising to determine fluid responsiveness remain to be seen.

Acute kidney injury in trauma patients. Harris A, Libert N, Duranteau J. Current Opinion in Critical Care. 2017 doi:10.1097/MCC.0000000000000463 

Multiple organ failure is a later complication of severe trauma that substantially increases morbidity and mortality. Acute kidney injury (AKI) after trauma is associated with an independent association with prolonged hospital stay and mortality. Severe trauma is a time when several renal aggressions occur at the same time making it challenging to establish a strategy to prevent AKI. Factors such as haemorrhage, rhabdomyolysis, traumatic inflammation and renal hits due to emergency surgery or infections may cause acute renal disorders.

The incidence of severe AKI ranges from 9 to 23% and a total of 2 to 8% of trauma patient will require renal replacement therapy. The main risk factors for the development of AKI in trauma patients include haemorrhage, rhabdomyolysis, trauma inflammation, excessive fluid resuscitation and abdominal compartment syndrome.

Trauma care aims at stopping haemorrhage as soon as possible. The earlier this is achieved the better for tissue perfusion. Post traumatic vasoplegic shock can occur and in this situation attention should be paid to arterial pressure to try to optimise renal perfusion. Fluid resuscitation with balanced solute solutions seem to be the most beneficial for trauma patients with regards to AKI although there are no randomised controlled trials looking at this. What this paper makes clear is that AKI is a very real risk for trauma patients and once the initial trauma resuscitation has been carried out special attention should be paid to maintaining renal perfusion. Given the diverse nature of why patients develop AKI after trauma it is difficult to have one protocol to try to reduce the risk.

Sex differences in mortality after abdominal aortic aneurysm repair in the UK. Sidloff D, Saratzis M, Sweeting J et al.  British Journal of Surgery 2017;104(12):1656-1664 doi:10.1002/bjs.10600

Abdominal aortic aneurysm (AAA) screening has been shown to be effective in men both at reducing AAA-related mortality and in cost-effectiveness. Consequently there is now an established AAA screening programme for men over the age of 65 in England and Wales. The benefit of screening for women has not been established. However, one in seven elective AAA repairs are on women and women account for approximately one-third of all deaths from ruptured AAA. Furthermore women have a fourfold higher rupture rate than men at equivalent aortic diameters which suggests there is a strong case for intimating AAA screening in women. Perioperative risk is critical in determining the effectiveness of a screening programme and risk estimates are lacking for women having AAA repairs.

Data from the UK National Vascular Registry was analysed for a 4 year period from 2010 to 2014 with the primary outcome being in-hospital mortality. 13% of the patients included were women. Mortality rates were higher in women for both elective AAA repair (open or endovascular) and emergency repair. The excess mortality rate was found to be largely independent of age, aneurysm diameter and smoking status. It is not clear why this difference in mortality exists although the Canadian Society for Vascular Surgery Aneurysm Study Group identified that women are more likely to be older, have a positive family history of AAA and have significant aortoiliac occlusive disease.

A well designed trial of matched women and men undergoing elective AAA repair would be needed to explain the differences seen. The higher mortality rate in women may have an impact on the benefit offered by any AAA screening programme.

Which characteristics predict frailty in older men?

Patterns and Predictors of Frailty Transitions in Older Men: The Osteoporotic Fractures in Men Study

Journal of the American Geriatrics Society, September 2017. doi:10.1111/jgs.15003

 Presented by: Dr R. Christie

Background

  • Frailty is a geriatric syndrome leading to reduced physiological reserve. Frail patients are therefore more vulnerable to adverse outcomes i.e. anaesthesia and surgery.
  • 2 small scale studies have suggested that frailty is a dynamic process and prevention and reversal may be possible.

Primary Objectives:

  • To determine patterns and probability of frailty progression and improvement.

Secondary Objectives:

  • To Identify predictors of transitions in frailty status

Design and Setting

  • Prospective observational cohort study across 6 US clinical centres
  • Recruited patients from osteoporotic fractures in men study (MrOS) which used mailings, newspaper advertisements and presentations aimed at older populations to recruit individuals
  • 5,086 men received a second visit at 4.6 +/- 0.4 years after recruitment to MrOS. 908 of the 5,994 originally recruited were not included in the study.

Subjects

  • Men, over 65.
  • 10% from minority groups (African-American, Asian).
  • All lived in the community and were able to walk independently at time of recruitment.

Intervention

  • At recruitment the cohort completed:
    • A self-administered questionnaire which included factors based on socioeconomic status and ADLs.
    • A mini mental state examination to assess cognitive function.
  • A fifth of the men also had physiological parameters measured.
  • Men were classified as robust, pre-frail or frail based on defined criteria at the start and end of the study period and the transition between groups was compared with data from the questionnaires, MMSE and physiological parameters.

Outcomes

Primary Outcomes:

  • Probability of transition between frailty states between visit 1 and visit 2.

Secondary Outcomes:

  • The odds of progression in frailty status from visit 1 to visit 2 based on baseline characteristics.
  • The odds of improvement in frailty status from visit 1 to visit 2 based on baseline characteristics.

Results

Probability of transition:

  • Robust patients:
    • Robust to Robust – 0.6
    • Robust to Prefrail – 0.32
    • Robust to Frail – 0.03
    • Robust to Death – 0.05
  • Pre frail patients:
    • Prefrail to Robust – 0.15
    • Prefrail to Prefrail – 0.55
    • Prefrail to Frail – 0.17
    • Prefrail to Death – 0.12
  • Frail Patients:
    • Frail to Robust – 0.005
    • Frail to Prefrail – 0.16
    • Frail to Frail – 0.45
    • Frail to Death – 0.28

Characteristics that correlate with progression of frailty:

  • DM
  • Instrumental activity of daily living limitations
  • Smoking
  • CCF
  • Low albumin
  • High interleukin 6

Characteristics that correlate with improvement in frailty:

  • Leg power
  • Marriage

Conclusions

  • Improvement in frailty status is possible and is associated with social, functional and clinical factors.
  • Future studies need to target interventions in frail and pre-frail states such as improving strength and lower limb power, improvement management of co-morbidities and social and nutritional support.

Strengths

  • Large study
  • Prospective
  • Well written and presented

Weaknesses

  • Single sex (male) and predominantly white cohort.
  • Residential/Nursing home residents and those living in assisted living not included. May not be representative of the over 65 population.
  • Only two visits over 4.6 +/- 0.4 year period.
    • Did not identify transitions in between visits nor identify ongoing factors that may have influenced transitions e.g. men who stopped smoking
  • Acute illnesses at time of visits may affect results classification of frailty.
  • Did not state cause of death in the 568 patients that died, and was this related to their frailty status.
  • Did not state why over 700 patients were left out of study.

Implications

  • Identified possible targets for intervention that could be further investigated to determine if they improve patient’s frailty scores. These include improving social support networks, smoking and increased physical activity.

Potential for impact

  • Nothing new identified
  • Confirmed what they had hypothesised from data already available
  • This paper is unlikely to drastically change what is already done in in pre-assessment clinics.

August 2017

Written by: Dr C. Williams

Computed tomography during intitial management and mortality among hemodynamically unstable blunt trauma patients: a nationwide retrospective cohort study. Tsutsam Y, Fukuma S, Tsuchiya A, Ikenoue T, Yamamoto Y, Shimizu S, Kimachi M, Fukuhara S. Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine 2017;25:74 doi:10.1186/s13049-017-0396-7

Commuted tomography (CT) is often used as an initial diagnostic procedure in the management of severe trauma. Often jokingly known as the ‘tunnel of death’ or the ‘doughnut of death’ CT scans do not feature in the clinical guidelines for managing a haemodynamically unstable trauma patient. However, it is starting to be used in cases of blunt trauma to identify the source of bleeding and assess for occult internal injury. Evidence for the effectiveness of CT for unstable patients is inconsistent with studies showing benefits, no difference and negative outcomes. This study aimed to examine the association between CT and mortality in unstable patients by retrospectively looking at the data for >5800 patients registered on the Japan Trauma Data Bank between 2004-2014.

The results found that patients who did not have a CT were more likely to have severe physiological conditions and a lower probability of survival than those having a CT. This could be because in Japan, over 90% of unstable blunt trauma patient receive a CT during their initial management. Therefore it stands to reason that if patients are too unstable to have a CT they are likely to have more severe injuries and a lower survival rate. After adjusting for confounding factors they also found that there was not a statistically significant association between CT and mortality.

From these findings the authors state that the results do not support the recommendation of the current guidelines that only haemodynamically stable patients should have a CT. However, and most importantly, the authors go on to say that in almost all hospitals in the database, the CT scanner is located in or very close to the emergency room allowing for rapid CT for unstable patients. Further studies are definitely required before dismissing the very real and serious risk of transporting an unstable patient through hospital corridors, sometimes in lifts to different floors and then putting them through the CT scanner. The decision to do this is not one that should be taken lightly.

Improving care for patients with pancreatitis. Siriwardena AK, O’Reilly DA. British Journal of Surgery 2017 doi:10.1002/bjs.10585

Acute pancreatitis is a condition that can still have mortality rates of up to 30% despite treatment. The mainstay of treatment is rapid diagnosis and instigation of treatment with early identification of patients likely to require critical care. This article summarises the comprehensive 2016 UK National Confidential Enquiry into Patient Outcome and Death (NCEPOD) review looking at the quality of care provided to patients admitted to hospital with acute pancreatitis. Published as ‘Treat the Cause’ it looked at the care of almost 15,000 patients from Wales, England and Northern Ireland during the first 6 months of 2014. Via a survey, multidisciplinary and independent notes reviews and assessing each hospitals infrastructure and support services the patient journey was assessed using the 2012 guidelines for the management of acute pancreatitis produced by the International Association of Pancreatology/American Pancreatic Association (IAP/APA). Overall care was regarded as reasonable with 45% of patients receiving ‘good practice’ care. However there were some key findings that stand out:

  1. In the early stages acute pancreatitis is not infective therefore antibiotic prophylaxis is not recommended. Despite this 61% of patients received prophylactic antibiotics potentially contributing to later problems including side-effects, emergence of antibiotic-resistant bacteria and unnecessary healthcare expenditure.
  2. Gallstone-induced acute pancreatitis should be treated by removing the cause i.e. cholecystectomy. Only 56% of hospitals reported that patients would undergo a cholecystectomy either during the index admission or within the first 2 weeks. This may be reflected by the fact that 30% of recurrent acute pancreatitis admissions were due to untreated gallstones. The recommendation is made that cholecystectomy for mild gallstone-pancreatitis during the index admission should be the standard of care.
  3. Modern management of pancreatitis requires multi-disciplinary care. As patients continue to be admitted to small and medium-sized hospitals this may not be possible as these hospitals may lack the 24-hour specialist care for optimal treatment – recommended as on-call pain team, gastroenterology, specialist surgery, pancreatology, interventional radiology and interventional endoscopy. The suggestion is made for pancreatitis multidisciplinary teams with reference to the Dutch Pancreatitis Study group which introduced a 24-hour/365-day online nationwide multidisciplinary expert panel to guide individual care and give advice on transfer.

The most important lesson from this NCEPOD report is that most of the improvements can be incorporated quickly into routine practice without the requirement for a large-scale financial investment or service reconfiguration.

In reality the second and third key findings may be more difficult to achieve without some degree of service reconfiguration. Cholecystectomies added to the emergency list invariably get delayed from day to day until they disappear from the list as they are often the least urgent cases. Maybe the surgical teams need to embrace this report and use it to highlight the need for ‘hot’ cholecystectomy lists to hospital management?

Preoperative geriatric assessment and tailored interventions in frail older patients with colorectal cancer. A randomized controlled trial. Ommundsen N, Wyller TB, Nesbakken A, Bakka AO, Jordhøy MS, Skovlund E, Rostoft S. Colorectal disease 2017 doi:10.1111/codi.13785

This randomised controlled trial looked at whether tailored interventions based on a preoperative geriatric assessment could reduce the frequency of postoperative complications in frail patients having surgery for colorectal cancer. Patients over the age of 65 and fulfilling the criteria for frailty were randomised to either the intervention group or usual care.

The intervention group underwent a preoperative geriatric assessment followed by tailored intervention – all performed during one session, as soon as possible after the diagnosis of colorectal cancer and surgery was planned. The optimal time from intervention to surgery was hypothesised to be approximately 3 weeks. Interventions were optimisation of medication for conditions such as atrial fibrillation, coronary disease, diabetes mellitus, renal failure and COPD, addressing nutrition and advice to increase calorific intake along with vitamin D and iron supplementation as needed and stopping inappropriate medciation such as antihypertensives if found to be hypotensive and nephrotoxic medication for patients with renal failure. Staff on surgical wards were instructed on measures to avoid postoperative delirium and patients were encouraged to maintain physical activity.

The primary endpoint was the incidence of postoperative complications, defined as any deviation from standard postoperative recovery. Perhaps unsurprisingly there was no difference in the complication rate between the two groups either for the primary endpoint or the secondary endpoints of length of stay, discharge to own home, readmittance, reoperation within 30-day or 30-day and three-month mortality figures. The intervention group did have a lower rate of less severe complications although not significant.

There are certain elements of this study that jump out immediately as cause for concern. Despite an inclusion period initially of 2 years and then prolonged to 3 and a half years only 122 patients were included. This seems a very small number and below the number calculated by the authors as required to power the study. This is recognised by the authors as a limitation. There were other limitations in this study which may have contributed to the lack of effect such as a very short time between intervention and surgery, no access to a multi-disciplinary team such as physiotherapy and occupational therapy, and suboptimal improvement in preoperative physical function. Furthermore, although the time from intervention to surgery was planned to be 3 weeks the initiation of the study coincided with a political decision to reduce waiting times for cancer patients and the time available for optimisation was reduced to a median of 6 days – to my mind this would not count as optimisation in any way.

The conclusion by the authors is that preoperative geriatric assessment and intervention is not effective. As the authors rightly point out further randomised controlled trials are needed to explore this further. This study highlights that although instinctively prehabilitation and particularly improving the patient’s preoperative functional ability seems the right and sensible approach, we have not quite reached a consensus on how to achieve this. It may also be coming to the point where the governmental targets need to address the fact that some patients would benefit from preoptimisation. Although they may have a cancer that needs an operation, the patient is more than just a cancer or a number for a target. Some patients need preoptimisation and without it can have a stormy perioperative journey, some may not survive. Regarding the patient as a whole entity rather than just a condition requiring surgery may be the way forward. These issues were looked at in both the June* and July** journal watch, both worth a read but with a particulerly interesting article by Sothisrihari et al. asking precisely the question about whether pre-optimisation of colorectal cancer patients should come before the 62-day pathway?

*Should pre-operative optimisation of colorectal cancer patients supersede the demand of the 62-day pathway? Sothisrihari S, Wright C, Hammond T. Colorectal Disease 2017 doi:10.1111/codi.13713

**Prehabilitation in perioperative care. Moorthy K, Wynter-Blyth V. British Journal of Surgery 2017;104(7):802-803. doi:10.1002/bjs.10516

Preoperatively screened obstructive sleep apnea is associated with worse postoperative outcomes than previously diagnosed obstructive sleep apnea. Fernandez-Bustamante A, Bartels K, Clavijo C et al. Anesthesia & Analgesia 2017 doi:10.1213/ANE.0000000000002241 

About 80 to 90% of patients with obstructive sleep apnoea (OSA) are undiagnosed when presenting for surgery. Additionally, rates of OSA are increasing in parallel with obesity rates. OSA is known to be associated with perioperative morbidity, but what is not know is whether patients with a day-of-surgery screened OSA diagnosis are also at risk of perioperative adverse events.

This study looked at retrospective data for almost 29,000 patients. Patients were groups as diagnosed OSA, pre-operatively screened OSA or no OSA. Patients with suspected OSA compared to those with diagnosed OSA had higher rates of postoperative reintubation, ventilation and critical care admission, prolonged length of stay in hospital and all-cause 30-day mortality even after adjusting for demographic, health and surgical differences. This study indicates that patients with suspected OSA are a group that fall into a high-risk population and would probably benefit from increased medical attention and focused care. The STOP-BANG tool has been found to have the best predictive value for OSA screening. This study highlights a common problem in that the inability to obtain preoperative diagnostic testing for OSA contributes to the high proportion of patients at moderate/high risk for OSA presenting for surgery without a formal diagnosis. The results of this study indicate that anaesthetists can reliably detect patients with suspected OSA who would fall into a high risk group for postoperative complications. Interestingly the risk for these patients is greatest beyond the immediate postoperative period. This echos the findings of the paper studied in the July journal watch.*

It could be that the worse postoperative outcomes seen in patients with suspected OSA is a reflection of a lack of awareness and appropriate postoperative management of the preoperative screening diagnosis of OSA. What is not yet clear is the best way to manage these patients. Admitting everyone to a critical care area for observation would not be feasible option in the majority of centres, but it is clear that these are a group of patients that may benefit from multidisciplinary interventions and a higher level of postoperative care.

* Postoperative respiratory complications in patients at risk for obstructive sleep apnea: a single-institution cohort study. Ramachandran SK, Pandit J, Devine S, Thompson A, Shanks A. Anesthesia & Analgesia 2017;125(1):272-279 doi:10.1213/ANE.0000000000002132

Regional anesthesia in diabetic peripheral neuropathy. ten Hoope W, Looije M, Lirk P. Current Opinion in Anesthesiology 2017;30:000-000 doi:10.1097/ACO.0000000000000506

Diabetes mellitus is a steadily increasing and underestimated problem. The prediction of more than 350 million diabetic patients worldwide by the year 2030 was passed in 2011. Consequently, the predicted number of diabetic patients by 2040 is set at 642 million. Approximately 10% of diabetic patients are symptomatic for diabetic neuropathy. Added to this fact is that diabetic patients are estimated to require surgery at least twice as often as non-diabetic patients and due to their comorbidities and the types of surgery performed they are more likely to undergo procedures under regional anaesthesia such as creation of arteriovenous fistula.

Regional anaesthesia is generally well tolerated but neuropathy may alter the way nerves respond to nerve blocks or neuraxial techniques. There is no current consensus on whether regional techniques should be avoided or need to be adapted in these patients. The pathophysiology behind the development of diabetic neuropathy is complex. Chronic hyperglycaemia is thought to trigger several pathways initially leading to inflammation and oxidative stress then causing microvascular changes, local iscaemia and decreased axonal conduction velocity.

In practice the implications of these changes are:

  1. The threshold of nerve stimulation is markedly increased meaning ultrasound guidance rather than electric nerve stimulation is most likely safer.
  2. Nerve blocks last much longer in the presence of diabetic neuropathy – the precise mechanisms for this is not known and using clinically relevant doses no excessive toxicity of local anaesthetics have been demonstrated in animal models.
  3. If a peripheral nerve catheter is used, diabetes is an independent predispoising risk factor for infection.

Despite these findings the authors conclude that there is no good clinical data to suggest that regional anaesthesia should be withheld from diabetic patients.

Development and assessment of pictorial guide for improved accuracy of visual blood loss estimation in cesarean delivery. Homcha B, Mets EJ, Goldenberg MDF et al. Simulation in Healthcare 2017 doi:10.1097/SIH.0000000000000246 

It is known that visually estimating blood loss during surgical procedures is an inaccurate method. During caesarean section the decision to administer blood products is often influenced by the estimated blood loss combined with clinical signs. However, estimating blood loss at caesearean section is complicated by a large volume loss for a short period of time as well as the presence of amniotic fluid. Maternal physiological changes during pregnancy can also exacerbate existing underestimation and overestimation of blood loss. The decision to give blood products is a balance between the risk of a blood transfusion versus the risk of haemorrhage, shock and potential death.

Previous studies have shown that higher blood loss correlates with less accurate estimated blood loss. Early identification of postpartum haemorrhage is a key factor in patient outcome and should be recognized before clinical changes reflect significant blood loss. This study hypothesized that a pictorial guide depicting materials commonly used during caesarean section and various measured blood volumes with the addition of simulated amniotic fluids would improve clinician accuracy in visual blood loss estimates.

A simulated caesarean scene was used to assess the accuracy of blood loss estimation with estimates done before and after access to the pictorial guide with participants allowed 3 minutes to assess blood loss. Initially, 52% of participants estimated more than 25% above or below the actual blood loss volume. With the use of the pictorial guide clinicians became more accurate with 93% of anaesthetists and all obstetricans estimating within 25% of the actual blood loss value.

There were limitations to the study – it had a small number of participants, the number of nurses/midwives was too small to be analysed and it was a simulated scenario, not assessed in a clinical scenario. It does however highlight that an institution specific pictorial guide tailored to the materials used (swabs etc.) may help to improve estimated blood loss, identification of postpartum haemorrhage and ultimately improve management and patient outcome.

Intraoperative music application in children and adolescents – a pilot study. Buehler PK, Spielmann S, Buehrer A et al. Acta Anaesthesiologica Scandinavica 2017 doi:10.1111/aas.12935

Hospitalisation, surgery and anaesthesia may affect children or adolescents leading to new-onset maladaptive behaviour, emotional distress and trauma. Maladaptive behaviour can include separation anxiety, temper tantrums, night-time crying, enuresis, general anxiety or poor appetite and has been described in up to 50% of paediatric patients after general anaesthesia. Other common effects after surgery are pain levels and post-operative nausea and vomiting, the occurrence of which and the treatment may interfere with other behaviour related outcomes.

In adult patients, exposure to intraoperative music has been shown to significantly lower pain levels. This was a pilot study to look at the effect of applying intraoperative music to paediatric aptients and its effect on behaviour, pain, nausea and vomiting. Children aged 4 to 16 years scheduled for elective circumcision or inguinal hernia repair under combined general and regional anaesthesia were included. They all wore headphones intraoperatively and were either exposed to music or not. All staff involved were blinded. Post-operative behaviour was recorded by parents on day 7, 14 and 28 post-surgery using an adapted ‘Post Hospital Behavioural Questionnaire’.

This study showed that intraoperative music in children undergoing minor surgical procedures may reduce the incidence of post-operative maladaptive behavior within the first post-operative week. However, it does not affect post-operative patient comfort, pain level, nausea or vomiting. This was a pilot study with a small number of participant so there are still some unanswered questions. But on first glance music appears to be beneficial and be a non-invasive and feasible application with minimal cost and effort.

Randomized clinical trial of psychological support and sleep adjuvant measures for postoperative sleep disturbance in patients undergoing oesophagectomy. Scarpa M, Pinto E, Saraceni et al. on behalf of the QOLEC group. British Journal of Surgery 2017 doi:10.1002/bjs.10609

Sleep disturbance is a common problem in hospital patients. It is particularly severe in those patients requiring a stay in the intensive care unit (ICU) usually related to noise, light as well as the critical illness itself and treatment events. Disrupted sleep is associated with increased morbidity and mortality and often remains a significant issue at 6 months after discharge from ICU. Oesophagectomy is a complex operation with a 50% risk of medical or surgical complications. Each hospital varies slightly in its approach but post-operative admission to ICU is usually required for at least 1-2 days followed by strict monitoring on the ward for a further 4-5 days. During this time patients will usually have at a minimum a chest drain, a central line and a nasogastic tube. As well as causing discomfort they contribute to sleep disturbance. It is thought that by enhancing the quality of sleep after oesophagectomy early quality of life may be improved.

This was a randomised controlled trial aiming to assess the effectiveness of psychological interventions and/or sleep adjuvant measures on postoperative sleep disturbance following oesophagectomy. Patients were allocated to one of 4 groups: psychological counselling for support plus measures to reduce sleep-wake rhythm disorders during ICU stay (sleep adjuvant measures), psychological counselling alone, sleep adjuvant measures only or standard care.

The trial was terminated early due to a move to a different ICU. Consequently only small numbers of patients were included. However, the results suggest that psychological support did appear to improve the early postoperative quality of life and reduced the impairment on sleep quality, latency and duration. Sleep adjuvant measures (quiet corner of ICU, earplugs and eyemasks) made no difference. Additionally, psychological intervention led to a significant decrease in the need for hypnotic drugs which is an independent predictor of poor postoperative quality of life. Further studies would be needed to determine whether psychological intervention helps but it is clear that we should be addressing sleep issues early in our patients to aid postoperative recovery.

 

July 2017

Written by: Dr C. Williams

A national survey of the effects of fatigue on trainees in anaesthesia in the UK.  McClelland L, Holland J, Lomas J-P, Redfern N, Plunkett E. Anaesthesia 2017 doi:10.1111/anae.13965

This article publishes the results of a survey carried out by two Welsh trainees looking at the impact of fatigue reported by anaesthetic trainees. With news headlines of junior doctors dying following crashes while driving after night shifts and recent BBC Inside Out South coverage of a junior doctor’s driving ability after a night shift* this is an important topic to look at. Since the introduction of the European Working Time Directive in 2009 the working patterns of junior doctors have changed with far more shift work and often rotas that change from days to nights and back again very quickly. Also with training arranged in the way it is now, many trainees may move hospital every 6 months to 1 year, sometimes over large geographical areas.  Maybe this issue has always been the case, maybe we are more aware due to increased knowledge, understanding and recognition of the effects of fatigue but what is clear is that it is not something that can be ignored. The results of this survey highlight some worrying figures. High numbers of trainees say that fatigue has affected their physical health, psychological wellbeing, personal relationships and ability to train including exams, audits/QI projects. A high proportion reported being involved in an accident or near miss when travelling home after a night shift. This has implications both to the safety of the trainee and to the public.

This survey has highlighted this important issue. It has been a contributing factor in the establishment of a ‘fatigue group’ in association with the AAGBI, GAT and the RCoA. There have been efforts made by some trusts to highlight the risks of fatigue and provide strategies and advice to help junior doctors. Of course, fatigue is not something that only affects doctors or even just healthcare professionals but anyone who works shifts particularly night shifts. Although this survey only concentrates on one set of junior doctors, it would seem sensible that strategies that work for trainee anaesthetists to cope with fatigue may be generalizable to other groups of people affects by this issue. Hopefully highlighting the problem of fatigue and supporting doctors, managers and trusts on how to tackle this issue will make things safer for doctors, and ultimately our patients and the public.

*http://www.bbc.com/news/av/uk-england-berkshire-38716140/doctors-fall-asleep-driving-after-punishing-night-shifts-the-bbc-learns

Prehabilitation in perioperative care. Moorthy K, Wynter-Blyth V. British Journal of Surgery 2017;104(7):802-803. doi:10.1002/bjs.10516

This is article looking at prehabilitation and the role it plays in patients with upper gastrointestinal cancer. It is a well known fact now that there are greater demands placed on surgical systems with the patient population undergoing major abdominal surgery becoming older and increasingly frail with multiple co-morbidities. This is coupled with organizational issues such as a drive for earlier postoperative discharge and with surgeons facing increased scrutiny of their work and complication rates in response to governmental and public demands for greater transparency. High-risk patients are undoubtedly at greater risk of adverse postoperative events and a longer recovery time. The article talks about enhanced recovery programmes which are well established in many surgical specialties and have led to post operative outcome improvements. However, they mainly focus on the intraoperative and postoperative phases of the patient journey. The concept of prehabilitation is based on the principle that amongst other things, structured exercise in the preoperative period will provide the patient with a ‘physiological buffer’ to withstand the stress of surgery. Although preoperative exercise is associated with improved preoperative functional capacity there is currently limited evidence to show that it improves postoperative outcomes. There are several clinical trials in progress that aim to address this evidence gap. Importantly, prehabilitation must be about more than just exercise. Addressing all the other factors that contribute to outcome such as body weight, nutrition, alcohol, smoking and the critical but often forgotten psychological aspect. The preoperative period is an ideal opportunity to make the most of a ‘teachable moment’ and emphasise the importance of making positive lifestyle changes. This is an exciting area that is being explored. The publication of new clinical trials should provide some answers. Future research is needed possibly looking at cost-effectiveness and how prehabilitation can be linked to enhanced recovery pathways. Ultimately the aim is a better outcome for the patient.

Claims for compensation after injuries relating to airway management: a nationwide study covering 15 years. Fornebo I, Simonsen KA, Bukholm IRK, Kongsgaard UE. Acta Anaesthesiologic Scandinavica 2017 doi:10.1111/aas.12914

One of the anaesthetist’s ‘raison d’être’ is to manage the airway by whichever method they chose for the given situation – facemask, oral or nasal airway, a supraglottic device or an endotracheal tube. However, no method is risk free and all may cause complications ranging dental damage, soft tissue trauma through to catastrophic complications due to failure to secure the airway. A subset of patients have specific characteristics that may mean we can predict a likely difficult airway. Equally there are patients who have none of these characteristics yet are found to have a difficult airway at induction of anaesthesia.

Although not common, disastrous outcomes with failed or difficult tracheal intubation are well known to anaesthetists. An integral part of our training is the learning strategies to manage both the anticipated and unanticipated difficult airway.

This study looked at compensation claims relating to airway management over a 15-year period in Norway. 0.8% of claims relating to anaesthesia involved airway management. 38% of claims related to dental injuries. Severe injuries were defined as failed intubation, misplaced endotracheal tube, aspiration or a ‘miscellaneous’ group. They accounted for 10% of all the claims but made up 37% of claims relating to emergency procedures. Interestingly all claims made from patients needing airway management in a pre-hospital setting and 87% of the claims from ICU were rejected. This may reflect the situation in which airway management is considered a life-saving procedure.

Although the results of this study are specific to Norway it serves to highlight that airway management can result in complications and we should continue to be vigilant particularly in emergency cases.

Intraoperative ketamine for prevention of postoperative delirium or pain after major surgery in older adults: an international, multicenter, double-blind, randomized clinical trial. Avidan MS, Maybrier HR, Abdallah AB, Jacobsohn E et al. The Lancet. 2017;390(10091):267-275 doi:10.1016/S0140-6736(17)31467-8

In patients over the age of 60 delirium is one of the most common complications and is associated with increased morbidity and mortality. It has many causes and the pathophysiology is not completely understood which makes it difficult to predict and treat. In surgical patients risk factors are likely to be pain, treatment with opioids and the inflammatory response to injury. In theory a drug that provides analgesia and prevents delirium would be an important advance in perioperative medicine. A postoperative infusion of dexmedetomidine has shown promise although further studies are recommended. However, this drug is expensive and requires a continuous intravenous infusion therefore is unlikely to be a practical solution.

It has been reported that intraoperative subanaesthetic ketamine administration reduces postoperative pain, reduces postoperative opioid requirement and reduces the postoperative markers of inflammation. Based on this the study authors hypothesise that intraoperative ketamine may reduce the incidence of postoperative delirium. But ketamine is also well known to be a psychoactive drug with hallucinogenic properties so could theoretically contribute to postoperative delirium.

This multicentre study randomly allocated patients to one of three groups – placebo (to receive normal saline), low dose ketamine (0.5mg/kg) or high dose ketamine (1mg/kg) to be given after induction of general anaesthesia but before surgical incision. They found that there was no difference in the incidence of delirium in any of the groups and there were more postoperative hallucinations and nightmares with increasing doses of ketamine.

In conclusion, ketamine does not reduce postoperative delirium and may actually increase harm by increasing the incidence of hallucinations and nightmares. Ketamine use has increased particularly with the introduction of enhanced recovery programmes – maybe the time has come for some further studies regarding its use in elderly patients.

Falls from the O.R. or procedure table. Prielipp RC, Weinkauf JL, Esser TM, Thomas BJ, Warner MA. Anesthesia & Analgesia 2017. doi:10.1213/ANE.0000000000002125 

Patients falling from the operating table is a scenario that thankfully most anaesthetists will not encounter. I know of one event that happened in a neighbouring theatre when I had just started my anaesthetic training. The patient was unharmed and that was the last I heard about it. The American Society of Anesthesiologists highlights that anaesthesia is the practice of medicine with one of its primary foci being ‘management and preservation of patient safety’. A patient falling from the operating table is a clear breakdown of this responsibility and can have medical, professional, legal and financial consequences.

This study looked at claims recorded in the Anaesthesia Closed Claims Project database looking for claims associated with falling from the year 2000 to now. There were 21 claims identified – 15 in patient having general anaesthsia and 4 in those receiving regional anaesthesia. Approximately half of the claims resulted in payouts to the patients ranging from $18,000 to $925,000. Patient falls from the operating table must be considered preventable adverse events. Injuries from falls such as these can be catastrophic including brain damage, paralysis and even death.

This paper talks very much about the anaesthetists duty and role in preventing falls. The reality is that it should preventing falls should be shared responsibility for every member of the team. Many of the falls occurred when patients were partially sedated or awakening from general anaesthesia and potentially confused or agitated. From experience this is the time at which other staff may be distracted and concentrating on other tasks. The entire operating theatre team need to be proactive in maintaining patient safety at all times.

 

Perioperative COX-2 inhibitors may increase the risk of post-operative acute kidney injury. Abrahamsson A, Oras J, Snygg J, Block L. Acta Anaesthesiologica Scandinavica 2017;61(7):714-721 doi:10.1111/aas.12912

This was a study looking at patients who had undergone pancreaticoduodenectomy. In 2012, enhanced recovery after surgery (ERAS) guidelines were published for these patients recommending a restrictive fluid regimen to avoid the fluid overload that has been shown to be hazardous for these patients. Acute kidney injury (AKI) is not uncommon after major abdominal surgery and is known to be a major cause of postoperative morbidity and mortality. Perioperative hypotension and hypovolaemia are known to contribute to AKI.

Anaesthetists in Gothenburg, Sweden made the observation that patients undergoing open pancreatic surgery with an ERAS restrictive fluid protocol were more likely to develop postoperative AKI and spend longer on ICU. Consequently, they reviewed the notes of patients who underwent pancreatic surgery prior to the introduction of the ERAS fluid protocol and compared this to patients who underwent surgery after the introduction of the ERAS fluid protocol. They found that the incidence of AKI was significantly higher in the patients who underwent surgery using the ERAS restrictive fluid protocol (13% vs 2% in the pre-ERAS patient group). They also found that COX-2 inhibitors were given more frequently to patients in the ERAS group.

They concluded that the combination of a goal-directed restrictive fluid therapy with the administration of COX-2 inhibitors significantly increases the risk of AKI.

Postoperative respiratory complications in patients at risk for obstructive sleep apnea: a single-institution cohort study. Ramachandran SK, Pandit J, Devine S, Thompson A, Shanks A. Anesthesia & Analgesia 2017;125(1):272-279 doi:10.1213/ANE.0000000000002132 

Obstructive sleep apnoea (OSA) is not an uncommon condition and is thought to affect up to 25% of middle-aged men and up to 10% of middle-aged women. It has a significant impact on quality of life, life expectancy, cardiovascular disease and respiratory disease. Recent evidence also suggest that it is associated with a 3 to 6 times increase in post-operative respiratory complications. The majority of patients with OSA remain undiagnosed and preoperative screening remains the most efficient method to identify those at risk.

This retrospective observational study looked back over the notes of 108,479 patients and assigned OSA risk retrospectively using the Perioperative Sleep Apnea Predictive (PSAP) score*. They found that a high PSAP score was associated with a higher incidence of postoperative respiratory complications and an increased need for postoperative intubation. Other factors that were associated with postoperative respiratory complications include the anaesthetic agent used, neuromuscular blocking agents and opioid use.

Patients with suspected OSA should be identified, assessed and commenced on appropriate treatment preoperatively where possible. They may also require a modification of the anaesthetic technique used to try to minimize the risk of postoperative respiratory complications (PRCs) and a recognition that they are at higher risk of developing PRCs.

*Ramachandran SK, Kheterpal S, Consens F et al. Derivation and validation of a simple perioperative sleep apnea prediction score. Anesth Analg. 2010;110:1007-1015

Body height and the spread of spinal anaesthesia for caesarean section: a prospective controlled trial. Acta Anaesthesiologica Scandinavica 2017;61(7):824-831 doi:10.1111/aas.12928

Spinal anaesthesia is the preferred anaesthetic technique for caesarean sections. However, as this article rightly points out there is a considerable variability in the dose regimens used. As a trainee one only has to ask several different consultants to realise that each one has a preferred dose for the ‘best’ spinal anaesthetic! The aim is a dose of intrathecal bupivacaine that maintains anaesthesia but minimizes the risk of maternal hypotension. Several patient variables are usually factored into predicting the spread of spinal anaesthesia including age, height, weight and body mass index. The time required to achieve an adequate sensory block for surgery tends to increase linearly with height and decrease with increasing weight.

This study hypothesized that shorter patients need a lower spinal anaesthesia dose than taller patients. 270 pregnant women were assigned to either the tall (T) group or shorter (S) group. Both groups were then randomly assigned to one of nine subgroups of intrathecal ropivacaine dose (between 7-15mg). They found that height did not significantly affect the height of the block achieved with the different doses. However, larger ropivacaine doses were associated with increased hypotension which was more pronounced in shorter patients.

This was a small study and maybe separating patients on height alone is too simplistic to answer the question. Ultimately, the answer as to the best dose of local anaesthetic for spinal anaesthesia remains to be discovered.

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