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Welsh Anaesthetic Trainees Journal Club

Month

September 2017

Journal Club: 20th September 2017

Postoperative delirium in elderly patients is associated with subsequent cognitive impairment. Sprung J, Roberts R, Weingarten T et al.

British Journal of Anaesthesia 2017;119(2):316-323

Presented by: Dr I. Roberts

Background  

Paper examined the risk for postoperative delirium (POD) in patients with mild cognitive impairment (MCI) or dementia, and the association between POD and subsequent development of MCI or dementia in cognitively normal elderly patients.

Design & Setting

  • Ran by Mayo clinic.
  • Made use of a cohort that already available on a database to ascertain if patients with cognitive dysfunction experienced post operative delirium.
  • Patients 65 yr of age enrolled in the Mayo Clinic Study of Aging who were exposed to any type of anaesthesia from 2004 to 2014 were included.
  • Cognitive status was evaluated before and after surgery by neuropsychological testing and clinical assessment, and was defined as normal or MCI/dementia.
  • Postoperative delirium was detected with the Confusion Assessment Method for the intensive care unit.

 Subjects

  • In 2004, 70–89 yr olds were identified from a Mayo Clinic Database, randomly selected, and invited to participate in the study.
  • In 2008, ongoing recruitment was initiated using the same protocols as baseline
  • In 2012, the lower limit of the age criterion was reduced to 50 years of age.
  • The study includes all participants enrolled and examined in person in the MCSA study from November 2004 to February 2014 who underwent surgeries and procedures under anaesthesia at Mayo Clinic in Rochester, MN, USA
  • Only participants who were 65 yr of age at enrolment were included.

 Intervention

  • Nil specific intervention.
  • The use of the CAM ICU scoring system was used to identify post op delirium.
  • A pre and post op cognitive impairment screen was used to ascertain both baseline and post op cognition levels.

Outcomes

Claimed to have confirmed previous findings that in a general surgical population elderly patients with cognitive dysfunction at the time of surgery are at higher risk for clinically evident post op delirium compared with patients without mild cognitive impairment.

Main finding is that elderly patients who are cognitively normal at a detailed assessment performed before surgery and who experience clinically evident post op delirium are more likely to develop cognitive impairment or dementia subsequently compared with those who do not experience post op delirium.

Results

  • The frequency of POD was higher in patients with pre-existing cognitive impairment compared with no cognitive impairment/dementia.
  • The frequency of MCI/dementia at the first postoperative evaluation was higher in patients who experienced POD compared with those who did not.

Conclusions

Mild cognitive impairment or dementia is a risk for post op delirium. Elderly patients who have not been diagnosed with cognitive impairment but experience post op delirium are more likely to be diagnosed subsequently with cognitive impairment or dementia.

Strengths

  • Ambitious project.
  • Made us of a large source of data that was readily available.
  • Appeared to confirm a notion that is already in existing literature.
  • Made use of validated means for detecting both cognitive dysfunction and post op delirium.

Weaknesses

  • Observational study only.
  • Mixed methodology with observation both retrospective and prospective.
  • Data observational in nature with no firm validated intervention being studied.
  • Lots of the conclusions seem to be inferred.
  • Did not drill into the data to ascertain if there was one particular factor causing post op delirium.
  • Did not offer any insights into how this phenomenon may be tackled in the future.
  • The journal club group felt it was a weak paper with no rigorous methodology that could be used to garner meaningful results.
  • Appears that this group had a large data set and used it to contrived this paper, which doesn’t appear to clinically add anything to this known phenomenon that already exists in the literature.

Implications

The reader will be aware of the notion that the long term effect of anaesthesia can result in cognitive impairment. The reader will also be appreciative of the fact that post op delirium can contribute to cognitive decline in at risk patients over time.

Potential for impact

  • Raises awareness amongst trainees about this phenomenon.
  • Impact level is poor due to weaknesses within the paper.

 

Journal Club: 12th September 2017

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.

Journal Club: 8th September 2017

Secondary analysis of outcomes after 11,085 hip fracture operations from the prospective UK Anaesthesia Sprint Audit of Practice (ASAP-2)

Anaesthesia 2016;71:506–514

Presented by: Dr M. Adamson

Background

Lack of high quality, prospective evidence to support particular anaesthetic practices for patients with hip fracture. RCTs are difficult to perform and observational studies are mostly retrospective case series with significant data omissions or concerns about data quality.

The National Hip Fracture Database (NHFD) collects observational data from >95% of all new cases of hip fracture in the UK (except Scotland), which can be audited against national standards.

The Anaesthesia Sprint Audit of Practice (ASAP) project, published 2014, was a national snapshot audit embedded within NHFD, collated anaesthetic and peri-operative variables for patients undergoing hip fracture surgery.  ASAP-1 found ‘striking’ inter-hospital variation in anaesthesia care, reflecting the uncertainties about what methods of anaesthesia might provide the best outcome for older, frailer patients with comorbidities requiring surgical hip fracture repair.

By revisiting the data collected for ASAP-1 and linking it to outcome data held by the NHFD, ASAP-2 aimed to determine whether there were any statistically significant associations between peri-operative patient factors, anaesthetic factors and outcomes.

Design & Setting

Data was taken from the ASAP-1 database and NHFD database. The original data was collected prospectively in the ASAP-1 database and then each patient was followed up for outcomes in the NHFD. The data collection period was May 1 2013 to July 31 2013.

Subjects

Patients >60yrs old who had hip fracture surgery between May 1 and July 31 2013 at one of 182 UK hospitals that routinely contribute to NHFD.

Intervention

There was no specific intervention. All patients underwent hip fracture surgery and the following data was collected.

Patient variables on hospital admission: age; sex; comorbidities; ASA physical status; place of residence (home, sheltered, rehabilitation, residential home, nursing home, inpatient, other); independence (self-caring/home-help/sheltered/residential/nursing); and cognition (abbreviated mental test score).

Dates and times of hospital admission and surgery; the type of anaesthesia administered (general, nerve block, spinal); the type and quantity of intrathecal injectate; the seniority of operative surgical and anaesthetic personnel; intra- operative blood pressures; and signs of bone cement implantation syndrome.

Systolic and diastolic blood pressures recorded at two times: immediately before commencement of anaesthesia; and the lowest recorded intra-operative value. Mean arterial blood pressure calculated as the diastolic pressure plus one-third of the difference between systolic and diastolic pressures. 

Outcomes

Outcome measures were recorded:

  • Postoperative cognition and residential destination on discharge.
  • Mortality at 30 postoperative days
  • Mortality 5 days after hospital admission.
  • Post-operative length of stay (the time from surgery to discharge from the acute hospital) 

Results

The NHFD recorded 16,904 operations between 1st May and 31st July 2013.

  • 11,130 (67.5%) were audited by ASAP-1
  • 45 duplicate records
  • 11,085 analysed in ASAP-1 and 2

The proportion of cases for which the anaesthetic technique was categorised identically by the National Hip Fracture Database and the ASAP data collectors ranged from 35% for general anaesthesia to 88% for general anaesthesia supplemented by epidural, peripheral nerve or surgical site injection of local anaesthetic.

No differences were found in outcomes (Mortality 5 day/30 day, length of stay, deterioration in cognition, independence or residential status) when comparing type of anaesthetic given.

Patients cared for by a combination of consultant or specialist surgeon and anaesthetist were on average one year younger (than patients cared for by other grades) but more often were ASA physical status 4 or 5 (p < 0.0001 for both). There were no differences in outcomes apart from survivors spent 0.7 days (17 h) less in hospital after surgery by a combination of consultant or specialist surgeon and anaesthetist, compared with other grades.

Mortality at five and 30 postoperative days was associated with lower intra-operative blood pressures.

  • The OR (95% CI) for 30-day mortality was 0.992 (0.986–0.998) for each 5 mmHg increase in systolic pressure, p = 0.0075, and 0.985 (0.977–0.992) for each mmHg increase in mean pressure, p < 0.0001. Similar relationships were seen for five-day mortality odds ratios. These relationships persisted when adjusted for Nottingham Hip Fracture Score.
  • An intra-operative systolic blood pressure below 85 mmHg compared with higher systolic pressures was associated with higher mortalities: five-day mortality 64/3,062 (2.1%) vs. 78/ 7,427 (1.1%) respectively, p = 0.017; 30-day mortality 181/3,062 (5.9%) vs. 338/7,427 (4.6%) respectively, p = 0.013.

The relative fall in systolic blood pressure was weakly correlated with more sub- arachnoid bupivacaine: r2 0.10 and 0.16 for hyperbaric and isobaric bupivacaine, respectively. A 20% relative fall in systolic blood pressure correlated with 1.4 ml hyperbaric bupivacaine 0.5% and 1.5 ml isobaric bupivacaine 0.5%.

Conclusions

No association between mortality and anaesthetic technique

No association between mortality and

  • Day of the week
  • Time of day
  • Grade of surgical or anaesthetic personnel

Mortality at 5 days and 30 days postoperatively were associated with lower intra-operative blood pressures

Lower intra-operative blood pressures were weakly associated with higher volumes of intrathecal local anaesthetic.

Strengths

  • Prospective data
  • Large numbers of patients
  • Data point completion rates (>90% of most fields)
  • ASAP data input by anaesthetists about anaesthesia likely to be more accurate than NHFD

Weaknesses

  • Observational study therefore can only say associations not causation
  • Results only as good as data input – incomplete data sets therefore affect results
  • Only included 67.5% patients who fractured their hip during the 3 month study period
  • The 30 day mortality rate for this period was lower than the annual average (5.1% vs 8.0%) which may be a reflection of some missing dat from hospitals that didn’t participate
  • Some of the hospitals eligible that weren’t included had higher than  average mortality rates and hence useful data may have been missed

Implications

  • Mode of anaesthesia makes no difference……its more about how you conduct anaesthesia
  • Avoid hypotension during anaesthesia for hip fracture surgery

Potential for impact

  • Only associations so not major impact but large numbers and suggestions are seem pragmatic

September 2017

Written by Dr C. Williams

The incidence and characteristics of 3-month mortality after intraoperative cardiac arrest in adults. Hur M, Lee H-C, Lee KH et al. Acta Anaesthesiologica Scandinavica 2017 doi:10.1111/aas.12955

Intraoperative cardiac arrest (IOCA) is thankfully a relatively uncommon event. In 2002 a study in the US reported rates of IOCA as high as 19.7 per 10,000 anaesthetic events. However more recent studies have given rates of 27-43 per 100,000. In contrast to most other in-hospital or out-of-hospital cardiac arrests IOCA generally occur in monitored patients and resuscitation is started immediately. Nevertheless IOCA is generally associated with poor clinical outcomes and a high in-hospital mortality rate (approximately 66%).

The majority of studies looking at IOCA have focused on the characteristics of the arrest or the optimal management. Very few studies have looked at clinical outcomes after IOCA. This study was conducted in Japan and looked at the records of almost 240,000 adult patients who underwent a surgical procedure under general anaesthetic from January 2005 to December 2014. 101 patients who suffered IOCA were identified but after exclusions 50 records were looked at. Excluded were brain dead organ donors and patients on cardiopulmonary bypass or ECMO. The primary outcome was 3-month mortality after IOCA.

The rate of IOCA in this study was 21 per 100,000 patients. Nineteen patients died in the operating room and a further 12 died within 3 months (mortality 62%). Three survivors had unfavourable neurological outcomes at 3 months. IOCA occurred most commonly during the maintenance phase of anaesthesia, followed by pre-induction. The most common initial cardiac rhythm seen was VF/VT. The most common cause of IOCA was pre-operative patient complications (42%), followed by surgical complications (36%) then anaesthetics related events (14%). In immediate non-survivors of IOCA, the incidences of emergency surgery, out of hours operating, pre-operative patient complications, need for intra or post arrest transfusion, were all higher. These patients also had higher total doses of adrenaline and a longer duration of cardiac compressions.

Although the overall incidence of IOCA has decreased, the outcomes remain largely unchanged compared to previous studies. It appears that IOCA in patients being operated on out-of hours results in a higher immediate mortality although not a higher unfavourable outcome in survivors. The exact cause for this is difficult to ascertain, mainly due to the fact that the number of IOCA are thankfully very small meaning that the numbers of patients included in the analysis for this study was only 50. Various other factors appear to be implicated as risk factors for immediate mortality after IOCA but no definite conclusions can be made. The ultimate conclusion is that a large-scale study into IOCA and risk factors associated with 3-month mortality is needed.

Postoperative complications in individuals aged 70 and over undergoing elective surgery for colorectal cancer. Colorectal disease 2017 doi:10.1111/codi.13821

Almost 60% of colorectal cancer cases are diagnosed in patients aged over 65-years. For non-metastatic disease surgery is the best management. In more advanced stages, surgery may be indicated for symptom relief such as obstruction, perforation or bleeding. It is known that elderly patients undergoing major surgery are higher risk. This study identified 190 patients between 2009-2015 undergoing colorectal resection aged over 70 years of age. Medical and surgical postoperative complications were reviewed and outcomes analysed comparing length of stay, critical care admission, 30-day readmission rates, 30-day and 1-year mortality.

97.9% of the patients were classified as ASA III or above with 60.5% assessed as fitting the criteria for frailty on geriatric preassessment. Medical postoperative complications occurred in 40.5% of patients whereas surgical postoperative complications occurred in 17.9%. The most common medical complication was infection with urinary tract infection, lower respiratory tract infections and catheter related sepsis being top of the list. The next most common category of medical complications was transient confusion or altered mental function. The most common surgical postoperative complications were surgical site infections and the need for reoperation.

The complications were classified using the Clavien-Dindo (CD) Classification system into CD grade 2 and CD grade 3 (more severe). CD grade 2 complications occurred in almost 40% and grade 3 in just over 10%. Unsurprisingly the more severe the complication the longer the postoperative length of stay – CD grade 2 resulted in a 114% increased postoperative length of stay, CD grade 3 by 162%. CD grade 2 complications did not significantly alter readmission or mortality (at 30 days or 1 year). However, grade 3 complications were associated with an increase in 1-year mortality rates. A complication of CD grade 2 or above increased the need for critical care admission.

Comparison of the results from this study to others looking at postoperative complications are difficult because many studies do not specify the definitions used for complications or derive data from ICD-9 coding. However, it is clear that complications can have a significant impact on the perioperative surgical course. Medical complications are more common therefore surgeons should have medical expertise concerning the most common medical postoperative complications. For vulnerable, multimorbid older patients collaboration with other medical specialties and a multi-disciplinary approach is of paramount importance to provide the best overall care for this group of patients.

Impact of reversal strategies on the incidence of postoperative residual paralysis after rocuronium relaxation without neuromuscular monitoring: a partially randomised placebo controlled trial. Nemes R, Fülesdi B, Pongrácz A et al. European Journal of Anaesthesiology 2017;34(9):609-616 doi:10.1097/EJA.0000000000000585 

There has been many recent papers looking at postoperative residual paralysis and the impact it has on postoperative recovery. The evidence indicated that there is a significant incidence of residual paralysis particularly when neuromuscular function is not monitored. Many anaesthetists argue that they can ensure adequate recovery of neuromuscular function without the need for a nerve stimulator and without having to give neostigmine. There has also been some concern about the use of neostigmine due to its undesirable muscarinic side-effects and its limited ability to reverse even a moderate neuromuscular block. Sugammadex is now well established as an alternative to neostigmine for the reversal of a neuromuscular block by encapsulation of the steroidal neuromuscular blockers. The cost of sugammadex compared to neostigmine is significant meaning that in several institutions its use is closely controlled. Studies published studying the reversal of rocuronium with sugammadex did not find any postoperative residual neuromuscular block in the first 60 minutes compared to a significant proportion of patients given neostigmine.

This was a partially randomised, placebo controlled, double-blind study aiming to investigate the incidence of postoperative residual neuromuscular block using acceleromyography after spontaneous recovery of rocuronium-induced block, compared to administration of sugammadex, neostigmine or a placebo. Patients undergoing surgery were given a general anaesthetic with propfol, fentanyl, sevoflurance and rocuronium. Neuromuscular block was measured by acceleromyography. If the anaesthetist deemed that pharmacological reversal was needed the patient was then randomly allocated to receive sugammadex (2mg/kg), neostigmine (0.05mg/kg) or a placebo. In recovery an independent anaesthetist blinded to the treatment given then reassessed the neuromuscular function using acceleromyography. The main outcome measure was a train-of-four measurement of less than 0.9 on arrival in recovery.

The results indicated that pharmacological reversal was more effective than spontaneous recovery of a neuromuscular block. No agent was 100% effective but there were less incidences of a residual block in patients given sugammadex than those given neostigmine. What was highlighted by this study was that the residual block in patients allowed to spontaneously recovery and those deemed to need pharmacological reversal but randomised to receive a placebo was no different. This would indicate that clinically estimating who should need reversal or not may not be the best method. Studies have indicated that the incidence of a clinically relevant residual block by anaesthetists is less than 1%. This study demonstrated a significant residual postoperative neuromuscular weakness requiring rescue treatment in 8.8% of patients. Although it could be argued that the higher rates may have been detected due to a higher level of monitoring and awareness during the study, this highlights the risk of unmonitored muscle relaxant use.

There are limitations to this study the main ones being very small groups of patients and only rocuronium was studied. Yet overall, this study serves as a reminder that neuromuscular blocks should be monitored and reversed adequately. Other studies have shown that inadequate reversal is implicated in the development of respiratory postoperative complications. The incidence of a residual block after sugammadex was significantly lower than neostigmine. The sharp reality in todays NHS is that the cost of sugammadex is a limiting factor and as such it should maybe be reserved for patients at particular risk of undesirable effects of a residual neuromuscular block.

Angiotensin II for the treatment of vasodilatory shock. Khanna A, English S, Wang X et al for the ATHOS-3 Investigators. New England Journal of Medicine 2017;377:419-430 doi:10.1056/NEJMoa1704154

Vasodilatory shock, the most common type of shock, is characterised by peripheral vasodilation and reduced blood pressure despite preserved cardiac output. Patients with severe vasodilation who have hypotension despite the use of high doses of vasopressors have a poor prognosis with a 30-day all cause mortality of over 50%. This was a randomised, double-blind, placebo controlled phase 3 trial to determine whether the addition of angiotensin II to background vasopressors would improve blood pressure in patients with catecholamine-resistant vasodilatory shock.

Vasodilatory shock requires prompt treatment to ensure organ perfusion through the reestablishment of adequate blood pressure while the underlying cause of the shock is identified and treatment. Vasopressors are used when intravenous fluid resuscitation alone fails to restore blood pressure.

Treatment available for patients with catecholamine-resistant vasodilatory shock are limited and the available treatments often have associated side-effects. Options include glucocorticoids, vasopressin, methylene blue and high-volume hemofiltration. New therapies have so far proved to be disappointing. The nitric oxide inhibitor 546C88 increased blood pressure in patients with septic shock but was associated with more frequent cardiovascular side-effects and increased mortality at 28-days.

In the ATHOS-3 trial (Angiotensin II for the Treatment of High-Output Shock) the primary endpoint was the response of mean arterial blood pressure (MAP) at hour 3 with a response either being a MAP >75mmHg or an increase above baseline of at least 10mmHg without an increase in vasopressor dose. Patients were included if they had vasodilatory shock unresponsive to fluid resuscitation (defined as at least 25ml/kg of body weight over the previous 24 hours) and high dose vasopressors (defined as 0.2mcg/kg/min of noradrenaline or equivalent). Patients were randomly assigned to either receive synthetic human angiotensin II or saline placebo. Significantly more patients given angiotensin II met the primary end-point criteria. In fact, for those given angiotensin II the MAP increased rapidly and the dose of both angiotensin II and vasopressors were able to be reduced. The rate of adverse events (specifically tachyarrhythmias, distal ischaemia, ventricular tachycardia and atrial fibrillation) were similar in the both the angiotensin II and the placebo groups.

The study had a relatively small sample size so the possibility of clinically important side-effects related to angiotensin II cannot be excluded. Also follow-up was only for 28-days so either beneficial or harmful long-term effects of angiotensin II therapy cannot be excluded. Larger trials of longer duration are needed to answer these questions and to directly compare angiotensin II with other vasopressors.

ICU admission after surgery: who benefits? Ghaffar S, Pearse R, Gillies M. Current opinion in critical care 2017;23(5):424-429 doi:10.1097/MCC.0000000000000448

The number of operations performed each year continues to grow and combined with an aging population, more and more procedures are performed on patients who previously may not have been considered for surgery. The last decade has also witnessed an increased recognition of the importance of and improvements in perioperative care. Overall mortality rates after surgery are low at 0.5% but complication rates are higher with the global figure suggested to be approximately 16% with complications being associated with an increase in mortality.

The incidence of adverse events will obviously vary by surgery, institution, region and nation. Differences in the process of care are often given as a cause in particular the access to critical care beds. Admission to ICU has been a standard after certain types of surgery for many years, however, ICU resources particularly in the UK are limited and expensive. Having the ability to identify those patients that would benefit the most from critical care admission is a major issue for those delivering perioperative care. The ability and need to identify high-risk patients, develop pathways to signpost to the most appropriate postoperative care placement and methods to allow as early detection as possible of the deteriorating patient are all vital to improve outcomes and best utilise finite resources.

Evidence from large epidemiological studies suggest that for many patients undergoing major elective surgery routine ICU admission may not provide any additional benefit and may contribute to an increase length of hospitalisation and cost. The evidence also suggests that for patients undergoing major emergency surgery where there is insufficient time to optimise comorbidities or where there is any other major physiological derangement are best managed in a critical care setting.

A study published in 2013 found that ICU bed provision and rate of admission did not correlate with overall mortality. In fact, countries that had the lowest mortality rates after surgery also had the lowest rates of ICU admission. An explanation for this could be the use of alternatives to ICU admission in some of the best performing European countries. Patients recovering from major elective noncardiac surgery require prompt and effective treatment of pain, hypothermia, cardiorespiratory compromise, fluid imbalance combined with early mobilisation and enteral nutrition. The main way that ICU provides a benefit in these scenarios is the access to high quality nursing care. This can be delivered in less intensive environments such as post anaesthetic care units or specialist wards. In this way patients will still receive a higher level of nursing care along with early identification of deterioration and rapid access to relevant services such as critical care outreach.

Another consideration is that of the use of ‘fast-track’ pathways in cardiac surgery for low to moderate risk patients. They have been established for many years and appear to be safe and shorten the ICU stay without increasing complication rates. Maybe this is an area that needs further exploration for noncardiac major elective surgery.

Clearly the benefits of ICU admission for many types of major surgery remain uncertain. Identifying the patients most at risk of death and complications following surgery remains the major challenge for perioperative care. As pointed out in this review, future research should focus on how postoperative care can best be structured to provide patient optimum care within the available resources.

Risk factors for peripheral nerve injuries following neuraxial labour analgesia: a nested case-control study. Haller G, Pichon I, Gay F-O, Savoldelli G. Acta Anaesthesiologica Scandinavica 2017 doi:10.1111/aas.12951

Neuraxial anaesthesia is the most common method for either labour analgesia or anaesthesia for delivery. Post-partum lower extremity motor and sensory dysfunctions occur in between 0.1-9.2% of deliveries and are a well known complication in obstetrics. Usually these symptoms are transient and resolve spontaneously within a year. For a small minority the damage is permanent. While the damage is easily identified the causation may be more difficult. Anecdotally and personal experience is that any type of neurological problem tends to be blamed on the neuraxial anaesthesia. Although most published data indicates that these complications are related to compression of the nerve roots, plexus and peripheral nerves due to obstetric factors (femoral nerve, lateral femoral cutaneous nerve, obturator nerve, pudendal nerve and common peroneal nerve). There are other studies that associate non-obstetric-related factors with peripheral nerve injuries mainly radiculopathies or catheter injuries.

The most feared but fortunately rare complication of neruaxial anaesthesia is an injury to the central nervous system. This paper quotes the rate as 1:145,000 to 1:240,000. This is comparable to the 2009 Royal College of Anaesthetists NAP3 report that quotes the cases of permanent harm relating to central neuraxial block in obstetrics as 1:80,000 to 1:320,000.

This study collected data from almost 20,000 obstetric patients having neuraxial procedures in the Maternity Department of Geneva University Hospital, a tertiary referral centre where over 80% of deliveries are performed under neuraxial anaesthesia. 19 patients (0.96%) were found to have peripheral nerve injuries. According to neurologists 15 of these cases were likely related to compression or tractions by the baby’s head or obstetric manoeuvres/instrumentation. In four cases a nerve root injury due to the Tuohy needle were suspected. Other risk factors for nerve injury included a gestational age >41weeks, late initiation of neuraxial anaesthesia, repeated anaesthetic procedures, assisted delivery with forceps and a newborn birth weight of >3.5kg.

This paper highlights that although patient and anaesthetic factors contribute to peripheral nerve injuries, obstetric related factors are the most prominent risk. Thankfully overall motor and sensory dysfcuntions following delivery and neuraxial anaesthesia are rare and typically self-limiting. Despite this fact the risk of nerve injury by a Tuohy needle or catheter insertion should not be minimised particularly as symptoms can persist for a long length of time and have a significant impact on the patient’s quality of life.

Early definitive treatment rate as a quality indicator of care in acute gallstone pancreatitis. Green R, Charman S, Palser T. British Journal of Surgery 2017 doi:10.1002/bjs.10578

The incidence of acute pancreatitis is rising with it now being one of the most common intra-abdominal emergency conditions. The most common aetiology is gallstones with them being implicated in 35 – 40% of pancreatitis cases. The available evidence and current guidelines recommend that patients with mild gallstone pancreatitis should have definitive treatment of their gallstones during the same hospital admission or within two weeks of discharge. Definitive treatment is namely a cholecystectomy or if unfit for surgery an endoscopic sphincterotomy. Adherence to these recommendations improves patient outcomes and reduces hospital length of stay and the risk of further episodes of pancreatitis. Compliance with guidelines is variable. This study aimed to examine variation in patients receiving early definitive treatment for gallstones following an episode of acute gallstone pancreatitis and determine its validity as an indicator of quality of care.

Using information from the Hospital Episode Statistics database just over 19,500 patients were identified. Of the patients only 6733 received early definitive treatment within two weeks of discharge. In total 28.5% received treatment during their admission and a further 6% had treatment within two weeks of discharge. In the 1-year follow up 23.9% of patients had one or more emergency admissions for gallstone pancreatitis related complications. 33.8% were readmitted within 2 weeks with the remaining 66.2% of readmissions occurring after the point at which the patient should have had early definitive treatment. Early treatment was associated with a 39% reduction in readmissions.

This study seems to support the idea that early definitive treatment for gallstone pancreatitis is associated with improved patient outcome. As well as improving patient morbidity and mortality the reduction in readmission rates with early treatment is associated with potential cost savings. This issue was touched on in the August journal watch.* This study provides further evidence to suggest that maybe surgeons and anaesthetists alike should take ‘hot’ cholecystectomies seriously.

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

How to better identify patients at high risk of postoperative complications? Talmor D, Kelly B. Current opinion in critical care 2017;23(5):417-423 doi:10.1097/MCC.0000000000000445 

As already discussed more patients are presenting for surgery at a later age with more co-morbidities. The challenge is how to identify the patients most at risk of postoperative complications. The aim of preoperative risk assessment is to help identify patients at increased risk of complications and allow appropriate postoperative management to be planned, ultimately to lead to improved patient outcomes.

There are a multitude of prediction scoring systems that can be used – covering them all in this short synopsis is impossible. However, most prediction scores predict postoperative mortality with, at best, moderate accuracy. Score incorporating surgery-specific and intraoperative events may improve the accuracy of traditional scores. The more ‘traditional’ risk factors of increased ASA score, emergency surgery, intraoperative blood loss and haemodynamic instability are consistently associated with increased mortality using most scoring systems.

Preoperative clinical risk indices and risk calculators estimate surgical risk with moderate accuracy. Surgery-specific risk factors are helpful in identifying patients at increased risk of 30-day mortality. Particular attention should be paid to intraoperative haemodynamic instability, blood loss, the extent of the surgical incision and the volume of resection in prioritising patient admission to higher levels of postoperative care.

Ultimately the prediction of postoperative complications remains difficult. Independent risk factors for worse outcomes include increasing age, frailty, chronic renal failure and poor cardio-respiratory reserve despite having at best only moderate discriminatory value. Many anaesthetists still appear to feel that risk scoring is a waste of time. It is an area that is developing but at the moment the risk scoring systems we have are the best that are currently available. There is no doubt that they only give predictions and no matter how good a scoring system is, it will never and can never be 100% accurate. But in a healthcare system where resources and critical care beds not infinite they can be useful in trying to prioritise which patients need higher levels of care postoperatively.

 

Journal Club: 29th August 2017

Validation of preoperative cardiopulmonary exercise testing-derived variables to predict in-hospital morbidity after major colorectal surgery.

British Journal of Surgery. West MA, Asher R et al. 2017;103: 744–752

Presented by Dr L. Emmett

Background

  • Major colorectal surgery carries substantial morbidity and mortality – 30 day mortality of 2.9%
  • Risk stratification permits collaborative decision making, optimisation and effective utilisation of hospital resources
  • CPET is an objective measure of physical fitness under stress, mimicking surgery
  • This study aimed to assess the predictive value of selected CPET variables and their association with in-hospital morbidity in major elective colorectal surgery

Methods

  • 6 UK hospitals recruited consecutive adult patients over a 3 year period

Inclusion criteria

  • Major elective colorectal surgery

Exclusion criteria

  • Emergency surgery
  • Neoadjuvant chemotherapy
  • Lower limb dysfunction
  • Inability to consent
  • Inflammatory bowel disease
  • Distant metastases

 

  • CPET was conducted according to American Thoracic Society and American College of Chest Physician guidelines
  • Standard protocols used for all patients – observations recorded were heart rate, 12 lead ECG, blood pressure and pulse oximetry. Ventilation and gas exchange were monitored using a metabolic cart
  • In-hospital morbidity was measured at 5 days post op using an objective scoring system, Dindo score and post op 30 day mortality were also recorded

Primary aim

  • Compare the postoperative morbidity score and the V02 at lactate threshold and peak exercise

Secondary aims

  • To compare multi variable relationship between patient demographics, CPET variables and post operative in hospital morbidity

Intervention

  • Statistical analysis of CPET variables matched with POMS tool
  • 425 patients to be recruited to demonstrate that these variables were better than chance at risk prediction

Results

  • 7% had postoperative complications
  • VO2 lactate threshold <11.1ml/kg/min and VO2 peak threshold <18.2ml/kg/min were associated with a statistically significant increase in post operative complications
  • BMI >27 and open procedures (rather than laparoscopic) associated with increased complications

Conclusions

  • There was a statistically significant increase in postoperative morbidity in those patients with a lower VO2 at lactate threshold, VO2 at peak, and O2 pulse at lactate threshold

Strengths

  • Conclusion matches primary aim
  • More evidence that CPET testing is valuable, potentially selecting appropriate patients and risk stratifying
  • Potential for increasing CPET provision, funding and awareness
  • No adverse effects
  • Strong statistical significant observed
  • In keeping with findings from other studies

Weaknesses

  • No new knowledge, only backing up existing evidence
  • Unblinded study, CPET data used in clinical management
  • Centre to centre variations in findings
  • CPET isn’t the whole story!

Implications and Potential for Impact

  • Further increasing evidence base
  • Increase provision of CPET services
  • Stimulate further research in high risk patients
  • Asks questions about utilisation with other risk scoring systems

 

Journal Club: 15th August 2017

Hydrocortisone, vitamin C and thiamine for the treatment of severe sepsis and septic shock

Chest 2017;151(6):1229-1238

Presented by Dr A. Wood

Background

  • Sepsis has a substantial global burden estimated at 15 to 19 million cases per year
  • Timely diagnosis and treatment have improved 28 day mortality to 25% in high income countries
  • Mortality rates approach 60% in low income countries
  • As well as short term mortality patients suffer multiple short and long term complications and have a reduced quality of life and increased risk of death for up to 5 years
  • Thiamine deficiency is associated with increased mortality in sepsis
  • Vitamin C maintains endothelial boundaries and is required for catecholamine synthesis
  • Vitamin C deficiency is correlated with multi-organ failure and death

Design & Setting

  • Retrospective observational study
  • Single centre study based in US
  • June 2015 – July 2016

Trial Question

Does intravenous vitamin C, hydrocortisone and thiamine in addition to standard treatment, improve mortality in ICU patients with severe sepsis or septic shock, compared with standard treatment alone?

Subjects

  • Included all patients with severe sepsis or septic shock and a procalcitonin level of >2ng/ml (based on 1992 American College of Chest Physicians/Society of Critical Care Medicine Consensus definitions)
  • Control group was first 7 months (47 patients)
  • Intervention group next 7 months (47 patients)
  • Baseline characteristics (demographics, diagnosis, co-morbidities, positive blood cultures and interventions) similar in each group

Exclusions

  • Patients <18 years old
  • Pregnancy
  • Patients with limitations of care

Intervention

  • All patients received standard intensive care treatment
  • The intervention group also received:
  • 1.5g QDS vitamin C IV for 4 days or until ICU discharge
  • Hydrocortisone 50mg QDS IV for 7 days or until ICU discharge followed by a 3 day taper
  • 200mg thiamine BD for 4 days or until ICU discharge

Both groups

  • Received empirical broad spectrum antibiotics (then deescalated according to microbiological data/clinical progress)
  • Managed with a conservative physiologic based fluid and vasopressor strategy
  • Ventilated with lung protective strategy
  • Received limited use of sedative agents (dexmedetomidine preferred)
  • Noradrenaline was vasopressor of choice titrated to MAP >65mmHg
  • Enteral nutrition commenced within 24 hours on ICU
  • DVT thromboprophylaxis for all
  • Permissive hyperglycaemia allowed
  • Routine stress ulcer prophylaxis not administered

Outcomes

Primary outcome

  • In-hospital mortality

Secondary outcome

  • Mean duration of vasopressor therapy
  • Use of Renal Replacement Therapy
  • Median ICU length of stay
  • 72 hours SOFA score

Results

Primary outcome: hospital mortality

  • 8.5% (4 of 47) in the treatment group compared to 40.4% (19 of 47) in the control group (p<0.001)

Secondary outcomes

  • Mean duration of vasopressor therapy: 18.3 +/- 9.8 hours after staring vitamin C treatment protocol vs 54.9 +/- 28.4 hours in control group (p<0.001)
  • Requirement for RRT for AKI: 3 patients (10%) in treatment group vs 11 patients (37%) in control group (p=0.02)
  • Median ICU stay LOS: 4 days for both groups
  • 72-hour SOFA score was 4.8+/- 2.4 in the treatment group vs 0.9+/- 2.7 in the control group (p<0.001)

Conclusions

  • Early use of intravenous vitamin C, together with corticosteroids and thiamine may reduce mortality and prove to be effective in preventing progressive organ dysfunction including AKI as well as reducing mortality of patients with severe sepsis and septic shock.
  • Additional studies are needed to confirm these preliminary findings

Strengths

  • Interesting hypothesis
  • Biologically plausible explanations for benefit in sepsis
  • Patient baseline characteristics well matched between the two groups
  • Vitamin C and thiamine are cheap and relatively safe
  • Multiple supporting trials

Weaknesses

  • Not an RCT
  • Small numbers (only 47 patients in each group)
  • Single centre non-blinded design
  • Three simultaneous interventions – which one was associated and responsible for clinical improvement?
  • Treatment and control periods were not concurrent and occurred during different seasons – could be a confounding factor
  • 60% of patients in the control group received corticosteroids
  • Details given for underlying cause of death in intervention group (including advanced dementia, severe heart failure, severe COPD) but not control group

Implications

  • Inexpensive and relatively safe interventions that may improve the outcome in sepsis
  • Could be something to consider?

Potential for impact?

  • The study is hypothesis generating
  • A large multi-centre RCT is needed to study this further and determine the efficacy of vitamin C, steroids and thiamine in severe sepsis and septic shock.

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.

 

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