Search

Welsh Anaesthetic Trainees Journal Club

Tag

Morbidity

Shuttle walk or CPET……..survival after oesophageal resection

Poor performance in incremental shuttle walk and cardiopulmonary exercise testing predicts poor overall survival for patients undergoing esophago-gastric resection

European Journal of Surgical Oncology 2018 https://doi.org/10.1016/ j.ejso.2018.01.242

 Presented by: Dr T Green

Background

Patients with oesophageal and gastric cancer have a poor prognosis with an untreated five year survival at time of diagnosis of 20% and an increase to only 40% following treatment.  It can take up to one year for many patients to recover from treatment and regain their preoperative quality of life and many patients will not achieve this.  Careful preoperative assessment is essential to select those who will benefit from surgical treatment.

The Incremental Shuttle Walk Test (ISWT) and Cardiopulmonary Exercise Testing (CPET) can be used to assess the preoperative fitness of patients.  CPET results include the Anaerobic Threshold (AT) and Maximal Oxygen Consumption (VO2 Max).  This study aims to assess the correlation between ISWT and CPET with postoperative survival and postoperative pulmonary complications.

Design & Setting

Observational study of patients undergoing surgery for gastric or oesophageal cancer with or without neoadjuvant chemo-radiotherapy between 2010 and 2014 (presumably at Royal Marsden Hospital / St Mary’s Hospital, London – not stated but based on authors’ affiliations)

Data collected on preoperative clinical stage, postoperative pathological stage, postoperative respiratory complications, all-cause mortality and mortality due to disease recurrence.

Subjects

81 patients assessed through the Perioperative Enhanced Recovery Protocol between 2010 and 2014.  All patients underwent either ISWT or CPET (or both).

Intervention

Observational study – no intervention.

Outcomes

  • Assessment of the utility of the ISWT and CPET for determination of postoperative respiratory complications and mortality.
  • ISWT score of 350m or above.
  • CPET values: AT 11 or above and VO2 Max 14ml/kg/min or above.

Results

  • 73 of 81 patients (90%) had both ISWT and CPET assessment.
  • No correlation between single time point ISWT or CPET results and postoperative respiratory complications.
  • A subset of patients (45) had ISWT both before and after chemoradiotherapy and of these, those who achieved a >10% increase in score were noted to have a reduced incidence of postoperative respiratory complications (19% in those whose ISWT score improved >10% vs 45% in those whose score remained within 10% of their pre-chemoradiotherapy score or whose score reduced by >10%). This did not reach statistical significance (p = 0.08).  There was no correlation between such improvement in ISWT score and overall mortality.
  • All cause mortality and mortality due to disease recurrence correlates strongly (p < 0.001) with ISWT score ≥350m, AT ≥11 and VO2 Max ≥14 (Median survival with ISWT <350m or VO2 Max <14 was 20 months vs >5 years. Median survival with AT <11 21 months vs >5 years.)

Conclusions

ISWT assessment before and after chemotherapy is indicated and a reduction in score indicative of deconditioning, should trigger patient-specific exercise-based intervention.  CPET, being considerably more complicated and expensive, should be reserved for cases with established cardiopulmonary comorbidities.

Strengths

  • Goals and methods clearly defined.
  • Negative results reported.
  • Recognition of limitations of current study.

Weaknesses

  • Observational study therefore no case-control analysis.
  • Small sample size, especially for those undergoing ISWT before and after neoadjuvant chemoradiotherapy leading to underpowered statistical analysis.
  • The concurrent study being performed by the authors assessing the introduction of patient-specific exercise-based prehabilitation appears to have preceded the results of this study and may introduce bias into the analysis and conclusions.

Implications

ISWT may be a cheaper, less complicated method of determining cardiopulmonary fitness prior to surgery for gastric or oesophageal cancer and may be of use in guiding the multidisciplinary team in determining the best course of action for a given patient (surgery or conservative management).

Potential for impact

The use the ISWT, a cheaper, simpler assessment of cardiopulmonary fitness versus CPET is attractive as long as this can reasonably be used to guide treatment options.  The use of CPET still has its place based on the results of this study.

SORT: A new tool to predict postoperative morbidity.

Predicting postoperative morbidity in adult elective surgical patients using the Surgical Outcome Risk Tool (SORT). Wong DJN, Oliver CM, Moonesinghe SR.

British Journal of Anaesthesia 2017;119(1):95-105 doi: 10.1093/bja/aex117

Presented by: Dr Alex Cormack

Background

  • Perioperative risk assessment is a key part of the consent process
  • Risk stratification tools also allow comparison between outcomes of different institutions
  • Morbidity following surgery can have a significant impact on quality of life and needs to be a consideration when considering surgical options
  • Morbidity is more common than mortality following surgery and potentially provides a more sensitive measure of comparison between different healthcare providers
  • P-POSSUM and POSSUM are currently the most frequently used tools for perioperative risk prediction

POSSUM:

  • Physiological and Operative Severity Score for the enumeration of Mortality and morbidity
  • Developed in the 1990s
  • For use in elective and emergency general surgical procedures
  • Does not apply to trauma patients
  • Calculated at the time the decision to operate is made
  • Variants include CR-POSSUM, Vascular-POSSUM and O-POSSUM
  • Requires 12 physiological and 6 operative parameters to calculate

P-POSSUM:

  • Portsmouth modification of the Physiological and Operative Severity Score for the enumeration of Mortality and morbidity.
  • A variation of the POSSUM tool

SORT:

  • Surgical Outcome Risk Tool
  • Developed after the 2011 NECEPOD report
  • Uses six parameters collected preoperatively
  • Designed to predict probability of 30 day mortality following surgery
  • The authors state that it ‘compared favourably with other previously validated risk stratification tools’ and ‘has been externally validated recently in a cohort of patients undergoing hip fracture surgery’.
  • Predictor variables: ASA grade (III, IV or V), surgical urgency (expedited, urgent or immediate), high risk specialities (GI, thoracic or vascular surgery), surgical severity (major or complex), malignancy, age (65-79 or >80)

 Design and Setting

  • Single centre prospective study at University College London Hospital to:

“develop and validate a new model to predict the likelihood of postoperative                       morbidity using predictor variables found in SORT, and then compare its      performance against POSSUM.”

  • 3 year period (June 2009 – May 2012)
  • Data collection carried out by trained research staff independent of the clinical teams responsible for the patient

Subjects

Inclusion criteria:

  • Patients undergoing elective major inpatient operations
  • 1934 patients included

Exclusion criteria:

  • Patients with duplicated or missing data
  • Patients who did not have POMS (Post Operative Morbidity Survey) scores recorded on Day 7

Intervention

  • Data collected:
    • 1934 patients identified, 1583 patients included
    • 58% female
    • 45% orthopaedic and 39% abdominal procedures
    • 6 deaths within 30 days of surgery
  • Data excluded:
    • 351 patients excluded
    • Missing predictor variables: DOB, ASA status, surgical speciality, malignancy status
    • Missing POMS outcomes: duplicated or missing entries
    • Clear summary of reasons for exclusion, no patients unaccounted for
  • POMS administered prospectively to patients at several time points postoperatively (day 3,5,7 or 8, 14 or 15 and 21)
  • Morbidity outcome measure selected was POMS-defined morbidity recorded after postoperative day 7 or 8
  • Data randomly split into two groups
    • 1/3 validation group (n=527)
    • 2/3 derivation group to define new model (n=1056)

Outcomes

  • Predictor variables from the original SORT variables were adjusted to generate SORT-morbidity models
  • Outcome variable was set as the presence of POMS defined morbidity on postoperative day 7 or 8
  • SORT-morbidity models then tested in the validation group using statistical analysis
  • Final model then tested against POSSUM

Results

  • No statistically significant difference between new SORT-morbidity model and POSSUM at discrimination of morbidity at 7 days post surgery
  • Linear shrinkage factors estimated to improve prediction of morbidity at later time points

Conclusions

  • New SORT-morbidity model is comparable to POSSUM at prediction of morbidity 1 week post operatively
  • Linear shrinkage factors can be applied to improve morbidity prediction further in the postoperative course

Strengths

  • Morbidity is an important consideration within the surgical consent process
  • Data collection carried out by research staff independent of clinical teams
  • Clear documentation of reasons for exclusion
  • Good number of data sets
  • New SORT-morbidity model found to compare favourably to POSSUM
  • POMS is a validated measure of morbidity to use in data collection

Weaknesses

  • Morbidity defined as POMS defined morbidity after day 7
    • Patients discharged prior to this time period excluded despite possible morbidity
  • Only looked at elective patients
  • Single centre study
  • Unequal representation of surgical specialities
  • Comparatively low mortality rate (0.31%) documented – the authors comment that rates of 0.37-0.67% have been documented elsewhere in the literature
  • POMS domains include some relatively minor measures of morbidity that may influence the results (for example urinary catheter following elective urology cases)
  • Required ‘linear shrinkage factors’ to enable morbidity to be predicted later than 7 days postoperatively

Implications and Potential for Impact

  • Possible development of a new tool to use alongside existing risk assessment tools
  • SORT-morbidity was only used in elective cases and therefore could not be used in a CEPOD setting without further studies
  • Potential for further studies to develop the SORT-morbidity tool for more widespread use
  • P-POSSUM currently universally understood amongst the theatre MDT whereas SORT is less widely understood
  • SORT and SORT-morbidity require fewer variables to calculate, however this is less relevant as SORT-morbidity has only been developed using elective cases

The use of SORT-morbidity as an alternative to P-POSSUM does not yet seem a realistic prospect. P-POSSUM is understood amongst surgical and anaesthetic professionals and allows management decisions to be made appropriately. It is used for both emergency and elective patients, and arguably its most important use is in planning the management of emergency patients. This is an area that the SORT-morbidity tool has not been developed for. Further studies and multi-centre validation would be required before it could reliably be used in clinical practice.

 

 

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.

 

Can CPET predict in-hospital morbidity?

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

 

Predicting morbidity after elective surgery……is there an easy method?

Objective model using only gender, age and medication list predicts in-hospital morbidity after elective surgery. Blitz JD, Mackersay KS, Miller JC, Kendale SM. British Journal of Anaesthesia 2017;118(4):5444-5550

Presented by: Dr C. Thomas

Background

  • Recognised need for objective, customised risk evaluation tool for elective surgery
  • For patient and physician
  • Aid informed consent
  • Improve safety by identification of high risk patients
  • Current models require physician input / lab data etc.
  • Aim – objective predictor of inpatient post op morbidity
  • Simple to use
  • Easy to include
  • Simple data – age, gender, list of medications
  • Hypothesis:
  • Gender, age and medication list could provide information about post-operative morbidity
  • Certain medications elevate risk
  • Simplified to number of medications / gender / age

Design and Setting

  • Review board approval – patient consent waived as no intervention mandated
  • Restrospective database study
    • Single centre
    • 2 year period
    • Electronic database (Clarity) – access to ICD-9 codes
    • ASA scores from anaesthetist at time (database)
  • Quaternary Care academic Centre – New York City
    • Large inpatient location, ambulatory locations
    • Patients with mod – high access to healthcare
  • Morbidity outcome was in hospital morbidity by
    • Post op complications – presence of any during admission
    • AF, PE, MI, VTE, CCF, Resp Failure, AKI
  • ICD-9 coding limited – excudes:
    • Haemorrhage, sepsis, cardiac arrest
  • Secondary database created:
    • 46 selected medications – presence or absence each patient (on admission)

Subjects

  • 26629 Adult surgical encounters (>18 years)
  • 02% separate patients, 16.98% >1 surgery/patient
  • Anaesthesia – GA / Regional / Neuraxial / Monitored anaesthesia care
  • Exclusions
    • Emergency surgery
    • No ASA score on database

Intervention

  • Developed predictive models for in hospital morbidity based on outcomes above
  • GAMMA – Gender-Age-Medications Morbidity Assessment
    • Morbidity based on gender, age and medications
    • Logistic regretion based on database
  • ASA-M
    • Morbidity using ASA score as independent variable
  • GAMMA-N –GAMMA-Number modification
    • Morbidity solely on gender age and number of medications
  • Binary logistic regression analyses – assessed for discrimination and power by c-statistic (binary outcomes ie yes or no to condition) – >0.8 indicates strong model.
  • Calibration assessed by Brier score (compares actual events with predicted). Score close to 0 suggests accurate.
  • Chi-Square for model significance.
  • Models developed with full data set and validated with k-fold cross validation – 10 folds.

Outcomes

  • Morbidity Risk from gender, age and medications
  • Morbidity Risk from ASA score
  • Morbidity Risk from gender, age and number of medications

Results

  • GAMMA – predicts post operative morbidity with high accuracy (c statistic 0.819, Brier 0.034)
  • ASA similar (c-statistic 0.827, Brier score 0.033)
  • GAMMA-N less predictive (c-statistic 0.795, Brier 0.050)

Conclusions

  • Authors conclude that combination of age, gender and medication list reliably predict post-operative morbidity.
  • Model has increased objectivity, can be used pre-operatively (lab values etc not required, different to models such as PPOSSUM)
  • Limited medical knowledge required therefore could be patient led.

Strengths

  • Large database
  • Authors recognise limitations
  • Easy to access data – on the whole not subjective (except ASA)

Weaknesses

  • Exclusion of haemorrhage, sepsis and cardiac arrest as complications
  • Other outcomes that patients would consider as morbidity? – very limited number of outcomes studied
  • Patient population – excludes limited resource patients – ? therefore not comparable nationally / internationally or patients not on medications for existing disease due to insurance limitations etc therefore risk may be underscored.
  • Limited list of medications included (46) therefore risk may be underscored for patients on less common or new medications etc. How would this be updated with advances in pharmaceuticals?

Implications

  • Difficult to assess from available information
  • If this tool was studied for other populations and proved accurate it could be implemented as a simple risk stratification tool for elective patients but further study would be required.

Potential for impact

  • Development of a patient led tool for risk assessment – patient led care
  • Pre-operative optimization – reduce their score by improving lifestyle etc to reduce medications
  • Risk stratification for allocation of resources? – such as elective joints requiring lowering of BMI before listed for surgery in some areas.

Powered by WordPress.com.

Up ↑