Written by Dr. C. Williams

Comparison of 4 cardiac risk calculators in predicting postoperative cardiac complications after non cardiac operations. Cohn S, Ros NF. The American Journal of Cardiology 2017 doi:10.1016/j.amjcard.2017.09.031

Identifying patients who are at high-risk of perioperative complications is something that we are still trying to refine. There are many risk calculators available to try to identify all kinds of risk – ranging from cardiovascular risk, risk of acute kidney injury, risk of post-operative cognitive dysfunction, risk of mortality and so on. Trying to work out which is the best risk calculator to use can seem like trying to negotiate your way through a minefield.

We know that cardiovascular complications after non cardiac surgery are an important cause of postoperative morbidity and mortality. One can use different risk calculators and get different estimates of the patients risk but which is the most reliable risk predictor? This is a question this paper tries to answer by looking at 4 different cardiac risk calculators.

Trying to identify high risk patients is not a new phenomenon – the first cardiac risk index was published by Goldman et al. in 1977. This was followed in 1999 by Lee at al publishing the revised cardiac risk index (RCRI). In 2013 Davies et al. improved prediction using a 5 factor reconstructed RCRI (R-RCRI). The 2014 ACC/AHA guidelines on Perioperative Cardiovascular Evaluation and Management of Patients Undergoing Noncardiac Surgery recommended using the RCRI or two newer tools created from the National Surgical Quality Improvement Program (NSQIP) database – namely the myocardial infarction or cardiac arrest (MICA) calculator or the American College of Surgeons surgical risk calculator (ACS-SRC).

Essentially this paper found that all 4 risk calculators performed well at defining low and elevated risk groups but tended to slightly underestimate cardiac events. There are two salient points made:

  1. The definitions for outcomes and timeframes used to develop the risk calculators are different therefore a valid direct comparison of outcomes is not possible
  2. If the risk calculators are used in a manner different from the way derived they do not perform as well

Ultimately risk calculators give an estimate of risk – it is not a black/white answer as to whether that patient will develop that particular complication. What they are useful for is to facilitate shared decision making discussions with patients and enable them to make an informed decision regarding their treatment choice.

Postoperative ERAS interventions have the greatest impact on optimal recovery: Experience with implementation of EAS across multiple hospitals. Aarts M, Rotstein O, Pearsall E metal on behalf of the iERAS group. Annals of Surgery 2018 doi:10.1097/SLA.0000000000002632 

ERAS (Enhanced recovery after surgery) pathways use evidence-based practices to minimise perioperative stress and promote early recovery. These multimodal care pathways incorporate multiple interventions within the preoperative, intraoperative and postoperative course of the patient’s perioperative journey. Multiple papers have been published which demonstrate that ERAS benefits patients when compared to standard care and show a decreased rate of complications, accelerated recovery and earlier discharge from hospital.

But while ERAS has been shown to be effective at improving outcomes, it can be difficult to implement not least because it requires a sustained collaborative effort from members of a multidisciplinary team. This paper aims to determine which component of ERAS has the largest impact on recovery for patients undergoing colorectal surgery and also to look at the relative benefits of ERAS in laparoscopic versus open surgery.

Of the 2876 patients studied only 20.1% had care that was compliant with all phases of the pathway. The poorest compliance was for the postoperative interventions yet these were the interventions most strongly associated with an optimal recovery. Compliance with ERAS was associated with improved outcomes regardless of whether surgery was open or laparoscopic. However, the impact of ERAS compliance was significantly greater in patients having open surgery.

In addition to the ERAS components two other potentially modifiable factors were found to significantly impact on patient outcomes namely operative technique and preoperative haemoglobin levels.

Maybe it is time to go back and reassess how ERAS is implemented. My view as an anaesthetist is that it seems that more emphasis is placed on the preoperative and intraoperative parts of the pathway – the question is whether this is because that is what happens or because those are the parts of the pathway that anaesthetists are more involved with? There is plenty of emerging evidence that postoperative care is as important as other parts of the pathway and if the results of this study are valid then it would seem that postoperative interventions make the most difference to patient outcomes. Once again this paper adds to the increasing body of evidence that as anaesthetists it may have come to the time that we need to step up to the mark and pay more attention to postoperative care. After all, why take so much care making sure our patients are as pre-optimised as possible and given the best intraoperative care if we do not follow this through to the postoperative phase?

Preoperative geriatric assessment and tailored interventions in frail older patients with colorectal cancer: a randomised controlled trial. Ommundsen N, Wyller TB, Nesbakken A et al. Colorectal Disease 2018 doi:10.111/codi.13785

The role of comprehensive geriatric assessment for older patients undergoing surgery is much discussed in the literature at the moment. Geriatric assessment and input has already been shown to make a difference and improve functional status in hip fracture patients. This paper aimed to looks at whether a preoperative geriatric assessment can identify older patients at risk of developing postoperative complications after surgery for colorectal cancer. Patients over the age of 65 years scheduled for elective colorectal cancer surgery and fulfilling criteria for frailty were randomised to either a preoperative geriatric assessment and a tailored intervention (based on the assessment) or usual care.

The findings of this paper were that a geriatric assessment and tailored intervention made no difference to the rate of complications or to the secondary endpoints of median length of stay, discharge to own home, need for readmittance or reoperation within 30 days or 30 day and 3 month mortality.

In my opinion there are significant limitations to the data in this study – despite running for a long period of time (2011 – 2014) only 122 patients were recruited and consequently the study is probably underpowered (acknowledged by the authors). Also, the optimal time from intervention to surgery was hypothesised to be 3 weeks – which seems a short time period for an intervention to make a significant difference to outcome. Furthermore the authors go on to detail that the actual time for pre optimisation was a median of 6 days. Additional evidence is needed to be able to draw conclusions as to the effectiveness of geriatric assessment on patient outcomes particularly given that geriatric input has been shown to be efficient in other surgical settings.

Does goal-directed haemodynamic and fluid therapy improve peri-operative outcomes? A systematic review and meta-analysis. Chong MA, Wang Y, Berbenetz NM, McConchie I. European Journal of Anaesthesiology 2018;35:1-15 doi:10.1097/EJA.0000000000000778 

There is much debate about the effectiveness of perioperative goal-directed haemodynamic and fluid therapy. The seminal study by Shoemaker et al published in 1988 demonstrated that patients receiving preoperative haemodynamic optimisation titrated to goals of end organ blood flow had improved outcomes. Since then there have been multiple randomised controlled trials looking at this. In my personal experience many anaesthetists have quite polarised views on the efficacy of goal directed therapy.

The authors carried out a systematic review and meta analysis of 95 randomised controlled trials where goal directed therapy was studied defined as fluid and/or vasopressor therapy titrated to haemodynamic goals. The findings of this comprehensive review demonstrate that goal directed therapy modestly improves mortality in non-trauma and non pregnant adult surgical patients. The authors suggest that based on the articles included for analysis, the numbers suggest tat for every 1000 patients treated with goal directed therapy, 18 deaths would be prevented.

However, the quality of evidence was low to very low with much clinical heterogeneity among the goal-directed therapy devices and protocols. This is likely to be an area of continuing interest for perioperative research and further well designed and adequately powered trials are needed. Hopefully the OPTIMISE-II and FLO-ELA trials may answer some of the questions surrounding goal directed therapy.

Clinical guideline and recommendations on pre-operative exercise training in patients awaiting major non-cardiac surgery. New GA, Ayyash R, Danjoux GR. Anaesthesia 2018 doi:10.1111/anae.14177

Pre-operative exercise has been much debated over the past few years. There have been several systematic reviews on the effects of pre-operative exercise with sufficient clinical trial data to support pre-operative exercise training as being safe and efficacious. But how exactly can one translate the evidence from clinical trials into clinical practice. This paper aims to provide practical and evidence-based guidelines on how to deliver pre-operative exercise training to patients awaiting major, non cardiac surgery.

Chronic physical inactivity accelerates age-associated declines in maximal aerobic capacity and functional fitness which consequently places individuals at increased risk of complications when undergoing major or complex surgery.

There are ten key recommendations which cover patient selection for exercise training in surgical patients, integration of exercise training into multi-nodal prehabilitation programmes and advice on exercise prescription factors and follow-up. This guideline also touches on the fact that successful implementation of rehabilitations programmes may prove challenging. A range of institutionalised cultural and attitudinal barriers exist that could affect pre-operative initiatives to a varying degree. System-related barriers include lack of educational opportunities highlighting the benefits of exercise, insufficient infrastructure and concerns about the feasibility of delivery and cost effectiveness of potential programmes. Several barriers to implementation are highlighted – the main ones being resistance to change from patients and staff and lack of funding or support from management.

Although the authors acknowledge that further research is needed to identify the optimal exercise prescription, this is a much needed clinical guidelines. Hopefully it will result in perioperative teams being able to incorporate pre-operative exercise training for patients into their routine practice.

Association between handover of anesthesia care and adverse postoperative outcomes among patients undergoing major surgery. Jones PM, Cherry RA, Allen BN et al. The Journal of the American Medical Association 2018;319(2):143-153 doi:10.1001/jama.2017.20040

This article looked at over 313000 patients to look at whether handing over of care from one anaesthetist to another during surgery is associated with a worse outcome. Given the shift work that many anaesthetists (particularly trainees) now work, handing over of care during surgery cannot always be avoided. Handovers may be temporary (initial clinician hands over care to another clinician for a break and then returns) or complete (care is completely handed over to another clinician). Handover is a potentially vulnerable time for the patient because all information required must be transferred between clinicians in a busy environment with many distractions. If crucial details are missed the patient may be at risk of an adverse event. The alternative theory is that a rested clinician taking over care from a fatigued clinician may improve the quality of care and reduce adverse events.

Complete intraoperative handover of care compared with no handover of care was associated with a higher risk of all-cause death, hospital readmission and major postoperative complications over 30 days (44% versus 29%). Intraoperative handovers were also associated with an increase in intensive care admissions and a longer hospital stay.

This is a topic which raises many questions. The authors note that in Canada the number of complete handovers of care is increasing each year. Fatigue and the effects that it has on performance at work is also much debated at the moment.* Knowing that fatigue exacerbates many human limitations, some departments have implemented policies of restricted duty hours for medical staff. It is likely that these policies have an impact on the number of handovers of care.

Given the increase in adverse events observed in this study, the public health implications are concerning. The most prudent approach would be to minimise unnecessary anaesthetic handovers. However the factor of fatigue cannot be ignored. At some point fatigue will have a measurable and detrimental effect on clinicians and handovers in this case would be reasonable. But the question of how to determine when the risk of a fatigued clinician exceeds the potential risk of a complete handover is not one that can currently be answered.

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