Complications of Anaesthesia

The start of a new year isn’t usually much fun. Short days, long nights, back to work and a guilt-driven desire to visit a gym and eat salad. On the other hand, it’s nearly time for the AAGBI Winter Scientific Meeting, and we recently published our free to access supplement issue, ‘Complications’! Our Friday morning session (12^th January) is all about the complications of anaesthesia and it is no coincidence the two are related. First up is Dr Alastair Glossop from Sheffield discussing respiratory complications followed by Dr Guillermo Martinez from Cambridge, who will give a much-anticipated talk about cardiovascular complications. Finally, we are delighted to have Dr Heidi Doughty, a consultant in Transfusion Medicine from the NHS Blood & Transplant service, present the complications of blood transfusion. If you are registered for #WSMLondon18 please do come along and engage with us either in person or on Twitter. If you aren’t yet registered, here is the link.

If you simply cannot wait to hear from our speakers, you’re in luck, as our 2018 supplement issue is simply everything you need to know about the complications of anaesthesia. Our special issues are growing in popularity, with each allowing for a particular topic to be set out in extraordinary depth. They are an excellent educational resource that we hope contribute in some way to enhancing the care we provide for our patients. In 2017, we published ‘Monitoring in the peri-operative period’ preceded by ‘Peri-operative medicine’ in 2016 and ‘Transfusion, Thrombosis and Bleeding Management’ in 2015. ‘Complications’ is already having an impact and we hope to see lots of discussions about the articles as we tweet each one over the coming week or so.

Valchanov and Sturgess set the scene (and issue an apology to Atul Gwande!) with their editorial ‘Complications: an anaesthetist’s rather than a surgeon’s notes’. They argue the complications issue is a timely publication, as demands on anaesthetists are increasing, the population is aging, we are seeing more patients with complex comorbid conditions and therefore complications are no-doubt increasing. The culture of complications is changing too, as it is becoming more acceptable to report critical incidents and learn from these reports in an open, no-blame and shared manner.

Merry and Mitchell provide an overview of complications in anaesthesia and question whether or not there is an easy way in which they can be defined or attributed to anaesthesia. Such questions seem trivial enough, but there are no easy answers. From the perspective of human error, which is statistically inevitable, they argue the occurrence of a complication or adverse event does not always equate with a failure in care standards. Nevertheless, every effort should be made to prevent such errors from precipitating these events. This leads nicely to the systematic review from Jones et al. where the role of human factors in preventing anaesthetic complications is examined (methodologically, this is a very difficult literature search/synthesis and the authors must be congratulated!). They included 74 studies and highlight the way in which human factors have become embedded into clinical practice in anaesthesia (Figure 1 and 2). Though the relationship between human factors and anaesthesia is emphasised with the example of complex trauma in the emergency department and operating theatre, the principles are transferrable to all manner of scenarios.

Figure 1 Human factors recognised by NAP4

Figure 2 Human factors recognised by NAP5

The respiratory and cardiovascular complications of anaesthesia are core topics for all and the articles by Mills and Sellers et al. are therefore essential reading. Professor Mills sets out the evidence-base for postoperative pulmonary complications and underlines the need for more research to establish the role of postoperative CPAP, non-invasive ventilation and high-flow nasal oxygen. Although the optimum level of intraoperative PEEP is uncertain, the use of lung-protective ventilation during anaesthesia likely reduces the incidence of postoperative pulmonary complications and there is therefore scope for us all to improve patient outcomes. Cardiac complications following major non-cardiac surgery are common and Sellers et al. argue patients should be better triaged to more advanced postoperative care environments based on their preoperative risk. Myocardial injury after non-cardiac surgery is a spectrum (Figure 3) and the use of postoperative troponin assays merits attention through further research. Overall therefore, there seems to be more questions than answers, but there are several measures we can take to prevent respiratory and cardiovascular complications.

Figure 3 The spectrum of myocardial injury and troponin rise after non-cardiac surgery

There are a range of different topics covered in this issue such as, for example, spinal cord and peripheral nerve injury following anaesthesia, peri-operative neurological complications associated with cardiac surgery and adverse drug reactions. Obstetric anaesthesia is an area with high patient expectation in combination with the need for time-critical high stakes anaesthetic intervention. It is of little surprise there are several commonly occurring obstetric complications together with a small number of rare yet potentially catastrophic complications. The narrative review from Maronge and Bogod discusses their pathophysiology, prevention and management in detail and is therefore a ‘must read’ for all those practicing obstetric anaesthesia. They argue women should be believed when describing symptoms consistent with an iatrogenic injury and that steps should be taken to ensure complications are identified early and treated appropriately.

Though the pathophysiology of perioperative acute kidney injury (AKI) is complex, the article from McKinlay et al. offers an excellent summary of the relationship between contributory surgical, anaesthetic and haemodynamic factors (Figure 4). It is somewhat alarming that, despite easily identifiable risk factors, perioperative AKI accounts for 30-40% of all in-hospital AKI cases and is associated with significant morbidity and mortality, even for seemingly trivial postoperative creatinine rises. Detailed recommendations are provided for preoperative, intraoperative and postoperative strategies to prevent renal complications and the authors call for more consistency in the diagnosis and reporting of postoperative AKI.

Figure 4 Schematic representation of the potential pathophysiology of perioperative AKI.

Finally, what should we do when complications occur? There are obvious consequences for patients but the impact on healthcare workers must also be considered. Cruikshanks and Bryden argue it is important to put matters right (if possible), apologise and explain the implications of complications when events don’t take their intended course. They list recommendations from the Francis report into the Mid-Staffordshire NHS Trust and argue poor handling of complications will likely lead to complaints and litigation through attempts by patients to receive explanations and support which should have been provided initially.

That’s all for now, but planning for the 2019 supplement ‘Pre-operative optimisation of the surgical patient’ is already well underway. We do hope you enjoy the 2018 complications supplement and that it provides ample education and stimulation whilst retaining clinical relevance to all. Please discuss and engage with the articles either through twitter or formally through our correspondence site as we are always interested to hear what you think. See you in London next week!