Understanding peri-operative risk

Welcome to the first issue of Anaesthesia for 2020, which is open access for all to read and download. Thankfully, modern anaesthesia is extremely safe, and reports of death due to anaesthetic-related complications are extremely rare. Some complications can be predicted, and it is sometimes even possible to employ strategies to mitigate the associated risk. This new paper from Ramalingam et al. prospectively examines the risk of transoesophageal echocardiography (TOE)-related complications in anaesthetised patients, and the results are alarming. Firstly, the incidence of complications was 1:1300, and the risk of death following a complication was ~40%, which is higher than previously thought. Secondly, complications occurred in patients without known risk factors. Ashworth and Greenhalgh provide some important commentary and context. It seems the benefits of peri-operative TOE continue to outweigh the risks for most cardiac surgical patients, but we can now provide patients with more precise estimates of the incidence of complications, which remain lower than the incidence of major surgical complications. One important recommendation is that insertion aids, such as a laryngoscope (or videolaryngoscope), are used. 

The prevalence of atrial fibrillation (AF) in general and peri-operative populations is increasing. This new secondary analysis of the VISION study finds that, in patients with a pre-operative history of AF undergoing non-cardiac surgery, postoperative cardiovascular events are more common than strokes. Interestingly, they also found that AF thrombo-embolic scores, such as CHADS2-VASc better predicted these events than the revised cardiac risk index. In the accompanying editorial, Brand and Mackay describe the background to this secondary analysis and deliberate whether its findings will change clinical practice. Not just yet, it seems, but we might in the future use similar methods together with the VISION database to derive a peri-operative risk prediction model for all patients undergoing non-cardiac surgery. 

Figure 1 Receiver operating characteristic curves for each risk score and the primary outcome of any cardiovascular event (defined as myocardial injury after non‐cardiac surgery (MINS), heart failure, stroke, resuscitated cardiac arrest or cardiovascular death) within 30 days of surgery in patients with a history of atrial fibrillation. Revised cardiac risk index (c‐index 0.60) is denoted by the black line, CHADS2 (c‐index 0.62) is denoted by the blue line, CHA2DS2‐VASc (c‐index 0.63) denoted by the red line and R2CHADS2 (c‐index 0.65) denoted by the green line.

When caring for acutely unwell patients, the adage that a GCS ≤ 8 should be the threshold for tracheal intubation (for which there is little supportive evidence) seems to be increasingly irrelevant. That said, this new prospective cohort study of tracheal intubation practice variation in Europe after traumatic brain injury finds that GCS is the main driver of tracheal intubation for such patientsLike we recently saw with practices associated with rapid sequence intubation, there were substantial differences between countries and between centres. In the accompanying editorial, Lockey and Wilson argue that we should now aim to develop strategies to reduce this variation, and that the harm done by poor pre-hospital cannot be undone by in-hospital management for patients with traumatic brain injury

Figure 2 Proportion of pre‐hospital and in‐hospital patients who had their tracheas intubated across Europe.

Anaesthetists are thought to be at increased risk of suicide amongst the medical profession, as highlighted by an Association of Anaesthetists survey published earlier this yearThese new guidelines are aimed specifically at anaesthetists, their departments and their employers. You can read the full paper here and access the infographic here. In our review section, we are delighted to publish a new network meta-analysis of the prevention of hypotension after spinal anaesthesia for caesarean section. The authors report that vasopressors are more efficacious than crystalloid infusions, with metaraminol the most effective. Phenylephrine was associated with more cases of maternal bradycardia. You can learn more about the theory and practice of network meta-analyses here. A further dimension to meta-analysis is the use of trial sequential analysis, the workings of which are described in this excellent editorial from Shah and Smith

Elsewhere this month, we have: a randomised controlled study of a new blood pressure monitora prospective study of patients declined emergency laparotomya quality improvement study of delirium after hip fracture surgerya randomised controlled trial of the quadratus lumborum block for analgesia after caesarean section; and two excellent regional anaesthesia papers looking at needle tip tracking technology. Over in Anaesthesia Reports we have reports describing and discussing: hyperparathyroid-induced hypercalcaemic crisis with intracardiac thrombithrombolysis for submassive pulmonary embolism with left ventricular outflow tract obstruction; and laparoscopic hepatectomy in a patient with uncontrolled polycythaemia vera.

We hope you enjoyed our recent TweetChat on a new international multidisciplinary consensus statement on fasting before procedural sedation in adults and children (#NotSoFast). The associated discussion was fascinating, and you can see all the tweets by searching for the hashtag or clicking here. It has been an extremely busy month on social media, with high scoring papers including:  the new Difficult Airway Society awake tracheal intubation guidelinesguidelines for the transfer of the brain-injured patient; and a paper about pre-incisional hypotension and the association with postoperative acute kidney injury.

There is still time to register for the Association of Anaesthetists Winter Scientific Meeting in London, and our journal session will be on Friday the 10th of January. Speakers include Dr Rosie Hogg, Dr Eric Albrecht and Dr John Carlisle. Finally, we will soon be publishing our 2020 supplement in collaboration with the British Journal of Surgery, which will cover all aspects of advances in peri-operative care. As ever, there will be a great blog, some useful infographics and lots of clinical take-home messages. 

See you in London!

Dr Mike Charlesworth and Professor Andrew Klein

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