A big PONV meta-analysis

Interesting Cochrane meta-analysis looking at PONV prophylaxis from German (Weibel et al. 2021) that included almost 100,000 study participants across 585 trials. Interesting not so much because it confirms much of what we already new (or assumed, based on our common PONV prophylaxis drug choices), but because it reassures us that side-effects from commonly used PONV drugs are low to non-existent.

PONV Takeaway:

Granisetron is probably the best single-agent or in combination with other agents because of it's efficacy (better than ondansetron), low-cost, long duration, and absent side-effects.

A cognitive aid to better manage perioperative bleeding

Although the benefits of cognitive aids to many areas of anaesthesia are well established, our resistance to using decision support tools persists. Whether due to misplaced perceptions of losing autonomy or Dunning Kruger-adjacent inflated belief in our ability to perform under pressure, is unclear.

In Anaesthesia, Kataife et al. (2021) describe a cognitive aid for better managing perioperative haemorrhage, the Haemostasis Traffic Light algorithm. Using a simulation-based RCT across two centres (University Hospital Zurich & The Italian Hospital of Buenos Aires, N=84), they showed that using the HTL improved case solutions (OR 7.23, 3.82-13.68), quickened therapeutic decisions, (HR 1.97, 1.18-3.29), improved therapeutic confidence, (OR 4.31, 1.67-11.11) and reduced workload perception.

The aim of the HTL is to improve both situational awareness and decision making, by integrating clinical judgement and point-of-care testing (ROTEM) within an accessible, structured algorithm.

Haemostasis Traffic Light takeaway:

Kataife's study again shows the benefit of cognitive aids, particularly in critical, time-sensitive situations. The anaesthesia and critical care community's historical resistance to decision-support tools requires challenge.

Surgery timing after COVID infection

Following their important 2020 study of the risk of surgery for COVID patients, the COVIDSurg Collaborative reports on their prospective cohort study aiming to determine the optimal delay for planned surgery after COVID infection.

Once again this was an international (116 countries), multicentre, prospective cohort study including all surgery types, over 140,000 patients, and 3,127 post-COVID. Once again the 30-day postoperative mortality was sobering: even in the 5-6 week post-COVID group, 30-day mortality was dramatically higher (OR 3.6, 2.0-5.2) compared to those without a COVID diagnosis. Worryingly the risk was consistent among both low-risk and high-risk surgical groups.

Although after the 7-week mark postoperative mortality was similar to non-post-COVID patients (OR 1.5, 0.9–2.1), those with persisting COVID symptoms still suffered a 6.0% 30-day mortality (3.2–8.7). (30-day mortality among non-COVID patients was 1.5% (1.4-1.5).

Post-COVID surgical timing takeaway:

Surgery should be delayed for at least 7 weeks after COVID, although those with persistent COVID symptoms will still have more than twice the 30-day mortality than those without.

Mentioned studies:

  1. Weibel S, Schaefer MS, Raj D et al. Drugs for preventing postoperative nausea and vomiting in adults after general anaesthesia: an abridged Cochrane network meta-analysis. Anaesthesia. 2021 Jul 1; 76 (7): 962-973.
  2. Kataife ED, Said S, Braun J et al. The Haemostasis Traffic Light, a user-centred coagulation management tool for acute bleeding situations: a simulation-based randomised dual-centre trial. Anaesthesia. 2021 Jul 1; 76 (7): 902-910.
  3. COVIDSurg Collaborative GlobalSurg Collaborative. Timing of surgery following SARS-CoV-2 infection: an international prospective cohort study. Anaesthesia. 2021 Jun 1; 76 (6): 748-758.