Month: May 2023

Scheduling surgery and COVID-19

The effect of COVID-19 infection on peri-operative mortality was characterised by the first CovidSurg study, which found an increased postoperative mortality across an international cohort if surgery was undertaken within the first 7 weeks following infection. In this issue, a service evaluation examined perioperative mortality in an English cohort (via OpenSAFELY) of over 3.5 million patients comparing pre-pandemic, pre-vaccination, and post-vaccination groups. It found that the same pattern of increased postoperative mortality following infection was present in both vaccinated and pre-vaccination cohorts, but that the absolute risk of death was much lower in England than CovidSurg data suggested. The implication of this is that in contrast with previous guidance, low risk patients might benefit from a shorter delay to surgery, in an approach more in line with other acute respiratory infections. An accompanying editorialexplores whether even modest changes in mortality can have large effects, and advocates considering individual risks and benefits.

Figure 1 Thirty-day postoperative mortality in the COVIDSurg study, solid line; the OpenSAFELY pandemic-no-vaccine era, short-dashed line; and the OpenSAFELY pandemic-with-vaccine era, long dashed line.

The first publication from the NAP7 study analyses the results of the activity survey – a snapshot of all cases performed under the care of an anaesthetist during four days in November 2021. They find several important trends in patient characteristics – compared to NAP5 in 2013 patients are older, have a higher BMI, and are more comorbid. Anaesthetic practice has also changed, with an increase in total intravenous anaesthesia cases from 8% to 26%, but a relative stable proportion of regional anaesthesia cases. Overall, these data show an increase in the complexity of anaesthetic patients, which is likely to have substantial effects on anaesthetic and peri-operative services. An editorialuses this data to explore the larger term trends in staffing and productivity within the NHS and explores the potential system wide changes which could improve productivity.

Figure 2 Trends in age and BMI over time in the NAP5–7 activity survey populations. Trends in age and BMI between NAP cycles. Data show (a) proportion of the activity survey population by age in non-obstetric patients and the BMI distribution in the (b) non-obstetric and (c) obstetric populations. NAP5 image; NAP6 image; NAP7 image. Proportions show the relative change in the population proportion within the group between NAP5 and NAP7. ↑, increase; ↓, decrease; ↔, no change. Percentages may not total 100 due to rounding.

Despite substantial advancements in human and technological factors associated with anaesthesia, tracheal intubation remains a fundamentally high-risk activity, associated with rare but potentially catastrophic adverse events. This multicentre randomised controlled trial comparing first attempted tracheal intubation using direct and video-laryngoscopes found that successful first pass intubation was significantly more common with a MacGrath videolaryngoscope using a Mac blade than with direct laryngoscopy (94% versus 82%). From secondary analyses, they found this effect persisted when limiting the analysis to consultants only, and that the total two attempt intubation failure rate was 4% for direct laryngoscopy and 1% for the McGrath. Whilst these results are consistent with other results published examining similar questions, this study stands out as showing a substantial benefit for videolaryngoscopy in an undifferentiated but low risk population in a large well-conducted trial where the benefits might have been expected to be limited. The accompanying editorial has generated much discussion by exploring the potential pitfalls of a first line videolaryngoscopy approach has advocating for ongoing training in direct approaches.

Table 1 Outcome parameters. Values are number (proportion) or median (IQR [range]).

Felton et al. report a study examining whether volatile organic compounds could be used as biomarkers for ventilator-associated pneumonia, finding that there were several candidate compounds. A test which could reliably rule this out would be very valuable in minimising inappropriate antibiotic exposure. An editorial explains the difficulties with finding and assessing biomarkers in the context of inconsistent results between studies.

A randomised controlled trial found that the use of pneumatic compression stockings reduced post-induction hypotension in elderly patients undergoing robot-assisted laparoscopic prostatectomy, with associated reductions in vasopressor use and no complications associated with their use. With further validation this represents a potential avenue for a non-invasive intervention to help maintain better cardiovascular stability during anaesthesia, which would be particularly valuable in this older patient group.

Concern about how to teach regional anaesthesia to novice practitioners, given the substantial learning curve and many individual micro-skills, informs Chuan et al. reporting their evaluation of a novel virtual reality trainer for regional anaesthesia, finding substantial inter-individual variability in learning. Also published in this issue was new guidance from the Association of Anaesthetists regarding the management of vagus nerve stimulation therapy in the peri-operative period, alongside this month’s Reviewer Recommendations which explains how to undertake and reportpatient and public involvement in research.

Finally, it was great to see the journal represented at the ANZCA ASM with a variety of Editors, Associate Editors and Anaesthesia Reports Editors in attendance. Booking for Annual Congress 2023 in Edinburgh is now open, and we hope to see you there too!

Paul Bramley and Andrew Klein