Three papers from the first BJA of the new decade highlight the importance of non-inferiority: protective ventilation strategies, dexamethasone for prolonging interscalene blocks, and high inspired oxygen and surgical site infections.
Although none investigated new questions, they all represent studies into areas of ongoing uncertainty. They are each a useful reminder that most perioperative interventions do not significantly improve outcomes, although the majority of these probably do not ever make it to publication.
Lung-protection and atelectasis
Généreux et al. investigated the atelectasis-preventing benefit of a common protective ventilation strategy (PEEP and regular recruitment manoeuvres). Notable not just because there was no difference in atelectasis after extubation, but because the use of ultrasound to measure atelectasis helped to better track the intraoperative and post-extubation changes between the intervention and control groups. [→ article summary]
High FiO2 and surgical infections (again)
Ferrando and colleagues set out to again challange whether high inspired oxygen concentrations reduces surgical infections after abdominal surgery. Once again, no benefit could be shown from higher intraoperative FiO2.
What makes their study more interesting, is the use of an individualised optimal ventilation strategy and postoperative CPAP, all aimed at optimising peripheral oxygenation while reducing the potential atelectasis-inducing effects of a high FiO2 technique.
Dexamethasone and interscalene blocks
Finally, McHardy et al. looked at the known block-prolonging effects of dexamethasone when used as an adjunct for interscalene blocks: is there any difference with dexamethasone given intravenously versus perineurally?
Thankfully the answer was no clinically significant difference in interscalene block duration regardless of dexamethasone route of administration. The fewer drugs that get unnecessarily injected perineurally the better!
- Généreux V, Chassé M, Girard F et al. Effects of positive end-expiratory pressure/recruitment manoeuvres compared with zero end-expiratory pressure on atelectasis during open gynaecological surgery as assessed by ultrasonography: a randomised controlled trial. Br J Anaesth. 2020 Jan 1; 124 (1): 101-109.
- Ferrando C, Aldecoa C, Unzueta C et al. Effects of oxygen on post-surgical infections during an individualised perioperative open-lung ventilatory strategy: a randomised controlled trial. Br J Anaesth. 2020 Jan 1; 124 (1): 110-120.
- McHardy PG, Singer O, Awad IT et al. Comparison of the effects of perineural or intravenous dexamethasone on low volume interscalene brachial plexus block: a randomised equivalence trial. Br J Anaesth. 2020 Jan 1; 124 (1): 84-91.