In the December issue…

The final issue of 2017 is accompanied by a special bonus issue freely available on line: the Royal College of Anaesthetists 25^th Anniversary Special Issue (see editorial by Hemmings & Hunter, pages 1073--4). This collection of narrative reviews and special articles is based on presentations from the “Landmarks in UK Anaesthesia” meeting held in London in March 2017.

The main December issue includes diverse offerings reflecting the broad scope of medicine relevant to anaesthesia. The relationship between intraoperative urine output, renal function and risk of acute kidney injury is of frequent concern to all anaesthetists. Mizota and colleagues (pages 1127–34) conducted a retrospective analysis of patients undergoing major abdominal surgery to show that urine output below 0.3 ml kg⁻¹ h⁻¹ was associated with increased risk of acute kidney injury. An editorial by Kunst & Ostermann (pages 1075–7) discusses the concept of “permissive oliguria” and the interplay between patient factors and clinical conditions on acute kidney injury.

Approaches to monitoring physiologic changes in the perioperative period are addressed in a number of articles. Real-time monitoring of lactate concentration using a five-lumen central venous catheter was found by Gouëzel and colleagues (pages 1110–7) to correlate closely with blood levels determined by laboratory analysis in high-risk cardiac surgical patients, but changes were less reliable, limiting clinical interpretation. In another study of cardiac surgery patients, Nakajima and colleagues (pages 1118–26) found increased expression of the pro-apoptotic protein Bax in platelets following cardiopulmonary bypass, which correlated with postoperative platelet dysfunction. A reliable minimally invasive monitor of intravascular volume is important with the increasing emphasis on careful replacement of fluids. Hocking and colleagues (pages 1135–40) show that peripheral intravenous analysis (PIVA) was a useful monitor of fluid removal in haemodialysis, with potential applications in surgical patients. Along the same lines, a noninvasive monitor of cerebral autoregulation would be useful in patients at risk of cerebral ischaemia. Sperna Weiland and colleagues (pp 1141–9) used a novel method of transcranial Doppler flow analysis in anaesthetized patients to show that cerebral autoregulation could be reliably monitored and was preserved under sevoflurane anaesthesia. An editorial by Grüne & Klimek (pages 1077–9) highlights this important step forward, but they caution that this approach is not yet ready for routine clinical use. Methods for monitoring depth of anaesthesia rely on electroencephalography, but the complex relation between this monitor and anaesthetic endpoints is incompletely understood. Plourde & Arsenau (pages 1150–60) measured the effects of dexmedetomidine on the thalomocortical electroencephalogram to show that reduced high frequency oscillations are associated with loss of consciousness in a rat model. Banks and colleagues (pages 1079–81) discuss some of the challenges in defining the electrophysiological correlates of the loss and return of consciousness, the holy grail of neuromonitoring.

Following on the Special Section on Pain Medicine in the October issue of the Journal, there are several more important contributions on pain in this issue. Lawrence and colleagues (pagers 1092–109; Editor’s Choice) report a systematic review to identify several validated measurement tools for risk assessment and monitoring of opioid analgesic use in non-cancer chronic pain patients. Koo and colleagues (pages 1161–8) used sensitive measures of pain and hyperalgesia to show that low dose intraoperative naloxone reduced postoperative hyperalgesia in patients receiving high dose remifentanil, but did not reduce postoperative pain. In the quest to discover analgesics with fewer side effects, van der Schrier and colleagues (pages 1169–77) report that the dual mechanism opioid tapendolol has reduced respiratory depression compared with oxycodone at equi-analgesic doses in healthy volunteers.

Several papers this month related to safety and outcomes, and increasingly important topic in these pages. Intraoperative hypotension is associated with myocardial, cerebral and renal ischaemia, so methods of prevention are important to improved outcomes. Jakobsson and colleagues (pages 1178–85) measured pre- and post-spinal anaesthesia changes in haemodynamic parameters to show that reduction in cardiac output before spinal anaesthesia is associated with increased postspinal hypotension and might serve as a predictor. Beloeil and colleagues (pages 1186–93) used a large French national database to determine adherence to national guidelines for two procedures for which preoperative testing is not recommended. They found that standard laboratory coagulation tests and ABO blood typing are still routinely performed, despite current guidelines and evidence against this practice, at a high economic cost. And finally, Nestler and colleagues (pages 1194–205) show that intraoperative recruitment manoeuvres and titrated positive end-expiratory pressure improved pulmonary function in obese patients undergoing laparoscopic surgery, but the benefits did not persist into the postoperative period.