Low end-tidal CO2 predicts death independently of blood pressure

The edition in brief

Today's anaesthesiology desk leads with capnography as a prognostic signal rather than a ventilation check. A retrospective cohort of 185,455 adults having non-cardiac surgery under general anaesthesia with mechanical ventilation found lower mean intraoperative end-tidal CO2 associated with in-hospital mortality, adjusted odds ratio 1.63 (95% CI 1.36 to 1.86) per 5 mmHg fall below the median, independent of both intraoperative hypotension and minute ventilation, with no interaction between end-tidal CO2 and hypotension. Overall mortality was 0.85 per cent. The CHEM-FACT trial randomised 40 adults having shoulder surgery in the beach chair position in a 2x2 factorial design to propofol or sevoflurane and to phenylephrine infusion or ephedrine boluses, monitoring cerebral oxygenation and metabolic rate with time-resolved near-infrared spectroscopy and diffuse correlation spectroscopy: neither choice changed the 30-minute averages, but phenylephrine produced a 9 per cent greater decline in relative tissue oxygen saturation over 30 minutes and a rising metabolic rate. A non-inferiority trial in 100 patients after total knee arthroplasty found single-shot liposomal bupivacaine in a parasacral ischial plane block non-inferior to a continuous catheter on 72-hour pain area under the curve, while the catheter gave lower opioid use and better early rehabilitation at the cost of a catheter failure, leak, dislodgement or blockage rate in the low single figures each. The practice-changer is a four-arm trial of 160 patients in which esketamine added to ropivacaine for a thoracoscopy-guided paravertebral block prolonged analgesia at all three doses, with 0.2 mg/kg the dose that gained the benefit without the delayed wake-up seen at 0.3 mg/kg.