IMPORTANCE An intraoperative higher level of positive end-expiratory positive pressure (PEEP) with alveolar recruitment maneuvers improves respiratory function in obese patients undergoing surgery, but the effect on clinical outcomes is uncertain. OBJECTIVE To determine whether a higher level of PEEP with alveolar recruitment maneuvers decreases postoperative pulmonary complications in obese patients undergoing surgery compared with a lower level of PEEP. DESIGN, SETTING, AND PARTICIPANTS Randomized clinical trial of 2013 adults with body mass indices of 35 or greater and substantial risk for postoperative pulmonary complications who were undergoing noncardiac, nonneurological surgery under general anesthesia. The trial was conducted at 77 sites in 23 countries from July 2014-February 2018; final follow-up: May 2018. INTERVENTIONS Patients were randomized to the high level of PEEP group (n = 989), consisting of a PEEP level of 12 cm H 2 O with alveolar recruitment maneuvers (a stepwise increase of tidal volume and eventually PEEP) or to the low level of PEEP group (n = 987), consisting of a PEEP level of 4 cm H 2 O. All patients received volume-controlled ventilation with a tidal volume of 7 mL/kg of predicted body weight. MAIN OUTCOMES AND MEASURES The primary outcome was a composite of pulmonary complications within the first 5 postoperative days, including respiratory failure, acute respiratory distress syndrome, bronchospasm, new pulmonary infiltrates, pulmonary infection, aspiration pneumonitis, pleural effusion, atelectasis, cardiopulmonary edema, and pneumothorax. Among the 9 prespecified secondary outcomes, 3 were intraoperative complications, including hypoxemia (oxygen desaturation with SpO 2 Յ92% for >1 minute). RESULTS Among 2013 adults who were randomized, 1976 (98.2%) completed the trial (mean age, 48.8 years; 1381 [69.9%] women; 1778 [90.1%] underwent abdominal operations). In the intention-to-treat analysis, the primary outcome occurred in 211 of 989 patients (21.3%) in the high level of PEEP group compared with 233 of 987 patients (23.6%) in the low level of PEEP group (difference, −2.3% [95% CI, −5.9% to 1.4%]; risk ratio, 0.93 [95% CI, 0.83 to 1.04]; P = .23). Among the 9 prespecified secondary outcomes, 6 were not significantly different between the high and low level of PEEP groups, and 3 were significantly different, including fewer patients with hypoxemia (5.0% in the high level of PEEP group vs 13.6% in the low level of PEEP group; difference, −8.6% [95% CI, −11.1% to 6.1%]; P < .001). CONCLUSIONS AND RELEVANCE Among obese patients undergoing surgery under general anesthesia, an intraoperative mechanical ventilation strategy with a higher level of PEEP and alveolar recruitment maneuvers, compared with a strategy with a lower level of PEEP, did not reduce postoperative pulmonary complications.

SUMMARYA 25-year-old man was found to have acute kidney injury (AKI) following ingestion of mephedrone. He presented to this local emergency department with worsening bilateral loin pain. He became oligoanuric, serum creatine peaked at 1214 mmol/l and he required several sessions of haemodialysis before kidney function began to improve. The mechanism of AKI and legal aspects of the use of mephedrone are discussed. BACKGROUND

A 36-year-old man presented to the emergency department acutely unwell after being found collapsed while running a halfmarathon. He presented with a reduced Glasgow coma score, was tachycardic, agitated, hypoxic and profusely sweating. He had taken a 'supplement' given to him prior to the race by a friend, as he was concerned about not finishing. This contained both caffeine and a large dose of ephedrine (60 mg in total). After initial resuscitation he was intubated, and was transferred to critical care. He subsequently developed rhabdomyolysis, requiring haemofiltration.

On awakening in the recovery room after a general anaesthetic for ear, nose and throat surgery, a 28-year-old woman reported central chest pain. She had received topical nasal cocaine solution preoperatively. She required intravenous opioids and sublingual glyceryl trinitrate before the pain settled. There was no evidence of significant myocardial injury and the patient was discharged later that day. The use of topical nasal cocaine solution in anaesthesia and its adverse myocardial effects are discussed.