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.

This hospital preceptor program includes processes to recruit, select, and provide ongoing evaluation of preceptor function. After volunteering, candidates are chosen by peer vote. A blended training program includes online, commercially available modules and nursing professional development practitioner-led sessions that engage preceptors in reflection and problem-solving. Preceptor education allows nurses to further develop their skills over 2 years. Formal evaluation found that preceptors gained efficiency in their role with low turnover rate and positive patient outcomes.

Clinicians discovered and began using lactate as a biomarker in the mid-1800s. Yet, its utility as a clinical tool continues to vex modern-day physicians. Although an increasing amount of literature has shown that elevations in lactic acid are generally unfavorable, 1-4 the underlying etiology, how to treat, and how to prevent increases in lactate remain elusive. In this month's Journal of Cardiothoracic and Vascular Anesthesia, Govender et al. 5 used intraoperative lactic acid concentration as a dynamic variable to be assessed during cardiac surgery. Cardiopulmonary bypass (CPB) is arguably one of the most precarious interventions in medicine, as it calls for meticulous attention to fluid composition, appropriate delivery of oxygen, and acid-base balance. Unlike previous investigators, Govender, et al. analyzed the change in intraoperative lactate levels, independent of the initial value, and associations with adverse outcomes. Hyperlactatemia can result from anaerobic or aerobic pathways and occurs when there is excess production or decreased clearance of lactate. 6,7 It occurs in nearly two-thirds of patients undergoing cardiac surgery. 1 Lactic acidosis has been separated broadly into 2 types: A and B. Type A lactic acidosis accounts for most clinical presentations and results when oxygen delivery is insufficient, such as during hypovolemia, blood loss, sepsis, and cardiogenic shock. 7 Whether a global or regional oxygen debt exists, the hypoxic conditions result in anaerobic metabolism. In this scenario, a glycolytic pathway much less efficient than the citric acid cycle ensues with lactic acid produced as a byproduct. Alternatively, during aerobic conditions accelerated metabolism owing to stress or inotropic medications can overwhelm the pyruvate dehydrogenase enzyme, leaving pyruvate to be broken down into lactate instead of acetyl-coenzyme A. This is known as type B lactic acidosis. Type B lactic acidosis also can be caused by medications, malignancies, malnutrition, or congenital errors in metabolism, among others. 7 Furthermore, epinephrine, which commonly is used in cardiac surgery, increases hepatic degree of lactate rise directly correlated with 30-day mortality.