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To evaluate whether a perioperative open-lung ventilation strategy prevents postoperative pulmonary complications after elective on-pump cardiac surgery. Methods: In a pragmatic, randomized, multicenter, controlled trial, we assigned patients planned for on-pump cardiac surgery to either a conventional ventilation strategy with no ventilation during cardiopulmonary bypass (CPB) and lower perioperative positive end-expiratory pressure (PEEP) levels (2 cm H 2 O) or an open-lung ventilation strategy that included maintaining ventilation during CPB along with perioperative recruitment maneuvers and higher PEEP levels (8 cm H 2 O). All study patients were ventilated with low-tidal volumes before and after CPB (6 to 8 ml/kg of predicted body weight). The primary end point was a composite of pulmonary complications occurring within the first 7 postoperative days. Results: Among 493 randomized patients, 488 completed the study (mean age, 65.7 years; 360 (73.7%) men; 230 (47.1%) underwent isolated valve surgery). Postoperative pulmonary complications occurred in 133 of 243 patients (54.7%) assigned to open-lung ventilation and in 145 of 245 patients (59.2%) assigned to conventional ventilation (p = 0.32). Open-lung ventilation did not significantly reduce the use of high-flow nasal oxygenotherapy (8.6% vs 9.4%; p = 0.77), non-invasive ventilation (13.2% vs 15.5%; p = 0.46) or new invasive mechanical ventilation (0.8% vs 2.4%, p = 0.28). Mean alive ICU-free days at postoperative day 7 was 4.4 ± 1.3 days in the open-lung group vs 4.3 ± 1.3 days in the conventional group (mean difference, 0.1 ± 0.1 day, p = 0.51). Extra-pulmonary complications and adverse events did not significantly differ between groups.

IntroductionHypoxia-inducible factor-1 (HIF1) controls the expression of genes involved in the cellular response to hypoxia. No information is available on its expression in critically ill patients. Thus, we designed the first clinical study in order to evaluate the role of HIF1α as a prognosis marker in patients suffering from shock.MethodsFifty consecutive adult patients with shock and 11 healthy volunteers were prospectively enrolled in the study. RNA was extracted from whole blood samples and expression of HIF1α was assessed over the first four hours of shock. The primary objective was to assess HIF1α as a prognostic marker in shock. Secondary objectives were to evaluate the role of HIF1α as a diagnostic and follow-up marker. Patient survival was evaluated at day 28.ResultsThe causes of shock were sepsis (78%), hemorrhage (18%), and cardiac dysfunction (4%). HIF1α expression was significantly higher in the shock patients than in the healthy volunteers (121 (range: 72-168) versus 48 (range: 38-54) normalized copies, P <0.01), whatever the measured isoforms. It was similar in non-survivors and survivors (108 (range 84-183) versus 121(range 72-185) normalized copies, P = 0.92), and did not significantly change within the study period.ConclusionsThe present study is the first to demonstrate an increased expression of HIF1α in patients with shock. Further studies are needed to clarify the potential association with outcome. Our findings reinforce the value of monitoring plasma lactate levels to guide the treatment of shock.