Alveolar recruitment manoeuvre results in improved pulmonary function in obese patients undergoing bariatric surgery: a randomised trial.

Perioperative ventilation is an important challenge of anaesthesia, especially in obese patients: body mass index is correlated with reduction of the pulmonary volume and they develop significantly more perioperative atelectasis and pulmonary complications. The alveolar recruitment manoeuvre is the most effective technique to reverse atelectasis. However, the clinical benefit on lung function in the perioperative period is not clear. The aim of the present study is to assess the perioperative clinical results of systematic alveolar recruitment manoeuvre associated with protective ventilation in patients undergoing laparoscopic bariatric surgery. It was a single-centre, randomised, double blind, superiority trial: control group with standard protective ventilation and recruitment group with protective ventilation and systematic recruitment manoeuvre. The primary outcome was a composite clinical criterion of pulmonary dysfunction including oxygen saturation, oxygen needs and dyspnoea in recovery room and at day 1. Secondary outcomes were recruitment manoeuvre tolerance, pulmonary and non-pulmonary complications, length of hospital stay and proportion of Intensive Care Unit admission. Two hundred and thirty patients were included: 115 in the recruitment manoeuvre group and 115 in the control group, 2 patients were excluded from the analysis in the control group. Patients in the recruitment manoeuvre group had significantly lower rate of pulmonary dysfunction in the recovery room (73% versus 84% (p = 0.043) and 77% versus 88% at postoperative day 1 (p = 0.043)). No significant differences were found for secondary outcomes. No patient was excluded from the recruitment manoeuvre group for intolerance to the manoeuvre. Recruitment manoeuvre is safe and effective in reducing early pulmonary dysfunction in obese patients undergoing bariatric surgery.

Low exogenous lactate clearance as an early predictor of mortality in normolactatemic critically ill septic patients.

OBJECTIVE: To evaluate the prognostic value of lactate clearance and lactate production in severely ill septic patients with normal or mildly elevated blood lactate concentration. DESIGN Prospective, observational study. SETTING: Nineteen-bed mixed medicosurgical intensive care unit. PATIENTS: Fifty-six patients with severe sepsis and blood lactate concentration <3 mmol/L. MEASUREMENTS AND MAIN RESULTS: Lactate metabolism was evaluated in all patients. Lactate clearance was measured by modeling the change in arterial blood lactate over time induced by an infusion of 1 mmol/kg sodium lactate for 15 mins. Lactate production was calculated as the product of lactate clearance times the blood lactate concentration before the infusion. Outcome was taken to be mortality at 28 days after the beginning of the septic episode. A logistic regression model taking into account different risk factors was constructed. Among the 56 patients, 17 (30.3%) died before the 28th day. Basal blood lactate concentration was not different between survivors and nonsurvivors, whereas lactate clearance and production were higher in survivors (0.86 +/- 0.32 vs. 0.58 +/- 0.18 L/hr/kg, p < .005, and 1.19 +/- 0.63 vs. 0.89 +/- 0.24 mmol/hr/kg, p = .055, respectively). An increase in blood lactate 45 mins after the end of the lactate infusion (Deltalact-T60) > or = 0.6 mmol/L was predictive of 28-day mortality with 53% sensitivity and 90% specificity. Multivariate analysis showed that only three factors were independently and significantly correlated with 28-day mortality: presence of more than two organ failures (odds ratio, 27; p = .04), age >70 yrs (odds ratio, 5.7; p = .032), and Deltalact-T60 > or =0.6 mmol/L (odds ratio, 14.2; p = .042). CONCLUSION: Low lactate clearance in severely ill septic patients with normal or mildly elevated blood lactate is predictive of poor outcome independently of other known risk factors such as age and number of organ failures.