Respiratory mechanics and mechanical power during low vs. high positive end-expiratory pressure in obese surgical patients - A sub-study of the PROBESE randomized controlled trial.
Scharffenberg M., Mandelli M., Bluth T., Simonassi F., Wittenstein J., Teichmann R., Birr K., Kiss T., Ball L., Pelosi P., Schultz MJ., Gama de Abreu M., Huhle R., PROBESE-investigators None., Protective Ventilation Network None., Clinical Trials Network of the European Society of Anaesthesiology and Intensive Care None.
STUDY OBJECTIVE: We aimed to characterize intra-operative mechanical ventilation with low or high positive end-expiratory pressure (PEEP) and recruitment manoeuvres (RM) regarding intra-tidal recruitment/derecruitment and overdistension using non-linear respiratory mechanics, and mechanical power in obese surgical patients enrolled in the PROBESE trial. DESIGN: Prospective, two-centre substudy of the international, multicentre, two-arm, randomized-controlled PROBESE trial. SETTING: Operating rooms of two European University Hospitals. PATIENTS: Forty-eight adult obese patients undergoing abdominal surgery. INTERVENTIONS: Intra-operative protective ventilation with either PEEP of 12 cmH2O and repeated RM (HighPEEP+RM) or 4 cmH2O without RM (LowPEEP). MEASUREMENTS: The index of intra-tidal recruitment/de-recruitment and overdistension (%E2) as well as airway pressure, tidal volume (VT), respiratory rate (RR), resistance, elastance, and mechanical power (MP) were calculated from respiratory signals recorded after anesthesia induction, 1 h thereafter, and end of surgery (EOS). MAIN RESULTS: Twenty-four patients were analyzed in each group. PEEP was higher (mean ± SD, 11.7 ± 0.4 vs. 3.7 ± 0.6 cmH2O, P