How Intra-Abdominal Insufflation Affects Mechanical Power in Various Body Positions?

We conducted a prospective observational study after ethics committee approval in patients over 18 years of age and American Society of Anesthesiologists (ASA) 1, 2, and 3 class patients undergoing elective laparoscopic cholecystectomy. All patients (n:60) included in the study were intubated and ventilated using a Drager Perseus A500 mechanical ventilator. All patients independent of the study are ventilated with this ventilator. The patients were ventilated in volume controlled ventilation (VCV) mode with a tidal volume of 7 ml/ kg, PEEP of 5 mmHg, I:E ratio of 1:2, respiratory rate of 12/min, fresh gas flow of 4 l/min, and FiO2 of 40%. Measurements were taken after hemodynamic stability was achieved. In 4 different conditions; the supine position pre-insufflation (Condition 1), the reverse Trendelenburg position 15º pre-insufflation (Condition 2), the supine position post-insufflation (Condition 3) and, the reverse Trendelenburg position 15º post-insufflation (Condition 4) peak pressure and hemodynamic data were recorded. The measurements of the patients were taken in the routine positions used during laparoscopic cholecystectomy operations. No non-routine positions were applied, and all patients independent of the study underwent surgery in this position. No interventional procedure was performed, and only observations were made during position changes. The patients were observed within 20 minutes after intubation. Mechanical power was calculated using predefined formula. Changes in 4 conditions were compared. The effect of obesity on mechanical power was investigated because it may affect compliance.