Large tidal volume ventilation improves pulmonary gas exchange during lower abdominal surgery in Trendelenburg’s position

摘要: Impaired pulmonary gas exchange is a common complication of general anaesthesia. Periodic hyperinflation the lungs and large tidal volume ventilation were first preventive measures to be widely embraced, but their effectiveness in clinical practice has never been clearly established by controlled studies. To assess effects high-risk patients we studied 24 adults having lower abdominal gynaecological surgery Trendelenburg (head down) position. Pulmonary oxygen was determined during four steady-states: awake control (AC), after 30 min conventional (CVt, 7.5 ml · kg−1) or high (HVt, 12.7 ventilation, introduced random order, five minutes manual hyperinflations (HI) lungs. The patients’ ventilated with air/O2 an Ohmeda volume-controlled ventilator via circle system. TheFiO2 at 0.5, andFETCO2 adding dead space HVt. Arterial blood analysis used calculate tension-based indices exchange. There significant deterioration (A-a)DO2 Group A, whose CVt (81.6 ± 7.2 166.8 13.7 mmHg, P < 0.001); not B, HVt(77.0 9.9 104.4 16.8 mmHg). When A B data pooled there no difference between randomized CVT HVt, improvement occurred HI. In this model compromised O2 inflation volumes (HVt HI) considerable benefit, HVt prevented HI reversed disorder.