Volume-controlled high frequency positive pressure ventilation for upper abdominal surgery. A clinical report.

Volume-controlled high-frequency positive pressure ventilation was evaluated and compared to intermittent positive pressure ventilation during anesthesia in 74 patients undergoing biliary tract surgery. There were no statistically significant differences in oxygenation or ventilation. Significantly lower airway pressures and lower tidal volumes were recorded during high frequency positive pressure ventilation. This technique was also used in eight morbidly obese patients during gastric stapling surgery, and provided adequate oxygenation and ventilation. Used intra-operatively, it also produced a quiet operative field, which the surgeons appreciated during cannulation of the biliary duct and stapling of the stomach. At the end of the anaesthesia, high frequency positive pressure ventilation was superimposed on spontaneous breathing and operated as a new mode of intermittent mandatory ventilation. This reduced the risk of hypoxia at the time of emergence from anaesthesia and at tracheal suctioning.