[Effects of three types of respiratory assistance (continuous positive pressure, intermittent positive pressure, classical respiratory physiotherapy) on PaO2 and PaCO2 in patients undergoing digestive tract surgery].

Two hundred and seventeen patients undergoing digestive tract surgery, either randomly or non-randomly allocated in two separate groups, and presenting postoperative hypoxemia, were studied during intensive care : 77 were ventilated by continuous positive pressure (CPP), 70 by intermittent positive pressure (IPP), and 70 were treated by classical respiratory physiotherapy. Results showed that CPP was the method of choice for ventilatory assistance following digestive tract surgery: hematosis was improved in a prolonged manner without modification of CO2 levels. The other procedures had a beneficial effect on PaO2 but at the price of a hyperventilation. Patients receiving IPP developed hypocapnea and hypoxemia five minutes after the end of the treatment. Physiopathological bases for these differences in gasometric behaviour in patients undergoing digestive tract surgery are analyzed as a function of the characteristics of CPP on the one hand, and IPP and respiratory physiotherapy on the other.