[Approach to artificial respiration using differential ventilation in open thoracic surgery]

The purpose of our study was to correct the vertical ventilation perfusion anomaly in lateral position using a differential ventilation with the two identical electronic synchronized "Servo" ventilators, during the thoracotomy. Our study included 44 patients. The differential ventilation has been investigated on the two clinically standardized simplified models. In model 1 distribution of the ventilation volume dependent-independent lung was 50%/50% with a selective PEEP in the dependent lung of 10 cm/H2O. In model 2 distribution of ventilation volume dependent-independent lung of 70%/30% with selective PEEP in the dependent lung of 5 cm H2O. Statistical analysis of our results shows that if we use the differential ventilation model 2 during the thoracotomy we could obtain: a) the lowest values of the shunt in the group of pulmonary patients b) elimination of an appearance of a single critical values of the shunt and a low value of PaO2 in both groups of patients.