CLINICAL-APPLICATION OF DIFFERENTIAL VENTILATION WITH SELECTIVE POSITIVE END-EXPIRATORY PRESSURE IN ADULT-RESPIRATORY-DISTRESS-SYNDROME

Differential ventilation in the lateral position with positive end-exp iratory pressure (PEEP) selectively applied to the dependent lung (DVS P) has been shown to reduce venous admixture and improve oxygenation w ithout compromizing cardiac output in short term studies of patients w ith acute respiratory Failure. We have applied this ventilation techni que as a long-term treatment in severe adult respiratory distress synd rome (ARDS) in an open clinical trial. Eleven patients with ARDS of va rying aetiology were treated with DVSP for a total of 34 days. Median duration of conventional ventilatory therapy before start of DVSP was 5 days (1 to 18 days), inspiratory oxygen fraction (FIO2) was 0.61+/-0 .16 (mean+/-s.d.), resulting in a mean arterial oxygen tension (PaO2) of 7.1+/-2.1 kPa (PaO2/FIO2=11+/-4 kPa). A gradual improvement in gas exchange was seen during the first 24 h of DVSP such that PaO2 increas ed to 8.4+/-1.4 with a decreased FIO2 (0.52+/-0.14) resulting in an in creased PaO2/FIO2 (16+/-5 kPa). Five out of the eleven patients surviv ed. No major complication was noted using DVSP as a method. We found a steady improvement in gas exchange over the first 24 hours in most pa tients. However, mortality rate was no lower than expected. Drawbacks with DVSP were increased demand on staff and difficulties with adequat e endo-bronchial suctioning.