Treatment of Cardiac and Renal Effects of PEEP with Dopamine in Patients with Acute Respiratory Failure

Abstract

The hemodynamic and renal effects of mechanical ventilation with positive end-expiratory pressure (PEEP) were studied with and without continuous dopamine administration in 10 patients with acute pulmonary failure. The application of 20 cm H2O PEEP during mechanical ventilation caused improvements in arterial blood O2 tension from 63 .+-. 6 to 81 .+-. 12 torr (mean .+-. SE) and intrapulmonary shunt fraction from 29 .+-. 3 to 21 .+-. 3%, but cardiac output, systemic O2 transport and renal function were impaired by 20, 19 and 47%, respectively. Dopamine infusion at a rate of 5 .+-. 0.05 .mu.g/kg per min reversed the deleterious effects of PEEP on cardiovascular and renal function: cardiac output increased from 4.5 .+-. 0.3 to 6.0 .+-. 0.5 l, urinary output from 1.0 .+-. 0.3 to 1.7 .+-. 0.4 ml/min, Na excretion and creatinine clearance by 50%. Systemic O2 transport was improved from 680 .+-. 44 to 925 .+-. 78 ml, arterial O2 tension from 81 .+-. 12 to 102 .+-. 14 torr and total deadspace to tidal volume ratio from 0.49 .+-. 0.02 to 0.44 .+-. 0.03 with dopamine. Apparently the depression of cardiovascular and renal functions that may occur in patients who need high levels of PEEP for the treatment of acute pulmonary failure can be treated successfully with dopamine infusion. This represents a valuable alternative to expansion of blood volume for the improvement of systemic O2 transport and arterial blood O2 tension in critically ill patients.