HEMODYNAMIC BASIS FOR COCAINE-INDUCED PULMONARY-EDEMA IN DOGS

We tested the hypothesis that cocaine-induced impairment of left ventricular function results in cardiogenic pulmonary edema. Mongrel dogs, anesthetized with alpha-chloralose, were injected with two doses of cocaine (5 mg/kg iv) 27 min apart. Cocaine produced transient decreases in aortic and left ventricular systolic pressures that were followed by increases exceeding control. As aortic pressure recovered, left ventricular end-diastolic, left atrial (Pla), pulmonary arterial (Ppa), and central venous pressures rose. Cardiac output and stroke volume were reduced when measured 4-5 min after cocaine administration. Peak Ppa and Pla were 31 +/- 5 (SE) mmHg (range 17-51 mmHg) and 26 +/- 5 mmHg (range 12-47 mmHg), respectively. Increases in extravascular lung water content (4.10 to 6.24 g H2O/g dry lung wt) developed in four animals in which Pla exceeded 30 mmHg. Analysis of left ventricular function curves revealed that cocaine depressed the inotropic state of the left ventricle. Cocaine-induced changes in hemodynamics spontaneously recovered and could be elicited again by the second dose of the drug. Our results show that cocaine-induced pulmonary hypertension, associated with decreased left ventricular function, produces pulmonary edema if pulmonary vascular pressures rise sufficiently.