THE PULMONARY AND SYSTEMIC HEMODYNAMIC EFFECTS PRODUCED BY MEPERIDINE AND HYDROXYZINE

¹ Departments of Pediatrics and Surgery, University of California School of Medicine, Los Angeles, California

The Pulmonary and systemic hemodynamic effects of meperidine and hydroxyzine individually and in combination were investigated. The preparation consisted of intact, unanesthetized dogs in which pulmonary artery, left atrial and aortic catheters and an electromagnetic flowmeter had been implanted at operation. Meperidine produced significantly increased computed pulmonary and systemic vascular resistance. Hydroxyzine produced significantly increased systemic vascular resistance, but had little significant effect on the pulmonary circulation. A combination of meperidine and hydroxyzine produced considerably fewer changes than meperidine alone. It was concluded that both agents individually and in combination produce hemodynamic changes which could alter the interpretation of a cardiac catheterization.