All issues > Volume 44(2); 2001

Original Article

J Korean Pediatr Soc. 2001;44(2):177-184. Published online February 15, 2001.

The Relationship between Change of Cardiac Function and Systemic Oxygen Consumption according to the Dose of Dopamine in the Rabbit

Hee Ju HJ Park¹, Seok Ho SH Yoon¹, Bong Seok BS Choi¹, Jung Hwoi JH Cho¹, Ku Tae KT Kim¹, Sun Young SY K¹, Sang Ook SO Nam¹, Bok Luel BL Lee²

¹Department of Pediatrics, College of Medicine, Pusan National University, Pusan, Korea
²Department of Phamacology, Pusan National University, Pusan, Korea

Abstract

Purpose
: We'd like to know the relationship between the changes of cardiac function and systemic O2 consumption according to the increasing dose of dopamine.
Methods
: Ten rabbits(from 2kg to 2.8kg) were used in this experiment. Anesthesia was induced with intraperitoneal pentobarbital sodium(35mg/kg) and tracheostomy was done. It was maintained by ventilation with a mixture of 1-3% halothane and 67-69% oxygen. Polyvinyl catheters were inserted into the femoral artery and vein and to check blood pressure and arterial blood gas analysis during the surgical procedure. Two other catheters were inserted into the internal carotid artery and external jugular vein and advanced into left ventricle and right atrium to check the pressure of each chamber, LV maximal dP/dt and to obtain blood samples of each chamber. Thoracotomy was done to expose aorta and coronary artery to check the cardiac output and coronary blood flow. We injected dopamine every 10 minutes according to the scheduled dose through external jugular vein and recorded heart rate, cardiac output, aortic pressure, maximal dP/dt, coronary blood flow by computer. Systemic O2 consumption was calculated by Fick method
Results
: The heart rate and mean aortic pressure increased slowly according to the dose of dopamine from 20μg/kg/min. The cardiac otuput the maximal dP/dt and coronary blood flow was not changed until 5μg/kg/min, but from 7.5μg/kg/min, it increased according to the dose of dopamine.
Conclusion
: Dopamine was a powerful inotrophic agent without increasing the systemic O2 consumption until 20μg/kg/min, but systemic O2 consumption increased markedly at more than 20 μg/kg/min of dopamine.

Keywords :Dopamine, Heart rate, Mean aortic pressure, Cardiac output, Maximal dP/dt, Coronary blood flow, Systemic O2 consumption