[The effect of adrenaline and noradrenaline on the oxygen supply of the myocardium during cardiopulmonary resuscitation].

The effect of epinephrine and norepinephrine on myocardial oxygen delivery and consumption during cardiopulmonary resuscitation using open cardiac massage after a 5-min period of electrically induced ventricular fibrillation was studied in 21 pigs with a mean body weight of 21 kg. Norepinephrine, like epinephrine, is a sympathomimetic agent with marked alpha- and beta-1-sympathomimetic activity, but the degree of beta-2-stimulation is less marked than that obtained with epinephrine. After mechanical measurements over 3 min (compression rate = 60/min), 7 animals received 10 ml physiological saline, 7 further animals, 45 micrograms/kg epinephrine, and the remaining 7 animals, 45 micrograms/kg norepinephrine. At 90 s and again at 5 min after the administration of epinephrine or norepinephrine, the mean arterial blood pressure was significantly higher than in the control group, while mean pulmonary artery pressure, central venous pressure and cardiac index were not significantly different. Total myocardial blood flow was only measured before the induction of cardiac arrest in the control group, where it was found be 193 +/- 30 ml/min/100 g. During the open cardiac massage but before the injection of catecholamines we found a myocardial blood flow of 51 +/- 23 in the control group, 71 +/- 10 in the epinephrine group, and 74 +/- 11 ml/min/100 g in the norepinephrine group. At 90 s after the injection, blood flow increased by 78% to 126 +/- 18, with epinephrine and by 45%, to 107 +/- 30 ml/min/100 g tissue with norepinephrine. At 5 min after administration of these catecholamines significant differences from the control group were present.(ABSTRACT TRUNCATED AT 250 WORDS)