The effects of controlled hypotension during mild hypothermia on coronary and systemic hemodynamics and myocardial contractility
Fukusaki, M.
Masui. Japanese Journal of Anesthesiology 33(12): 1351-1361
1984
ISSN/ISBN: 0021-4892 PMID: 6530738 Document Number: 241284
The effects of controlled hypotension during mild hypothermia on coronary and systemic hemodynamics and myocardial contractility in halothane -N2O-O2 anesthetized dogs were investigated. The flow of the ascending aorta and the left coronary artery was measured with electromagnetic flow meter probes, and the pressure of femoral artery and left ventricle was measured. After obtaining each parameter, the dogs were cooled to 32.degree. C, and the control data were obtained. Systolic arterial blood pressure was reduced to 80% of the control value by drip infusion of prostaglandin E1 (PGE1), nitroglycerin (TNG), sodium nitroprusside (SNP) and trimethaphan (TMP) and maintained for 30 min. The cardiovascular responses were as follows. The changes after cooling. Heart rate cardiac index (CI), and coronary blood flow (CBF) decreased. Total peripheral resistance (TPR) and coronary vascular resistance (CVR) increased. CBF/triple-product (CBF/TP) and Vmax decreased. The changes associated with infusion of the agents during hypothermia. CI decreased with 4 groups, and the reduction was marked with TMP. TPR was unchanged with TNG, SNP and PGE, but increased with TMP. CBF was reduced with 4 groups, and the reduction was marked with TMP. CVR decreased with TNG, and unchanged with SNP and PGE1, but increased with TMP. CBF/TP increased with TNG, and unchanged with SNP and PGE1, but decreased with TMP. Vmax was unchanged with PGE1 and TNG, but reduced with SNP and TMP. When hypotensive anesthesia is used during mild hypothermia, TNG, SNP and PGE1 may offer more advantages on cardiovascular hemodynamics than TMP in halothane -N2O-O2 anesthetized dogs.