This study was conducted to compare the effects of esmolol and propranolol on cardiovascular system, arterial oxygenation and sodium nitroprusside [SNP] dose requirements during SNP-induced hypotension.
Twenty patients were allocated into two equal groups. Group I: received esmolol infusion [300 micro g. Kg-I. min-I] as an adjuvant to SNP after lowering the mean arteraial blood pressure [MAP] to 60 mmHg for 20 min. group II: received propranolol [0.01mg. Kg-I] as an adjuvant to SNP after lowering the MAP to 60 mmHg for 20 min by SNP. All patients received morphine 0.1 mg. Kg-I i. m. one hour before operation. Anaesthesia was induced with thiopentone sodium 5 mg. Kg-I and maintained with 60% N O in O supplemented with halothane 0.5-1%. Intubation was facilitated with succinlylcholine 1 mg. Kg-I and muscle relaxation was maintained with d-tubocurarine 0.5 mg. Kg-I and ventilation was controlled. We found a significant increase in heart rate and a significant decrease in arterial oxygenation 20min after lowering the MAP to 60 mmHg by SNP in both groups. After beta-blockade, there was a significant decrease in heart rate and SNP dose-requirement which was more significant in esmolol group than in propranolol group, but the reduction in arterial oxygenation was more significant in propranolol group than in esmolol group. At the end of operation, there was no significant change in heart rate in esmolol group, while there was a significant decrease in propranolol group and the reduction in arterial oxygenation was more significant in propranolol group than in esmolol group. We can conclude that administration of esmolol infusion is better than a bolus dose of propranolol during SNP-induced hypotension regarding more reduction in heart rate, improvement in arterial oxygenation and lowering of SNP dose-requirements with no of changes in heart rate postoerataively
Mohamed H. El Abrak ,
Comparison of esmolol and propranolol for potentiation of nitroprusside induced hypotension,
Tanta Med. J. 1993;
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