Effects of Hydralazine Pretreatment on Esmolol-induced Controlled Hypotension during Spine Surgery. |
Kum Suk Park, Young Jin Roh, Jong Su Kim, Sang Hwan Do |
Department of Anesthesiology, Seoul National University College of Medicine, Seoul, Korea. shdo@snu.ac.kr |
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Abstract |
BACKGROUND Controlled hypotension improves surgical field and decreases transfusion requirement in surgical patients and can be induced with various kinds of drugs including esmolol and hydralazine. METHODS This study examined the effect of a combination of esmolol and hydralazine as hypotensive agents in spine surgery. In the esmolol group (n = 15), after boluses of esmolol (0.5 mg/kg) injection, esmolol was infused to maintain the mean arterial pressure of 55-65 mmHg. In the hydralazine-esmolol group (n = 15), hydralazine (0.3 mg/kg) was administered 15 minutes before esmolol injection which was done in the same way as that of the esmolol group. RESULTS The mean arterial pressure decreased to the target range more rapidly in the hydralazine-esmolol group. The heart rate was increased by hydralazine, but reduced by esmolol. The cardiac output remained elevated after hydralazine injection in the hydralazine-esmolol group, and decreased significantly by esmolol in the esmolol group. The administered dose of esmolol was much less in the hydralazine-esmolol group than in the esmolol group. CONCLUSIONS Our data suggest that hydralazine can enhance the efficacy of esmolol-induced controlled hypotension. It can reduce the requirement of esmolol and maintain a higher cardiac output during hypotension. |
Key Words:
controlled hypotension; esmolol; hydralazine |
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