OBJECTIVE: For several surgical procedures spinal anesthesia is preferred to general anesthesia. However some of its most important effects are reducing blood pressure (hypotension) and heart rate. In this study, we evaluated the effect of prophylactic intramuscular ephedrine before spinal anesthesia. METHODS: This study was conducted on 100 cases in A.S.A class, I (American society of anesthesiologists) between 20-60 years old who had no co-existing disease. They were randomly divided into two groups (each with 50 cases). The test group received 2Smg (%5ml) intramuscular ephedrine 10-15 minutes before spinal anesthesia & the subjects in control group received 5ml normal saline (0.9% ) as placebo. After receiving 500ml Ringer's solution, spinal anesthesia with 2cc lidocaine %5 was done. Heart rate, systolic & diastolic blood pressure have been measured seven times before ephedrine or placebo injection, before spinal anesthesia & during the procedure at the 2nd, 5th, 15th, 30th & 4Sth minutes. Then data were recorded & compared.
FINDINGS: In this study, those who received prophylactic ephedrine had a raised heart rate & blood pressure before spinal anesthesia, but this rise was not more than %10 of the baseline & there was no need to treat their hypotention or reduced heart rate during anesthesia or the operation. But %28 of control group has received ephedrine for treatment of hypotention & %36 of them received atropine to manage bradycardia. After statistical analysis & comparing of these two groups, we have seen that the range of fall of heart rate, systolic & diastolic blood pressure in the study group was narrower than that in control group & their differences were
meaningful (p=0.000).
CONCLUSION: The results show that the patients who have received intramuscular ephedrine before spinal anesthesia, have a rather higher level of hemodynamic stability. Therefore, in patients for whom hemodynamic changes, specially a reduced blood pressure is dangerous such as those with a heart disease, old patients or those undergoing caesarean section using of this method could be useful.