Comparison of Bolus Phenylephrine and Mephentermine for Maintenance of Arterial Pressure during Spinal Anaesthesia in Caesarean Section

Anaesthesia to a parturient is not only unique but requires highest degree of care because the anaesthesiologist has to look after two individuals, the mother and foetus. In elective caesarean section under spinal anaesthesia hypotension has been reported in as many as 85 % of patients. Hypotension may be detrimental to the mother and the resulting placental hypoperfusion to the foetus. Careful positioning and volume preloading with crystalloid or colloids have been used to prevent it, but these are not complete measures and Vasopressor is required to correct hypotension quickly. Hence, the present study is carried out to compare the bolus of phenylephrine and mephentermine for the maintenance of arterial pressure during spinal anesthesia. The study enrolled 60 full term pregnant females of ASA grade I and II belonging to the age group of 20-40 years, undergoing elective ceaserean section, were divided into two groups, Group P and Group M, receiving 100mg of phenylephrine and 6mg in 1 ml of mephentermine as bolus intravenous, respectively. The patients who refused for spinal anaesthesia, patients having gastrointestinal diseases, liver diseases, hyperemesis gravidarum, hyperlipidemia and patients having cardiac diseases, pregnancy induced hypertension, supine hypotension syndrome were excluded from the study. The data obtained is statistically analysed by using ANOVA test and students two-tailed t-test. The values are found to be significant statistically at pless than0.05 level. The final results suggest that phenylephrine and mephentermine are both effective in maintenance of arterial pressure during spinal anesthesia in caesarean delivery. Hoewever, phenylephrine has a quickonset of action and decreases the heart rate which may be favourable in patients in whom tachycardia is undesirable. Here, the major limitation is that the non-cooperation of patients.