ABSTRACT : To compare phenylephrine,mephentermine and ephedrine in producing best fetal pH as outcome by maintaining 100% baseline SBP after SAB for elective LSCS.

METHODS : This randomised double blinded study was conducted at GGH,Kakinada. 75 patients with no difference in baseline demographic data posted for elective LSCS were randomly divided into 3 groups of 25 each(E,P,M) to receive ephedrine=5mg/ml, phenylephrine=30µ/ml,mephentermine=0.5mg/ml respectively as bolus immediately after spinal injection with bupivacaine 0.5%(hyperbaric) prophylactically & followed by infusion at the rate of 15 ml/h to maintain SBP at 100% baseline.Umbilical blood gases,maternal haemodynamic parameters &complications were recorded.Results were compared by using ANOVA analysis

RESULTS : : The umbilical pH was comparable in all the 3 groups (P > 0.05).The mean SBP from spinal block until delivery was similar over time for all the three groups. The incidence of reactive hypertension was more in group M (P < 0.05) than in group E and group P.Total drug consumption to meet target blood pressure till delivery was 39.3 ± 14.6 mg in group E, 1.7 ± 0.9 mg in group M, and 283.6 ± 99.8 mcg in group P.The incidence of nausea and vomiting was comparable in the 3 groups.

CONCLUSIONS : All the three vasopressors were equally effective in maintaining maternal BP,but phenylephrine is better vasopressor in reduction of fetal acidosis and neonatal outcome than ephedrine and mephenteramine during spinal anesthesia for cesarean section.