Background: There is accumulating evidence that Phenylephrine delivered as an infusion is the most effective method for preventing maternal hypotension and intra-operative nausea and vomiting. We designed a double-blind, placebo-controlled study to find out the optimal infusion dose that is associated with least number of physician interventions needed to maintain maternal systolic blood pressure (SBP) within 20% of baseline.

Methodology: With due permission of ethical committee and written informed consent of the patients, ASA physical status I and II pregnant women with singleton gestation at a gestational age of >36 weeks were recruited for the study. Parturients were randomly allocated to a placebo group (PE0) or three fixed rate phenylephrine infusion regimens- phenylephrine 30µg/min (PE 30), phenylephrine 50µg/min (PE 50), phenylephrine 70µg/min (PE 70)

Results: The hypotension episodes were also significantly more frequent in group PE0 compared to groups PE30, PE50 and PE70. Maximum fall in SBP from baseline was significantly reduced in phenylephrine groups PE50 and PE70 compared PE0.

Conclusion: Phenylephrine administered as prophylactic infusion at fixed rate of 50μg/min initiated immediately after subarachnoid block in caesarean section maintains greater maternal hemodynamic stability.

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Dr Manjit Singh Kanwar

Assistant Professor, Dr Radhakrishnan Government Medical College, Hamirpur