Abstract :
Introduction and Aims: Hypotension after subarachnoid block for caesarean section is the commonest
but serious complication encountered by anaesthesiologists. Various vasopressors are used to prevent/treat
this complication. This study was done to compare the efficacy of three commonly used vasopressors –
phenylephrine, ephedrine, mephentermine for treatment of perioperative hypotension.
Material and Methods: Sixty American Society of Anaesthesiologists (ASA) physical status class
II parturients undergoing elective caesarean section under subarachnoid block were randomly allotted
three groups (P, E, M) (n = 20) to receive intravenous boluses of phenylephrine 100 mcg, ephedrine
6mg & mephentermine 6mg respectively, following hypotension. Maternal Haemodynamic parameters,
complications & neonatal APGAR scores were recorded. P-value < 0> P-value < 0> Results: Demographic values, baseline vital parameters and mean number of vasopressor boluses required
were similar in the three groups (P > 0.05). The mean trends of systolic blood pressure (P = 0.06), diastolic
blood pressure (P = 0.7) and mean arterial pressure (P = 0.6) were similar in the three groups. Heart rate
was raised during periods of hypotension; the mean heart rate was lower in the phenylephrine group after
vasopressor administration. The overall trend was similar (P = 0.1) among the three groups. There was (P
= 0.003) higher incidence of bradycardia in the phenylephrine group. The neonatal APGAR scores were >
7 in the three groups at the 1st and 5th minute (P = 0.5).
Conclusion: All three vasopressors effectively maintained arterial blood pressure during the subarachnoid
block for caesarean section. Phenylephrine caused a significant reduction in heart rate compared to
ephedrine or mephentermine.
Keyword :
Hypotension, Caesarean Section, Spinal, Anaesthesia, Vasopressor, Phenylephrine, Ephedrine Mephentermine.