Comparison of Norepinephrine and Cafedrine/Theodrenaline Regimens for Maintaining Maternal Blood Pressure during Spinal Anaesthesia for Caesarean Section

Abstract

Common phenomena of spinal anaesthesia for caesarean sections are hypotension and cardiovascular depression, both of which require immediate action. Akrinor® (theodrenaline and cafedrine), a sympathomimetic agent commonly used in Germany for such cases, was phased out with little notice at the end of 2005. Phenylephrine was not and is not an approved drug. Norepinephrine became the first-line drug. The outcome in neonates delivered by elective caesarean section under spinal anaesthesia was studied. At our university hospital, all elective caesarean sections under spinal anaesthesia from 2005 and 2006 were analysed regarding hypotension and the vasopressor administered. If maternal arterial pressure decreased by more than 20% of baseline, patients in 2005 received Akrinor®; patients in 2006 received norepinephrine. Neonatal umbilical blood pH as well as Apgar scores at one, five and ten minutes after delivery were measured. Other than the vasopressor, all patients were treated and all data were collected in an identical manner, per our hospital's Standard Operating Procedures (SOP). There were 251 patients eligible for the study; 123 in 2005 and 128 in 2006. A vasopressor was administered to 153 women for treatment of hypotention, 82 women (group A = Akrinor®) in 2005 and 71 women (group NE = norephinephrine) in 2006. There were no significant differences between the groups regarding arterial umbilical blood pH or Apgar scores. Despite treatment, prolonged hypotension (>10 minutes) occurred in both groups (group A: n=10; group NE: n=12). The neonatal arterial blood pH did not show any significant difference between the two groups. Two patients in group A, none in group NE, suffered from clinically relevant tachycardia (>50% increase of baseline). Our results thus suggest that norepinephrine is a safe vasopressor suitable for the treatment of peripartal hypotension without any risk of neonatal acidosis in elective caesarean section under spinal anaesthesia.