Phenylephrine versus cafedrine/theodrenaline (Akrinor) for the treatment of spinal anaesthesia-induced maternal hypotension during caesarean section: a retrospective single-centre cohort study

OBJECTIVE: The main objective of this study was to assess the impact of phenylephrine and cafedrine/theodrenaline on the mother and newborn after spinal anaesthesia for caesarean section. SETTING: University teaching hospital. DESIGN: A single-centre retrospective data cohort study. PATIENTS: All obstetric patients who were scheduled for caesarean section in a 2-year period. INTERVENTIONS: Administration of either intravenous phenylephrine prophylactically or cafedrine/theodrenaline (Akrinor) reactively to maintain blood pressure after spinal anaesthesia. MAIN OUTCOME MEASURE: Maternal hypotension, heart rate during caesarean section and after admission to IMC, fetal arterial cord pH and base excess levels, maternal volume resuscitation and the use of rescue medication. RESULTS: 852 data sets could be included: n=440 Akrinor, n=412 in the phenylephrine cohort. During caesarean section blood pressure was slightly higher in the phenylephrine group compared with the Akrinor group, while hypotension <100 mm Hg systolic blood pressure (SBP) occurred significantly more often during arrival at the IMC after surgery when phenylephrine was used. Heart rate was lower and rescue medication was significantly more frequently given in the phenylephrine cohort. Irrespective of the medication used, women with baseline levels of <120 mm Hg SBP had a high risk to develop hypotension <100 mm Hg after spinal anaesthesia for caesarean section. While there was no statistical difference in mean umbilical arterial pH levels, the incidence of acidosis, defined as pH <7.2, was significantly higher with phenylephrine. CONCLUSION: Phenylephrine was not superior to Akrinor to treat spinal anaesthesia-induced maternal hypotension during caesarean section. TRIAL REGISTRATION NUMBER: DRKS00025795.