title: Randomized double-blind comparison of ephedrine and phenylephrine for management of post-spinal hypotension in potential fetal compromise.
abstract: BACKGROUND
  Most studies comparing phenylephrine and ephedrine have been conducted during elective caesarean sections in healthy mothers with no fetal compromise. The effect of vasopressors on fetal outcome may differ between healthy and compromised fetuses. There has been little research into the effect of phenylephrine and ephedrine, when used for management of post-spinal hypotension in the presence of potential fetal compromise.
  
  
  METHODS
  Healthy women with a singleton pregnancy undergoing emergency caesarean section for fetal compromise under spinal anaesthesia were studied. One-hundred-and-six consecutive subjects, who developed hypotension after spinal anaesthesia, were randomly allocated to two groups of 53 each, to receive either phenylephrine (Group P) or ephedrine (Group E). For every systolic blood pressure reading <100mmHg patients received phenylephrine 100μg or ephedrine 8mg depending on group allocation. Umbilical blood gas parameters and Apgar scores were recorded.
  
  
  RESULTS
  There was no statistically significant difference in umbilical arterial pH (P=0.79), umbilical venous pH (P=0.98), other blood gas parameters, incidence of fetal acidosis (P=1.00) and Apgar scores. The number of hypotensive episodes, vasopressor doses for treatment of the first hypotensive episode and the total number of doses used during the study period were comparable. The median [IQR] total number of doses of phenylephrine and ephedrine used before delivery were 2 [1-2] and 2 [1-2], respectively (P=0.67). More patients receiving ephedrine (24.5%) developed tachycardia than those receiving phenylephrine (3.8%) (P=0.004). Bradycardia was more common with phenylephrine, with 39.6% of patients in Group P as compared to only 1.9% of patients in Group E developing a heart rate <60beats/min after vasopressor administration (P=0.001).
  
  
  CONCLUSIONS
  Both phenylephrine 100μg and ephedrine 8mg boluses are equally efficacious when treating post-spinal hypotension in the presence of potential fetal compromise. However, phenylephrine may be a better choice in the presence of maternal tachycardia.
authors.affiliation: Department of Anaesthesiology and Critical Care, University College of Medical Sciences and Guru Teg Bahadur Hospital, Delhi, India. Electronic address: medhamohta@hotmail.com.
authors.forename: M
authors.initials: M
authors.lastname: Mohta
authors.affiliation: Department of Anaesthesiology and Critical Care, University College of Medical Sciences and Guru Teg Bahadur Hospital, Delhi, India.
authors.forename: M
authors.initials: M
authors.lastname: Aggarwal
authors.affiliation: Department of Anaesthesiology and Critical Care, University College of Medical Sciences and Guru Teg Bahadur Hospital, Delhi, India.
authors.forename: A K
authors.initials: AK
authors.lastname: Sethi
authors.affiliation: Department of Anaesthesiology and Critical Care, University College of Medical Sciences and Guru Teg Bahadur Hospital, Delhi, India.
authors.forename: P
authors.initials: P
authors.lastname: Harisinghani
authors.affiliation: Department of Obstetrics and Gynaecology, University College of Medical Sciences and Guru Teg Bahadur Hospital, Delhi, India.
authors.forename: K
authors.initials: K
authors.lastname: Guleria
mesh_terms: D000328:Adult; D000773:Anesthesia, Obstetrical / Q000009:adverse effects*; D000775:Anesthesia, Spinal / Q000009:adverse effects*; D004311:Double-Blind Method; D004809:Ephedrine / Q000627:therapeutic use*; D005260:Female; D006340:Heart Rate, Fetal / Q000187:drug effects; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007022:Hypotension / Q000188:drug therapy*; D010656:Phenylephrine / Q000627:therapeutic use*; D011247:Pregnancy; D011446:Prospective Studies; D013599:Systole / Q000187:drug effects
chemical_list: D010656:Phenylephrine; D004809:Ephedrine
keywords: Caesarean section; Ephedrine; Fetal compromise; Phenylephrine; Spinal anaesthesia