title: Prophylactic glycopyrrolate prevents bradycardia after spinal anesthesia for Cesarean section: a randomized, double-blinded, placebo-controlled prospective trial with heart rate variability correlation.
abstract: OBJECTIVE
  To determine if prophylactic glycopyrrolate prevents bradycardia after spinal anesthesia.
  
  
  METHODS
  Prospective, randomized, double-blinded, placebo-controlled study.
  
  
  METHODS
  Large university-affiliated community hospital.
  
  
  METHODS
  81 consecutive term parturients (not in active labor) who were scheduled for elective Cesarean section.
  
  
  METHODS
  Parturients received 1.0 to 1.5 L of intravenous Ringer's lactate and either glycopyrrolate 0.4 mg or an equal volume of saline, with caregivers blinded to the immediate sequelae of study drug. Each patient received intrathecal bupivacaine (12 to 14 mg) with morphine sulfate (0.1 to 0.2 mg).
  
  
  METHODS
  Continuous heart rate (HR) and blood pressure monitoring occurred for 20 minutes, with the minimum HR recorded for each 5-minute epoch. Heart rates < 60 beats per minute defined bradycardia. Heart rate variability (HRV) analysis occurred offline.
  
  
  RESULTS
  None of 34 patients administered glycopyrrolate and 6 of 35 (17%) patients receiving saline experienced bradycardia (P = 0.02476). Time domain, frequency domain, and nonlinear and embedded spectrum entropy analyses all reflected the decrease in HRV accompanying administration of glycopyrrolate.
  
  
  CONCLUSIONS
  Bradycardia after spinal anesthesia occurs commonly. Prophylactic glycopyrrolate may prevent the bradycardia, but not necessarily the hypotension.
authors.affiliation: Department of Anesthesia, Lankenau Hospital and Lankenau Institute for Medical Research, Wynnewood, PA 19096, USA.
authors.forename: Dmitri
authors.initials: D
authors.lastname: Chamchad
authors.forename: Jay C
authors.initials: JC
authors.lastname: Horrow
authors.forename: Lev
authors.initials: L
authors.lastname: Nakhamchik
authors.forename: John
authors.initials: J
authors.lastname: Sauter
authors.forename: Nancy
authors.initials: N
authors.lastname: Roberts
authors.forename: Boris
authors.initials: B
authors.lastname: Aronzon
authors.forename: Andrew
authors.initials: A
authors.lastname: Gerson
authors.forename: Mikhail
authors.initials: M
authors.lastname: Medved
mesh_terms: D000759:Adjuvants, Anesthesia / Q000627:therapeutic use*; D000328:Adult; D000775:Anesthesia, Spinal / Q000009:adverse effects* / Q000379:methods; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D001919:Bradycardia / Q000139:chemically induced / Q000517:prevention & control*; D002045:Bupivacaine / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use; D002585:Cesarean Section / Q000379:methods; D004311:Double-Blind Method; D005260:Female; D006024:Glycopyrrolate / Q000627:therapeutic use*; D006339:Heart Rate / Q000187:drug effects; D006785:Hospitals, University; D006801:Humans; D007022:Hypotension / Q000139:chemically induced / Q000517:prevention & control; D009020:Morphine / Q000008:administration & dosage / Q000627:therapeutic use; D011247:Pregnancy; D011446:Prospective Studies
chemical_list: D000759:Adjuvants, Anesthesia; D000779:Anesthetics, Local; D009020:Morphine; D006024:Glycopyrrolate; D002045:Bupivacaine