Phenylephrine in Spinal Anesthesia in Preeclamptic Patients

This study is currently recruiting participants. (see Contacts and Locations)
Verified April 2014 by Northwestern University
Sponsor:
Information provided by (Responsible Party):
Cynthia Wong, Northwestern University
ClinicalTrials.gov Identifier:
NCT00458003
First received: April 4, 2007
Last updated: April 16, 2014
Last verified: April 2014
  Purpose

Hypotension remains a common clinical problem after induction of spinal anesthesia for cesarean delivery. Maternal hypotension has been associated with considerable morbidity (maternal nausea and vomiting and fetal/neonatal acidemia). Traditionally, ephedrine has been the vasopressor of choice because of concerns about phenylephrine's potential adverse effect on uterine blood flow. This practice was based on animal studies which showed that ephedrine maintained cardiac output and uterine blood flow, while direct acting vasoconstrictors, e.g., phenylephrine, decreased uteroplacental perfusion. However, several recent studies have demonstrated that phenylephrine has similar efficacy to ephedrine for preventing and treating hypotension and may be associated with a lower incidence of fetal acidosis. All of these studies have been performed in healthy patients undergoing elective cesarean delivery.

Preeclampsia complicates 5-6% of all pregnancies and is a significant contributor to maternal and fetal morbidity and mortality. Many preeclamptic patients require cesarean delivery of the infant. These patients often have uteroplacental insufficiency. Given the potential for significant hypotension after spinal anesthesia and its effect on an already compromised fetus, prevention of (relative) hypotension in preeclamptic patients is important. Spinal anesthesia in preeclamptic patients has been shown to have no adverse neonatal outcomes as compared to epidural anesthesia when hypotension is treated adequately. Due to problems related to management of the difficult airway and coagulopathy, both of which are more common in preeclamptic women, spinal anesthesia may be the preferred regional anesthesia technique. Recent studies have demonstrated that preeclamptic patients may experience less hypotension after spinal anesthesia than their healthy counterparts. To our knowledge, phenylephrine for the treatment of spinal anesthesia-induced hypotension has not been studied in women with preeclampsia. The aim of our study is to compare intravenous infusion regimens of phenylephrine versus ephedrine for the treatment of spinal anesthesia induced hypotension in preeclamptic patients undergoing cesarean delivery. The primary outcome variable is umbilical artery pH.


Condition Intervention
Preeclampsia
Hypotension
Drug: Ephedrine
Drug: Phenylephrine

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Investigator)
Primary Purpose: Treatment
Official Title: Phenylephrine Versus Ephedrine to Treat Spinal Anesthesia-Induced Hypotension in Preeclamptic Patients During Cesarean Delivery

Resource links provided by NLM:


Further study details as provided by Northwestern University:

Primary Outcome Measures:
  • The umbilical artery pH in the phenylephrine group will be higher than in the ephedrine group, although the overall incidence of absolute fetal acidosis is not anticipated to be different between groups. [ Time Frame: Immediately after delivery ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Efficacy of study drug in preventing and treating hypotension associated with spinal anesthesia in women with preeclampsia [ Time Frame: During and immediately after study drug infusion ] [ Designated as safety issue: Yes ]

Estimated Enrollment: 100
Study Start Date: July 2006
Estimated Study Completion Date: December 2014
Estimated Primary Completion Date: December 2014 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Phenylephrine
Subject will receive a phenylephrine infusion to prevent and to treat hypotension associated with spinal anesthesia
Drug: Phenylephrine
Phenylephrine concentration: 100 mcg/mL. The infusion will be initiated immediately after completion of the spinal injection at a rate of 1 mL/min and continued for a minimum of 2 min after which the infusion will be stopped, continued or increased based on the SBP each minute. After each SBP measurement the infusion will be stopped if SBP > 80% baseline, and the infusion will be continued or restarted if the SBP is approximately equal to 80% baseline. The infusion will be increased by 1 mL/min if the SBP < 80% baseline. Each time there is hypotension the patient will receive a 1 mL IV bolus of the study solution and the infusion will be increased by 1 mL/min until delivery.
Active Comparator: Ephedrine
Subject will receive an ephedrine infusion to prevent and to treat hypotension associated with spinal anesthesia
Drug: Ephedrine
Ephedrine concentration: 8 mg/mL. The infusion will be initiated immediately after completion of the spinal injection at a rate of 1 mL/min and continued for a minimum of 2 min after which the infusion will be stopped, continued or increased based on the SBP each minute. After each SBP measurement the infusion will be stopped if SBP > 80% baseline, and the infusion will be continued or restarted if the SBP is approximately equal to 80% baseline. The infusion will be increased by 1 mL/min if the SBP < 80% baseline. Each time there is hypotension the patient will receive a 1 mL IV bolus of the study solution and the infusion will be increased by 1 mL/min until delivery.

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  Eligibility

Ages Eligible for Study:   18 Years to 60 Years
Genders Eligible for Study:   Female
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • ASA PS II - III women
  • 18 years old and older
  • scheduled for cesarean delivery (no trial of labor)
  • eligible for spinal anesthesia
  • diagnosis of preeclampsia

Exclusion Criteria:

  • patients with failed trial of labor
  • preexisting hypertension
  • body mass index (BMI) ≥ 40 kg/m2
  • resting heart rate < 60 bpm
  • progression to eclampsia, > twin gestation
  • known fetal anomalies
  • contraindications to spinal anesthesia
  • emergency procedure or refusal of consent
  • failure to achieve a T6 level of anesthesia
  • conversion to general anesthesia
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00458003

Contacts
Contact: Robert J McCarthy, PharmD 312-926-9015 r-mccarthy@northwestern.edu

Locations
United States, Illinois
Northwestern University Recruiting
Chicago, Illinois, United States, 60611
Contact: Robert J McCarthy, PharmD    312-926-9015    r-mccarthy@northwestern.edu   
Principal Investigator: Cynthia A. Wong, M.D.         
Northwestern Memorial Hospital Recruiting
Chicago, Illinois, United States, 60611
Contact: Robert McCarthy, PharmD    312-926-9015    r-mccarthy@northwestern.edu   
Principal Investigator: Cynthia A Wong, M.D.         
Sponsors and Collaborators
Northwestern University
Investigators
Principal Investigator: Cynthia A. Wong, M.D. Northwestern University
  More Information

Publications:
Nelson-Piercy C, James PR. Management of hypertension before, during, and after pregnancy. Heart 2004;90:1499-1504.

Responsible Party: Cynthia Wong, Professor of Anesthesiology, Northwestern University
ClinicalTrials.gov Identifier: NCT00458003     History of Changes
Other Study ID Numbers: 0524-31
Study First Received: April 4, 2007
Last Updated: April 16, 2014
Health Authority: United States: Institutional Review Board

Keywords provided by Northwestern University:
Preeclampsia
Spinal Anesthesia
Hypotension
Cesarean Delivery
Phenylephrine
Ephedrine

Additional relevant MeSH terms:
Hypertension, Pregnancy-Induced
Hypotension
Pre-Eclampsia
Vascular Diseases
Cardiovascular Diseases
Pregnancy Complications
Anesthetics
Ephedrine
Phenylephrine
Oxymetazoline
Pseudoephedrine
Central Nervous System Depressants
Physiological Effects of Drugs
Pharmacologic Actions
Central Nervous System Agents
Therapeutic Uses
Central Nervous System Stimulants
Sympathomimetics
Autonomic Agents
Peripheral Nervous System Agents
Vasoconstrictor Agents
Cardiovascular Agents
Adrenergic Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action
Nasal Decongestants
Respiratory System Agents
Bronchodilator Agents
Anti-Asthmatic Agents
Adrenergic alpha-1 Receptor Agonists

ClinicalTrials.gov processed this record on July 20, 2014