Preventing Hypotension in Parturients With an Elevated Body Mass Index (BMI)

This study has been completed.
Duke University
Information provided by (Responsible Party):
Ronald George, IWK Health Centre Identifier:
First received: July 22, 2011
Last updated: April 1, 2015
Last verified: April 2015
Previous research regarding the use of phenylephrine has excluded obese subjects (BMI >35). This subgroup of patients represents a large portion of the obstetric patient population locally and nationally. It is unclear whether previous research should be extrapolated to the obese patient population. This study is being done to compare the incidence of hypotension, intraoperative nausea and vomiting, and neonatal acidosis between obese patients who receive a prophylactic phenylephrine infusion versus those who receive phenylephrine boluses for the treatment of established hypotension. This study will help us determine whether using a phenylephrine infusion or a phenylephrine bolus is the best way to prevent/treat spinal induced hypotension during cesarean deliveries in obese patients.

Condition Intervention Phase
Drug: Phenylephrine bolus
Drug: phenylephrine infusion
Phase 4

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Single Group Assignment
Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: A Double Blind Randomized Controlled Trial of Phenylephrine for the Prevention of Spinal Induced Hypotension in Obese Parturients

Resource links provided by NLM:

Further study details as provided by IWK Health Centre:

Primary Outcome Measures:
  • incidence of nausea and vomiting [ Time Frame: intraoperative ] [ Designated as safety issue: No ]
  • incidence of nausea and vomiting [ Time Frame: 2 hrs postoperative ] [ Designated as safety issue: No ]
  • incidence of nausea and vomiting [ Time Frame: 24hrs postoperative ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • incidence of hypotension [ Time Frame: intraoperative ] [ Designated as safety issue: No ]
  • neonatal acidosis [ Time Frame: intraoperative ] [ Designated as safety issue: No ]

Enrollment: 170
Study Start Date: November 2010
Study Completion Date: December 2014
Primary Completion Date: December 2014 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Phenylephrine bolus Drug: Phenylephrine bolus
10 ml of 100mcg/ml phenylephrine and placebo infusion
Experimental: Phenylephrine infusion Drug: phenylephrine infusion
60ml infusion of 100mcg/ml phenylephrine and placebo bolus


Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Female
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • English speaking
  • ASA Physical Status I-II
  • Non-laboring women
  • Single gestations ≥ 36 weeks
  • Obese women (Body Mass Index 35 - 55 kg/m2)
  • Non-emergent CD under spinal anesthesia

Exclusion Criteria:

  • Height < 5'0"
  • Antiemetic drug use in the 24 hours prior to CD
  • Allergy to phenylephrine, or any other standardized medication
  • Hypertensive disease of pregnancy (i.e. mild & severe preeclampsia)
  • Chronic hypertension receiving antihypertensive treatment
  • Severe Cardiac disease in pregnancy with marked functional limitations
  • Patients on Monoamine Oxidase Inhibitors or Tricyclic Antidepressants
  • Subject enrollment in another study involving a study medication within 30 days of CD
  • Any other physical or psychiatric condition which may impair their ability to cooperate with study data collection
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Please refer to this study by its identifier: NCT01481740

United States, North Carolina
Duke University Medical Center
Durham, North Carolina, United States, 27710
Canada, Nova Scotia
IWK Health Centre
Halifax, Nova Scotia, Canada, B3H 6K8
Sponsors and Collaborators
IWK Health Centre
Duke University
Principal Investigator: Ronald B George, MD FRCPC IWK Health Centre
  More Information

Responsible Party: Ronald George, Primary Investigator, MD, FRCPC, Assistant Professor, IWK Health Centre Identifier: NCT01481740     History of Changes
Other Study ID Numbers: 4999-01460 
Study First Received: July 22, 2011
Last Updated: April 1, 2015
Health Authority: Canada: Ethics Review Committee

Keywords provided by IWK Health Centre:
spinal induced hypotension
nausea and vomiting
cesarean delivery

Additional relevant MeSH terms:
Cardiovascular Diseases
Vascular Diseases
Adrenergic Agents
Adrenergic Agonists
Adrenergic alpha-1 Receptor Agonists
Adrenergic alpha-Agonists
Autonomic Agents
Cardiotonic Agents
Molecular Mechanisms of Pharmacological Action
Nasal Decongestants
Neurotransmitter Agents
Peripheral Nervous System Agents
Physiological Effects of Drugs
Protective Agents
Respiratory System Agents
Vasoconstrictor Agents processed this record on May 26, 2016