Up-Down Determination of the ED90 of Phenylephrine for Hypotension Prophylaxis in Cesarean Delivery

This study has been terminated.
(Results Invalid, study closed, analysis cannot proceed.)
Sponsor:
Information provided by (Responsible Party):
Ronald George, IWK Health Centre
ClinicalTrials.gov Identifier:
NCT00796328
First received: November 19, 2008
Last updated: September 3, 2014
Last verified: September 2014
  Purpose

This study is designed to determine the ED90 for an infusion of phenylephrine to prevent spinal induced low blood pressure in parturients presenting for an elective cesarean delivery. The up-down methodology (UDM) is commonly used study method to determine the dose of a drug that causes the desired effect in over 90% of the subjects to whom it given. For example: the investigators want to know what is the best dose of phenylephrine (from a range of commonly used doses) to prevent a drop in blood pressure during cesarean delivery ninety times out of one hundred when it is given at that dose. The ED90 is the effective dose at which 90% of subjects will have a "positive" response to a phenylephrine infusion, i.e. no drop in blood pressure. The investigators hypothesize that the ED90 will be between 40 - 60 mcg/min.

The primary outcome measure is the ED90 for phenylephrine infusions that prevents a drop in blood pressure in women undergoing cesarean delivery.


Condition Intervention Phase
Spinal Induced Hypotension in Cesarean Delivery
Drug: Phenylephrine infusion
Phase 4

Study Type: Interventional
Study Design: Endpoint Classification: Efficacy Study
Intervention Model: Single Group Assignment
Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor)
Primary Purpose: Prevention
Official Title: Up-down Determination of the ED90 of the Initial Rate of Infusion of Phenylephrine for the Prophylaxis of Spinal Induced Hypotension in Parturients Undergoing Cesarean Delivery

Resource links provided by NLM:


Further study details as provided by IWK Health Centre:

Primary Outcome Measures:
  • Effective Dose of Phenylephrine at Which 90% of Subjects Have no Spinal Induced Hypotension [ Time Frame: Spinal administration until delivery ] [ Designated as safety issue: No ]
    The effective dose at which 90% of subjects will have a "positive" response to a phenylephrine infusion, i.e. no spinal induced hypotension. We hypothesize that the ED90 will be between 40 - 60 mcg/min.


Enrollment: 45
Study Start Date: November 2008
Study Completion Date: July 2009
Primary Completion Date: February 2009 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: 1 Drug: Phenylephrine infusion
Up-down, biased coin design

  Eligibility

Ages Eligible for Study:   18 Years and older
Genders Eligible for Study:   Female
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  1. Non-emergent cesarean delivery with planned spinal anesthesia (i.e. elective planned cesarean delivery for malposition, patient choice, cervical pelvic disproportion, previous cesarean delivery and other diagnosis that require a predetermined cesarean delivery)
  2. American Society of Anesthesia physical status class I & II (ASA I - Healthy, ASA II - mild and controlled systemic disease, eg. controlled essential hypertension)
  3. Age ≥ 18 years (Standard within the obstetrical literature)
  4. Term gestational age
  5. English-speaking

Exclusion Criteria:

  1. Morbid Obesity (Body Mass Index ≥ 45 kg/m2) (Morbidly obese parturients require a dose of local anesthetic less than the standardized dose in this study, typically have an exaggerated response to vasopressors, and the blood pressure cuff occasionally needs to be replaced by an intra-arterial catheter due to limitations in size)
  2. Height < 5'0" (Women < 5'0" are likely to require a dose of local anesthetic less than the standardized dose in this study)
  3. Laboring women
  4. Urgent or emergency cesarean delivery
  5. Hypertensive disease of pregnancy
  6. Severe maternal cardiac disease
  7. Subjects on monoamine oxidase inhibitors (MAOI's) or tricyclic antidepressants
  8. Fetal anomalies or intrauterine fetal death
  9. Failed spinal anesthesia
  10. Subject enrollment in another study involving a study medication within 30 days of CD
  11. Any other physical or psychiatric condition which may impair their ability to cooperate with study data collection
  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.

No Contacts or Locations Provided
  More Information

No publications provided

Responsible Party: Ronald George, Primary Investigator, MD, FRCPC, Assistant Professor, IWK Health Centre
ClinicalTrials.gov Identifier: NCT00796328     History of Changes
Other Study ID Numbers: IWK-4462-2008
Study First Received: November 19, 2008
Results First Received: March 14, 2014
Last Updated: September 3, 2014
Health Authority: Canada: Ethics Review Committee

Additional relevant MeSH terms:
Hypotension
Cardiovascular Diseases
Vascular Diseases
Oxymetazoline
Phenylephrine
Adrenergic Agents
Adrenergic Agonists
Adrenergic alpha-1 Receptor Agonists
Adrenergic alpha-Agonists
Autonomic Agents
Cardiotonic Agents
Cardiovascular Agents
Molecular Mechanisms of Pharmacological Action
Mydriatics
Nasal Decongestants
Neurotransmitter Agents
Peripheral Nervous System Agents
Pharmacologic Actions
Physiological Effects of Drugs
Protective Agents
Respiratory System Agents
Sympathomimetics
Therapeutic Uses
Vasoconstrictor Agents

ClinicalTrials.gov processed this record on October 22, 2014