Ideal Dose of Phenylephrine to Treat Low Blood Pressure During Cesarean Section

This study has been completed.
Sponsor:
Information provided by:
Samuel Lunenfeld Research Institute, Mount Sinai Hospital
ClinicalTrials.gov Identifier:
NCT00379691
First received: September 21, 2006
Last updated: March 19, 2007
Last verified: March 2007
  Purpose

The purpose of this study is to determine the minimum effective bolus dose of phenylephrine to prevent post-spinal hypotension in Cesarean section in 95 % of our patients. An adequate response will be defined as the absence of hypotension or nausea/vomiting during the period from induction of spinal anesthesia to uterine incision prior to fetal delivery.


Condition Intervention
Hypotension
Nausea
Drug: phenylephrine

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Safety/Efficacy Study
Intervention Model: Single Group Assignment
Masking: Double-Blind
Primary Purpose: Prevention
Official Title: Phenylephrine Dose-Finding Study to Minimize Hypotension Due to Spinal Anesthesia for Cesarean Section

Resource links provided by NLM:


Further study details as provided by Samuel Lunenfeld Research Institute, Mount Sinai Hospital:

Primary Outcome Measures:
  • The primary outcome will be the minimum dose of phenylephrine which effectively prevents both hypotension and nausea/vomiting between intrathecal injection of the local anesthetic and delivery of the fetus.

Secondary Outcome Measures:
  • Maternal Demographics: Maternal age-weight-height
  • Nausea and Vomiting
  • Time of intrathecal injection, skin incision, uterine incision, and delivery
  • Total dose of phenylephrine
  • Hypertension (> 120 % of baseline)
  • Bradycardia (< 50 bpm)
  • Upper sensory level of anesthesia by pinprick upon delivery
  • Umbilical artery and vein blood gases

Estimated Enrollment: 50
Study Start Date: August 2006
Study Completion Date: December 2006
Detailed Description:

The purpose of this study is to determine the minimum effective bolus dose of phenylephrine to prevent post-spinal hypotension in CS in 95 % of our patients. The study will be conducted in a randomized double-blinded fashion. This dose-response study will be conducted as per the up-down sequential allocation method, modified by the Narayana rule, designed to cluster the results around the ED95.

Blood pressure will be monitored every minute from intrathecal injection to the delivery of the child. Phenylephrine will be administered every time the blood pressure is equal to or lower than the control value.Hypotension will be defined as a SBP less than 80 % of the baseline value, in which case the treatment will be a failure. Hypertension will be defined as a SBP more than 120 % of baseline value. If a patient presents hypertension for two consecutive measurements, the case will be considered a drop out.An adequate response will be defined as the absence of hypotension or nausea/vomiting during the period from induction of spinal anesthesia to uterine incision prior to fetal delivery.

The results of this study will define the minimum effective dose of phenylephrine to prevent post-spinal hypotension and nausea/vomiting secondary to hypotension in Cesarean section, thus optimizing the safety profile with respect to maternal and fetal side effects of this vasopressor.

  Eligibility

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

Inclusion Criteria:

  • Elective CS under spinal anesthesia
  • Normal singleton pregnancy beyond 36 weeks gestation
  • ASA physical status I/II
  • Weight 50-100 kg, height 150-180 cm
  • Age over 18 years

Exclusion Criteria:

  • Patient refusal
  • Allergy or hypersensitivity to phenylephrine
  • Preexisting or pregnancy-induced hypertension
  • Cardiovascular or cerebrovascular disease
  • Fetal abnormalities
  • History of diabetes, excluding gestational diabetes
  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: NCT00379691

Locations
Canada, Ontario
Mount Sinai Hospital
Toronto, Ontario, Canada, M5G 1X5
Sponsors and Collaborators
Samuel Lunenfeld Research Institute, Mount Sinai Hospital
Investigators
Principal Investigator: Jose CA Carvalho, MD PhD Department of Anesthesia and Pain Management, Mount Sinai Hospital, University of Toronto
  More Information

No publications provided

ClinicalTrials.gov Identifier: NCT00379691     History of Changes
Other Study ID Numbers: 06-01, 06-0186-E
Study First Received: September 21, 2006
Last Updated: March 19, 2007
Health Authority: Canada: Ethics Review Committee

Keywords provided by Samuel Lunenfeld Research Institute, Mount Sinai Hospital:
spinal
Cesarean section
hypotension
nausea
vomiting
phenylephrine

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 23, 2014