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

Phenylephrine Dose-Finding Study to Minimize Hypotension Due to Spinal Anesthesia for Cesarean Section

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.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

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.

Study Type

Interventional

Enrollment

50

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Ontario
      • Toronto, Ontario, Canada, M5G 1X5
        • Mount Sinai Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

Female

Description

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Single Group Assignment
  • Masking: Double

What is the study measuring?

Primary Outcome Measures

Outcome Measure
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

Outcome Measure
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

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Jose CA Carvalho, MD PhD, Department of Anesthesia and Pain Management, Mount Sinai Hospital, University of Toronto

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

August 1, 2006

Primary Completion

December 7, 2022

Study Completion (Actual)

December 1, 2006

Study Registration Dates

First Submitted

September 21, 2006

First Submitted That Met QC Criteria

September 21, 2006

First Posted (Estimate)

September 22, 2006

Study Record Updates

Last Update Posted (Estimate)

March 21, 2007

Last Update Submitted That Met QC Criteria

March 19, 2007

Last Verified

March 1, 2007

More Information

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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