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

Hypotension Clinical Trial

Official title:

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

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00379691
• Other study ID #: 06-01
• Secondary ID: 06-0186-E
• Status: Completed
• Phase: N/A
• First received: September 21, 2006
• Last updated: March 19, 2007
• Start date: August 2006
• Est. completion date: December 2006

Study information

• Verified date: March 2007
• Source: Samuel Lunenfeld Research Institute, Mount Sinai Hospital
• Contact: n/a
• Is FDA regulated: No
• Health authority: Canada: Ethics Review Committee
• Study type: Interventional

Clinical Trial Summary

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.

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 50
• Est. completion date: December 2006
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Female
• Age group: 18 Years and older

Eligibility

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 Design

Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Single Group Assignment, Masking: Double-Blind, Primary Purpose: Prevention

Related Conditions & MeSH terms

• Hypotension
• Nausea

Intervention

Drug:
• phenylephrine

Locations

Country	Name	City	State
Canada	Mount Sinai Hospital	Toronto	Ontario

Sponsors (1)

Lead Sponsor	Collaborator
Samuel Lunenfeld Research Institute, Mount Sinai Hospital

Country where clinical trial is conducted

Canada, 

Outcome

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