Ideal Dose of Phenylephrine to Treat Low Blood Pressure During Cesarean Section - Full Text View

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:

MedlinePlus related topics: Cesarean Section High Blood Pressure Low Blood Pressure Nausea and Vomiting

Drug Information available for: Phenylephrine Phenylephrine hydrochloride Oxymetazoline Oxymetazoline hydrochloride

U.S. FDA Resources

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 February 25, 2015