Phenylephrine for Spinal Induced Hypotension
This study is designed to determine the ED90 for a single dose of phenylephrine for the treatment of spinal induced hypotension in parturients presenting for an elective CD. The ED90 is the effective dose at which 90% of subjects will have a "positive" response to phenylephrine. The primary outcome measure is the ED90 for bolus phenylephrine. Secondary outcomes include the need for additional vasopressors, glycopyrolate to treat bradycardia, and the presence of hypertension following administration of phenylephrine.
|Study Design:||Endpoint Classification: Efficacy Study
Intervention Model: Single Group Assignment
Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
|Official Title:||Up-down Determination of the ED90 of Phenylephrine for Spinal Induced Hypotension in Parturients Undergoing Cesarean Delivery|
- The primary outcome measure is the ED90 for bolus phenylephrine. [ Time Frame: Intraoperative ] [ Designated as safety issue: No ]
- Secondary outcomes include the need for additional vasopressors, glycopyrolate to treat bradycardia, and the presence of hypertension following administration of phenylephrine. [ Time Frame: Intraoperative ] [ Designated as safety issue: No ]
|Study Start Date:||January 2008|
|Study Completion Date:||October 2008|
|Primary Completion Date:||August 2008 (Final data collection date for primary outcome measure)|
Drug: Phenylephrine bolus
The initial dose of phenylephrine will be 100 mcg, a dose within the clinical range currently in use at our center. The subsequent dose is based upon the response of the preceding subject in the usual up-and-down method (UDM), which is outlined in the "data analysis" section of the protocol. The dosing changes will be in increments of 20 micrograms. A successful response to this dose will be entered into a spreadsheet, designed by our statistician, which will determine the subsequent dose based upon the UDM. If a failure is observed in the previous subject, the dose is stepped up in the next subject. If a success is observed the next subject is randomized with probability of 0.10 to the next lower dose and with probability 0.90 to the same dose.