Up-Down Determination of the ED90 of Phenylephrine for Hypotension Prophylaxis in Cesarean Delivery
This study is designed to determine the ED90 for an infusion of phenylephrine to prevent spinal induced low blood pressure in parturients presenting for an elective cesarean delivery. The up-down methodology (UDM) is commonly used study method to determine the dose of a drug that causes the desired effect in over 90% of the subjects to whom it given. For example: the investigators want to know what is the best dose of phenylephrine (from a range of commonly used doses) to prevent a drop in blood pressure during cesarean delivery ninety times out of one hundred when it is given at that dose. The ED90 is the effective dose at which 90% of subjects will have a "positive" response to a phenylephrine infusion, i.e. no drop in blood pressure. The investigators hypothesize that the ED90 will be between 40 - 60 mcg/min.
The primary outcome measure is the ED90 for phenylephrine infusions that prevents a drop in blood pressure in women undergoing cesarean delivery.
|Spinal Induced Hypotension in Cesarean Delivery||Drug: Phenylephrine infusion||Phase 4|
|Study Design:||Intervention Model: Single Group Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Prevention
|Official Title:||Up-down Determination of the ED90 of the Initial Rate of Infusion of Phenylephrine for the Prophylaxis of Spinal Induced Hypotension in Parturients Undergoing Cesarean Delivery|
- Effective Dose of Phenylephrine at Which 90% of Subjects Have no Spinal Induced Hypotension [ Time Frame: Spinal administration until delivery ]The effective dose at which 90% of subjects will have a "positive" response to a phenylephrine infusion, i.e. no spinal induced hypotension. We hypothesize that the ED90 will be between 40 - 60 mcg/min.
|Study Start Date:||November 2008|
|Study Completion Date:||July 2009|
|Primary Completion Date:||February 2009 (Final data collection date for primary outcome measure)|
Drug: Phenylephrine infusion
Up-down, biased coin design