Clinical trial NCT01415284: ED50 Determination of Hydroxyethylstarch for Treatment of Hypotension During Cesarean Section Under Spinal Anesthesia
Official title: ED50 Determination of Hydroxyethylstarch for Treatment of Hypotension During Cesarean Section Under Spinal Anesthesia
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: PHASE4
Conditions: Obstetric Anesthesia
Spinal Anesthesia
Hypotension
Fluid Therapy
Cesarean Section
Keywords: Obstetric anesthesia
Spinal anesthesia
Hypotension
Fluid therapy
Cesarean section
phenylephrine
cardiac output
Lead sponsor: Maisonneuve-Rosemont Hospital
Sponsor class: OTHER
Collaborators: name: Université de Montréal
First posted: 2011-08-11
Enrollment: 30
Sex: FEMALE
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: NON_RANDOMIZED
Intervention model: SINGLE_GROUP
Primary purpose: TREATMENT

Brief summary: The purpose of this trial is to determine the effective volume of hydroxyethylstarch 130/0.4 which would prevent the occurence of maternal hypotension in 50% of healthy pregnant women undergoing a cesarean section under spinal anesthesia.

Detailed description: The incidence of spinal anesthesia-induced hypotension in pregnant women undergoing a cesarean section is high. A preoperative fluid bolus of undetermined volume is frequently administered to lower the incidence of maternal hypotension, with a somewhat poor efficacy. Recently, several investigations have shown that the use of a phenylephrine infusion after the induction of spinal anesthesia results in a significant reduction in hypotensive episodes. Given the high efficacy of this therapy (incidence of hypotension around 20%), it is possible to determine the effective volume of fluid which would prevent hypotension in 50% of the patients studied (ED50).

Healthy term pregnant women undergoing elective cesarean section under spinal anesthesia will be recruited in this trial. The spinal anesthesia regimen will be standardized and all subjects will receive a phenylephrine infusion. The fluid investigated is hydroxyethylstarch (HES) 130/0.4 (Volulyte(R)). The ED50 will be determined using an up-down sequential allocation method initially described by Dixon \& Massey. The determination of the HES ED50 will help the anesthesiologist in further treating maternal hypotension appropriately.

Eligibility criteria: Inclusion Criteria:

* Healthy pregnant women (ASA I or II)
* Normal pregnancy
* Term gestation (37 weeks and above)
* Elective cesarean section
* Spinal anesthesia

Exclusion Criteria:

* Cardiopathies
* Hypertensive disease/ pre-eclampsia / eclampsia
* Any contraindication to neuraxial anesthesia
* Patient refusal
* Body mass index \> 30 at first antenatal visit and \> 32 at cesarean section
* Twin pregnancy
* Known allergies to HES
* Emergency cesarean section

Primary outcomes:
measure: Volume of HES which will prevent hypotension if 50 % of the subjects.
timeFrame: 4 months
Secondary outcomes:
measure: Incidence of hypotension episodes
timeFrame: 1 hour
measure: Incidence of hypertensive episodes
timeFrame: 1 hour
measure: cardiac output
timeFrame: 1 hour
measure: Apgar score
timeFrame: 10 minutes
measure: umbilical artery pH
timeFrame: 2 hours
measure: additional vasopressors administered
timeFrame: 1 hour
Other outcomes:
Locations:
city: Montreal
country: Canada
facility: Maisonneuve-Rosemont Hospital
state: Quebec
Study officials:
affiliation: Maisonneuve-Rosemont Hospital
name: Christian Loubert, MD, FRCPC
role: PRINCIPAL_INVESTIGATOR
References: