None listed
Conditions
Brief summary
Background: Spinal anesthesia for caesarean delivery is frequently associated with maternal hypotension. The sitting position for spinal anesthesia and prophylactic administrations of ondansetron or phenylephrine have been reported to provide a protective effect. We studied the effect of ondansetron or ondansetron + phenylephrine in obstetric patients. Methods: This prospective double-blind, randomised, placebo-controlled study includes healthy pregnant women scheduled for elective caesarean delivery under spinal anesthesia. Women will be randomly allocated into four groups to receive either placebo, ondansetron 8 mg intravenously before induction of spinal anesthesia, phenylephrine infusion (50 mcg/min) or ondansetron plus phenylephrine infusion (50 mcg/min). Demographic, obstetric, intraoperative timing and anaesthetic variables will be assessed at 16 time points. Anesthetic variables assessed will include blood pressure, heart rate, oxygen saturation, nausea, vomiting, electrocardiographic changes, skin flushing, discomfort or pruritus and vasopressor requirements. Study hypothesis: the combination of ondansetron plus phenylephrine infusion can help to reduce the incidence and severity of maternal hypotension compared with placebo, ondansetron or phenylephrine infusion.
Interventions
The syringes have no identifying markers indicating group allocation. The nurse injects the contents of the 10 mL syringe intravenously over 60 s and starts the 50 mL syringe IV continuous infusion at 15 mL/h five minutes before the lumbar puncture is performed. The anaesthetist caring for the woman is blinded to group allocation.
Arm 1: ondansetron 8 mg with 0.9% saline solution (total volume 10 mL) intravenously over 60 s AND phenylephrine 10 mg with 0.9% saline solution to a total volume of 4
The syringes have no identifying markers indicating group allocation. The nurse injects the contents of the 10 mL syringe intravenously over 60 s and starts the 50 mL syringe IV continuous infusion at 15 mL/h five minutes before the lumbar puncture is performed. The anaesthetist caring for the woman is blinded to group allocation. Arm 1: ondansetron 8 mg with 0.9% saline solution (total volume 10 mL) intravenously over 60 s AND phenylephrine 10 mg with 0.9% saline solution to a total volume of 49 mL (50 mcg/min continuous infusion) at 15 mL/h, both administered 5 min prior to spinal anesthesia Arm 2: placebo of 0.9% saline solution 10 mL (administered intravenously over 60 s) AND phenylephrine 10 mg with 0.9% saline solution to a total volume of 49 mL (50 mcg/min continuous infusion) at 15 mL/h, both administered 5 min prior to spinal anesthesia. Arm 3: ondansetron 8 mg with 0.9% saline solution (total volume 10 mL, administered intravenously over 60 s), AND 0.9% saline solution 50 mL (continuous infusion) at 15 mL/h, both administered 5 min prior to spinal anesthesia. Arm 4: placebo of 0.9% saline solution 10 mL (administered intravenously over 60 s) AND 0.9% saline solution 50 mL (continuous infusion) at 15 mL/h, both administered 5 min prior to spinal anesthesia. The duration of the continuous infusion for all arms is until end of procedure.
Sponsors
University Hospital Gregorio Maranon
Study design
Allocation
Randomised controlled trial
Intervention model
Factorial
Primary purpose
Prevention
Masking
Blinded (masking used) (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
All
Age
20 Years to 45 Years
Healthy volunteers
Yes
Inclusion criteria
American Society of Anaesthesiologists class I women scheduled for lower segment caesarean delivery under spinal anesthesia enrolled during anesthesia consultation or early in the third trimester. Written informed consent must be obtained from all patients to participate in this study.
Exclusion criteria
Exclusion criteria included refusal to participate, contraindication to spinal anaesthesia, age less than 20 years or greater than 45 years, obesity (body mass index (BMI) at term greater than 30 kg/m2), any ASA physical status not equal to 1, previous fluid therapy and history of allergy to or side effects from ondansetron or phenylephrine.
Outcome results
None listed