Spinal anesthesia induced hypotension in elective cesarean section.
Conditions
Interventions
Intervention Group:Participants in the intervention group receive six milligrams of intravenous ondansetron, prepared in a two milliliter sterile solution. The medication is administered slowly throug
Sponsors
Karaj University of Medical Sciences
Eligibility
Sex/Gender
Female
Age
18 Years to 45 Years
Inclusion criteria
Inclusion criteria: Pregnant women scheduled for elective cesarean section (non-emergency). Gestational age between 37 and 41 weeks. ASA physical status I or II. Eligibility and clinical indication for spinal anesthesia according to hospital protocol. No known allergy or contraindication to ondansetron. No uncontrolled chronic medical conditions, including severe cardiac disease, significant arrhythmias, advanced hepatic or renal impairment No chronic hypertension requiring medication or severe preeclampsia. BMI between 18.5 and 35. Not taking medicines that significantly affect hemodynamics, such as beta-blockers, antiarrhythmics, or vasoactive drugs. Written informed consent obtained prior to enrollment.
Exclusion criteria
Exclusion criteria: Known allergy or hypersensitivity to ondansetron or other 5-HT3 antagonists. Long QT syndrome or significant cardiac arrhythmias. Major cardiac disease (heart failure, high-grade AV block, cardiomyopathy). Moderate to severe hepatic disease. Moderate to severe renal impairment. Severe preeclampsia or eclampsia. Coagulopathy or any contraindication to spinal anesthesia. Use of QT-prolonging medications. Inability to provide informed consent or poor cooperation. Participation in another clinical trial within the past 30 days.
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| Incidence of hypotension after spinal anesthesiaDefinition: Occurrence of systolic blood pressure reduction to smaller than 100 mmHg or a reduction of twenty percent from baseline, measured from the start of spinal anesthesia until the end of the cesarean section using standard noninvasive blood pressure monitoring.Primary Outcome 2Magnitude of systolic blood pressure reduction from baselineDefinition: Difference between baseline systolic blood pressure before spinal anesthesia and the lowest systolic blood pressure recorded afterward. Measured using automated hospital monitors.Primary Outcome 3Requirement for vasopressor administration to treat hypotensionDefinition: Need for administration of a vasopressor drug, such as ephedrine or phenylephrine, to manage hypotension during the procedure. Documented as yes or no, with total administered dose recorded when applicable. Timepoint: Measurement of systolic and diastolic blood pressure at three time points:Before spinal anesthesia as the baseline valueEvery one minute for the first five minutes after spinal anesthesiaEvery five minutes until the end of surgery or until hemodynamic stabilization. Method of measurement: Systolic blood pressure, diastolic blood pressure and mean arterial pressure: Measured and recorded using an automated noninvasive blood pressure monitor with an upper-arm cuff; measurements taken at baseline (before drug/placebo), time zero (start of spinal anesthesia), every five minutes intraoperatively and every fifteen minutes up to one hour postoperatively.Heart rate: Recorded by electrocardiographic monitoring or the patient monitor pulse rate at the same time points as blood pressure.Incidence of hypotension (primary outcome): Defined from recorded blood pressure values as a decrease of twenty percent or more from baseline systolic blood pressure or systolic blood pressure less than ninety millimeters of mercury, reported up to one hour after surgery.Need for vasopressor, type and dose: Any vasop | — |
Secondary
| Measure | Time frame |
|---|---|
| Nausea, vomiting, and changes in heart rate and fluid requirements are possible side effects. Timepoint: Nausea, vomiting, heart rate changes and other secondary outcomes will be measured at the following time points:Baseline before spinal anesthesiaOne minute after spinal anesthesiaThree minutes after spinal anesthesiaFive minutes after spinal anesthesiaEvery five minutes until the end of the surgery. Method of measurement: Hemodynamic variables including heart rate, oxygen saturation, and diastolic blood pressure will be measured using the standard operating room monitoring device. Measurements will be automatically recorded at predefined intervals by the hospital monitor and documented in the data collection form. | — |
Countries
Iran (Islamic Republic of)
Contacts
Public ContactNavid Sadati
Karaj University of Medical Sciences
Outcome results
None listed