Role of Ondansetron in Spinal Anaesthesia Induced Hypotension

Assiut University

Status and phase: Not yet enrolling; Phase 3; Phase 2

Conditions: Spinal Anaesthesia Induced Hypotension

Treatments: Drug: Ondansetron (Zofran); Drug: Saline (NaCl 0,9 %) (placebo)

Study type: Interventional

Funder types: Other

Identifiers

NCT06727201

Role of ondansetron

Details and patient eligibility

About

The objective of this study is to determine the effect of ondansetron on the total consumption of norepinephrine infusion needed to prevent spinal anaesthesia induced hypotension in cesarean section.

Full description

Ondansetron has been reported to attenuate the incidence of spinal anaesthesia-induced hypotension (SAIH) and norepinephrine requirement during caesarean section.

The mechanism of hypotension following spinal anaesthesia involves the reduction in vascular resistance caused by the sympathetic block and the activation of the Bezold-Jarisch reflex, leading to vasodilation and hypotension. Peripheral serotonin receptors, 5-Hydroxytryptamine3 (5HT3), are required for the activation of the Bezold-Jarisch reflex. In a rabbit model, a 5-HT3 receptor antagonist was reported to suppress bradycardia and hypotension by preventing the Bezold-Jarisch reflex.

Enrollment: 160 estimated patients

Sex: Female

Ages: 19 to 40 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Age from 19 to 40 years old.
• Singleton pregnancies with a gestational age of at least 37 weeks.
• pregnant women are scheduled for elective caesarean delivery.
• Patients with stable vital signs.
• Patients with normal laboratory investigations.
• patients undergoing spinal anaesthesia for caesarean delivery via Pfannenstiel incision with exteriorizaion of the uterus.

Exclusion criteria

• Patient's refusal.
• Age < 19 or > 40 years.
• Height<150 cm, weight < 60 kg, body mass index (BMI) ≥40 kg/m2.
• Contraindications to spinal anaesthesia (Coagulopathy, increased intracranial pressure, or local skin infection).
• Patients with cardiac morbidities.
• hypertensive disorders of pregnancy as pre-eclampsia.
• peripartum bleeding.
• Patients with respiratory morbidities.
• Convulsions.
• Bleeding diathesis.
• Known allergy to any drugs used in this study.

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Single Blind

---

160 participants in 2 patient groups, including a placebo group

Ondansetron (Zofran)

Active Comparator group

Description:

Ondansetron will be given intravenously in a dose of 0.1mg/kg 10 minutes before spinal anaesthesia as single shot

Treatment:

Drug: Ondansetron (Zofran)

Saline placebo

Placebo Comparator group

Description:

Normal saline will be administered by intravenous infusion 10 minutes before spinal anaesthesia

Treatment:

Drug: Saline (NaCl 0,9 %) (placebo)