Clinical trial NCT06727201: Role of Ondansetron in Spinal Anaesthesia Induced Hypotension
Official title: The Effect of Ondansetron on the Total Consumption of Norepinephrine Infusion Used to Prevent Spinal Anaesthesia Induced Hypotention in Cesarean Section.
Study type: INTERVENTIONAL
Overall status: NOT_YET_RECRUITING
Phase: PHASE2
PHASE3
Conditions: Spinal Anaesthesia Induced Hypotension
Keywords: Ondansetron
Spinal anaethesia
Hypotension
Norepinephrine
Lead sponsor: Assiut University
Sponsor class: OTHER
First posted: 2024-12-10
Enrollment: 160
Sex: FEMALE
Minimum age (years): 19
Maximum age (years): 40
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: PREVENTION

Brief summary: 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.

Detailed 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.

Eligibility criteria: 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.

Primary outcomes:
measure: Total consumption of norepinephrine during the whole surgical procedure.
timeFrame: Just after subarachnoid block till the end of surgery
Secondary outcomes:
measure: Incidence of hypotension, hemodynamic data and postoperative complications(nausea,vomiting,hypertension and bradycardia).
timeFrame: Just after subarachnoid block till 24 hours postoperative
Other outcomes:
Locations:
city: Assiut
country: Egypt
facility: Assiut university
Study officials:
affiliation: Assiut University
name: Mohamed H Bakri, professor
role: STUDY_DIRECTOR
affiliation: Assiut University
name: Ola M Wahba, A.professor
role: STUDY_DIRECTOR
affiliation: Assiut University
name: Abdelrahman H Mohammed, A.professor
role: STUDY_DIRECTOR
References:
citation: Sheng ZM, Sun HQ, Mao JQ, Liu J, Liang G, Mei Z. Comparative dose-response study on the infusion of norepinephrine combined with intravenous ondansetron versus placebo for preventing hypotension during spinal anesthesia for cesarean section: a randomised controlled trial. Int J Surg. 2024 Feb 1;110(2):832-838. doi: 10.1097/JS9.0000000000000920.