ABSTRACT 

Background

Spinal anesthesia is an effective regional anesthesia technique, which is preferred in almost 86% of cesarean sections in the United States and United Kingdom. At least 80% of cesarean sections done at the Aga Khan University hospital are under spinal anesthesia. Shivering is a common complication of spinal anesthesia; it occurs in 40%-64% of patients after neuraxial anesthesia. Shivering may cause maternal and fetal hypoxemia, maternal discomfort and a problem to the anesthesiologists when it comes to monitoring the patient during cesarean sections.

Ondansetron a 5ht3 receptor antagonist is effective in treatment and prevention of post anesthesia shivering. In published studies use of fixed dose in patients with different weights in the various groups, masked the dose effect ondansetron in preventing shivering. Such that not adjusting the dose according to the weight of patients in the sample group resulted in a higher occurrence of shivering. No study compares different doses of ondansetron in preventing shivering in parturient women who have had spinal anesthesia for cesarean section.

Objectives: To determine if a weight-adjusted dose is better than a fixed dose of ondansetron in preventing shivering following spinal anesthesia for cesarean delivery.

Study design: 

Double blinded Randomized Controlled Trial

Method: This is a randomized, double-blinded controlled trial of 124 women scheduled for elective cesarean surgery. The Women will be allocated into two equal groups. The intervention group will receive intravenous ondansetron weight adjusted dosing at 0.1mg/kg and control group will get a fixed dose of 4mg before spinal anesthesia. The occurrence and severity of shivering and other outcomes, such as headache, pruritus will be assessed and recorded during the surgery and postoperative period.

Data will be collected using questionnaires.Data analysis undertaken using the SPSS version 15. Chi-square tests, will be used to compare incidence of shivering between the two groups. To compare severity of shivering between the groups, the Wilcoxon sum rank test will be used. A significance level of 0.05 will be used for all hypothesis test.