Efficacy of Intravenous Midazolam-Ketamine Combination Versus Placebo for Prevention of Post-Spinal Shivering in Elective Cesarean Section

About This Study

Spinal anesthesia is the preferred anesthetic method for elective cesarean deliveries, but it frequently causes post-spinal shivering. Shivering causes marked maternal discomfort, interferes with clinical monitoring, and increases oxygen consumption and metabolic workload. This study aims to assess whether a prophylactic intravenous combination of low-dose midazolam and low-dose ketamine reduces the occurrence and severity of shivering compared with a placebo in women undergoing elective cesarean delivery under spinal anesthesia. A total of 120 parturients will be randomly assigned into two equal groups: * Combination Group: Receives intravenous midazolam (0.0375 mg/kg) combined with ketamine (0.25 mg/kg) diluted in 20 mL of 0.9% normal saline. * Control Group: Receives 20 mL of 0.9% normal saline intravenously as a placebo. In both groups, the intravenous infusion is administered over 10 minutes immediately following delivery of the infant and clamping of the umbilical cord, ensuring no transplacental transfer of the study medications to the newborn. The primary objective is to evaluate the proportion of patients who develop shivering during the first 60 minutes after arrival in the post-anesthesia care unit (PACU). Secondary objectives include shivering severity, the requirement for rescue anti-shivering medication, intraoperative and postoperative sedation levels, hemodynamic stability, body temperature course, potential medication side effects, and maternal satisfaction.

Conditions Studied

Interventions

• •Midazolam and Ketamine
• •0.9% Sodium Chloride

Eligibility

Inclusion Criteria:

* Pregnant women aged 18 to 40 years old.
* American Society of Anesthesiologists (ASA) physical status I or II.
* Singleton pregnancy.
* Term pregnancy (37 to 41 weeks of gestation).
* Scheduled for elective cesarean section under spinal anesthesia.

Exclusion Criteria:

* Patient refusal.
* Body mass index (BMI) ≥ 40 kg/m².
* Contraindications to spinal anesthesia (e.g., coagulopathy, local infection at the puncture site).
* Known hypersensitivity or allergy to midazolam or ketamine.
* Pre-existing hypertension, pre-eclampsia, or cardiovascular disease.
* Severe cardiovascular, renal, or hepatic dysfunction.
* Neurological or psychiatric disorders (including epilepsy or history of psychosis).
* Baseline (preoperative) body temperature \< 36°C or \> 37.5°C.
* Chronic use of sedatives, opioids, or medications affecting thermoregulation.