Effect of Preoperative Oral Energy Drinks Compared to Warming Matress on Body Temperature During Combined Spinal-epidural Anesthesia for Elective Cesarean Delivery.

Inclusion Criteria: * Women pregnant with a single fetus; * American Society of Anesthesiologists (ASA) physical status II; * Willingness to undergo elective cesarean delivery under combined spinal-epidural anesthesia; * A body mass index (BMI) \< 35 kg·m-2; * A gestational age of 38-40 weeks. Exclusion Criteria: * Contraindications for combined spinal-epidural anesthesia; * A diagnosis of delayed gastric emptying, hyperemesis gravidarum until late pregnancy, or consumption of drugs that affect gastrointestinal motility within 3 days before surgery; * Preoperative body temperature \>38°C or \<36°C or the use of drugs that affect body temperature; * Pregnancy combined with diabetes, hypertension, or metabolic disorders (eg, hypothyroidism or hyperthyroidism); * Ear diseases (eg, otitis media, tympanic membrane perforation, etc) affecting measurement of ear temperature; * Intraoperative malfunction of the warming blanket; * Patients who were simultaneously undergoing other operations (eg, removal of uterine fibroids and ovarian cysts) or had a surgical time \>1.5 hours; * Patients with blood transfusion or autologous blood transfusion intraoperatively; * Patients who did not receive the anesthetic specified in the protocol; * Patients who failed to drink 125ml energy drinks before surgery.