The incidence of intraoperative nausea and vomiting in patients who undergo caesarean section (C/S) under regional anesthesia is approximately 30-80%. Hypotension, pain, visceral manipulation, fundal pressure, removal of the uterus during repair, intra-abdominal irrigation, central neural opioids, intravenous oxytocin and antibiotics are possible risk factors. Oxytocin and prophylactic antibiotics are administered simultaneously during C/S operation, especially after the umbilical cord is clamped. Simultaneous administration of drugs such as oxytocin and prophylactic antibiotics may induce nausea and vomiting after umbilical cord clamping in the patient. In this study, it was aimed to investigate the effect of prophylactic antibiotic administration 30 minutes before the incision and after cord clamping on intraoperative nausea and vomiting in patients undergoing elective C/S under regional anesthesia.

This study was planned to be carried out in Başkent University Zübeyde Hanım Research Center Operating Room with 120 pregnant women (≥ 37 gestational weeks) undergoing elective C/S under regional anesthesia in a prospective, randomized, double-blind manner.

Group 1 (Prophylactic antibiotic 30 minutes before skin incision): Antibiotic diluted in 10 ml syringe 30 minutes before skin incision and after cord clamping, 0.9% NaCl in 10 ml syringe will be administered intravenously within 15 seconds.

Group 2 (prophylactic antibiotic after cord clamping): 30 minutes before the skin incision, 0.9% NaCl in a 10 ml injector and after the cord is clamped, the antibiotic diluted in a 10 ml syringe will be administered intravenously within 15 seconds.

Intraoperative nausea-retching-vomiting episodes (0 = No symptoms, 1: Nausea (uncomfortable feeling with vomiting), 2: Gag (vomiting effort in which gastric contents cannot be expelled), 3: Vomiting (Gastric contents are forced by mouth. ejection)] will be recorded. Nausea scores will be evaluated on the verbal analog scale (VAS) with 11 points (0 = no nausea, 10 = the most severe nausea). Before anesthesia, all patients will be informed about the verbal analog scale (VAS) for nausea. VAS 1-3 = Mild Nausea, VAS 4-6 = Moderate nausea, VAS 7-10 = Severe nausea. Evaluations will be made at certain time intervals.

Before CSEA application Time interval between CSEA application and fetus discharge Time interval between fetus exit and expulsion of the uterus Time interval between expulsion of the uterus and insertion into the abdomen Time interval between insertion of the uterus in the abdomen and closing the fascia Time interval between fascia closure and skin closure Time interval between skin closure and patient transport to the recovery unit Nausea-retching-vomiting episodes, current systolic/diastolic blood pressure values, nausea-vomiting scores, antiemetic and / or ephedrine requirement, amount of intravenous fluid infused will be recorded.

Intraoperative prophylactic antibiotic use is considered as one of the possible causes of intraoperative nausea and vomiting in patients who underwent cesarean section under regional anesthesia. We believe that the results of our study can make contribution on both intraoperative nausea-vomiting etiology in cases undergoing cesarean section under regional anesthesia and the steps that can be taken to prevent it.

Inclusion Criteria:

• Pregnant women (≥ 37 gestational weeks) undergoing elective C/S under regional anesthesia

Exclusion Criteria:

• Emergency C/S cases
• Patients who had nausea before C/S
• Patients who used antiemetics within 24 hours before C/S
• Patients who have a history of smoking, postoperative nausea-vomiting, motion sickness, and hyperemesis before C/S
• Patients with history of diabetes, morbid obesity (Body Mass Index> 40) and gastrointestinal disease
• Psychiatric disorders
• Patients who are allergic to the drugs to be used in the study
• Patients for whom regional anesthesia is contraindicated

Pregnant women undergoing C/S under regional anesthesia

A computer-generated random numbers table and sealed envelopes will be used to ensure randomization. The gynecologist performing the surgery, the anesthesiologist and the patients will not know the Group allocation. The medications will be prepared by the anesthesia technician responsible for the study. Prophylactic antibiotic and placebo will be prepared in 10 ml in the syringe and labeled as study drug.