Granisetron Use, Blood Pressure, and Nausea and Vomiting During Cesarean Delivery Under Spinal Anesthesia

This study will observe 80 adults having a cesarean delivery under spinal anesthesia at Kayseri City Hospital. It will compare patients who receive granisetron as part of routine care to prevent nausea and vomiting with patients who do not receive preventive anti-nausea medicine. Granisetron use is decided by the treating anesthesiologist, not assigned by the study. Patients in the granisetron group receive the medicine within 5 minutes before or after spinal anesthesia. The main measurement is the total dose of ephedrine used during the operation. Ephedrine is a medicine used to treat low blood pressure. The study will also record low blood pressure at scheduled measurement points and nausea and vomiting during the operation. Patient enrollment is planned from October 15 to December 15, 2026.

Inclusion Criteria: * Pregnant women aged 18 years or older with a singleton pregnancy. * American Society of Anesthesiologists (ASA) physical status II. * Elective or emergency cesarean delivery under spinal anesthesia at Kayseri City Hospital. * Written informed consent to participate. * Routine intraoperative monitoring and a prophylactic antiemetic decision made independently by the treating anesthesiologist. Exclusion Criteria: * Age below 18 years. * Cesarean delivery performed under general or epidural anesthesia, or intraoperative conversion from spinal to general anesthesia. * Multiple pregnancy. * Serious cardiovascular disease, severe arrhythmia, or advanced heart failure. * Severe preeclampsia, eclampsia, or HELLP syndrome. * Known allergy to 5-HT3 receptor antagonists. * Massive intraoperative bleeding or blood transfusion. * Refusal to participate or absence of written informed consent. * Missing intraoperative hemodynamic measurements or other required study data.