Palonosetron vs Combination of Granisetron and Dexamethasone in Preventing PONV in Laparoscopic Cholecystectomy.

This prospective double-blinded, randomized controlled study was conducted at Hospital Canselor Tuanku Muhriz, Universiti Kebangsaan Malaysia, Malaysia after obtaining approval from the Institutional Ethics Committee of Universiti Kebangsaan Malaysia (UKM).

Patients aged 18 to 65 years old, American Society of Anesthesiologists (ASA) physical status I or II, scheduled for elective laparoscopic cholecystectomy under general anesthesia were recruited using convenient sampling. Patients with heart diseases, prolonged QT syndrome, a family history of sudden death, known allergies, or contraindications to the study drugs were excluded. No premedication was administered to the patients, and an intravenous (IV) drip was not started preoperatively.

After obtaining written informed consent, patients were randomized to one of two groups using computer-generated random numbers. Group A received IV palonosetron 0.075 mg, and Group B received IV granisetron 1 mg and IV dexamethasone 4 mg as antiemetics.

Patients were fasted for at least 6 hours prior to surgery. In the operating room, standard monitoring was applied to every patient, including continuous electrocardiography (ECG), non-invasive blood pressure monitoring (NIBP), pulse oximetry, capnography with multi-gas analyzer including minimum alveolar concentration (MAC), and monitoring of all gas levels.

Patients were pre-oxygenated with oxygen. Induction of anesthesia was conducted using IV fentanyl 2 mcg/kg and IV propofol 2 mg/kg. Upon loss of consciousness, IV rocuronium 0.6 mg/kg was administered to facilitate endotracheal intubation, following which patients were mechanically ventilated with a mixture of oxygen and air. Anesthesia was maintained with sevoflurane at MAC of 1.0 to 1.2. Ventilation parameters were adjusted to maintain normocapnia (end-tidal carbon dioxide of 35-40 mmHg) and saturation of oxygen above 96%.

Group A patients received 1 ml of IV 0.9% saline while Group B patients received IV dexamethasone 4 mg after intubation. The amount of IV morphine given to the patients intraoperatively was recorded and did not exceed 0.1 mg/kg. Rescue analgesia with IV fentanyl was administered if needed, not exceeding 100 mcg. The surgeon infiltrated 10 ml of levobupivacaine 0.5% into the incisions at the end of surgery. Patients were kept adequately hydrated throughout the surgery with an IV drip of 2 ml/kg/h as maintenance, any fluid deficit was replaced. Pneumoperitoneum in laparoscopic procedure was achieved by carbon dioxide insufflation with intra-abdominal pressure of less than 14 mmHg.

Thirty minutes prior to the end of the surgery, Group A received a slow bolus of IV palonosetron 0.075 mg, while Group B received a slow bolus of IV granisetron 1 mg. Intravenous neostigmine 0.05 mg/kg and IV atropine 0.02 mg/kg were administered as a reversal agent. The pneumoperitoneum was evacuated by the surgeon, and the nasogastric tube was suctioned and removed before extubation. The patients were transferred to the recovery bay after extubation. Rescue analgesia with IV fentanyl was administered in the recovery bay if needed, not exceeding 50 mcg.

Patients were monitored by blinded anesthetists for nausea and vomiting in four time periods: 30 minutes, 4 hours, 24 hours, and 48 hours post-anesthesia. Nausea was defined as an unpleasant sensation associated with the urge to vomit and its severity was rated by patients on a scale of 0 (no nausea) to 10 (worst possible nausea). Vomiting was defined as the forceful expulsion of gastric contents from the mouth, and the frequency of vomiting was recorded. If a patient experienced severe nausea (nausea score of 4 and more) and vomiting, rescue antiemetic of IV metoclopramide 10 mg was administered. Regular IV metoclopramide was administered if the patient experienced a second episode of vomiting or more. A complete response (free from emesis) was defined as no nausea, no vomiting and no need for any rescue medication. Side effects of the study drugs (palonosetron, granisetron, and dexamethasone) such as headache, constipation, dizziness, bloatedness, and palpitation were recorded. At the end of the study, patients were asked if they were satisfied with the antiemetics given to them. Patient satisfaction was assessed by using a Likert scale, which included a five-point scale; very satisfied, satisfied, neutral, dissatisfied, and very dissatisfied. Surgeries that lasted more than four hours, required conversion to open cholecystectomy or other procedures, and severe PONV that did not resolve with rescue anti-emetics were considered dropouts in this study.