Mirtazapine Versus Dexamethasone in Preventing Postoperative Nausea and Vomiting

this double-blinded randomized study will be conducted at Ain-Shams university hospitals. Patients are aged 21-60 years and body weight 60-100 Kg of the American Society of Anaesthesiologists (ASA) physical status I or II scheduled for laparoscopic cholecystectomy under general anesthesia will be enrolled in this study., patients will be randomly divided into 2 equal groups; The M(Mirtazapine) group:(n=45) each patient will receive an oral disintegrating tablet (ODT) of mirtazapine 30 mg with sips of water and 100 ml 0.9% sodium chloride (normal saline [NS]) (IVI) over 15 min as a placebo 1 h preoperatively.

The D (Dexamethasone) group: (n=45) each patient will receive a placebo tablet identical to Mirta tablet orally with sips of water and Dex 8 mg ampoule diluted in 100 ml 0.9% NS IVI over 15 min, 1 h preoperatively.

standard monitoring in the form of (ECG, pulse oximeter, NIBP, peripheral temperature monitoring) will be attached to all patients and capnography will be connected after intubation. baseline measures will be recorded, and subsequent values will be recorded every 15 min. Patients will be observed for 24 hours postoperative. And the following will be recorded; Time to awakening (time from the end of anesthesia until the patients opened their eyes on command) and Time to the first analgesia. Patients´ vital data (BP, HR, RR, O2 saturation) will be monitored every 15 minutes for the first postoperative hour, then every 4 hours. Postoperative pain will be assessed every 4 hours with a 10-cm visual analog scale VAS (0=no pain to 10=most severe pain) score. The incidence of occurrence of postoperative Nausea and vomiting will be evaluated every 4 hours on a two-point verbal scale (0, none; 1, nausea or vomiting). The severity of nausea and vomiting will be assessed using a verbal numerical rating scale from 0 = no nausea/ vomiting and 10 = nausea/ vomiting as bad as it could be.The complete response is defined as no nausea, no vomiting, and no antiemetic medication during a 24-h postoperative period

Inclusion criteria

• ASA physical status I or II
• body weight 60-100 Kg
• scheduled for laparoscopic cholecystectomy under general anaesthesia

Exclusion criteria

• Patient's refusal to participate in the study,
• Obesity with body mass index (BMI) >35 kg/m2,
• Physical status: ASA III or above,
• Patients with a history of PONV, motion sickness, or major systemic diseases
• Patients who received an antiemetic drug within 48 h before surgery,
• Patients facing liver or kidney problems with a high level of BUN or serum creatinine,
• A history of allergy to the study drugs.
• Pregnant, lactating, or menstruating patients