Dexmedetomidine Versus Dexamethasone Adding to Ondansetron for Prophylaxis Against Postoperative Nausea and Vomiting After Laparoscopic Cholecystectomy

General anesthesia is widely used in several surgeries. It can cause some complications such as postoperative nausea and vomiting (PONV). PONV is more common in general anesthesia than spinal anesthesia. PONV remains an extremely significant challenge due to its complex mechanism, resulting in serious consequences. Therefore an effective way to prevent or arrest PONV is urgently needed as Also, it can cause electrolyte imbalance and aggravate bleeding that delay hospital discharge.

The causes of PONV are multifactorial and can largely be categorized as patient risk factors, anaesthetic technique, and surgical procedure. Antiemetics work on several different receptor sites to prevent or treat PONV.

No single antiemetic pharmaceutical has been provided to be a universal solution to PONV. In general, multimodal combination treatment has superior viability for PONV prophylaxis compared with monotherapy .

Because nausea and vomiting were defined as two separate phe-nomena, studies should report and evaluate the variables distinctly . While since few patients experience vomiting without nausea, the incidence of PONV and postoperative nau¬sea (PON) is fairly similar, thus original papers often do not try to distinguish these variables . So, if PONV but not PON was reported in trails, we considered the PONV variables as a very close substitute for PON; when both PONV and PON were reported simultaneously, we assessed the nausea values. The most com¬monly used time interval to measure the role of antiemetic is 24 hours 6.

Ondansetron is a serotonin receptor antagonist, which is very important in preventing nausea and vomiting due to surgery and chemotherapy; it exhibited an anti-vomiting effect by inhibiting 5-Hydroxytryptamine type 3 (5-HT3) receptors in the vomiting centre .