Post-operative nausea and vomiting (PONV) is a frequent complication of surgery, with considerable medical and economic impact. It is also associated with high levels of patient discomfort and dissatisfaction. To many patients, PONV is a distressing event that reportedly is more feared than post-operative pain. The cause of PONV is complex and can be due to multiple factors. These factors may include certain characteristics of the patient (such as female gender, non-smoking status, and having experienced PONV in the past), the surgical procedure (intra-abdominal laparoscopic procedures, gynecologic surgeries, breast surgeries), and the type of anesthetic that is used. Untreated, the incidence of post-operative nausea and vomiting (PONV) in high risk patients can reach 70-80%. In addition, it is important to note that PONV can present during the first 24 hours after surgery or beyond. PONV alone is one of the leading causes for delayed discharge and unplanned hospital admission following outpatient surgery. Furthermore, more than 35% of surgical outpatients experience PONV following discharge, many of whom did not experience nausea or vomiting in the recovery room.~An important factor in the development of Post-operative nausea and vomiting (PONV) appears to be the release of the biogenic amine serotonin (5-HT3) in the brainstem and the peripheral nervous system. Serotonin induces nausea and vomiting via the 5-HT3 receptor.~Currently, medications that block the 5-HT3 receptor are widely accepted as a first-line anti-emetic in both the prevention and treatment of PONV. Ondansetron is the most commonly prescribed. An intra-venous dose of Ondansetron administered intra-operatively is predicted to reduce PONV by 15-20% when compared to patients who receive a placebo. However, Ondansetron has a half-life of approximately six hours and must be re-dosed in patients with prolonged or delayed-onset PONV.~By contrast, Palonosetron is another 5-HT3 receptor antagonist that has a longer half-life than Ondansetron, thus reducing the need for re-dosing; a single dose of Palonosetron was shown to be superior to a single dose of Ondansetron in the treatment of delayed nausea and vomiting associated with chemotherapy.~Furthermore, there is now evidence that a multimodal approach to the prevention of post-operative nausea and vomiting is more effective than any single medication. A recent study determined that a combination regimen of Ondansetron and Dexamethasone (a steroid medication known to prevent nausea and vomiting) provided significantly better prophylaxis against PONV than Ondansetron alone.~Therefore, the rationale for conducting this study is to evaluate whether the administration of a single dose of Palonosetron combined with Dexamethasone is superior to a single dose of Palonosetron alone in the prevention of both immediate and delayed PONV in high risk patients undergoing laparoscopic abdominal or gynecologic surgery.~In order to answer the question of whether Palonosetron plus Dexamethasone is significantly more effective at reducing the incidence of PONV than Palonosetron alone, we will enroll patients that are high risk for PONV who are undergoing laparoscopic abdominal or gynecologic surgery. This subset includes: female patients, non-smokers, and patients with a history of PONV.~Each study patient will receive Palonosetron alone or Palonosetron plus Dexamethasone immediately prior to the start of her/his surgery. We will then use an 11 point nausea scale to determine how many patients had a complete response to the medication (complete response = NO nausea and NO vomiting at any time during the study period of 0-72 hours post surgery). If a patient does experience nausea or vomiting, we will record the time and severity of the PONV as well as whether any medication was given to relieve the nausea and vomiting. If a patient is discharged from the hospital before their 72nd hour post surgery, (s)he will receive a journal in which to record any symptoms or nausea or vomiting and a member of the research team will call to obtain the information.~We predict that the combination of Palonosetron plus Dexamethasone will be superior to Palonosetron alone in the prevention of PONV. We will compare the incidence of patients with a complete response to the study medication (NO nausea and NO vomiting for 72 hours post surgery) to determine if this hypothesis is valid.
The purpose of this study is to determine if subjects who receive Palonosetron plus Dexamethasone have less post-operative nausea and vomiting (PONV) than those who receive Palonosetron alone.