Efficacy of Low Dose Promethazine for Postoperative Nausea and Vomiting

Study Overview
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Brief Summary
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There has been an increase in ambulatory surgical procedures performed across Canada; ambulatory procedures account for almost 70% of all surgeries. Postoperative nausea and vomiting (PONV) and pain are the most frequently reported adverse events by patients prior to discharge after ambulatory surgery. The incidence can be as high as 70 to 80% in high-risk patients. PONV is a cause of morbidity particularly in gynecological procedures and the incidence of patients experiencing PONV is as high as 58-75%. Apart from delayed recovery, the occurrence of PONV has been linked to gastric aspiration, psychological distress and wound dehiscence. The occurrence of PONV delays patient discharge and further more is a leading cause of unexpected admission after ambulatory anesthesia Promethazine, is an antiemetic medication that has been widely used over the last 50 years, and although effective at reducing PONV, it tends to cause sedation. In this study, we are trying to determine if a smaller dose of promethazine, in addition to the standard treatment for post-surgical nausea and vomiting, will be more beneficial than the standard treatment on its own. It is hypothesized that the use of low dose promethazine (3 mg) as part of a multimodal antiemetic regimen will be efficacious in preventing PONV without the sedative effects of promethazine.

Conditions
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Ambulatory Gynecological Laparoscopic Procedures

Intervention / Treatment
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* Drug: Promethazine
* Drug: Promethazine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 1. Patient is between 18 - 60 yrs of age 2 Patient's health is graded as class I-III according to the American Society of Anesthesiologists physical status classification. 3. The patient has 2 or more of the following risk factors: Female Non-smoker History of PONV/motion sickness Use of post-operative opioids (current surgery) 4. Undergoing ambulatory gynecological laparoscopic procedures of at least 30 minutes duration Exclusion Criteria: preexisting nausea, vomiting or retching, gastric outlet or intestinal obstruction clinical evidence of a difficult airway obesity (body mass index > 40 kg m-2) scheduled to receive propofol for anesthesia maintenance current pregnancy psychiatric illness clinically significant major organic disease preoperative QTc interval > 440 ms on electrocardiogram known hypersensitivity to promethazine, granisetron, ondansetron or other 5 HT3-receptor antagonists

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| No Intervention: Saline<br> | |
| Other: Promethazine 6.25 mg<br> | Drug: Promethazine<br> <br> |
| Other: Promethazine 3 mg<br> | Drug: Promethazine<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Absence of emetic episode for 24 h in the postoperative period |  |  |