Caffeine in the Prevention of Post-operative Nausea and Vomiting

Study Overview
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Brief Summary
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The objective of this study is to determine if caffeine 500 mg intravenously is efficacious when added to standard anti-emetic prophylaxis in the prevention of post-operative nausea and vomiting (PONV) in patients undergoing ambulatory surgery under general anesthesia.

Detailed Description
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This is a prospective, randomized, double-blind, placebo-controlled study of caffeine, 500 mg, intravenously, in addition to standard anti-emetic prophylaxis, in the prevention of post-operative nausea and vomiting in patients undergoing ambulatory surgery under general anesthesia. Consenting patients will be randomized to receive either a single dose of caffeine, 500 mg, or saline placebo, administered as a single IV dose approximately 15 minutes before emergence from anesthesia. All patients will receive our customary anti-emetic prophylaxis, determined by four major risk factors for PONV: female gender, nonsmoking status, history of PONV or motion sickness, and perioperative opioid use. Patients at low risk for PONV (no risk factors) will receive no prophylaxis; patients at moderate risk for PONV (1 or 2 risk factors) will receive dexamethasone 8 mg at induction plus dolasetron 12.5 mg approximately 15 min before the end of anesthesia; patients at high risk for PONV (3 or 4 risk factors) will receive the same treatment as those at moderate risk, plus additional prophylaxis at the discretion of the attending anesthesiologist (e.g., scopolamine patch, metoclopramide 10 mg IV, or other standard drugs). Postoperatively, the presence of PONV will be recorded. If rescue medication is used, the amount and time of administration will be recorded. The length of stay in the PACU (Phase I and Phase II) will be recorded. Patients will be asked to report any headache, and to rate their nausea, pain, alertness, fatigue, and overall satisfaction in the PACU, and again by phone 24 hours postoperatively. Amount of pain medication utilized in the PACU will also be measured.

Official Title
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A Prospective, Randomized, Double-blind, Placebo-controlled Study of Caffeine in the Prevention of Post-operative Nausea and Vomiting in Patients Undergoing Ambulatory Surgery Under General Anesthesia

Conditions
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Postoperative Nausea and Vomiting

Intervention / Treatment
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* Drug: Caffeine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patient having ambulatory surgery Patient receiving general anesthesia Exclusion Criteria: Patient is not willing to sign informed consent Patient does not speak or understand sufficient English

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

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
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: I<br>Saline placebo | Drug: Caffeine<br>* 500 mg IV<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Complete response (no PONV and no use of rescue medication) during the first 24 hours following anesthesia |  | 1-24 hours post-operatively | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Nausea during the first 24 hours following anesthesia |  | 1-24 hours post-operatively | 
| Vomiting during the first 24 hours following anesthesia |  | 1-24 hours post-operatively | 
| Proportion of patients who use rescue medication during the first 24 hours following anesthesia |  | 1-24 hours post-operatively | 
| Post Anesthesia Care Unit (PACU) length of stay (Phase I, Phase II) |  | hours post-operatively | 
| Incidence of headache |  | 1-24 hours post-operatively | 
| Degree of fatigue |  | 1-24 hours post-operatively | 
| Overall satisfaction |  | 1-24 hours post-operatively | 
| Alertness |  | 1-24 hours post-operatively | 
| Admissions |  | 1-24 hours post-operatively | 
| Amount of pain medication required |  | 1-24 hours post-operatively |