The quality of evidence (I-III) and classification of recommendations (A-E, L) are defined at the end of the "Major Recommendations."
Management of Postoperative Nausea and Vomiting (PONV)
Risk Factors for PONV
- Physicians should be aware of the risk factors associated with PONV, and the baseline risks should be reduced whenever possible. (III-A)
Optimization in the Preoperative Period
- When the choice is available, patients should be advised that the risk of PONV decreases when regional rather than general anesthesia is administered. (III-A)
- The perioperative use of opioids should be minimized. Surgeons should evaluate the risks/benefits of opioid administration in light of the increased risk of PONV. (III-B)
Pharmacological Prophylaxis
- Prophylactic antiemetics should be administered to patients with moderate or high risk of developing PONV. (II-1 A)
- In patients with a high risk of developing PONV, combination antiemetic therapy should be considered. (III-B)
Non-pharmacological Prophylaxis
- Acupoint electrical stimulation may be used as an alternative or adjuvant therapy for prevention of PONV. (II-1 A)
Rescue Treatment for PONV
- For patients with PONV who did not receive prophylaxis or in whom prophylaxis failed, antiemetic treatment should be administered as soon as feasible. (III-A)
- When prophylaxis with one drug has failed, a repeat dose of this drug should not be initiated as a rescue therapy; instead, a drug from a different class of antiemetic drugs should be administered. (III-A)
Post-discharge Nausea and Vomiting
- As patients who undergo surgery in surgical daycare units may have PONV after they are discharged, they should be given instructions for its management. (III-B)
- Patients at high risk of developing PDNV should be provided with rescue treatment. (III-B)
Definitions:
Quality of Evidence Assessment*
I: Evidence obtained from at least one properly designed randomized controlled trial.
II-1: Evidence obtained from well-designed controlled trials without randomization.
II-2: Evidence obtained from well-designed cohort (prospective or retrospective) or case-control studies, preferably from more than one center or research group.
II-3: Evidence obtained from comparisons between times or places with or without the intervention. Dramatic results from uncontrolled experiments (such as the results of treatment with penicillin in the 1940s) could also be included in this category.
III: Opinions of respected authorities, based on clinical experience, descriptive studies, or reports of expert committees.
Classification of Recommendations**
A. There is good evidence to recommend the clinical preventive action.
B. There is fair evidence to recommend the clinical preventive action.
C. The existing evidence is conflicting and does not allow to make a recommendation for or against use of the clinical preventive action; however, other factors may influence decision-making.
D. There is fair evidence to recommend against the clinical preventive action.
E. There is good evidence to recommend against the clinical preventive action.
L. There is insufficient evidence (in quantity or quality) to make a recommendation; however, other factors may influence decision-making.
*The quality of evidence reported in these guidelines has been adapted from the Evaluation of Evidence criteria described in the Canadian Task Force on Preventive Health Care
**Recommendations included in these guidelines have been adapted from the Classification of Recommendations criteria described in the Canadian Task Force on Preventive Health Care.
