The postoperative interview: assessing risk factors for nausea and vomiting

Area of Science:

• Anesthesiology
• Patient Safety
• Surgical Outcomes

Background:

• Postoperative nausea and vomiting (PONV) is a common complication.
• Previous studies often focused on single etiologic factors.
• Standardized assessment methods for PONV symptoms were lacking.

Purpose of the Study:

• Identify risk factors for PONV.
• Examine surgery type impact on PONV in female patients.
• Investigate hospital and anesthesiologist variations in PONV rates.
• Determine if case-mix explained inter-hospital differences.

Main Methods:

• Utilized postoperative interview data from 16,000 inpatients across four teaching hospitals (1988-89).
• Employed a closed-question standardized format for interviews conducted by research nurses.
• Applied multiple logistic regression analysis to control for multiple risk factors simultaneously.

Main Results:

• Identified significant PONV risk factors: younger age, female sex, lower physical status, no preoperative conditions, nonsmokers, elective procedures, longer anesthesia, inhaled anesthetics, intraoperative opioids, gynecologic/ophthalmologic surgery.
• Minor gynecologic surgery showed increased risk in women (relative odds = 2.30).
• Marked variations in PONV rates (39%-73%) existed across hospitals and anesthesiologists, unexplained by patient case-mix.

Conclusions:

• Patient-reported PONV rates were persistently high prior to the introduction of modern antiemetic drugs.
• Significant inter-hospital and inter-anesthesiologist variability in PONV rates suggests modifiable factors.
• A comprehensive, multi-factorial approach is crucial for understanding and managing PONV.