Source: Pusch et al, Anesth 2002;96:1381-1385

Reviewer:  R. Prasad, MD

Summary:

• Women presenting with orthostatic dysregulation and arterial hypotension in their history exhibit an increased risk of PONV.

• adds yet another possible risk factor for PONV
• however, not much better for predicting risk than Apfel score alone

• prospective observer-blinded clinical trial
• 200 women for elective gynecologic surgery (power analysis assumed 20% diff in PONV btwn groups, PONV incidence 40%, 90% power with p 0.05: needed only 134 pts).
• stratified based on an orthostatic test on day before surgery: orthostatic dysregulation (OR; systolic blood pressure decrease > 20 mmHg on standing up) vs nonorthostatic dysregulation (NOR; systolic blood pressure decrease < 20 mmHg).
• standardized anesthetic: versed po, fentanyl, propofol, rocuronium, nitrous, sevo

• 49 OR group, 151 NOR group.
• Similar in multiple parameters, except:
• Wt, BMI slightly lower in OR group (66kg vs 71kg, 24.5 vs. 26.6)
• h/o PONV higher in OR group (43% vs. 25%); however, Apfel PONV risk scores similar
• Logistic regression on their data:

• Women with h/o dizziness or fainting on standing up had higher incidence of orthostatic rxn
• Women with h/o hypotension had higher frequency of PONV within 24 h