Point-of-Care Guides

Predicting Postoperative Nausea and Vomiting

MARK H. EBELL, MD, MS, Athens, Georgia

Clinical Question

Which patients are likely to experience postoperative nausea and vomiting?

Evidence Summary

Postoperative nausea and vomiting are uncomfortable for patients, can prolong hospitalization, and can lead to more serious complications, including aspiration pneumonia. Accurately predicting which patients are at risk of postoperative nausea and vomiting can help physicians decide when to recommend prophylactic antiemetics. A study comparing different prophylactic strategies concluded that dexamethasone with or without ondansetron (Zofran), ideally administered intraoperatively, should be used as initial agents.1

A review found three predictive scores for postoperative nausea and vomiting and attempted to validate them in 1,444 patients.2 Another review identified three additional predictive scores and attempted to validate all six scores in 1,566 patients.3 Participants in both validation studies were undergoing general anesthesia without prophylactic antiemetics. A subsequent study used a neural network (i.e., artificial intelligence software) to predict postoperative nausea and vomiting; however, this is not practical for physicians without specialized software.4

The scores vary considerably in complexity. Some are multivariate equations that are not practical for bedside use without a calculator; however, simpler scores consisting of four or five items have been shown to be as accurate or nearly as accurate as more complex equations.2-6

The Apfel score (Table 15) includes four variables and assigns one point for each. The score was prospectively validated in 520 patients from a different hospital than that used in the original study and was found to have good predictive accuracy.3,5 The Koivuranta score (Table 26) includes five variables and assigns one point for each. The score was also shown to validate well in several studies.2,3,6 Both scores performed similarly in the validation studies. Another study found that both scores performed well in a prospective comparison in 1,388 Dutch inpatients.7

Applying the Evidence

A 54-year-old female nonsmoker is about to undergo a laparoscopic cholecystectomy. The surgeon estimates that the procedure will take 90 minutes, and predicts that she will require postoperative opioids for pain relief. The patient has no history of post-operative nausea and vomiting because she has never been under general anesthesia, but she is somewhat susceptible to motion sickness. What is the patient's risk of postoperative nausea and vomiting?

Answer: Using the Apfel score (Table 15), the patient receives four out of four possible points. Using the Koivuranta score (Table 26), she receives four out of five possible points. You refer to a recent study that recommends 4 mg of dexamethasone and 4 mg of ondansetron for prevention of postoperative nausea and vomiting, and recommend that she receive these antiemetics intraoperatively.1

Address correspondence to Mark H. Ebell, MD, MS, at mebell@mcg.edu. Reprints are not available from the author.

REFERENCES

1. Apfel CC, Korttila K, Abdalla M, Kerger H, Turan A, Vedder I, et al., for the IMPACT investigators. A factorial trial of six interventions for the prevention of postoperative nausea and vomiting. N Engl J Med 2004;350:2441-51.

2. Eberhart LH, Hogel J, Seeling W, Staack AM, Geldner G, Georgieff M. Evaluation of three risk scores to predict postoperative nausea and vomiting. Acta Anaesthesiol Scand 2000;44:480-8.

3. Apfel CC, Kranke P, Eberhart LH, Roos A, Roewer N. Comparison of predictive models for postoperative nausea and vomiting. Br J Anaesth 2002;88:234-40.

4. Traeger M, Eberhart A, Geldner G, Morin AM, Putzke C, Wulf H, et al. Prediction of postoperative nausea and vomiting using an artificial neural network [in German]. Anaesthesist 2003;52:1132-8.

5. Apfel CC, Laara E, Koivuranta M, Greim CA, Roewer N. A simplified risk score for predicting postoperative nausea and vomiting: conclusions from cross-validations between two centers. Anesthesiology 1999;91:693-700.

6. Koivuranta M, Laara E, Snare L, Alahuhta S. A survey of postoperative nausea and vomiting. Anaesthesia 1997;52:443-9.

7. Van den Bosch JE, Kalkman CJ, Vergouwe Y, Van Klei WA, Bonsel GJ, Grobbee DE, et al. Assessing the applicability of scoring systems for predicting postoperative nausea and vomiting. Anaesthesia 2005;60:323-31.

This guide is one in a series that offers evidence-based tools to assist family physicians in improving their decision making at the point of care.