Many outpatient practitioners administer some type of antiemetic to surgical patients regardless of the PONV risk, according to the results of an Outpatient Surgery reader poll of 32 readers. Forty-one percent said all surgical patients should receive PONV prophylaxis and 12 percent were unsure. Even though studies indicate that such a universal approach is not cost-effective, many practitioners seem to feel otherwise. "Delay of discharge and patient dissatisfaction are more costly than drug costs," wrote one director of nursing at a center where even elderly patients undergoing cataract extraction receive a prophylactic 5-HT3 receptor antagonist. Noted another medical director of a multispecialty center where nearly all patients receive at least one prophylactic antiemetic drug: "Aggressive use of PONV prophylaxis at our center has helped keep PONV consistently below 5 percent."

The meaning of multimodal
In their quest to conquer PONV, outpatient practitioners are responding to research showing that the regimen is most clinically effective when tailored to the patient's risk level. Regardless of whether they ascribe to an "across-the-board" approach, 94 percent of responders said they increase the number of antiemetic agents as the PONV risk rises. Sixty percent agree with current expert consensus that multimodal prophylaxis is best for high-risk patients with multiple risk factors, and 61 percent agree that it does not make sense to administer a higher dose of the same agent if it doesn't prevent PONV in the first place. "Repeating the same medication in treating PONV is like taking multiple shots at a target with bad aim," wrote Roxanne Baden, director of surgical services with the Center for Orthopedic Surgery, Inc.

Most practitioners also realize that modern multimodal prophylaxis means more than simply administering two antiemetic drugs that target different emetic receptors. Eighty-one percent indicated they use one or more of these measures to prevent PONV: Propofol-based anesthesia; minimization of volatile inhalational agents via regional/local anesthesia, BIS monitoring, MAC; adequate hydration; supplemental O2; limited opioid/increased NSAID use; elimination of N2O; acupressure; 'aromatherapy' with isopropyl alcohol prep pads.

Antiemetic cornerstones
The poll suggests that a 5-HT3 receptor antagonist and propofol anesthesia are the cornerstones of PONV prophylaxis. For numerous clinical scenarios that we presented, this combination was the most popular. On propofol, the comment of Janice J. Davis, CRNA with Lexington Medical Center, reflected that of many responders: "With the introduction of propofol, I have seen a dramatic reduction in PONV."

The results also suggest that dexamethasone is fast becoming a staple in the PONV prophylaxis armamentarium. More than one-third of responders said they would use it prophylactically in the following patients: A 32-year-old female smoker with a history of PONV undergoing breast enhancement under general anesthesia; a 7-year-old boy undergoing adenoidectomy; a 33-year-old obese woman with a history of PONV undergoing laparoscopic excision of endometriosis; and a 29-year-old nonsmoking woman with a history of PONV undergoing tubal ligation.

Droperidol also remains a common choice despite the FDA 'black box' safety warning about potential cardiac complications, particularly for patients with multiple risk factors. Fifty percent of responders said they believe droperidol still has a place in the prevention and treatment of PONV. More than 20 percent reported they would administer it prophylactically, often as part of a multimodal regimen, to the laparoscopic and breast enhancement patients and the 7-year-old boy.

Despite research indicating that 5-HT3 receptor antagonists and dexamethasone are more effective for prophylaxis than metoclopramide, the poll suggests that outpatient practitioners commonly use metoclopramide prophylactically. A full 50 percent said they would use it for the laparoscopic and breast enhancement patients.

Underlying uncertainty
Despite their tendency to pre-treat aggressively, many outpatient practitioners remain unsure of the best way to approach PONV prophylaxis. Twenty-five percent said they are unsure if multimodal prophylaxis is the best approach for patients with multiple risk factors, and 23 percent said they are unsure if they should administer a higher dose of the same agent if the PONV prophylaxis doesn't work. This uncertainty is also reflected in widely variant practice patterns reported by our readers. Concluded one: "I'm not sure ... how much these medications help in preventing PONV. At times, it seems we just add another drug. Some just seem to make them more drowsy and, when awake, the patient is again experiencing PONV." Fortunately, PONV research is moving at a fast pace, and researchers continue to uncover answers to the complex question of how to prevent PONV most effectively.