The relationship between patient risk factors and early versus late postoperative emetic symptoms

Postoperative nausea and vomiting (PONV) remain common complications after elective surgery. Prophylactic antiemetic drugs are frequently administered to patients with well known risk factors for developing PONV. We designed this prospective observational study to assess the relationship between common patient risk factors for developing PONV and the occurrence of early (0-24 h) versus late (24-72 h) emetic symptoms.

One hundred thirty patients undergoing elective laparoscopic (n = 88) or plastic (n = 42) surgery were assigned a risk score for developing PONV based on the Apfel risk scoring system, which assigns one point each for female gender, nonsmoking status, history of PONV or motion sickness, and postoperative opioid use. It was assumed that all patients would receive an opioid analgesic in the postoperative period. The patients received 0, 1, 2, or 3 antiemetic drugs for prophylaxis. The occurrence of nausea, vomiting, and need for rescue antiemetics was assessed at specific time intervals from 0 to 6, 6-24, and 24-72 h after surgery. In addition, the impact of PONV on recovery of normal activities of daily living was assessed using a standardized patient questionnaire.

One or more prophylactic antiemetics were administered to 87%, 90%, and 95% of the patients in the two, three, and four Apfel risk-factor groups, respectively. In the presence of three or four risk factors, >/=2 antiemetics were administered to 56% and 75% of the patients, respectively. Vomiting was reported in 11% and 22% of patients in the three and four risk factor groups compared with 6% in the two risk factor group at 0-6 h, and 13% and 27% (vs 0%) at 6-24 h, respectively. However, in the 24-72 h postoperative period, the incidences of emesis were low and did not differ in the three risk groups (9%, 5%, and 11%, respectively). The occurrence of moderate-to-severe nausea was increased in the higher risk groups at 0-6 h and 6-24 h (19%-28% vs 6% and 20%-30% vs 9%, respectively). However, the incidences of nausea in the 24-72 h period in the three and four risk factor groups were not different from the two-risk factor group (5% and 8% vs 6%, respectively). The need for rescue antiemetics and interference of emetic symptoms with normal activities was greater in the four risk factor group compared with the two and three risk factor groups.

Despite the frequent use of multiple antiemetic drugs for prophylaxis, an Apfel risk score of three or four (vs 2) was associated with a higher incidence of emetic sequelae in the first 24 h after surgery. However, the occurrence of late (24-72 h) emetic symptoms was low and appeared to be unrelated to the patient's Apfel risk score.