Gender differences in narcotic-induced emesis in the ED.

Narcotic analgesia is commonly given in the emergency department. Narcotic-induced nausea and vomiting is thought to be a common occurrence, but the gender incidence and associations are not well defined. The aim of this study was to document the sex-related complication of nausea and vomiting after opiate administration for pain relief in the ED. The study hypothesis was that men and women have the same rate of narcotic-induced emesis in the ED. A prospective, convenience study of the use of narcotic analgesic on patients in an innercity Level I Trauma Center was undertaken. Information concerning the reason for narcotics, complications, number of doses, and route of administration were studied. The emergency physicians were allowed clinical judgment to treat the patients with any narcotic agent in any dose increment. The data were entered into an SPSS program (Chicago, IL). Analysis between groups (men v women) was then conducted by an independent t test. We compared the 2 groups across 6 categories: cause of injury, presenting pain scale, first drug given, first dose given, first route of drug, and requires an anti-emetic. A Bonferroni procedure was used to correct for the higher probability of significant findings when multiple tests were performed. All findings that are significant are after Bonferroni. The study was Institutional Review Board (IRB) approved. A total of 325 consenting patients were studied from October 1996 to April 1998. The patients consisted of 174 men and 151 women, with an average of 35.8 years of age. The race of the patients was 70% African American and 20% Hispanic. Of the total of 325 patients, 20.3% (74) required an anti-emetic because of nausea and/or vomiting. A significant difference occurred in causes of pain for women (t = 2.79, P <.007). The causes of pain for women were general pain, fracture, abdominal, back pain, and other as compared with men with gun shot wounds, general, fracture, low back, and flank. Women showed no significant difference with regard to presenting pain scale (t =.122, P <.903), first drug given (t = 1.643, P <.101), and first dose given (t =.708, P <.408). The majority of patients received morphine (55.4%), followed by meperidine (24.3%), and hydrocodone (13.5%). The most frequent route of administration was intravenous (IV, 45.2%), intramuscular (IM, 35.7%), with oral being the least frequent route (19.1%). There was a difference for women with first route given (t = 2.543, P <.01) and requires anti-emetic (t = 3.06, P <.002). The majority of women received IM (58.6%) versus IV (37.7%), whereas the majority of men (62.3%) received IV versus IM (41.4%). A significant number of patients became nauseated and/or vomited from Emergency Department-administered narcotics. The nausea and vomiting was associated with female sex and the cause of pain. A comparative study of other pain medications versus narcotics for incidence of induced nausea and emesis would be useful.