Changing Opioid Use for Right Lower Quadrant Abdominal Pain in the Emergency Department

Abstract

To compare the use of opioid analgesia in the treatment of emergency department patients with acute right lower quadrant (RLQ) abdominal pain between 1998 and 2003 and to explore the relationship between opioid use and abdominal computed tomography (CT) scanning. This was a retrospective cohort study of patients presenting in 1998 and 2003 to an urban emergency department with a triage complaint of RLQ pain. The authors abstracted use and timing of abdominal CT scanning and opioid analgesia. Other predictor variables were patient demographics. Risk ratio for receiving opioids with CT scan versus without CT scan, stratifying by year, were calculated. Proportional-hazards analysis was used to control for time in the emergency department. Of the 187 patients seen in 1998, 38 (20%) underwent CT scanning and 43 (23%) received opioids. Of the 137 patients seen in 2003, 77 (56%) underwent CT scanning and 72 (53%) received opioids. In 1998, the risk ratio for receiving opioids in patients who underwent CT scanning (vs. without) was 3.7 (95% confidence interval [CI] = 2.3 to 6.1); in 2003, it was 1.5 (95% CI = 1.0 to 2.1). Opioids were overwhelmingly given before CT scanning in those patients who received both (81% in 1998 and 98% in 2003). The mean time to administration of the first opioid dose in 1998 was 155 minutes and in 2003 was 94 minutes. The proportional-hazards analysis confirmed a strong association between CT scanning and opioid administration in 1998 (relative hazard, 2.7; 95% CI = 1.5 to 5.1) and substantial attenuation of the association in 2003 (relative hazard, 1.3; 95% CI = 0.8 to 2.1). The hospitalization rate was not significantly different in 2003 (33%) versus 1998 (27%) (p = 0.28). The risk ratio of receiving opioids in admitted patients was 2.8 (95% CI = 1.7 to 4.6) in 1998 and 2.0 (95% CI = 1.5 to 2.7) in 2003. Opioid administration to patients with RLQ pain has dramatically increased between 1998 and 2003. During these five years, the number of patients receiving opioids more than doubled and the time to first administration of opioids decreased by one hour. The authors show that this cannot be attributed to an increased use of CT scanning.