Opioid analgesia for acute abdominal pain in the elderly: Is the diagnosis of gallbladder pathology hindered?

Abstract

Study objectives: Inadequate treatment of acutely painful conditions is a widespread problem in emergency department (ED) settings. Recent literature has suggested that this problem is even more pronounced in elderly populations, where fear of side effects or masking underlying pathology may dissuade clinicians from properly treating pain. The assessment of undifferentiated abdominal pain in the elderly can be difficult, and some evidence exists demonstrating that classical physical examination findings such as the sonographic Murphy sign are unreliable in this population. This study sought to assess the effects of opioid analgesia on the ability of the sonographic Murphy sign to detect acute gallbladder disease (cholecystitis or cholelithiasis) in an elderly population. Methods: A retrospective, consecutive-sample study of 119 adult ED patients (in a Level I trauma center, ED census 70,000) receiving right upper quadrant ultrasonography in 2002 was undertaken. Age, sex, final diagnosis, and timing of opioid analgesia administration were documented. Logistic regression analysis with odds ratio (OR) and 95% confidence intervals (CIs) was used to compare patients older and younger than 65 years and who received opioid analgesia before ultrasonography with those who did not. Final ED or hospital diagnosis and 2-week follow-up was used as the criterion standard, and the negative predictive value of the sonographic Murphy sign for gallbladder disease was calculated. Results: The medical record review included 119 patients (73 female, mean age 49 years). Opioid analgesia was administered before ultrasonography in 25 patients (21%). Gallbladder disease was diagnosed in 43 patients (36%). Sonographic Murphy sign was positive in 30 patients (25%). There were 32 patients (27%) older than 65 years. Compared with younger adults, adults older than 65 years were no less likely to receive opioid analgesia (OR 1.07, 95% CI 0.40 to 2.88, P =.89). There was no association between age older than 65 years and the likelihood of a false negative sonographic Murphy sign (OR 1.74, 95% CI 0.62 to 4.93, P =.29). For patients older than 65 years, no association was found between receiving opioids and a false negative sonographic Murphy sign (OR 1.42, 95% CI 0.46 to 4.44, P =.55). Conclusion: This study found a high rate of inadequate analgesia for acute abdominal pain that is consistent with previous reports. No difference was found in the rate of opioid analgesia administration in the elderly subgroup, in contrast with studies demonstrating a bias against adequate analgesia in this population. In addition, ultrasonography and the sonographic Murphy sign were found to be no less accurate in the elderly, even when premedicated with opioid analgesia. This finding runs counter to limited evidence previously published and should be further investigated using a prospective model.