229 The Relevance of Hydromorphone-Induced Euphoria Among Emergency Department Patients With Acute Abdominal Pain

Abstract

Nearly 12 million patients present to US emergency departments (ED) annually with abdominal pain. Intravenous (IV) opioids are often used to treat this pain. While common opioid side effects such as pruritis, nausea, and respiratory depression have been well studied, only scant data on opioid-induced euphoria have been reported. Opioid-induced euphoria is important to understand because it contributes to long-term opioid sequelae such as return visits to the ED and addiction. The goal of this study was to measure euphoria in patients with acute abdominal pain and to determine whether patients can distinguish euphoria from relief of pain. This was a planned analysis of data from a randomized study of hydromorphone vs lidocaine for acute abdominal pain. Adults ≤65 years old with ≤ 7 days of severe abdominal pain were included. Severe was defined as warranting the use of IV opioids, as determined by the attending physician. Exclusion criteria were contraindications or allergy to either medication, chronic pain, and recent use of opioids. Patients were randomized in a 1:1 ratio to 120 mg of IV lidocaine or 1 mg of IV hydromorphone, administered as drip over 10 minutes. To assess euphoria, subjects were asked 15 minutes later to provide a 0-10 response to each of the following questions: 1) How good did the medication make you feel? 2) How high did the medication make you feel? 3) How happy did the medication make you feel? and 4) How much would you like to get the medication again? These questions were validated in previous work conducted in healthy volunteers and substance abusers without pain. Pain scores at baseline and 60 minutes were also measured. We report data as means (SD) with 95% CI. To determine the relative importance of relief of pain versus type of medication, we built 4 linear regression models in which each euphoria question was the dependent variable and relief of pain and type of medication were the independent variables. 154 patients were enrolled. 77 received lidocaine and 77 hydromorphone. Lidocaine pain scores improved by 3.6 (SD: 2.8), hydromorphone by 5.1 (SD: 2.8) (95% CI for difference of 1.5: 0.6, 2.4). On the 0-10 feeling good scale, lidocaine patients reported a mean of 4.8 (SD: 3.2), hydromorphone 6.7 (SD: 3.6) (95% CI for difference of 1.9: 0.8, 3.0). On the 0-10 feeling high scale, lidocaine patients reported a mean of 3.4 (SD: 3.4), hydromorphone 4.9 (SD: 3.6) (95% CI for difference of 1.5: 0.4, 2.7). On the feeling happy scale, lidocaine patients reported a mean of 3.4 (SD: 3.3), hydromorphone 5.1 (SD: 3.7) (95% CI for difference of 1.7: 0.6, 2.8). On the use again scale, lidocaine patients reported a mean of 5.4 (SD: 3.5), hydromorphone 7.3 (3.3) (95% CI for difference of 1.9: 0.8, 3.0). In the feel good regression model, the β coefficient for pain improvement was 0.27 (p<0.01); for medication it was 0.20 (p=0.01). In the feel high model, the β for pain improvement was 0.20 (p=0.02); for medication it was 0.17 (p=0.04). In the happy model, the β for pain improvement was 0.28 (p <0.01); for medication it was 0.17 (p=0.04). In the use again model, the β for pain improvement was 0.32 (p<0.01); for medication it was 0.19 (p=0.02). Among ED patients with acute abdominal pain, hydromorphone-induced euphoria is a measurable phenomenon, but it was generally less important for patients than relief of pain.