Study of Haloperidol for Abdominal Pain in the Emergency Department (SHAPE)

INTRODUCTION: Intravenous haloperidol has been shown to decrease milligram morphine equivalents (MME) of analgesia and reduce hospital admissions for diabetic gastroparesis. The objective of this study was to evaluate whether haloperidol decreases MME for the treatment of non-specific abdominal pain diagnoses in the emergency department (ED), including gastroparesis, cyclic vomiting, cannabinoid hyperemesis syndrome, and unspecified abdominal pain. The primary outcome compared the difference in MME between encounters. Secondary outcomes included admission rate, pain scores, length of stay, rescue therapy administration, and adverse effects. METHODS: This retrospective chart review included patients ≥ 18 years old who presented to the ED. Patients must have had ≥ 2 ED encounters for abdominal pain, one in which they received conventional therapy with opioids (C-encounter), and the other in which they received haloperidol (H-encounter). Agitated patients were excluded. Seventy-five patients were needed to detect a 3 MME difference with 80% power and two-sided alpha of 0.05. RESULTS: We analyzed 107 patients with self-matched encounters. The median dose of haloperidol administered was 5.0 milligrams (mg) (interquartile range [IQR] 2.0 – 5.0). C-encounters had significantly more MME administered than H-encounters (median 5.7 mg [IQR 4.0 – 8.0] vs 0.0 mg [IQR 0.0 – 2.5], P < 0.001). These results remained significant despite route of haloperidol administration. C-encounters had higher rates of rescue therapy administration than H-encounters, (56% vs 33.6%, P < 0.001). There were higher rates of ketorolac administration in the H-encounter (P = 0.02). CONCLUSION: Encounters in which patients received haloperidol and ketorolac for abdominal pain had a statistically significant reduction in MME administered and lower rates of rescue therapy administration than encounters in which patients were treated with opioids.