Haloperidol effects on perioperative changes in QTc-duration: A prospective in-hospital study

Introduction.- Haloperidol may prolong QTc-interval, but is often prescribed peri-operatively to hip-fracture patients, who have several risk factors for QTc-prolongation. We aimed to determine (1) how QTc-duration changes perioperatively, (2) whether low-dose haloperidol use influences these changes, and (3) the associations between clinical variables and potentially dangerous QTc-prolongation. Design.- Prospective cohort study in a tertiary university teaching hospital. Participants: 89 patients (mean age 89 years, 24% male), enrolled in the MAPLE-trial (RCT of melatonin versus placebo on the occurrence of delirium in hip-fracture patients). Measurements: ECGs were made before and after hip surgery, 39 patients were treated with haloperidol. QTc-duration was measured by hand, blinded for haloperidol and pre-/post-surgery status. Mixed model analysis was used to estimate changes in QTc-duration. Logistic regression analysis was used to determine risk factors for potentially dangerous QT-prolongation (increase by > 50ms or to > 500 ms). Results.- Patients with normal pre-surgery QTc-duration had a significant increase (mean 12 ms,SD28) in post-surgery QTc-duration. A significant decrease (mean 19 ms, SD 34) occurred in patients with prolonged pre-surgery QTc-duration. Haloperidol use did not influence the course of changes in QTc-duration (P = 0.351). Potentially dangerous QTc-prolongation (n = 8) was not associated with measured risk factors. Conclusion.- QTc-duration changed differentially, increasing in patients with normal, but decreasing in patients with abnormal baseline QTc-duration. Potentially dangerous QTc-prolongation was not associated with haloperidol use or other risk factors. In conclusion, low-dose oral haloperidol did not affect perioperative QTc-interval.