Association of QTc Dispersion with Mortality, Intensive Care Unit (ICU) Admission, Intubation, and Hospital Stay Duration in Acute Methadone Poisoning

OBJECTIVE
The objective of this study is to investigate the prognostic significance of QTc dispersion (QTcd) in patients with acute methadone poisoning and its association with critical clinical outcomes, including mortality, Intensive Care Unit (ICU) admission, intubation, and hospital stay duration.

METHOD
A retrospective cross-sectional analysis was performed using medical records from 311 individuals who presented with acute methadone toxicity to the emergency department of [blinded for review] between March 20, 2023 and June 1, 2023. Eligibility was based on a confirmed record of methadone ingestion supported by a positive urine drug screen. To calculate QTcd, the longest and shortest corrected QT (QTc) intervals recorded across the 12-lead electrocardiogram (ECG) were identified, and their difference was taken. The final study population included 100 patients, categorized into prolonged QTcd (QTcd > 60 ms, n = 50) and non-prolonged QTcd (QTcd ≤ 60 ms, n = 50) groups.

RESULTS
This retrospective study included 100 consecutive patients with acute methadone poisoning. The mean QTcd was 64.26 ± 24.55 ms, significantly higher than in the normal population (P < 0.001). Comparison of the two groups revealed no meaningful variation in demographic factors, methadone intake, or time elapsed before Emergency Department (ED) admission (all P > 0.05). Pulse rate was notably higher among individuals with prolonged QTcd (P = 0.03), but there were no significant differences in other vital signs. Hospital stay duration, ICU admission (n = 8), need for intubation (n = 6), and mortality (n = 4) were comparable across both groups.

CONCLUSION
This study indicates that QTcd did not predict major clinical outcomes such as mortality, ICU admission, or intubation.