9 Impact of Methadone Initiation in Intubated Burn Patients: A Retrospective Review

Abstract

Introduction Methadone can be used to wean opiates and reduce length of mechanical ventilation (MV) in critical care and burn patients. The objective of this study was to assess the impact of methadone use on ventilator-free days and clinical outcomes in burned patients requiring MV. Methods This was a retrospective study of adult patients admitted to a burn center for initial management of burn injuries who required MV for at least 48 hours between September 2013 and November 2019. Patients were excluded from the study if they had prior methadone use, total body surface area (TBSA) of less than 5%, or expired within the first 28 days of admission. The primary endpoint was the difference in ventilator-free days among those who received methadone compared to those who did not. Secondary endpoints include length of stay, mortality, sedative agent and average daily dose, analgesic agent and average daily dose, and incidence of delirium. Baseline demographics were compared using descriptive statistics. Nominal data was compared using Chi-square test. Continuous data was analyzed using student’s t-test or Mann-Whitney U test, as appropriate. Multivariate regression was used to identify variables for possible association with MV duration. Results A total of 83 patients were included in the study; 52 received methadone and 31 were controls. Patients were generally well-matched between groups, however patients receiving methadone were younger (45.3 vs 56.2 years, p = 0.002) and had a larger TBSA (30.4 vs 19.1%, p = 0.001). Patients who received methadone had fewer ventilator free days of the first 28 (9.5 vs 15.0 days, p = 0.009) and a longer ICU stay (57.2 vs 35.8 days, p = 0.025). There was no difference between groups in terms of mortality, reintubations, and incidence of delirium. Patients who received methadone had longer duration of analgesia (20.7 vs 12.0 days, p = 0.011) and sedation (19.0 vs 12.4 days, p = 0.026) while on MV. Conclusions This study found that methadone use contributed to fewer ventilator-free days and longer ICU stays, which was unexpected but worth discussing. There are several limitations to this study. This study occurred during a time period in which the pain management and sedation strategies of this burn unit were evolving, and strategies may not have been consistent between providers. The study included a small sample size and baseline demographics demonstrated significant differences in age and TBSA between the two groups. Additionally, pain scores were not collected as part of this study, which would have provided better insight into the effectiveness of pain management. The use of methadone as an adjunct for pain control remains undetermined.