Abstract
AIM: In the post-operative period of cardiac surgeries, the majority of patients are admitted to the intensive care unit (ICU) for ongoing management, where delirium frequently occurs as a complication. However, the association between various analgesic regimens and the onset of postoperative delirium in ICU patients following cardiac surgery remains poorly understood. The present study employs a target trial emulation (TTE) framework to examine the effects of early postoperative pain management on the incidence of delirium in patients immediately admitted to the ICU after cardiac surgery. PATIENTS AND METHODS: Study participants were selected from the MIMIC-IV version 3.1 database, comprising 5356 adult patients who were admitted for the first time and underwent cardiac surgery, followed by immediate transfer to the intensive care unit (ICU). The TTE framework was applied, utilizing the clone-censor-weighting (CCW, refer to the Statistical Analysis section) method for data analysis. RESULTS: In this study of 5356 adult patients who underwent cardiac surgery and were immediately transferred (within 24 h post-surgery) to the intensive care unit postoperatively, in comparison with the morphine group, patients receiving fentanyl exhibited a significantly elevated risk of delirium within seven days postoperatively (hazard ratio [HR] = 1.69; 95% confidence interval [CI]: 1.41-1.95) and demonstrated an earlier onset of delirium. CONCLUSION: The findings of this study, conducted within a TTE framework, indicate that the utilization of fentanyl for pain management during the initial 24 h following cardiac surgery is associated with a higher incidence and earlier onset of postoperative delirium compared to morphine.