D104-09 Postoperative Delirium in a Lung Transplant Recipient: The Interplay of Polypharmacy and Primary Graft Dysfunction

Introduction Delirium is a frequent and multifactorial complication after lung transplantation, affecting up to 40% of recipients. Complex medication regimens—including immunosuppressants, opioids, antidepressants, and antimicrobials—can precipitate or exacerbate encephalopathy. Differentiating medication-induced delirium from infectious or ischemic etiologies is critical for timely intervention. This case describes severe postoperative delirium complicated by polypharmacy and early graft dysfunction. Case Description A 65-year-old woman with idiopathic pulmonary fibrosis and systemic lupus erythematosus underwent bilateral lung transplantation. Postoperatively, she received standard immunosuppression and antibiotic prophylaxis, along with home duloxetine and nortriptyline for depression and fentanyl for analgesia. She was extubated on postoperative day (POD) 1 but developed altered mental status and hypoxia, necessitating reintubation for presumed graft dysfunction (Figure 1). The following day, she developed fever (42.2 °C), tachycardia, and hypotension requiring vasopressors. Given concurrent renal dysfunction, broad-spectrum antibiotics were initiated for suspected sepsis. However, serotonin syndrome was also considered due to overlapping serotonergic medications, although the absence of clonus and hyperreflexia argued against it. Duloxetine, nortriptyline, trazodone, gabapentin, and fentanyl were discontinued. EEG demonstrated diffuse slowing and sharp waves consistent with delirium, and brain MRI was unremarkable. Cyproheptadine was trialed for possible serotonergic contribution. With discontinuation of the offending medications, her agitation and hyperthermia resolved, and mental status normalized. She was later discharged home with stable graft function. Discussion This case emphasizes the diagnostic complexity of delirium in lung transplant recipients. The interplay of sedatives, opioids, and antidepressants—combined with metabolic stress, infection risk, and ischemia—creates a high-risk environment for neurotoxicity. Early recognition of medication-related delirium requires a structured approach that includes medication reconciliation, EEG monitoring when available, and careful differentiation from infectious or ischemic causes. Minimizing polypharmacy, especially serotonergic and centrally acting agents, is key to preventing recurrence. This case highlights that individualized pharmacologic management and interdisciplinary collaboration can lead to rapid recovery and avoidance of prolonged mechanical ventilation or unnecessary interventions in the early postoperative period. This abstract is funded by: None