Pre- and Post-Transplantation Risk Factors for Delirium Onset and Severity in Patients Undergoing Hematopoietic Stem-Cell Transplantation

Purpose To determine pre- and post-transplantation risk factors for delirium onset and severity during the acute phase of myeloablative hematopoietic stem-cell transplantation (HSCT). Patients and Methods Ninety adult patients with malignancies admitted to the Fred Hutchinson Cancer Research Center for their first HSCT were assessed prospectively from 1 week before transplantation to 30 days after transplantation. Delirium was assessed three times per week using the Delirium Rating Scale and the Memorial Delirium Assessment Scale. Potential risk factors were assessed by patient self-report, charts, and computerized records. Multivariable analysis of time to onset of a delirium episode was undertaken using Cox proportional hazards regression with time-varying covariates. Analysis for delirium severity was carried out using a linear mixed effects model. Validation and sensitivity analyses were performed on the final models. Results Forty-five patients (50%) experienced a delirium episode. Pretransplantation risk factors for onset and higher severity of delirium were higher mean alkaline phosphatase and blood urea nitrogen (BUN) levels. Poorer pretransplantation executive functioning was also associated with higher delirium severity. Higher doses of opioid medications were the only post-transplantation risk factor for delirium onset (hazard ratio, 1.05; 95% CI, 1.02 to 1.08). Higher opioid doses, current and prior pain, and higher BUN levels were post-transplantation risk factors for greater delirium severity (all P<.01). Conclusion Pre- and post-transplantation factors can assist in identifying patients who are at risk for delirium during myeloablative HSCT and may enable clinical interventions to prevent delirium onset or decrease delirium symptoms. J Clin Oncol 29: 895-901. (C) 2011 by American Society of Clinical Oncology