Delirium in patients undergoing hematopoietic stem cell transplantation

Delirium is common in patients with malignant disease and is associated with significant morbidity. Studies have not examined the epidemiology of delirium in patients undergoing hematopoietic stem cell transplantation (HSCT). The objectives of this study were to determine the prevalence, incidence, severity, and duration of delirium in the acute phase of HSCT and to determine the pretransplantation risk factors for the occurrence and severity of delirium during this period.

Ninety adult patients with malignancies who were admitted to the Fred Hutchinson Cancer Research Center for their first HSCT were assessed prospectively from 1 week pretransplantation to 30 days posttransplantation. Delirium occurrence using the Delirium Rating Scale (DRS) and severity using the Memorial Delirium Assessment Scale (MDAS) were assessed three times per week. Pretransplantation risk factors were assessed by patient self-report, charts, and computerized records.

The cumulative posttransplantation incidence of delirium events (DRS score > 12) was 66 (73%), and the incidence of delirium episodes (DRS score > 12 for 2 of 3 consecutive assessments) was 45 (50%). The mean +/- standard deviation duration of delirium episodes was 4.8 +/- 2.8 assessments (approximately 10 days). Pretransplantation risk factors for having a delirium episode were lower cognitive functioning (Trailmaking B test [a standardized test of visual conceptual and visuomotor tracking and cognitive flexibility]; P = 0.0008), higher blood urea nitrogen (P = 0.002), higher alkaline phosphatase (P = 0.008), lower physical functioning (SF-12 [self report questionnaire that is a general measure of functioning]; P = 0.03), and higher magnesium (P = 0.03). Pretransplantation risk factors for higher delirium severity scores were higher creatinine (P < 0.0001), the presence of total body irradiation (P = 0.0001), higher magnesium (P = 0.0003), lower Mini-Mental State Examination score (P = 0.002), malignancy diagnosis category (P = 0.002), female gender (P = 0.008), higher alkaline phosphatase (P = 0.02), older age (P = 0.03), and prior alcohol or drug abuse (P = 0.046).

Half of patients who undergo HSCT experience a delirium episode during the 4 weeks posttransplantation. Pretransplantation risk factors can assist in identifying patients who are more likely to develop delirium posttransplantation.