Adverse drug events resulting in admission to the intensive care unit in oncology patients: Incidence, characteristics and associated cost

Purpose: Describe the incidence, characteristics and cost of adverse drug events that necessitate admission to the intensive care unit in oncology patients. Methods: This was a prospective observational 5-months study at a medical/surgical intensive care unit of a comprehensive teaching cancer center. Patients admitted to the intensive care unit were screened to determine whether the admission was due to an adverse drug event. The adverse drug events were characterized based on the suspected medication, system involved and preventability. Patient demographics, length of stay, mortality and the total patient charges during their intensive care unit stay were recorded. Results: During the study period, 249 patients were screened and an adverse drug event was the primary cause of 57 (22.9%) admissions. The most common medications associated with an adverse drug event requiring intensive care unit admission were antineoplastics (n = 37), analgesics (n = 9) and anticoagulants (n = 4). Ten adverse drug events were considered preventable. The average length of stay for patients with adverse drug events resulting in intensive care unit admission was 6.2 days ±9.8 (SD) and the mortality rate was 28.1%. Hematological malignancy was independently associated with adverse drug events resulting in intensive care unit admission. The average patient charges for the intensive care unit stay was US$11,692 ± 17,529 (SD), which corresponded to about US$1.5 million in annual patient charges for a 12-bed intensive care unit at a cancer institution. Conclusions: Adverse drug events resulting in intensive care unit admission in oncology patients are common and often associated with significant morbidity, mortality, and cost.