Abstract Introduction In patients with hematologic malignancies, infectious complications and drug-induced toxicities frequently coexist, complicating diagnostic and therapeutic decisions in the intensive care unit (ICU). Tyrosine kinase inhibitors (TKIs), such as dasatinib, have transformed chronic myeloid leukemia (CML) management but carry well-documented risks of pleural effusions, interstitial lung disease, and cytopenias. These toxicities may clinically and radiographically mimic infection. Immunocompromised hosts are simultaneously predisposed to severe bacterial infections, including polymicrobial bacteremia and intra-abdominal abscesses. Differentiating infectious from TKI-related pulmonary or systemic toxicity remains a critical challenge in critical care hematology. Case Summary A 77-year-old man with atypical chronic myeloid leukemia (aCML), transfusion-dependent anemia, chronic thrombocytopenia, and heart failure with reduced ejection fraction presented with acute hypoxic respiratory failure and systemic decompensation shortly after transitioning to dasatinib. Laboratory evaluation revealed marked leukocytosis (WBC 166 × 109/L), severe anemia (Hb 5.5 g/dL), thrombocytopenia (27 × 109/L), lactic acidosis, and acute kidney injury. Chest imaging demonstrated bilateral interstitial opacities and pleural effusions, initially raising concern for dasatinib-induced pulmonary toxicity versus infection. Blood cultures grew Enterobacter cloacae and Enterococcus faecium, suggesting a gastrointestinal or portal venous source. Abdominal CT revealed splenomegaly with a wedge-shaped hypodensity and intraparenchymal gas, consistent with an infected splenic infarct. Dasatinib was held during the initial evaluation but later resumed once infection was confirmed as the primary driver of decompensation. The patient was managed with intravenous ertapenem and daptomycin, renal dose adjustments, cautious diuresis, and red cell transfusions. Severe thrombocytopenia precluded invasive drainage. Clinical status improved with partial recovery of renal and respiratory function. Palliative care was engaged for advanced care planning given frailty and anticipated prolonged therapy. Discussion This case underscores the diagnostic complexity of concurrent infectious and drug-induced complications in immunocompromised patients. Dasatinib-associated pulmonary toxicity can closely mimic infectious pneumonia, and in critically ill hematology patients, polymicrobial bacteremia often indicates concealed intra-abdominal infection. Early multidisciplinary collaboration among hematology, infectious diseases, and critical care teams is essential. Adherence to antimicrobial stewardship principles and individualized dosing are crucial, particularly in the setting of renal dysfunction and polypharmacy. Recognition of infected splenic infarction as a source of sepsis is vital in immunocompromised hosts, as prompt diagnosis and targeted therapy can be lifesaving. This abstract is funded by: none
Abdulle et al. (Fri,) studied this question.