Epidemiology and Outcomes of Hospitalized Patients with Hematological Malignancy and Acute Respiratory Failure.

INTRODUCTION Patients with hematologic malignancies are at increased risk for acute respiratory failure (ARF), which is a leading cause of intensive care units admission and mortality in this population. This study aimed to characterize the epidemiology, clinical outcomes, and healthcare utilization associated with ARF in hospitalized patients with hematologic malignancies, using a nationally representative dataset. METHODS We conducted a retrospective cohort study using the 2016-2019 National Inpatient Sample. Adult hospitalizations with hematologic malignancies were identified using International Classification of Disease, Tenth Revision, Clinical Modification codes and stratified by presence of ARF and by use of invasive mechanical ventilation (IMV). RESULTS Among 2,427,924 hospitalizations for hematologic malignancies, 304,515 (12.5%) had ARF. Compared to non-ARF admissions, admissions with ARF were older, with a mean age of 70.1 versus 65.9 years, had more comorbidities, with 61.1% having a Charlson comorbidity index greater than 3 compared to 40.9%, and experienced higher rates of sepsis (71.6% vs. 38.3%) and acute kidney injury (AKI) (43.5% vs. 20.1%). In-hospital mortality among admissions with ARF was 22.7% compared to 2.2% in those without ARF. These admissions also had longer hospital stays (10.95 days vs. 6.58 days) and incurred higher hospital costs ($37,645 vs. $19,505). Among admissions with ARF, 84,260 (27.7%) required IMV. This subgroup had the highest mortality at 49.7%, a mean length of stay of 16.3 days, and incurred the highest hospital costs at $69,923. IMV use was also associated with higher complication rates, including sepsis (80.4%) and AKI (62.4%). Increased age, AKI, and neutropenia were independent predictors of in-hospital mortality among admission with hematological malignancies who required invasive mechanical ventilation. CONCLUSION ARF affects more than one in 10 hospitalized patients with hematologic malignancies. Although improved compared to historical data, it remains linked to increased mortality and healthcare utilization, particularly among those requiring IMV. These findings highlight the need for early risk stratification and targeted interventions to improve outcomes in this high-risk population.