Neutropenia May Increase ARDS Risk in Critically Ill Patients Admitted to ICU

In critically ill patients admitted to the intensive care unit (ICU), the presence of neutropenia was associated with an increased risk of acute respiratory distress syndrome (ARDS), according to study results published in American Journal of Respiratory and Critical Care Medicine. Researchers also found that the presence of neutropenia was associated with a higher risk of mortality among critically ill patients with ARDS in the ICU.

The study was an analysis of prospectively collected data of critically ill patients who were enrolled in 3 ongoing ICU cohorts at the New York-Presbyterian-Weill Cornell Medicine in New York City, New York; Brigham and Women’s Hospital in Boston, Massachusetts; and Asan Medical Center in Seoul, South Korea. Patient-level data from 6 Acute Respiratory Distress Syndrome Network (ARDSNet) trials were also assessed.

Neutropenia, defined as a total white blood cell count of less than 1.0×10³ cells/μL, was determined at day 0. The primary outcome in the analysis of the 3 ICU cohort trials was the association between neutropenia and risk of ARDS, whereas the primary outcome for the analysis of the ARDSNet trials was the association between neutropenia and 60-day mortality.

In the analysis of the ICU cohorts, approximately 7.1% (n=87) of the 1229 enrolled critically ill patients had neutropenia at admission. The rate of nonpulmonary sepsis was higher in patients with neutropenia (62.1% vs 34.6%; P <.001). Additionally, ARDS developed in a higher proportion of patients with neutropenia compared with patients without neutropenia (28.2% vs 17.3%, respectively). In the adjusted analysis, neutropenia was significantly associated with the development of ARDS (odds ratio, 2.48; 95% CI, 1.43-4.22; P <.001).

Approximately 4.7% (n=204) of the 4333 patients with ARDS in the ARDSNet trials had neutropenia. A significantly higher proportion of patients with neutropenia and ARDS had nonpulmonary sepsis (27.5% vs 21.1%; P =.039). In the adjusted analysis, neutropenia was significantly associated with 60-day mortality in patients with ARDS (hazard ratio [HR], 1.38; 95% CI, 1.10-1.73; P =.005). This association dissipated in a post hoc analysis adjusted for interleukin 6 levels (HR, 1.41; 95% CI, 0.86-2.32; P =.171).

Limitations of these analyses included the lack of relevant confounders, including transfusion and net fluid balance data, as well as the lack of data on whether treatment with granulocyte colony-stimulating factor was used in these cohorts.

The investigators concluded “that neutropenia is associated with development of ARDS among critically ill patients and with higher mortality among patients with ARDS.”

Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.

Reference

Price DR, Hoffman KL, Oromendia C, et al. Effect of neutropenic critical illness on development and prognosis of acute respiratory distress syndrome. Published online September 28, 2020. Am J Respir Crit Care Med. doi:10.1164/rccm.202003-0753LE