LONDON – An elevated red blood cell distribution width predicted poor outcomes from community-acquired pneumonia in a retrospective analysis of more than 3,000 adult patients.
Red blood cell distribution width (RDW) is routinely measured as a check for anemia, but there have been several previous reports that the marker predicts poor outcome in a variety of conditions, including heart failure and sepsis. "It’s used in hematology, but it proves to be an outstanding marker of adverse outcome in some very important diseases of internal medicine. ... We found it actually works in community-acquired pneumonia [CAP] as well," Dr. Eyal Braun said in an interview at the European Congress of Clinical Microbiology and Infectious Diseases.
Dr. Eyal Braun
Last year, Dr. Braun and his associates at Rambam Health Care Campus, Haifa, Israel, reported that among 637 CAP patients aged 60 years and younger, elevated RDW levels on admission were associated with significantly higher rates of mortality and severe morbidity (Crit. Care 2011;15:R194).
The current study looked at the overall general population of internal medicine wards, comprising a total of 3,815 patients aged 18 years and older seen between Jan. 1, 2005, and Dec. 31, 2010. The patients had a mean age of 69.6 years, and 56% were men.
In the multivariate analysis, factors associated with mortality at 90 days were age greater than 80 years, a high Charlson comorbidity index (above 7), a bloodstream infection (BSI), a blood urea nitrogen (BUN) level greater than 30 mg/dL, an abnormal white blood cell (WBC) count, a systolic blood pressure less than 90 mm Hg, and an elevated RDW greater than 15% (odds ratio, 2.1). Variables associated with complicated hospitalization included a high Charlson comorbidity index, an abnormal WBC count, a BUN greater than 30 mg/dL, a hemoglobin level less than 10 g/dL, a BSI on admission, and an elevated RDW (OR 1.5), Dr. Braun reported in a poster.
The rates of mortality and complicated hospitalization were significantly higher among patients with an increased RDW, regardless of the WBC count or hemoglobin levels, he and his associates found.
In the interview, Dr. Braun said that an elevated RDW might help identify which patients who present with CAP need to be admitted to the hospital. Despite many existing scores aimed at identifying increased risk among CAP patients, "people are still dying from CAP. ... The bottom line is mortality from CAP is still high."
Dr. Braun stated that he has no relevant financial disclosures.