Measurement of Procalcitonin as an Indicator of Severity in Patients With Chronic Obstructive Pulmonary Disease Admitted With Respiratory Illness.

Introduction Exacerbations of chronic obstructive pulmonary disease (COPD) are a frequent reason for hospital admission and a major cause of morbidity and mortality. A useful biomarker or indicator of disease severity at the time of presentation could help guide treatment and identify those with poor prognosis who need early aggressive intervention. We hypothesized that patients who present to the hospital with COPD exacerbations who are found to have elevated procalcitonin (PCT) levels will have worse outcomes such as longer admissions, increased intensive care unit (ICU) utilization, and more frequent readmissions than those with normal levels, regardless of presence or absence of infiltrate on initial chest X-ray (CXR).