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). Methods We conducted a retrospective chart review of patients admitted to our facility with a respiratory complaint and a diagnosis of COPD to examine the relation between PCT and disease severity. A total of 156 unique encounters were reviewed, with 87 included in the final data set. Data was collected on baseline medical conditions as well as clinical status at the time of presentation. Primary endpoints included the need for overnight ICU admission, hospital length of stay greater than seven days, and repeat visit within 30 days of discharge. Secondary endpoints included the need for intubation at the time of admission, in-hospital mortality or discharge to hospice, and ICU length of stay. Results Patients with elevated PCT levels (>0.25ng/mL) had a significantly increased likelihood of a need for ICU admission (odds ratio 3.18) and hospital length of stay greater than seven days (odds ratio 3.38). There was no statistically significant difference in the Emergency Department readmission rate or any of the secondary outcomes. Conclusions Our data suggests that PCT may be a useful early biomarker for patients with COPD presenting with an acute respiratory illness.