Simple Blood Tests May Be Able to Predict COPD Exacerbation Severity

There is a positive association between increased red blood cell distribution width (RDW) and chronic obstructive pulmonary disease (COPD), suggesting the importance of simple blood tests in predicting the severity of COPD exacerbation at the time of hospitalization.

The results of the retrospective study were published in the Journal of Personalized Medicine.

While the quantification of the severity of COPD exacerbations is typically made based on symptoms, physical signs, and response to therapy, "at present, there is no method for quantifying the severity of COPD exacerbations," the authors explained.

In the current study, the researchers aimed to investigate the relationship between complete blood count (CBC) parameters, including hemoglobin level, mean corpuscular volume (MCV), mean platelet volume (MVC), and RDW with COPD exacerbation severity. It was a single-center study conducted at a tertiary medical center in Northern Israel.

The study included a total of 1011 patients, aged 18 years and older, who had been diagnosed with COPD by The Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria and had been hospitalized with acute COPD exacerbation between January 1, 2012, and December 31, 2015. Of these patients, 207 were excluded for reasons such as malignancy, chronic inflammatory disease, and hematologic disease. After exclusion, 804 participants were included in the analysis.

The researchers measured the severity of COPD exacerbations using PaCO₂ levels, which were evaluated during hospitalization, as well as the length of hospital stay. Additionally, the researchers used variables: age, gender, Hemoglobin level, MCV, RDW, platelet count, mean platelet volume (MVP), PaCO₂, oxygen saturation, and C-reactive protein (CRP) as predictors of COPD exacerbation severity.

Multiple regression analyses showed that PaCO₂ during hospital stay was significantly higher in patients with MCV greater than 100 fL (62 mmHg) compared with patients with normal (56 mmHg) or low MCV (52 mmHg; all P < 0.001, respectively), and in patients with RDW above 15 fL compared with patients with normal RDW (58 mmHg vs 53 mmHg; P < 0.001).

Additionally, a multiple regression analysis found high RDW and CRP levels were associated with increased hospital stay. Patients with RDW greater than 18 fL were more likely to have an increased stay of 7.5 days, compared with 5.9 days among patients with RDW levels between 14 and 18 fL, and 5.1 days for patients with RDW less than 14 fL (P < .001). Patients with elevated CRP levels had significantly longer hospital stays compared with patients with normal CRP level (6.1 days v 4.5 days; P < .001).

The findings of this study support previous research that RDW can preduct prognosis in COPD by identifying a positive correlation between RDW and CRP levels.

The researchers acknowledge some limitations to their study, including missing data, the availability of measurements only being at baseline, and not evaluating a correlation between CBC parameters and respiratory tract infections.

Despite limitations the researchers believe this study suggest how using simple blood tests can be used for early predicting severity of COPD exacerbations within a hospital setting, for “it proved that inexpensive and simple laboratory parameters can be considered as biomarkers of the severity of COPD exacerbation, and their use to escalate the treatment of COPD exacerbation should be further investigated,” wrote the researchers.

Reference

Saad E, Maamoun B, Nimer A. Increased red blood cell distribution predicts severity of chronic obstructive pulmonary disease exacerbation. Journal of Personalized Medicine. 2023;13(5):843. doi:10.3390/jpm13050843