Surrogate scale for evaluating respiratory function based on complete blood count parameters.

BACKGROUND

In this study, we aimed to identify a simple method for evaluating respiratory function using complete blood count parameters.

METHODS

The complete blood count parameters, including red blood cell (RBC) count, hemoglobin (Hb) level, lymphocyte (Lym) and platelet (Plt) count, and partial pressure of oxygen (PO2 ) level, were measured using automated analyzers in patients with chronic obstructive pulmonary disease (COPD), aged subjects, and young subjects (control group). The red cell index (RCI) was calculated using the following equation: (RBC × Hb)/(Lym × Plt); in theory, the RCI is inversely proportional to the respiratory function.

RESULTS

We observed a significant relationship between the RCI and PCO2 values, and between the RCI and FEV1/FVC values (P < .05). The RCI in the COPD, and aged subject groups were all significantly higher than that in the control group (P < .05). The cutoff value for normal respiratory function was 2.3. The positive rates for an abnormal increase in RCI were also considerably higher in each observation group than in the control group (P < .05).

CONCLUSION

The RCI can be considered as a simple and effective tool for evaluating respiratory function.