PURPOSE: Calculating alveolar arterial gradient (A-a gradient) is widely used in assessing different acute lung diseases. Few studies evaluate the use of calculated A-a gradient in chronic lung diseases. study the correlation between calculated and measured Diffusion Lung Capacity for Carbon Monoxide (DLCO).
METHODS: In retrospective study, we collected data for 121 patients who had pulmonary function test (PFT) and blood gas analysis (ABG), done at our pulmonary function laboratory. Each patient had both test done within seven days, and ABG done at room air. We studied the correlation between calculated A-a gradient from ABG, and measured DLCO(As percent of predicted) in PFT.
RESULTS: Out of 121 patients - 62 (51%) were females and 59 (49%) were males. Their mean age was 54.75 year, and mean body mass index (BMI) was 32. Smoking history was positive in 58 patients (48%), and negative in 63 patients (52%). Mean DLCO value (as percent of predicted) was 61.41%, and mean A-a gradient value was 23.82. Correlation analysis showed Pearson correlation of -0.183 with significance value of 0.044.
CONCLUSION: There is a statistically significant negative correlation between calculated A-a gradient and measured DLCO.
CLINICAL IMPLICATIONS: Calculating A-a gradient may be as helpful as measuring the DLCO in assessing the severity and monitor the progression of different lung diseases.
DISCLOSURE: Fadi Hammoudeh, No Financial Disclosure Information; No Product/Research Disclosure Information