Correlation between FEVI (Forced Expiratory Volume in First Second) and Pulmonary Arterial Pressure among Patients of Chronic Obstructive Pulmonary Disease
Background: To determine the relationship of
Forced Expiratory Volume in first second (FEV1)
with pulmonary arterial pressure among patients
with chronic obstructive airway disease.
Methods: In this cross sectional study 276
patients, using -0.17 correlation between FEV1 and
pulmonary artery pressure with 95% confidence
level and 80% power of test, were enrolled . All
patients 40 years or above, diagnosed with COPD of
minimum duration 3 years were included. Doppler
Echocardiography for the measurement of
pulmonary arterial pressure was done. All the
patients were also subjected to spirometery for the
measurement of forced expiratory volume in one
second. Spearman’s RANK correlation test was
applied to see the relationship between FEV1 and
pulmonary arterial pressure. P value of < 0.05 was
considered significant.
Results: Mean age was 63.94+10.11 years. Mean
duration of COPD was 13.19+5.15 years. The mean
FEV1 (percent predicted) was 32.84+13.43. Among
these 276 patients, 133 (48%) patients had Pulmonary
Hypertension (PH). The mean PAP was 61.99 + 14.33.
The correlation was calculated between FEV1 and
PAP by using Pearson Correlation Coefficient and
was found to be –0.406 (p=0.000).
Conclusion: Increase in severity of COPD (as
measured by falling FEV1) is strongly correlated
with increasing severity of pulmonary artery
pressure and thus warrants echocardiographic
screening of COPD cases with mild to very serious
disease.
Key Words: Chronic obstructive airway
disease(COAD), Pulmonary hypertension(PH),
Forced expiratory volume in one second(FEV1).