Chonnam Med J.  1995 Dec;31(2):211-223.

Correlations of Arterial Blood Gas, Pulmonary Function and Pulmonary Arterial Pressure in Chronic Obstructive Pulmonary Disease

• Koh YI
• Kim YC
• Jung IJ
• Jang AS
• Yang JY
• Jeong MH
• Choi IS
• Park KO

Abstract

BACKGROUND: Pulmonary hypertension is a commom and potentially serious complication of chronic obstructive pulmonary disease (COPD) and impacts not only on survival but also on the quality of life. However, it is difficult to detect the pulmonary hypertension as the signs and symptoms of pulmonary hypertension in patients with COPD are non-specific, and the pulmonary artery pressure (PAP) is different even in patients with same degree of airway obstruction and arterial hypoxemia.
SUBJECTS AND METHOD
We compared the calculated pulmonary artery pressure (CAPA) from tricuspid regurgitant flow velocity detected by Doppler echocardiography with the measured pulmonary artery pressure (MPAT) from cardiac catheterization in 45 patients with cardiac and pulmonary diseases. To elucidate the relationship of pulmonary artery pressure with PaO2, PaCO2 and pulmonary function, we conducted Doppler echocardiogram, arterial blood gas analysis and pulmonary function test on 10 patients with chronic obstructive pulmonary disease.
RESULTS
1) There was an excellent correlation between CPAP and MPAP (N=45, r=0.89, p< 0.001). 2) In COPD patients, there was a tendency of negative correlation between CPAP and PaO2 (r=-0.42, p> 0.05). PaO2 was significantly lower in patients with pulmonary hypertension than patients without pulmonary hypertention (63.0+/-12.1 mmHg, vs. 48.7+/-6.3 mmHg p<0.05). 3) CPAP showed no significant correlation with PaO2 nor with FEV1. 4) Using the cut-off value of PaO2 55 mmHg, the sensivity for pulmonary hypertention was 85.7%, specificity 100%, positive predictive value 100%.
CONCLUSION
Calculated PAP from tricuspid regurgitant flow velocity using Doppler echocardiography has good correlation with directly measured PAP. Arterial Oxygen tension is the best predictor of pulmonary hypertention in patients with COPD. It would be useful to evaluate PAP and hematocrit and left ventricular function as well as arterial blood gases and function in more cases of COPD to determine the possible additional factors of pulmonary hypertension other than PaO2.

MeSH Terms

Airway Obstruction
Anoxia
Arterial Pressure*
Blood Gas Analysis
Cardiac Catheterization
Cardiac Catheters
Echocardiography, Doppler
Gases
Hematocrit
Humans
Hypertension, Pulmonary
Lung Diseases
Oxygen
Pulmonary Artery
Pulmonary Disease, Chronic Obstructive*
Quality of Life
Respiratory Function Tests
Sensitivity and Specificity
Ventricular Function, Left
Gases
Oxygen