Related Experiment Video
Updated: Aug 24, 2026

Assessment of Pulmonary Capillary Blood Volume, Membrane Diffusing Capacity, and Intrapulmonary Arteriovenous Anastomoses During Exercise
Published on: February 20, 2017
Increased arteriovenous carboxyhemoglobin differences in patients with inflammatory pulmonary diseases
Hiroyasu Yasuda1, Takahiko Sasaki, Mutsuo Yamaya
1Department of Geriatric and Respiratory Medicine, Tohoku University School of Medicine, Sendai, Japan.
Purpose:
Exhaled carbon monoxide and arterial blood carboxyhemoglobin concentrations increase in inflammatory pulmonary diseases. The present study was undertaken to elucidate whether arteriovenous carboxyhemoglobin (a-vHb-CO) concentration differences are also useful to define the site of inflammation, either in the lung or organs other than the lung.
Materials And Methods:
We examined concentrations of carboxyhemoglobin in both arterial and peripheral venous blood and exhaled carbon monoxide in patients with acute pulmonary inflammation including bronchial asthma (n = 18) and pneumonia (n = 33), and those in patients with extrapulmonary inflammatory diseases, including acute pyelonephritis (n = 28) and active rheumatoid arthritis (n = 16).
Results:
The values of carboxyhemoglobin in both arterial and peripheral venous blood were significantly higher in patients with pulmonary and extrapulmonary inflammation compared with those in control subjects (n = 22). Furthermore, a-vHb-CO differences in patients with inflammatory pulmonary diseases were higher than those in patients with acute pyelonephritis and patients with rheumatoid arthritis, and than those in control subjects. The a-vHb-CO differences correlated with the WBC count of peripheral venous blood in patients with pneumonia. In patients with bronchial asthma, the a-vHb-CO differences inversely correlated with FEV(1), although they did not correlate with WBC count of peripheral venous blood. The a-vHb-CO differences in patients with acute pyelonephritis were higher than those in patients with active rheumatoid arthritis.
Conclusion:
The present study suggests that a-vHb-CO differences may be a useful means to define the site of inflammation, either in the lung or organs other than the lung, in patients with a fever of unknown origin. The large a-vHb-CO differences may be caused by carbon monoxide production in pulmonary inflammation.
Related Concept Videos
Chronic Obstructive Pulmonary Disease-IV: Assessement and Diagnostic Studies
Medical History
Oxygen Transport in the Blood
Hemoglobin
When all four heme groups are bound to oxygen, the resulting molecule is called oxyhemoglobin. As a result, arterial blood...
Chronic Obstructive Pulmonary Disease-II: Pathophysiology
Chronic Inflammation
Chronic Obstructive Pulmonary Disease-III: Symptoms and Complications.
Symptoms of COPD can be classified as primary or systemic. Primary symptoms relate to reduced airflow, while systemic or extrapulmonary symptoms relate to COPD's broader impact on the body.
Primary Symptoms of COPD:
Chronic Obstructive Pulmonary Disease III: Chronic Bronchitis Features
