[Measurement of CO diffusion capacity (II): Standardization and quality criteria]

Area of Science:

• Pulmonary Physiology
• Respiratory Medicine

Background:

• Diffusion capacity measures the respiratory system's gas exchange ability, crucial for diagnosing alveolar-capillary unit dysfunction.
• Carbon monoxide diffusion capacity (DLCO) is the key parameter, with emerging methods using nitric oxide (NO).

Purpose of the Study:

• To analyze the practical aspects of the single-breath diffusion capacity technique.
• To discuss clinical applications and factors influencing DLCO measurements.

Main Methods:

• Focus on the single-breath technique, the most widely used and standardized method.
• Analysis of procedure recommendations, calibration, calculations, and adjustments.
• Exploration of inter-laboratory variability and standardization's impact.

Main Results:

• DLCO increases with elevated pulmonary capillary blood volume (e.g., polycythemia, pulmonary hemorrhage).
• DLCO decreases in conditions with reduced alveolar volume or diffusion defects (e.g., interstitial diseases, pulmonary embolism).

Conclusions:

• Standardization improves the reliability and reproducibility of DLCO measurements.
• DLCO is a valuable diagnostic tool for various pulmonary and vascular conditions affecting gas exchange.