Measurement of Gas Exchange By Karen L Wood, MD, Grant Medical Center, Ohio Health Reviewed / Revised Apr 2022 | Modified Sep 2022 View Patient Education Diffusing Capacity for Carbon Monoxide Pulse Oximetry Arterial Blood Gas (ABG) Sampling Oxygenation Carbon Dioxide Carboxyhemoglobinemia Methemoglobinemia Topic Resources Diffusing capacity for carbon... A-a Gradient Arterial Blood Gas Interpretation... Oxyhemoglobin dissociation... Gas exchange is measured through several means, including Diffusing capacity for carbon monoxide Pulse oximetry Arterial blood gas sampling Diffusing Capacity for Carbon Monoxide The diffusing capacity for carbon monoxide (DLCO) is a measure of the ability of gas to transfer from the alveoli across the alveolar epithelium and the capillary endothelium to the red blood cells.