Lint: carbon-monoxide-transfer-coefficient

"Carbon monoxide transfer coefficient (often abbreviated as KCO) is a parameter often performed as part of pulmonary function tests. It is also often written as DLCO/VA (diffusing capacity per litre of lung volume) and is an index of the efficiency of alveolar transfer of carbon monoxide."

"Interpretation of KCO depends on other parameters such as"

"TLC: total lung capacity"

"In the context of normal VA, a low KCO (provided there is no anaemia or recent smoking) could suggest ³:"

"In the context of a low VA, the next step is to look at the VA/TLC ratio."

"Low VA/TLC ratio (< 0.8)"

"a normal KCO (not able to be interpreted): this could imply obstruction with ventilation distribution abnormalities, the KCO might turn “normal”. In this scenario, no further valid inferences can be made regarding KCO"

"a normal KCO (not able to be interpreted): this could imply obstruction with ventilation distribution abnormalities, the KCO might turn “normal”. In this scenario, no further valid inferences can be made regarding KCO"

"a normal KCO (not able to be interpreted): this could imply obstruction with ventilation distribution abnormalities, the KCO might turn “normal”. In this scenario, no further valid inferences can be made regarding KCO"

"however, if KCO is low despite those caveats this could imply extensive impairment in pulmonary gas exchange efficiency, e.g. severe emphysema"

"Normal VA/TLC ratio (≥ 0.8)"

"a high KCO indicates a predominance of VC over VA due to"

"an increase in pulmonary blood flow from areas of diffuse (pneumonectomy) or localised (local destructive lesions/atelectasis) loss of gas exchange units to areas with preserved parenchyma; this frequently leads to more modest increases in KCO (although a high KCO can also be seen with normal VA when there is "increased pulmonary blood flow" or redistribution (e.g. left-to-right shunt and asthma)"

"an increase in pulmonary blood flow from areas of diffuse (pneumonectomy) or localised (local destructive lesions/atelectasis) loss of gas exchange units to areas with preserved parenchyma; this frequently leads to more modest increases in KCO (although a high KCO can also be seen with normal VA when there is "increased pulmonary blood flow" or redistribution (e.g. left-to-right shunt and asthma)"

"a low KCO: could suggest intra-parenchymal restriction with impaired gas exchange efficiency as in some interstitial lung diseases (ILD)"

"a normal KCO: could suggest intra-parenchymal restriction with preserved KCO (can be a common finding in patients with HRCT abnormalities showing a pattern consistent with idiopathic interstitial pneumonia); normal KCO, therefore, should not be misinterpreted as “no ILD”"

"a normal KCO: could suggest intra-parenchymal restriction with preserved KCO (can be a common finding in patients with HRCT abnormalities showing a pattern consistent with idiopathic interstitial pneumonia); normal KCO, therefore, should not be misinterpreted as “no ILD”"

"a normal KCO: could suggest intra-parenchymal restriction with preserved KCO (can be a common finding in patients with HRCT abnormalities showing a pattern consistent with idiopathic interstitial pneumonia); normal KCO, therefore, should not be misinterpreted as “no ILD”"

"In the context of normal VA, a low KCO (provided there is no anaemia or recent smoking) could suggest ³:"

"In the context of a low VA, the next step is to look at the VA/TLC ratio."

"a high KCO indicates a predominance of VC over VA due to"

"a low KCO: could suggest intra-parenchymal restriction with impaired gas exchange efficiency as in some interstitial lung diseases (ILD)"

"a normal KCO: could suggest intra-parenchymal restriction with preserved KCO (can be a common finding in patients with HRCT abnormalities showing a pattern consistent with idiopathic interstitial pneumonia); normal KCO, therefore, should not be misinterpreted as “no ILD”"

"Low VA/TLC ratio (< 0.8)"

"Normal VA/TLC ratio (≥ 0.8)"

"incomplete alveolar expansion but preserved gas exchange i.e. extra-parenchymal restriction such as pleural, chest wall or neuromuscular disease)"

"extra-vascular haemoglobin (e.g. alveolar haemorrhage)"

"a low KCO: could suggest intra-parenchymal restriction with impaired gas exchange efficiency as in some interstitial lung diseases (ILD)"

"a normal KCO: could suggest intra-parenchymal restriction with preserved KCO (can be a common finding in patients with HRCT abnormalities showing a pattern consistent with idiopathic interstitial pneumonia); normal KCO, therefore, should not be misinterpreted as “no ILD”"