The Utility of Measurement of Partial Pressure of Arterial Transcutaneous Carbon Dioxide Monitoring in Sleep Apnea Syndrome

Abstract

　Background: Sleep apnea syndrome (SAS) is accompanied by decreased alveolar ventilation due to upper airway stenosis and obstruction during sleep. This in turn induces a combination of hypoxemia and hypercapnia, a state in which the arterial partial pressure of carbon dioxide can be used as a key index for ascertaining patient condition and clinical course under treatment. Patients with SAS are also suspected to exhibit alveolar hypoventilation when awake. To thoroughly evaluate patients in an awake state at SAS diagnosis or at the start of treatment, we non-invasively measured the arterial partial pressure of carbon dioxide and investigated the usefulness of this approach.

　Methods: Using the TOSCA 500^TM a device for measurement of partial pressure of arterial transcutaneous carbon dioxide (PtcCO₂), we determined PtcCO₂ and investigated its correlation with the severity of SAS on initial examination in an awake state.

　Results: PtcCO₂ correlated weakly but non-significantly with severity and BMI, and was maintained within normal range even in severe cases.

　Conclusion: Severe SAS patients keep PtcCO₂ within normal range.