Mathematically Arterialised Testing of Hypercapnic Subjects Study

A Prospective Observational Cohort Study to Investigate the Physiological Agreement Between Arterial Sampling (the Reference Method) and Mathematically Arterialised Venous Blood

Prospective observational cohort study of patients admitted to hospital with suspected hypercapnic respiratory failure and requiring treatment with non-invasive ventilation (NIV) as part of standard, routine management. Contemporaneous blood gas samples will be obtained via arterial, capillary, and venous methods. The venous samples will undergo mathematical arterialisation via the v-TAC system. In line with standard medical care, arterial samples will be obtained before starting NIV and at two set points afterwards (day 1 post-NIV, and pre-discharge). Pre-existing clinical thresholds will be used to assess the reliability of v-TAC against ABG, the existing gold standard and will conduct a retrospective model of decision-making once the blood sampling component of the study is concluded.

Inclusion Criteria:

• Aged 18 years or above.
• Admitted for consideration of home Non Invasive Ventilation.
• Due to undergo arterial blood gas sampling as part of routine clinical care

Exclusion Criteria:

• Inability to provide informed consent.
• Clinical necessity to perform blood gas sampling prior to allowing sufficient time for informed consent.
• Inability to obtain reliable SpO2 readings