Detecting Systemic Carbon Dioxide Levels With a Novel Biosensor; The DISCO-study

he study is an open, prospective, single center clinical observational pilot investigation including 9 patients and 2 healthy volunteers. The aim is to compare the carbon dioxide values measured by the IscAlert sensor, which is inserted in proximity to the nasal mucosa, with the transcutaneous carbon dioxide values measured at the forehead by a transcutaneous carbon dioxide-monitor, the arterial carbon dioxide measurements performed by blood gas analyses, and carbon dioxide measurements registered with the IscAlert sensor implanted in the muscle of the forearm. The study wants to investigate if the nasal mucosa application and measurements are feasible, what kind of possible complications such a measurement can cause, and if the measurements can be a surrogate marker for systemic carbon dioxide values. The study will include patients with a tendency to hypoventilation, thereby giving rise to a carbon dioxide retention; 3 patients with chronic obstructive pulmonary disease with suspected hypercapnic respiratory failure who are evaluated for non-invasive mask-treatment and long-term oxygen treatment supply if needed. 3 patients with neuromuscular disorders and 3 patients with obesity hypoventilation syndrome who are evaluated for non-invasive mask treatment. The measurements will last for about 8 to 14 hours at night while the patients are sleeping. In addition, the study will also include 2 healthy volunteers as a control group. They will have the equipment mounted on them for about 8 hours during the day in connection with normal office work. Follow up by telephone 7 days +/-2 days after the measurements are finished. The inclusion period is expected to be about 9 months.