Validation of a Miniature SpO2 Sensor in Healthy Subjects and Patients With Long-term Oxygen Therapy.

Objectives:

• To determine accuracy of SpO2 measurements by the novel sensor compared to 2 reference pulse oximeters in healthy subjects undergoing a normobaric hypoxic challenge provoking SpO2 desaturation.
• To determine accuracy of SpO2 measurements by the novel sensor compared to 2 reference pulse oximeters and to arterial blood gas analysis in patients qualifying for LTOT, breathing room air at rest (lying, sitting, standing position) and during exercise (slow walking, 6-MWT, ergometer cycle).

Healthy volunteers

Inclusion criteria

• Age 18 - 60 years,
• Non smoker,
• Good general health and physical fitness
• Informed Consent

Exclusion criteria

• Current or history of tobacco smoking (> 5 py)
• Current alcohol or drug abuse
• Heart disease or untreated arterial hypertension
• Pulmonary disease
• Epilepsy or other major neurologic disease
• Dark skin colour
• Known anemia
• Severe metabolic disease (e.g. diabetes)
• Pregnancy

Patients

Inclusion criteria

• Age ≥ 18 years
• Long term oxygen therapy at rest and/or on physical effort
• Hypoxemia in arterial blood gas analysis at rest PaO2 ≤ 55 mmHg or < 60 mmHg with PHT or polycythemia (men Hb > 174 g/L, women Hb > 140 g/L) or:

Oxygen desaturation on effort (SpO2 < 90%)

• Pulmonary disease including Chronic Obstructive Pulmonary Disease, Interstitial Lung Disease and Sarcoidosis
• Informed Consent

Exclusion criteria

• Severe hypoxemia (pO2 <40 mmHg)
• Severe hypercapnia (pCO2 >55 mmHg)
• Acute respiratory infection or systemic infection,
• Severe systolic heart disease (LVEF < 25%)
• Myocardial infarction during the last month before inclusion
• Unstable angina pectoris
• Severe aortic stenosis (mean gradient > 40mmHg, valve area <1 cm2)
• Rhythmogenic heart disease
• Severe or untreated arterial hypertension (blood pressure > 180mmHg systolic, >100mmHg diastolic)
• Anemia (Hb < 120 g/l)
• Known or suspected coagulation disorder (e.g. INR > 4)
• Severe or untreated metabolic disorder
• Neurologic disease or dementia
• Pregnancy
• History of non-compliance to medical treatment
• Current alcohol, drug abuse or current tobacco smoking
• Dark skin color