The aim of the study is to examine if automated oxygen delivery with O2matic is better than manually controlled oxygen therapy for patients admitted to hospital with an exacerbation in Chronic Obstructive Pulmonary Disease (COPD).

O2matic is a closed -loop system based on continuous non-invasive measurement of pulse and oxygen-saturation that is processed in an algorithm that controls the flow of oxygen to the patient.

The primary hypothesis is that O2matic increases time within acceptable oxygen-saturation interval. Secondary hypotheses are that O2matic compared to manual control reduces time with severe hypoxia (SpO2 < 85 %), hypoxi (SpO2 below intended interval) and hyperoxia (SpO2 above intended interval).

Closed-loop control of oxygen therapy is described in the literature used for preterm infants, trauma patients, medical emergency use and patients with COPD. For the latter, closed-loop therapy has been used for patients admitted to hospital with an exacerbation, for domiciliary oxygen use and during exercise. O2matic is a closed-loop system that is based on continuous and non-invasive measurement of pulse, oxygen-saturation and respiratory frequency. The algorithm in O2matic controls oxygen delivery with the aim of keeping the saturation within the desired interval, which could be 88-92 % for COPD-patients in accordance with international guidelines on this topic. Saturation interval can be set for the individual patients, as can the range of acceptable oxygen-flow. If saturation or oxygen-flow can't be maintained within the desired intervals an alarm will sound.

All studies on closed-loop systems have shown that this method is better than manually control by nurse to maintain saturation within the desired interval. Furthermore, some studies have indicated that closed-loop has the possibility to reduce admission time and to reduce time spent with oxygen therapy, due to more efficient and fast withdrawal from oxygen supplementation.

In the present study O2matic will be tested versus manual control, for patients admitted with an exacerbation in COPD, and in need of supplemental oxygen. During the study the patients will either have oxygen controlled with O2matic or manually by nursing staff. All patients will have continuous logging of pulse, oxygen-saturation and oxygen-flow with O2matic, but only in the O2matic active group, the algorithm will control oxygen-delivery.

The primary hypothesis will be tested, which is that O2matic is better than manual control for maintaining oxygen-saturation within the desired interval and reducing time with unintended hypoxia and hyperoxia. For this purpose 20 patients will be included in a crossover design with 4 hours of O2matic-controlled oxygen treatment and 4 hours with manually titrated oxygen with a 16 hours washout between periods.

No safety issues has been reported in the literature. Before use O2matic will be approved by The Danish Medicines Agency, The Ethics Committee in the Capital Region of Denmark and by the regional Data Protection Board. The study will be conducted according to GCP standards with independent monitoring. All adverse events and serious adverse events will be monitored and serious adverse events will be reported to Danish Medicines Agency.

Inclusion Criteria:

• COPD verified by FEV1/FVC < 0,70
• Admission due to exacerbation in COPD
• COPD exacerbation and pneumonia can be included
• Duration of admission > 48 hours
• Need for oxygen supplementation at inclusion (SpO2 <= 88 % without O2 suppl.)
• Cognitively able to participate in the study
• Willing to participate and give informed consent.

Exclusion Criteria:

• Need or anticipated need for mechanical ventilation (except intermittent CPAP)
• Major co-morbidities (cancer, heart disease, thromboembolic disease, uncontrolled diabetes)
• Asthma or other respiratory condition requiring higher SpO2 than normal for COPD- patients
• Pregnancy
• Acute thromboembolic disease (< 2 weeks)
• Cognitive barriers for participation