Oxygen Control and Weaning by O2matic to Patients Admitted With an Exacerbation of COPD

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 and oxygen-saturation (SpO2). The algorithm in O2matic controls oxygen delivery with the aim of keeping the SpO2 within the desired interval, which could be 88-92 % for COPD-patients in accordance with international guidelines on this topic. SpO2-interval can be set for the individual patients, as can the range of acceptable oxygen-flow. If SpO2 or oxygen-flow cannot 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 for 3 consecutive days. 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 is that O2matic compared to manual control allows for faster weaning from oxygen supplementation, and that more patients will be weaned from oxygen supplementation within a time frame of 3 days. Furthermore it will be tested if O2matic compared to manual control leads to faster achieved respiratory stability, allowing for hospital discharge. It will be tested if O2matic is better than manual control in maintaining oxygen-saturation within the desired interval and reducing time with unintended hypoxia and hyperoxia. Patients sense of security and feeling of anxiety and dyspnea will be evaluated by questionnaires.

No safety issues has been reported in the literature. O2matic is approved for clinical testing 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 Good Clinical Practice (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 Forced Expiratory Volume in 1. second (FEV1) divided by Forced Vital Capacity (FVC) < 0,70
• Admission due to exacerbation in COPD
• COPD exacerbation and pneumonia can be included
• Expected duration of admission > 48 hours
• Need for oxygen supplementation (SpO2 <= 88 % on room air)
• Cognitively able to participate in the study
• Willing to participate and give informed consent

Exclusion criteria

• Need or anticipated need for mechanical ventilation (intermittent Continuous Positive Airway Pressure (CPAP) is allowed)
• Major comorbidities causing hypoxemia (Cancer, heart disease, pulmonary emboli)
• Asthma or other respiratory condition requiring higher SpO2 than normal for COPD
• Pregnancy
• Cognitive barriers for participation