Automatic oxygen titration with O2matic® to patients admitted with COVID-19 and hypoxemic respiratory failure

Introduction

Patients with coronavirus disease (COVID-19) and pneumonitis often have hypoxemic respiratory failure and a need of supplementary oxygen. Guidelines recommend controlled oxygen, for most patients with a recommended interval of SpO₂ between 92 and 96%. We aimed to determine if closed-loop control of oxygen was feasible in patients with COVID-19 and could maintain SpO₂ in the specified interval.

Methods

Patients were prospectively enrolled in an observational study on a medical ward dedicated to patients with COVID-19. Closed-loop controlled oxygen was delivered by O2matic® which can deliver 0-15 liters/min and adjusts flow every second based on 15 seconds averaging of SpO₂ measured by pulse oximetry. Lung function parameters were measured at admission.

Results

Fifteen patients (six women, nine men) participated in the study. Average age was 72 years. Lung function was severely impaired with FEV₁, FVC and PEF reduced to approximately 50%. The average stay on the ward was 3.2 days and O2matic was used on average for 66 hours, providing 987 hours of observation. O2matic maintained SpO₂ in the desired interval for 82.9% of the time. Time with SpO₂ > 2% below interval was 5.1% and time with SpO₂ > 2% above interval was 0.6%.

Conclusion

Closed-loop control of oxygen to patients with COVID-19 is feasible and can maintain SpO₂ in the specified interval in the majority of time. Closed-loop automated control could be of particular benefit for patients in isolation with decreased visibility, surveillance and monitoring. Further studies must examine the clinical benefits.

TOB-STOP-COP (TOBacco STOP in COPd trial): study protocol-a randomized open-label, superiority, multicenter, two-arm intervention study of the effect of "high-intensity" vs. "low-intensity" smoking cessation intervention in active smokers with chronic obstructive pulmonary disease

BACKGROUND

Cigarette smoking is the leading cause of chronic obstructive pulmonary disease (COPD), and it contributes to the development of many other serious diseases. Smoking cessation in COPD patients is known to improve survival and reduce the number of hospitalization-requiring acute exacerbations of COPD. However, smoking cessation interventions in these patients have only been successful for approximately 15-20% for consistent smoking abstinence in 12 months. Thus, more effective interventions are needed for this patient group. The aim of this study is to determine whether a high-intensity intervention compared to a low-intensity intervention can increase the proportion of persistent (> 12 months) anamnestic and biochemical smoking cessation in active smokers with COPD.

METHODS

This study is a randomized controlled trial. A total of 600 active smokers with COPD will be randomly assigned 1:1 to either a standard treatment (guideline-based municipal smoking cessation program, "low intensity" group) or an intervention ("high-intensity" group) group, which consists of group sessions, telephone consultations, behavior design, hotline, and "buddy-matching" (smoker matched with COPD patient who has ceased smoking). Both groups will receive pharmacological smoking cessation. The primary endpoint is anamnestic and biochemical (cotinine analysis in urine) validated smoking cessation after 12 months.

DISCUSSION

The potential benefit of this project is to improve smoking cessation rates and thereby reduce smoking-related exacerbations of COPD. In addition, the project can potentially benefit from increasing the quality of life and longevity of COPD patients and reducing the risk of other smoking-related diseases.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04088942 . Registered on 13 September 2019.

Automated oxygen control with O2matic® during admission with exacerbation of COPD

PURPOSE

It is a challenge to control oxygen saturation (SpO2) in patients with exacerbations of COPD during admission. We tested a newly developed closed-loop system, O2matic®, and its ability to keep SpO2 within a specified interval compared with manual control by nursing staff.

PATIENTS AND METHODS

We conducted a crossover trial with patients admitted with an exacerbation of COPD and hypoxemia (SpO2 ≤88% on room air). Patients were monitored with continuous measurement of SpO2. In random order, they had 4 hours with manually controlled oxygen and 4 hours with oxygen delivery controlled by O2matic. Primary outcome was time within a prespecified SpO2 target interval. Secondary outcomes were time with SpO2 <85%, time with SpO2 below target but not <85%, and time with SpO2 above target.

RESULTS

Twenty patients were randomized and 19 completed the study. Mean age was 72.4 years and mean FEV1 was 0.72 L (33% of predicted). Patients with O2matic-controlled treatment were within the SpO2 target interval in 85.1% of the time vs 46.6% with manually controlled treatment (P<0.001). Time with SpO2 <85% was 1.3% with O2matic and 17.9% with manual control (P=0.01). Time with SpO2 below target but not <85% was 9.0% with O2matic and 25.0% with manual control (P=0.002). Time with SpO2 above target was not significantly different between treatments (4.6% vs 10.5%, P=0.2). Patients expressed high confidence and a sense of safety with automatic oxygen delivery.

CONCLUSION

O2matic was able to effectively control SpO2 for patients admitted with an exacerbation of COPD. O2matic was significantly better than manual control to maintain SpO2 within target interval and to reduce time with unintended hypoxemia.