This study is a multicenter randomized controlled trial to determine the effectiveness of a closed loop/autonomous oxygen titration system (O2matic PRO100) to maintain normoxemia (goal range SpO2 90-96%, target 93%) during the first 72 hours of acute injury or illness, compared to standard provider-driven methods (manual titration with SpO2 target of 90-96%).

Ensuring adequate oxygenation is a primary goal in surgical and medical patients to treat and prevent morbidity associated with hypoxemia. However, excessive oxygen administration resulting in hyperoxemia is common, leading to unnecessary utilization of supplemental oxygen, which is a particularly limited resource in austere settings. Building on the previous Strategy to Avoid Excessive Oxygen (SAVE-O2) clinical trials1 (Trauma: NCT045349559; Burn: NCT04534972), the investigators seek to determine effective strategies to implement a targeted normoxemia approach to avoid both hyperoxemia and hypoxemia and reduce supplemental oxygen use, using the PRO100 closed loop/autonomous oxygen system. This research is critical for both military and civilian care settings in determining the effectiveness of an autonomous oxygen system to use to 1) reduce harm associated with both hypoxemia and hyperoxemia and 2) reduce excess use of oxygen.

Objectives: the investigators propose the following two objectives:

Determine the effectiveness of an autonomous oxygen titration system to improve normoxemia and reduce hypoxemia and hyperoxemia in acutely injured and ill patients receiving supplemental oxygen. The investigators will compare patient-hours spent in normoxemia (SpO2 90-96%), hypoxemia (SpO2 <88%), and hyperoxemia (SpO2 >96%) among patients randomized to autonomous vs manual oxygen titration.

Determine the impact of an autonomous oxygen titration system on overall utilization of supplemental oxygen. The investigators will compare the total volume of supplemental oxygen administered to patients randomized to autonomous vs manual oxygen titration during the 72-hour intervention period.

Hypothesis: The investigators hypothesize that the use of an autonomous oxygen titration system will be more effective at maintaining normoxemia and reducing time spent in hypoxemia/hyperoxemia than standard manual titration in non-mechanically ventilated patients and will reduce the overall use of supplemental oxygen.

Inclusion Criteria:

• Age 18 years or older
• Hospitalized or will be hospitalized from Emergency Department for major trauma, burn, acute care surgery, or acute respiratory illness
• Able to be randomized within 36 hours of hospital arrival
• Receiving supplemental oxygen 1-10 liters per minute for documented or presumed hypoxemia (must be higher than baseline for those on chronic oxygen therapy)
• Signed and dated informed consent from patient or legally authorized representative (LAR)

Exclusion Criteria:

• Anticipated hospital discharge within 24 hours
• Imminent plans to discontinue supplemental oxygen
• Imminent plans to administer high flow nasal oxygen, non-invasive ventilation, or invasive mechanical ventilation
• Clinical team unwilling or unable to follow the prescribed oxygen titration method in either randomized group
• Known prisoner
• Known pregnancy
• Known contraindicated conditions for use of the PRO100 device: carbon monoxide poisoning, incapable of handling airway secretions, increased methemoglobin, cyanide poisoning, cluster headaches, undrained pneumothorax, sickle cell crisis, paraquat poisoning or a history of bleomycin poisoning, patients for whom the SpO2 signal is not stable