Conservative Oxygen Therapy Reduces ICU Death Rates: Study

The findings of new research raise concerns about oxygen therapy using a conventional approach, indicating that individuals may face a greater risk of death than those treated with a conservative hospital protocol for oxygen. 

In a study published this week in the Journal of American Medical Association (JAMA), researchers found patients treated with conservative oxygen therapy had nearly a nine percent lower risk of dying while in the intensive care unit (ICU).

Italian researchers wanted to determine if changes in oxygen supplementation in the ICU could reduce death rates among patients. They performed a randomized clinical trial at Modena University Hospital in Italy from March 2010 to October 2012, evaluating data for all adults admitted to the ICU with an expected stay of 72 hours or longer.

The original planned sample of patients was targeted at 660, however the hospital was forced to evacuate 25% of its patients after a violent earthquake affected the region. The study was stopped early with a final group of only 480 patients.

Researchers randomly assigned the patients to either receive conservative or conventional oxygen therapy, focusing on arterial blood gas levels, which are an indicator of a patient not breathing properly.

Conventional ICU oxygen treatment calls for patients to receive higher pressures of oxygen through ventilation or face and nose cannulas. The conventional oxygen protocol aims for arterial blood gas pressure of up to 150 mm Hg.

Conservative therapy calls for oxygen pressure to be reduced during a patient’s critical phase in the ICU. It aims for arterial blood gas pressure levels between 70 and 100 mm Hg; lower but still within healthy ranges.

Overall, the researchers concluded blood gas levels were significantly higher among patients in the conventional group, they averaged 102 mm Hg compared to 87 mm Hg in the conservative group.

Researchers report that 11% of patients in the conservative group died during their ICU stay, compared to 20% in conventional group. Overall hospital mortality was also lower in the conservative group; 24% compared to 33% in the conventional model group. The conservative oxygen method led to an 8.6% reduction in death rates.

The number of patients with new shock episodes and liver failure was also lower in the conservative group. The occurrence of infection was similar among both groups, but the conservative group had a lower risk of bloodstream infection and also experienced more hours free of mechanical ventilation.

Researchers did emphasize the findings are considered preliminary because the study was stopped early due to lack of patients from the 5.9 magnitude earthquake.

One-quarter of the hospital beds were evacuated until the end of 2013. Researchers opted to end the study early and calculate the results based on the data already collected since continuing to meet the 600 patient goal would have prolonged the study by nearly two years.