Low Versus High Pulse Oxygen Saturation Directed Oxygen Therapy in Critically Ill Patients: a Randomized Controlled Pilot Study

Background: Data on the safety and feasibility of pulse oxygen saturation (SpO) directed oxygen therapy in mainland China are scarce. The aim of this pilot study was to test the feasibility of SpO directed oxygen therapy and to calculate sample size base on differences in 28-day mortality rates for a large sample-sized randomized trial.

Methods: This prospective pilot study enrolled 214 adult patients with an expected intensive care unit (ICU) stay of more than 72 hours. Patients were randomized into a low SpO group (SpO 90-95%) or high SpO group (SpO 96-100%). The primary outcome was 28-day mortality.

Results: One hundred patients were included in the low SpO group, and 114 patients were included in the high SpO group. The demographic and baseline characteristics were not different. The time-weighted SpO average was significantly lower in the low SpO group than in the high SpO group [mean ± standard deviation (SD), 95.7%±2.3% 98.2%±1.8%, P<0.001]. Twenty-six patients (26%) in the low SpO group died within 28 days after inclusion, while 37 patients (32.5%) in the high SpO group died (P=0.301). The time to death within 28 days between the two groups was not different (P=0.284).

Conclusions: SpO directed oxygen therapy in critically ill patients was feasible. Our pilot trial necessitates and rationalizes our large-sample multicenter trial.