Masimo announced today the findings of an abstract presented at the 2018 Congress of the French Society of Anesthesia and Resuscitation (SFAR) in Paris in which researchers at CHU Angers in France investigated the ability of Masimo ORi™ (Oxygen Reserve Index) to help clinicians reduce the number of days ICU patients experience hyperoxemia while on mechanical ventilation. ORi, available outside the U.S., is a noninvasive and continuous parameter intended as a relative indicator of a patient's oxygen reserve during moderate hyperoxia (partial pressure of oxygen in arterial blood [PaO2] in the range of 100 to 200 mmHg). ORi can be trended and has optional alarms to notify clinicians of changes in oxygenation.
Noting that hyperoxemia can lead to patient morbidity and mortality in ICU patients, and that oxygen saturation (SpO2) cannot detect hyperoxemia, Dr. Brochant and colleagues sought to evaluate whether ORi might be useful in helping clinicians determine when to reduce the fraction of inspired oxygen (FiO2) during oxygen therapy, so as to avoid hyperoxemia. In this initial analysis, the first 131 patients in the study, whose data were collected between May 2017 and March 2018, were randomly assigned into an ORi and a control group. In the ORi group, FiO2 was reduced if ORi was > 0. In the control group, the FiO2 level was adjusted according to SpO2. Clinicians recorded blood gas results, episodes of atelectasis, and the length of time spent on mechanical ventilation, for up to 28 days. The principal point of comparison was the proportion of ventilated days with hyperoxemia.
The researchers found that the percentage of days with hyperoxemia was significantly lower in the ORi group: median 14% [interquartile range 0-31%], vs. 29% [IQR 11-50%] in the control group, p=0.005. Average daily PaO2 and FiO2 values were not significantly different between the two groups, suggesting that FiO2 was not systematically lowered in the ORi group. The average number of days without ventilation and median time spent in the ICU were also not significantly different.
The researchers concluded that the use of ORi may help clinicians reduce the percentage of days with hyperoxemia, that analysis of the full group of patients may allow assessment of its effect on the occurrence of atelectasis, and that additional studies may be useful in evaluating the impact of this monitoring on the morbidity and mortality of patients.