Effect of liberal or conservative oxygen therapy on the prognosis for mechanically ventilated intensive care unit patients: a meta-analysis

Conservative versus liberal oxygen therapy for intensive care unit patients: meta-analysis of randomized controlled trials

BACKGROUND

It remains unclear whether conservative oxygen therapy (COT) or liberal oxygen therapy (LOT) is more beneficial to the clinical outcomes of intensive care unit (ICU) patients. We systematically reviewed the efficacy and safety of conservative versus liberal oxygen therapy for ICU patients.

METHODS

We systematically searched PubMed, Embase, Web of Science, Scopus, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, MedRxiv, and BioRxiv for reports on randomized controlled trials (RCTs) that compared the effects of COT versus LOT on the clinical outcomes of ICU patients published in English before April 2024. The primary outcome was the mortality rate, secondary outcomes included ICU and hospital length of stay, days free from mechanical ventilation support (MVF), vasopressor-free time (VFT), and adverse events.

RESULTS

In all, 13 RCTs involving 10,632 patients were included in analyses. Meta-analysis showed COT did not reduce mortality at 30-day (risk ratio [RR] = 1.01, 95% confidence interval [CI] 0.94 to 1.09, I2 = 42%, P = 0.78), 90-day (RR = 1.01, 95% CI 0.95 to 1.08, I2 = 9%, P = 0.69), or longest follow-up (RR = 1.00, 95% CI 0.95 to 1.06, I2 = 22%, P = 0.95) compared to LOT in ICU patients. In subgroup analyses, no significant difference was observed between the two groups in terms of the different ICU, baseline P/F, and actual PaO2. In addition, COT did not affect ICU length of stay, hospital length of stay, or VFT, it only affected MVF days.

CONCLUSIONS

COT did not reduce all-cause mortality in ICU patients. Further RCTs are urgently needed to confirm the impact of COT strategy on specific populations.

Conservative versus conventional oxygen therapy in type I acute respiratory failure patients in respiratory intensive care unit, Zagazig University

The present study aimed to assess the effect of a conservative (permissive hypoxemia) versus conventional (normoxia) protocol for oxygen supplementation on the outcome of type I respiratory failure patients admitted to respiratory intensive care unit (ICU). This randomized controlled clinical trial was carried out at the Respiratory ICU, Chest Department of Zagazig University Hospital, for 18 months, starting in July 2018. On admission, 56 enrolled patients with acute respiratory failure were randomized in a 1:1 ratio into the conventional group [oxygen therapy was supplied to maintain oxygen saturation (SpO2) between 94% and 97%] and the conservative group (oxygen therapy was administered to maintain SpO2 values between 88% and 92%). Different outcomes were assessed, including ICU mortality, the need for mechanical ventilation (MV) (invasive or non-invasive), and ICU length of stay. In the current study, the partial pressure of oxygen was significantly higher among the conventional group at all times after the baseline reading, and bicarbonate was significantly higher among the conventional group at the first two readings. There was no significant difference in serum lactate level in follow-up readings. The mean duration of MV and ICU length of stay was 6.17±2.05 and 9.25±2.22 days in the conventional group versus 6.46±2.0 and 9.53±2.16 days in the conservative group, respectively, without significant differences between both groups. About 21.4% of conventional group patients died, while 35.7% of conservative group patients died without a significant difference between both groups. We concluded that conservative oxygen therapy may be applied safely to patients with type I acute respiratory failure.