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

ABSTRACT BACKGROUND: For critically ill patients, physicians tend to administer sufficient or even excessive oxygen to maintain oxygen saturation at a high level. However, the credibility of the evidence for this practice is unclear. OBJECTIVE: To determine the effects of different oxygen therapy strategies on the outcomes of mechanically ventilated intensive care unit (ICU) patients. DESIGN AND SETTING: Systematic review of the literature and meta-analysis conducted at Jiangxi Provincial People's Hospital, Affiliated to Nanchang University, Nanchang, China. METHODS: We systematically searched electronic databases such as PubMed and Embase for relevant articles and performed meta-analyses on the effects of different oxygen therapy strategies on the outcomes of mechanically ventilated ICU patients. RESULTS: A total of 1802 patients from five studies were included. There were equal numbers of patients in the conservative and liberal groups (n = 910 in each group). There was no significant difference between the conservative and liberal groups with regard to 28-day mortality (risk ratio, RR = 0.88; 95% confidence interval, CI = 0.59-1.32; P = 0.55; I2 = 63%). Ninety-day mortality, infection rates, ICU length of stay, mechanical ventilation-free days up to day 28 and vasopressor-free days up to day 28 were comparable between the two strategies. CONCLUSIONS: It is not necessary to use liberal oxygen therapy strategies to pursue a higher level of peripheral oxygen saturation for mechanically ventilated ICU patients. Conservative oxygen therapy was not associated with any statistically significant reduction in mortality.

Observation of the curative effect of conservative oxygen therapy in mechanical ventilation of patients with severe pneumonia / 中华危重病急救医学

Objective:To compare the effects of conservative oxygen therapy and conventional oxygen therapy on the efficacy and prognosis of mechanical ventilation support in patients with severe pneumonia.Methods:A prospective randomized controlled study were conducted, 110 patients with severe pneumonia requiring mechanical ventilation in intensive care unit (ICU) of Hefei First People's Hospital from May 2019 to May 2021 were selected and divided into conventional oxygen therapy group (51 cases) and conservative oxygen therapy group (55 cases) according to random number table method. Patients in both groups were treated with invasive to non-invasive sequential mechanical ventilation strategy, and the target of oxygen therapy in the conventional oxygen therapy group was set as the arterial partial pressure of oxygen (PaO 2) > 150 mmHg (1 mmHg = 0.133 kPa) or pulse oxygen saturation (SpO 2) > 0.96. In the conservative oxygen therapy group, PaO 2 was set at 70-100 mmHg or SpO 2 at 0.90-0.92. The changes of blood gas analysis, mechanical ventilation time, ICU stay time, ICU mortality, new organ dysfunction and infection more than 48 hours after admission were observed in two groups before and after treatment. Kaplan-Meier method was used to analyze the difference in cumulative survival rate between the two groups. Results:After treatment, pH value, PaO 2 and oxygenation index (PaO 2/FiO 2) in both groups were significantly higher than before treatment, and arterial partial pressure of carbon dioxide (PaCO 2) was significantly lower than before treatment. pH value in the conservative oxygen therapy group was significantly higher than that in the conventional oxygen therapy group (7.4±0.1 vs. 7.3±0.3). PaO 2, PaCO 2 and PaO 2/FiO 2 were significantly lower than those in conventional oxygen therapy group [PaO 2 (mmHg): 68.9±4.7 vs. 75.2±6.0, PaCO 2 (mmHg): 42.1±5.6 vs. 50.5±7.5, PaO 2/FiO 2 (mmHg): 329±126 vs. 365±108, all P < 0.05]. The mechanical ventilation time in the conservative oxygen therapy group was significantly longer than that in the conventional oxygen therapy group (days: 19.7±3.5 vs. 13.9±4.5, P < 0.05), but there was no significant difference in ICU hospitalization time between the conservative oxygen therapy group and the conventional oxygen therapy group (days: 26.5±5.0 vs. 25.5±4.6, P > 0.05). Compared with the conventional oxygen therapy group, the ICU mortality, the incidence of nosocomial bloodstream infection, and the incidence of liver insufficiency, shock, and ICU acquired weakness (ICUAW) were decreased significantly in the conservative oxygen therapy group [ICU mortality: 27.3% (15/55) vs. 45.1% (23/51), liver insufficiency: 1.8% (1/55) vs. 7.8% (4/51), shock: 3.6% (2/55) vs. 9.8% (5/51), ICUAW: 5.5% (3/55) vs. 11.8% (6/51), the incidence of new bloodstream infection: 5.5% (3/55) vs. 11.8% (6/51), all P < 0.05]. Kaplan-Meier analysis showed that the cumulative survival rate of the conservative oxygen therapy group was significantly higher than that of the conventional oxygen therapy group (72.7% vs. 54.9%; Log-Rank test: χ 2 = 4.244, P = 0.039). Conclusion:Conservative oxygen therapy can reduce ICU mortality, the incidence of shock, liver insufficiency, ICUAW, and bloodstream infection in patients with severe pneumonia, but prolong mechanical ventilation time.

Effect of conservative and conventional oxygen therapy on the prognosis of critically ill patients: a Meta-analysis / 中华危重病急救医学

Objective? To?compare?the?efficacy?and?safety?of?conservative?and?conventional?oxygen?therapy?in?critically?ill?patients.? Methods? Relevant?literature?and?randomized?controlled?trials?(RCTs)?about?the?effect?of?conservative?oxygen?therapy?and?conventional?oxygen?therapy?on?the?prognosis?of?intensive?care?unit?(ICU)?critically?ill?patients?was?searched?from?CNKI,?VIP,?Wanfang?Data,?Chinese?Clinical?Trial?Registry,?PubMed,?Embase,?the?Cochrane?Library,?and?ClinicalTrials.gov?by?using?the?keywords?"critically?ill?patients,?conservative?oxygen?therapy,?liberal?oxygen?therapy,?conventional?oxygen?therapy,?mortality"?until?October?30th?in?2018.?The?main?outcome?indicators?were?short-term?mortality?(28-day?mortality?or?ICU?mortality);?secondary?indicators?were?90-day?mortality,?duration?of?mechanical?ventilation,?the?length?of?ICU?stay,?total?hospitalization?time,?new?infection?rate?in?ICU?and?incidence?of?new?organ?dysfunction?in?ICU.?In?the?conservative?oxygen?therapy?group,?the?aim?of?pulse?oxygen?saturation?(SpO2)?was?0.90-0.92?or?the?arterial?partial?oxygen?pressure?(PaO2)?was?70-100?mmHg?(1?mmHg?=?0.133?kPa),?while?in?conventional?oxygen?therapy?group?SpO2?>?0.96?or?PaO2?>?150?mmHg.?Literature?search,?quality?evaluation?and?data?extraction?was?conducted?independently?by?the?two?authors.?The?quality?of?these?study?was?evaluated?using?Cochrane?risk?deviation?assessment?tool,?and?the?relevant?data?were?analyzed?using?RevMan?5.3?software.? Results? Four?studies?were?included?in?the?analysis,?these?studies?were?assessed?as?moderate?to?high?quality?studies.?A?total?of?1?076?patients?were?enrolled,?with?539?in??the?conservative?oxygen?therapy?group?and?537?in?the?conventional?oxygen?therapy?group.?Compared?with?conventional? oxygen?therapy?group,?short-term?mortality?[odds?ratio?(OR)?=?0.66,?95%?confidence?interval?(95%CI)?=?0.50-0.87,?P?=?0.003]?and?the?incidence?of?new?organ?dysfunction?in?ICU?(OR?=?0.64,?95%CI?=?0.41-0.99,?P?=?0.04)?were?significantly?decreased?in?conservative?oxygen?therapy?group,?duration?of?mechanical?ventilation?was?significantly?prolonged?[standardized?mean?difference?(SMD)?=?17.17,?95%CI?=?7.14-27.21, P?=?0.000?8].?But?there?was?no?significantly?difference?in?90-day?mortality?(OR?=?0.83,?95%CI?=?0.59-1.17,?P?=?0.28),?new?infection?rate?in?ICU?(OR?=?0.90,??95%CI?=?0.66-1.21,?P?=?0.47),?the?length?of?ICU?stay?(SMD?=?-0.22,?95%CI?=?-1.02-0.59,?P?=?0.60)?and?total?hospitalization?time?(SMD?=?1.44,?95%CI?=?-1.43-4.31,?P?=?0.32)?between?the?two?groups.? Conclusion? Compared?with?conventional?oxygen?therapy,?conservative?oxygen?therapy?can?reduce?short-term?mortality?and?the?incidence?of?organ?dysfunction?in?critically?ill?patients,?but?cannot?decrease?the?length?of?ICU?stay?and?total?hospitalization?time.