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For acutely ill patients, oxygen saturation should not exceed 96%, an international panel recommended.
A multidisciplinary team of clinicians was brought together by The BMJ as part of the Rapid Recommendation initiative to focus on the most effective approach to oxygen therapy for patients with acute medical illness. The team used findings from an April 2018 systematic review in the Lancet. The review indicated that additional oxygen in inpatients with normal oxygen saturation led to increases in mortality. The group came to the following conclusions:
1. Strong recommendation for patients receiving oxygen therapy to have peripheral capillary oxygen saturation (SpO2) of ≤96%
2. Weak recommendation for not beginning oxygen therapy at 90%-92% saturation for patients with acute stroke or myocardial infarction (MI)
3. Strong recommendation for not beginning oxygen therapy ≥93% saturation for patients with acute stroke or MI
Oxygen therapy should be implemented carefully like other clinical interventions, noted Daniel Horner, BA, MBBS, MD, of Royal College of Emergency Medicine in London, and Ronan O'Driscoll, MD, of Salford Royal NHS Foundation Trust in Salford, England, in an accompanying editorial. Previous recommendations pointed to the 2008 British Thoracic Society guidelines of 94%-98% and the 2015 Thoracic Society of Australia and New Zealand guideline of 92%-96%, the editorialists noted.
Change is needed in when and how clinicians use oxygen, the review's corresponding author, Reed Siemieniuk, MD, PhD, of McMaster University in Hamilton, Ontario, told MedPage Today. "Right now, way too many patients receive oxygen when they shouldn't and often those who do need oxygen, receive too much," said Siemieniuk.
"Because of this, some patients die that wouldn't have otherwise. With very few exceptions, oxygen should only be given to patients with low oxygen saturations. Healthcare teams need to be careful not to give too much oxygen when it is prescribed," Siemieniuk continued.
The paper included a corresponding infographic, which serves as a decision-making resource that highlights the recommendations, the quality of the evidence on which they're based, and the benefits and harms of oxygen therapy.
The researchers highlighted that patients randomized to considerable quantities of supplemental oxygen therapy were more like to die (RR 1.21; 95% CI 1.03-1.43). "The increase in mortality was highest in the trials with the greatest increase in SpO2; this suggests a dose-response relation and strengthens the inference that excessive oxygen is a cause of death," the study authors wrote.
The data for lower limits were based on patients who had enrolled in clinical trials with baseline SpO2 >90%. The findings are more certain for patients with initially higher SpO2(>92%) because the majority of patients in the trials had a SpO2 ≥ 92% at baseline.
For instance, the largest trial evaluated found that 240 stroke patients had an initial SpO2of 90%-93.9%. Another trial looked at 1062 MI patients with an initial SpO2 ≤94%. Because these trials focused on MI and stroke patients, it is not clear whether or not these outcomes are applicable to other conditions.
For stroke and MI, the confidence intervals data concerning absolute effects showed that giving these patients additional oxygen did not contribute to an important mortality decrease. Moreover, for stroke patients, additional oxygen is unlikely to decrease disability, the investigators emphasized.
Supplemental oxygen therapy in patients with acute MI is unlikely to reduce chest pain, recurrent MI, or coronary revascularization intervention necessity, Siemieniuk's group reported.
Siemieniuk acknowledged the limitations of their work as it "does not tell us exactly when oxygen is helpful," Siemieniuk said. "The panel did not discuss patients receiving elective surgery or neonates -- our recommendations may or may not apply to these patients," Siemieniuk emphasized.
Future studies are needed to determine whether or not supplemental oxygen benefits patients that have a SpO2 <92% and presenting with a stroke or MI and to also decide whether or not supplemental oxygen is harmful for patients with other conditions marked by SpO2 85%-94%.
The need for further research "should not delay change that is already supported by a compelling body of evidence," the editorialists concluded.
Siemieniuk did not report any disclosures.
--By Ashley Lyles, Staff Writer, MedPage Today
- Siemieniuk R, et al "Oxygen therapy for acutely ill medical patients: a clinical practice guideline" BMJ 2018; 363: k4169.
- Source Reference: Horner D, O'Driscoll R "Oxygen therapy for medical patients" BMJ 2018; 363: k4436.
- Source Reference: Chu DK et al "Mortality and morbidity in acutely ill adults treated with liberal versus conservative oxygen therapy (IOTA): A systematic review and meta-analysis" Lancet 2018; 391(10131): 1693-1705.