Date: January 28th, 2019

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. The Lancet 2018.

Guest Skeptic: Dr. Robert Edmonds is an emergency physician in the US Air Force in Virginia. This is Bob’s ninth visit to the SGEM.

DISCLAIMER: THE VIEWS AND OPINIONS OF THIS PODCAST DO NOT REPRESENT THE UNITED STATES GOVERNMENT OR THE US AIR FORCE.

Case: You’re working a shift in a rural emergency department when a 68-year-old man presents with a two-day course of worsening cough, shortness of breath, and fever. Their workup reveals a multifocal pneumonia with signs of sepsis.  The patient has an oxygen saturation of 98% on room air and your nurses ask if you want the patient to receive supplemental oxygen.

Background: The liberal use of supplemental oxygen therapy in acutely ill adults has a long history in the hospital, but high-quality therapy supporting its practice is unclear.

Recently, the role of oxygen therapy in non-hypoxic patients has been challenged in myocardial infarction patients, as seen in a number of trials including DETO2X-AMI

We covered the DETO2X-AMI trial on SGEM#192. The SGEM Bottom Line was that the routine administration of supplemental oxygen in patients with suspected or confirmed acute myocardial infarction who are not hypoxic does not appear to provide a patient-oriented benefit.

In the 2015 AVOID study there was some suggestion of increased MI size in the group of STEMI patients that received oxygen at 8 L/min compared to a room air control group. This study expands upon that investigation to patients with other conditions as well.

While supplemental oxygen is undoubtedly beneficial for patients acutely desaturating, in respiratory distress, or suffering from carbon monoxide poisoning just to name a few, there is widespread “indication creep” for this therapy.

In neonatal resuscitation oxygen is treated like a drug that should be appropriately dosed, with careful attention to limit its use to the minimum required amount out of a fear of harm from its excess use.

In acutely ill adults, this same concept is not yet as widespread and liberal administration is still common place.

Clinical Question: Is liberal oxygen therapy vs. conservative oxygen therapy for acutely ill adults effective and safe?

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. The Lancet 2018.

* Population: Acutely ill adults (>18 years old) with any condition requiring non-elective hospital admission and the potential to be exposed to supplemental oxygen

* Exclusions: Studies with patients who are younger than 18, pregnant, limited to patients with chronic respiratory disease, on extracorporeal life support, treated with hyperbaric oxygen or undergoing elective surgery

* Intervention: A higher oxygen target (liberal group). This was measured by FiO2, PaO2, arterial oxygen saturation measured by blood analysis or peripheral oxygen saturation measured by pulse oximeter.

* Comparison: The lower oxygen target (conservative group)

* Outcomes: The authors do not report any one outcome as a primary outcomes, but instead listed morbidity and mortality.

* Mortality: In-hospital, 30 days, and at the longest follow-up

* Morbidity: Disability measured by the modified Rankin Scale, risk of hospital-acquired pneumonia, risk of any hospital-acquired infection or hospital length of stay.

Authors’ Conclusions: “In acutely ill adults, high-quality evidence shows that liberal oxygen therapy increases mo...