🩺 THIS WEEK IN EM
Oxygen Targets in Critical Illness: Are We Still Aiming at the Right Range?
Oxygen is one of the easiest therapies in the hospital to give casually. Nobody gets nervous when the sat is 99%. But the old assumption that more oxygen must be safer has been taking hits for years, especially once you start thinking about hyperoxia as an exposure rather than a harmless default.
The anchor trial here is PILOT, a pragmatic cluster-randomized, cluster-crossover trial published in NEJM in 2022. Investigators assigned mechanically ventilated critically ill adults to lower, intermediate, or higher pulse-oximetry targets: 88-92%, 92-96%, and 96-100%, respectively. Across 2,541 patients, the primary outcome of ventilator-free days through day 28 was essentially the same across groups. In-hospital mortality by day 28 was also similar, and there were no major differences in cardiac arrest, arrhythmia, myocardial infarction, stroke, or pneumothorax.
That does not mean oxygen targets never matter. It means the evidence does not support casually assuming that pushing every ventilated patient toward the high end improves outcomes. In practice, this is more a warning against reflex hyperoxia than a mandate to aggressively de-oxygenate everyone.
The real ED question is whether this changes how you should think about the non-intubated sick patient. Not in a simplistic one-to-one way. PILOT studied critically ill adults receiving invasive mechanical ventilation in the ED or medical ICU at a single academic center, not the dyspneic borderline-septic patient in bed 12. But it does push against the lazy habit of treating 99-100% as inherently better in every critically ill patient once the immediate crash phase is over. Once the patient is stabilized, there is no prize for parking every critically ill patient at an SpO2 of 100%. Avoid hypoxemia, obviously. But stop treating liberal oxygen as automatically benign.
Bottom line: In mechanically ventilated critically ill adults, lower, intermediate, and higher oxygen saturation targets produced similar ventilator-free days and similar in-hospital death by day 28, with data censored at hospital discharge, in the PILOT trial.
Semler MW, Casey JD, Lloyd BD, et al. Oxygen-Saturation Targets for Critically Ill Adults Receiving Mechanical Ventilation. N Engl J Med. 2022;387(19):1759-1769.
HFNC vs NIV: Is High-Flow Good Enough, or Are We Getting Too Comfortable With It?
High-flow nasal cannula has become one of those therapies that quietly moved from nice option to default move in a lot of departments. Part of that is deserved. It is easier to tolerate, easier to leave in place, and far easier to sell to a frightened patient than a tight mask with pressure support. The problem is that comfort is not the same thing as equivalence across every respiratory failure syndrome.
RENOVATE, published in JAMA in 2025, is the best recent attempt to sort that out. It enrolled 1,800 adults with acute respiratory failure across five clinical groups and analyzed 1,766 after postrandomization consent exclusions. Patients were assigned to high-flow nasal oxygen or NIV in five syndromes: nonimmunocompromised hypoxemia, immunocompromised hypoxemia, acute cardiogenic pulmonary edema, COPD exacerbation with respiratory acidosis, and hypoxemic COVID-19. The primary outcome was intubation or death within 7 days.
The headline is more nuanced than HFNC wins or NIV still rules. High-flow met the trial’s prespecified group-specific noninferiority criteria in four groups: nonimmunocompromised hypoxemia, acute cardiogenic pulmonary edema, COPD with respiratory acidosis, and COVID-19. It did not demonstrate noninferiority in immunocompromised hypoxemia. What high-flow clearly did better was tolerability: assigned support was used for longer on day 1 with HFNC than NIV, and discomfort scores were lower.
That is the useful read for emergency practice. This trial supports treating HFNC as a reasonable initial strategy in selected acute respiratory failure patients, especially nonimmunocompromised hypoxemia and hypoxemic COVID-19, where the signal is cleaner and tolerance may make or break success. But it does not justify turning NIV into a historical artifact, and it definitely does not support acting as if all respiratory failure syndromes behave the same just because the cannula is easier to leave on. If the physiology in front of you looks like a patient who may truly need pressure support, don't let the ease of high-flow seduce you into under-treating them.
Bottom line: In the RENOVATE trial, high-flow nasal oxygen met prespecified noninferiority criteria versus noninvasive ventilation for intubation or death within 7 days in 4 of 5 acute respiratory failure groups and was better tolerated, but important caveats remained: the immunocompromised hypoxemia group did not demonstrate noninferiority, and sensitivity analyses without dynamic borrowing were less reassuring in some smaller groups.
Maia IS, Kawano-Dourado L, Tramujas L, et al. High-flow nasal oxygen vs noninvasive ventilation in patients with acute respiratory failure: the RENOVATE randomized clinical trial. JAMA. 2025;333(10):875-890.
HEART vs EDACS: Which Chest Pain Tool Actually Helps Disposition?
Emergency physicians love chest pain tools partly because chest pain is uncomfortable medicine. The risk of missing an MI is real, the medicolegal shadow is always there, and everyone wants a pathway that feels safe, fast, and defensible. That is how we ended up with recurring score tribalism.
EDACS earned its reputation by efficiently identifying a large low-risk group. In the original derivation and validation study, the EDACS accelerated diagnostic protocol classified roughly 42% to 51% of patients as low risk with very high sensitivity for 30-day major adverse cardiac events. That is a real operational advantage. HEART, meanwhile, became sticky because it is intuitive, familiar, and easy to teach.
The more recent question is what happens after high-sensitivity troponin changes the whole ecosystem. A 2023 multicenter JAMA Network Open study found that a HEART pathway using high-sensitivity troponin was associated with higher AMI detection within 30 days and lower resource use compared with a conventional-troponin HEART pathway, with no change in 30-day all-cause mortality. Then a 2025 multicenter study looked specifically at the observation-zone patients left behind by a 0/2-hour hs-cTn protocol. Both EDACS-ADP and the HEART pathway identified groups with 1% or less 30-day risk of MI or death, but both had low efficacy in that intermediate-risk population. In other words: both pathways can identify small low-risk subsets, but neither cleanly solves the hardest chest pain patients once hs-troponin has already done the first sort.
That is the more useful shift in mindset. This is less about declaring one champion score and more about building a pathway that respects ECG findings, serial troponin behavior, symptom timing, and who you are actually willing to discharge from the gray zone. Score choice matters. Troponin-era workflow matters more. If your shop uses HEART, use it well. If it uses EDACS, that is defensible too. The higher-yield question is whether your hs-troponin pathway actually handles the intermediate-risk chest pain patient intelligently instead of turning every gray-zone result into an admission.
Bottom line: EDACS and HEART can both identify low-risk chest pain patients, but neither is magic. In current practice, how your pathway uses high-sensitivity troponin may matter more than score loyalty.
Than M, Flaws D, Sanders S, et al. Development and validation of the Emergency Department Assessment of Chest pain Score and 2 h accelerated diagnostic protocol. Emerg Med Australas. 2014;26(1):34-44.
Yore M, Sharp A, Wu YL, et al. Emergency Department Cardiac Risk Stratification With High-Sensitivity vs Conventional Troponin HEART Pathway. JAMA Netw Open. 2023;6(12):e2348351.
DiLena DD, Huang J, Rauchwerger AS, et al. Identifying low-risk patients within the observation zone of a 0/2-h high-sensitivity troponin diagnostic protocol for chest pain evaluation. Int J Cardiol. 2025;440:133730.
🔭 NEXT WEEK
Renal colic analgesia: is magnesium the better adjunct, or is lidocaine still the more useful second move?
Acute atrial fibrillation: did RAFF4 just make vernakalant the new pharmacologic cardioversion favorite?
Hip fracture pain: why are so many older adults still getting IV opioids before a nerve block?
The Hallway Consult is built for EM clinicians who want the useful version of the literature. Forward it to a colleague if it helped.
— The Hallway Consult team
The Hallway Consult is built for EM clinicians who want the useful version of the literature. Forward it to a colleague if it helped.