This Week in Emergency Medicine — Sep 29, 2026

This AudioScholar briefing is generated by artificial intelligence for healthcare professionals and trainees. It is not medical advice.

Welcome to This Week in Emergency Medicine. This week we're covering 10 notable papers spanning resuscitation and prehospital care, bedside diagnostics in cardiac arrest and pulmonary embolism, and mental health in the emergency department. Let's dive in.

We start with resuscitation, where three papers ask how we deliver the basics. In Resuscitation, Couper and colleagues report a pre-planned Bayesian secondary analysis of the PARAMEDIC-3 trial, which randomised just over six thousand adults in out-of-hospital cardiac arrest to an intraosseous-first or an intravenous-first vascular access strategy [2]. Reframed in probability terms, the intraosseous-first approach had only about an eighteen percent chance of improving thirty-day survival, meaning roughly a four in five probability that it was the inferior strategy, and for return of spontaneous circulation at handover the probability of inferiority was ninety-eight percent. The authors are careful to add that the probability of a moderate or large harm was low, so the overall effect is likely modest, but taken with the main trial this analysis gives no support to routine intraosseous-first access in adult arrest. Alongside it, also in Resuscitation, Iida and colleagues analysed more than one hundred and fifty thousand non-cardiac out-of-hospital arrests in the All-Japan Utstein Registry, comparing bystander rescue-breathing resuscitation with compression-only resuscitation [3]. Rescue breathing was given in about one in eight cases and was associated with very slightly lower thirty-day mortality and slightly fewer unfavourable neurological outcomes. The absolute differences across the whole cohort were small enough to be of uncertain clinical meaning, but the association was clearest in children and in drowning-related arrests, which is biologically coherent for a hypoxic mechanism and is consistent with existing guidance that ventilation still matters in asphyxial arrest. This is registry data with all the confounding that implies, not a trial.

The third resuscitation paper moves from what we give to how the team works. In Prehospital Emergency Care, Yang and colleagues describe a region-wide pit-crew resuscitation training programme rolled out across twenty-seven emergency medical services agencies in south-central Connecticut, studied as a before-and-after interrupted time series in nearly two thousand adults with non-traumatic arrest [4]. At the moment of implementation there was an immediate increase in sustained return of spontaneous circulation, with odds about forty percent higher, and then a gradual rise in neurologically intact survival of roughly twenty percent per four-month interval afterwards. Importantly, overall survival to hospital discharge did not change at any point. This is an uncontrolled observational design vulnerable to secular trends, so it is supportive rather than confirmatory, but it adds to the case that structured team choreography is a modifiable system variable.

The second theme is bedside diagnostics, and here two papers deal with what we can and cannot see quickly. Silwanis and colleagues, in Resuscitation, reviewed the first post-arrest electrocardiogram in two hundred and fourteen resuscitated patients at a single tertiary centre, with coronary angiography as the reference standard [5]. Of those, one hundred and one had angiographically confirmed occlusive infarction, and occlusion patterns without ST elevation clustered around a small number of recognisable morphologies, led by left-main equivalent and Smith-modified Sgarbossa criteria, with Aslanger pattern, shark-fin and hyperacute T waves less common. The finding that should give us pause is that patients with these non-ST-elevation occlusion patterns went to angiography less often than those with classic ST elevation, and the group with such a pattern who did not get angiography had the highest thirty-day mortality, at about three quarters. The authors also found that a prolonged PR segment was independently associated with reduced thirty-day survival. This is retrospective, single-centre and subject to referral bias, so it is best read as a description of a recognition gap rather than proof that angiography in these patterns rescues outcome. Turning to pulmonary embolism, the European Journal of Emergency Medicine publishes a systematic review and meta-analysis by Mani and colleagues pooling thirty-three studies and nearly four thousand patients on focused transthoracic echocardiography [8]. Individual echo signs were highly specific but insensitive, with McConnell's sign and right ventricular outflow tract early systolic notching both around ninety-eight percent specific while sensitivities ranged from almost nothing up to about two thirds. Adding lower limb deep vein ultrasound lifted pooled sensitivity to around sixty percent while keeping specificity near ninety-eight percent. The conclusion the authors draw is the familiar one stated with better numbers: a positive bedside finding can move you decisively toward the diagnosis, but a negative bedside study does not exclude pulmonary embolism, and computed tomography pulmonary angiography remains the test that rules it out.

Our third theme is prehospital and trauma procedures. In Prehospital Emergency Care, Pearson and colleagues ran a crossover study in thirty healthy volunteers comparing preoxygenation strategies when flush-rate oxygen is not available [6]. A non-rebreather mask at flush rate achieved an expired oxygen fraction of about eighty-five percent, whereas combining a non-rebreather with a nasal cannula at fifteen litres each reached about sixty-eight percent, and at twenty-five litres each about seventy-five percent. Both combinations failed the pre-specified non-inferiority margin. These are healthy volunteers, not critically ill patients, but the physiology argues against the workaround of splitting flow between two devices. From the same journal, Tomasino and colleagues compared prehospital minithoracostomy with prehospital chest drainage in ninety-four major trauma patients managed by a physician-led helicopter service [7]. Minithoracostomy was not associated with longer scene time, and recorded complications occurred in none of the fifty evaluable minithoracostomy patients versus six of ten evaluable drainage patients. The authors themselves label this hypothesis-generating: allocation was by clinician judgment, complication ascertainment differed between the two procedures, and event numbers were tiny. Rounding out trauma, CJEM brings a health records review by Al-Haimus and colleagues of nearly five thousand trauma team activations [9]. Early hypofibrinogenemia, defined as an initial fibrinogen below one point five grams per litre, occurred in only about three percent of patients, but half of those patients died in hospital. Systolic blood pressure below ninety was associated with roughly two and a half times the odds, worsening base deficit tracked with higher odds, and penetrating injury was associated with lower odds than blunt mechanisms. This is an exploratory association analysis awaiting prospective validation, not a prediction rule.

Finally, mental health in the emergency department, where two papers examine what happens after the department visit. The headline trial comes from JAMA Internal Medicine, where Musey and colleagues report the PACER randomized clinical trial: three hundred and seventy-five adults discharged from six academic emergency departments with low-risk chest pain and at least moderate anxiety, randomised to recommended primary care follow-up, peer-supported internet-based cognitive behavioural therapy, or therapist-delivered telehealth cognitive behavioural therapy [1]. Anxiety scores improved meaningfully in all three groups over twelve months. Peer-supported internet therapy beat primary care referral by just over one point on the seven-item anxiety scale, a small effect overall, but the difference reached nearly three points among patients with severe anxiety at baseline, and the odds of patient-reported global improvement were about three times higher in both therapy arms. Depression, somatisation and disability improved within groups with no significant differences between them. So this supports a scalable telehealth pathway for a very common discharge population, with the caveat that the average benefit is modest and concentrated in the most anxious patients. Complementing that, Annals of Emergency Medicine publishes work by Foster and colleagues on more than two thousand adolescents who screened positive for suicide risk in the emergency department within the Pediatric Emergency Care Applied Research Network cohort [10]. Within three months, about one in nine of those adolescents attempted suicide and about one in five had a mental health-related revisit or hospitalisation. A suicide attempt in the prior month roughly two and a half times the odds of a subsequent attempt, past nonsuicidal self-injury roughly doubled the odds, and hopelessness and prior psychiatric hospitalisation carried smaller increases. The authors frame these as factors worth weighing when assessing risk after a positive screen, not as a validated disposition tool.

If you only have time for one paper this week, make it the PACER trial in JAMA Internal Medicine [1]. It is a genuine randomized trial in one of the largest and most frustrating discharge populations we see, and it reopens the question of whether the emergency department visit itself should be a point of entry for anxiety treatment rather than a rule-out and a referral letter.

Here is what this week's evidence adds up to in Emergency Medicine. First, in adult out-of-hospital cardiac arrest the Bayesian re-analysis of PARAMEDIC-3 makes an intraosseous-first strategy more likely harmful than helpful, though the probable magnitude is small, while bystander rescue breathing shows small associated benefits concentrated in children and drowning in registry data that cannot establish causation. Second, how teams are trained may matter as much as what they administer, with a single regional pit-crew programme associated with better neurologically intact survival but no change in overall survival to discharge. Third, on diagnostics, bedside echocardiography rules pulmonary embolism in but does not rule it out, and post-arrest occlusion without ST elevation clusters into recognisable patterns that appear to be under-angiographed, both observations firm enough to inform interpretation but not yet to replace definitive testing. Fourth, in prehospital airway management, splitting oxygen flow between a mask and a nasal cannula underperformed flush-rate non-rebreather in volunteers. And fifth, for anxiety after low-risk chest pain, telehealth cognitive behavioural therapy delivers a modest average benefit that is largest in the most severely anxious, evidence that is randomised but so far not reflected in guidelines.

That's your roundup for This Week in Emergency Medicine. The full transcript and references are available on the episode page in your AudioScholar library. This is an AI-curated summary — for clinical decisions, always consult primary sources and current guidelines. See you next week.

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This is an automated summary generated by artificial intelligence, which can make mistakes. Always review the original source materials.