This Week in Emergency Medicine — Jul 14, 2026

Welcome to This Week in Emergency Medicine. This week we are covering six notable papers spanning critical care and resuscitation, diagnostic imaging pathways, and the safety of our daily emergency department procedures. Let's dive in.

We begin with diagnostic pathways and the ongoing effort to balance clinical safety with the overuse of advanced imaging. For years, emergency clinicians have relied on clinical decision rules to rule out pulmonary embolism, but patients with active cancer have traditionally been excluded or managed aggressively. A major multi-center randomized clinical trial published in JAMA, known as the Hydra study, sought to challenge the practice of proceeding directly to computed tomographic pulmonary angiography, or CTPA, in cancer patients [1]. Researchers randomized six hundred and ninety-eight patients with active cancer and suspected pulmonary embolism to either the YEARS diagnostic algorithm—which uses three clinical criteria and a variable D-dimer threshold—or to immediate CT angiography. The results were highly reassuring. Among patients where a pulmonary embolism was ruled out at baseline, only one point eight percent in the YEARS group experienced a symptomatic venous thromboembolism or possible pulmonary embolism-related death within ninety days, compared to five point five percent in the CT-only group. This met the strict criteria for noninferiority. Crucially, using the YEARS algorithm allowed clinicians to completely avoid computed tomographic imaging in twenty-two percent of the patients, without any significant difference in the proportion of negative scans between the groups. This means that for one in five of your oncology patients presenting with suspected pulmonary embolism, you can safely avoid a contrast-enhanced chest scan by applying the YEARS algorithm.

While the YEARS trial demonstrates how clinical decision rules can safely reduce imaging, another study published in the Emergency Medicine Journal reminds us that implementing these rules is heavily influenced by the clinicians themselves [4]. This prospective multi-center study looked at over eight thousand nine hundred children with minor blunt head trauma who were classified as very low risk for clinically important traumatic brain injuries based on the Pediatric Emergency Care Applied Research Network, or PECARN, rules. Despite being at very low risk, over seven percent of these children still underwent head computed tomography scans. When analyzing why, researchers found that several clinician characteristics were independently associated with ordering these unnecessary scans. Clinicians with more years of clinical experience actually had slightly higher odds of ordering a scan, with a two percent increase in odds for every additional year of practice. Furthermore, clinicians whose clinical practice consisted of less than fifty percent pediatric patients had about a fifty-five percent increase in the odds of ordering a computed tomography scan. Finally, clinicians who reported a lower tolerance for risk and a strong desire to avoid uncertain outcomes had about a thirty percent increase in scan-ordering odds. This suggests that simply knowing a clinical decision rule exists is not always enough to change practice. To safely lower imaging rates in children, we may need to involve clinicians with dedicated pediatric expertise and actively address individual biases and risk tolerances in our departments.

Next, we turn to the evolving role of ultrasound in the emergency department, looking at both a novel diagnostic application and the safety of our daily procedural practices. Point-of-care gastric ultrasound is gaining traction as a way to assess a patient's prandial status prior to emergency procedures, and a systematic review published in Internal and Emergency Medicine evaluated its diagnostic test characteristics when performed by emergency physicians [3]. Analyzing nine studies involving over six hundred and fifty patients, the review found that gastric ultrasound is highly feasible, typically taking less than five minutes to perform. In adult patients, gastric ultrasound showed good to excellent performance, with a sensitivity of eighty-six to one hundred percent and a specificity of seventy to ninety-two percent for determining whether a patient had a full or empty stomach. However, in pediatric patients, the performance was much more variable, with sensitivity between eighty-two and eighty-four percent, but specificity dropping as low as twenty-two percent in some studies. Because of the low-to-very-low quality of the included studies and a high risk of bias, the authors recommend caution before using gastric ultrasound to guide clinical decisions, though it remains a promising diagnostic adjunct that warrants further prospective study.

While we explore new diagnostic uses for ultrasound, we must also remain vigilant about the infectious risks associated with our current ultrasound-guided procedures. In May of two thousand twenty-five, the United States Centers for Disease Control and Prevention and the Department of Public Health issued a national warning regarding the contamination of non-sterile ultrasound gel with the bacteria Paraburkholderia fungorum, recommending the use of sterile gel for all percutaneous procedures. A national survey published in the American Journal of Emergency Medicine evaluated how emergency departments across the country responded to this warning, specifically focusing on ultrasound-guided peripheral intravenous line placements [6]. Out of one hundred and forty-three unique emergency departments, only about twenty-four percent made changes to their policies or gel selection following the federal recommendation, though nearly half of the responding departments were already compliant and did not need to modify their practices because they already used sterile gel. Still, the survey revealed that more than twenty percent of departments continue to use non-sterile single-use gel packets or other non-sterile lubricants for ultrasound-guided peripheral intravenous access, and some still use gel from multi-use bottles. Given the clear federal recommendations and the documented risk of healthcare-associated infections, this study highlights a significant gap in compliance and suggests that emergency departments should review their local protocols to ensure sterile gel is consistently used for all ultrasound-guided vascular access.

Our final theme brings us to critical care, where we examine prognostic tools after cardiac arrest and the safety of emergency transfusions in hemorrhagic shock. Predicting neurological recovery in comatose survivors of out-of-hospital cardiac arrest is notoriously difficult, and clinicians frequently rely on serum biomarkers like neuron-specific enolase. A decade-long retrospective cohort study published in Resuscitation analyzed six hundred and forty-six adult cardiac arrest survivors to evaluate the prognostic accuracy of peak neuron-specific enolase levels measured within seventy-two hours of arrest [5]. The researchers found that a peak level of sixty micrograms per liter or higher was highly specific for a poor neurological outcome at six months, with a specificity of ninety-eight point five percent. However, the study also revealed a critical clinical caveat: normal neuron-specific enolase levels, defined as less than seventeen micrograms per liter, do not guarantee a good recovery. In fact, over twenty-six percent of patients with normal levels still suffered a poor neurological outcome. In this normal biomarker group, poor outcomes were independently driven by older age, non-shockable arrest rhythms, non-cardiac causes of arrest, higher arterial oxygen levels, and elevated lactate. For patients with intermediate biomarker levels, poor outcomes were associated with systemic organ dysfunction and early cerebral edema. This highlights that while a very high biomarker level is a strong predictor of poor recovery, a normal level can be falsely reassuring, and clinicians must use a multimodal approach that integrates age, systemic physiology, and brain imaging rather than relying on a single lab value.

Moving from post-arrest care to acute resuscitation, the use of Rhesus D antigen-positive blood products for patients in hemorrhagic shock is becoming increasingly common in prehospital and emergency settings when Rhesus-negative products are unavailable. However, this practice has long been restricted in females of childbearing potential due to the fear of D-alloimmunization and subsequent hemolytic disease of the fetus and newborn in future pregnancies. A narrative review published in Prehospital Emergency Care synthesized the current literature, modeling studies, and epidemiological data to evaluate this risk [2]. The authors found that the actual risk of future fetal death from hemolytic disease of the fetus and newborn following an emergency transfusion of Rhesus-positive blood is exceedingly low, estimated by modeling studies to occur in fewer than one-tenth of one percent of females of childbearing potential who are exposed. This low risk is due to several cumulative factors, including the low baseline prevalence of Rhesus-negative individuals, the low rate of actual alloimmunization, reduced pregnancy rates following major trauma, and highly effective modern perinatal care. Given that rapid prehospital transfusion provides a clear, proven survival benefit for patients in hemorrhagic shock, the review concludes that withholding Rhesus-positive blood products from a critically bleeding female of childbearing potential is clinically unjustified when Rhesus-negative blood is unavailable. To mitigate the long-term risks, emergency systems should implement post-exposure protocols that include administering Rhesus immune globulin and establishing structured follow-up to detect alloimmunization.

If you only have time for one paper this week, make it the Hydra study published in JAMA [1]. This landmark randomized trial provides the high-quality evidence we have been waiting for, demonstrating that the YEARS algorithm is just as safe as routine computed tomographic pulmonary angiography for ruling out pulmonary embolism in patients with active cancer, allowing us to safely avoid unnecessary radiation and contrast exposure in nearly a quarter of these high-risk patients.

Here are the key takeaways from this week in Emergency Medicine:

First, the YEARS algorithm can be safely used to rule out pulmonary embolism in patients with active cancer, reducing unnecessary chest computed tomography scans by twenty-two percent.

Second, when treating pediatric minor head trauma, be aware of cognitive biases and risk tolerances; clinicians with more experience or those who see fewer pediatric patients are more likely to order unnecessary head computed tomography scans despite negative PECARN criteria.

Third, point-of-care gastric ultrasound is highly feasible and accurate for assessing prandial status in adults, but its low specificity in children and overall high risk of bias in current literature mean we should exercise caution before using it to guide clinical decisions.

Fourth, check your department's ultrasound-guided peripheral intravenous line protocol to ensure compliance with federal guidelines, as a significant number of institutions still use non-sterile gel or lack clear policies despite national warnings of bacterial contamination.

Fifth, when predicting neurological outcomes after cardiac arrest, remember that while a peak neuron-specific enolase level above sixty micrograms per liter is highly specific for a poor outcome, a normal level is not a guarantee of recovery, with over a quarter of patients with normal levels still experiencing poor neurological outcomes.

And finally, in females of childbearing potential presenting with hemorrhagic shock, do not delay or withhold life-saving blood products; transfusing Rhesus-positive blood when Rhesus-negative options are unavailable is supported by current evidence, as the absolute risk of future fetal complications is less than one-tenth of one percent.

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.