In this Roadside to Resus, we take the 2026 Fifth Universal Definition of Myocardial Infarction back to the patients we see in the ED and pre-hospital setting. We start with the key question, when does myocardial injury become an infarction?

From there, we work through the new primary, secondary and procedure-related MI categories—and why finding the cause matters more than attaching a number to the event.

We also get into the troponin decisions that cause debate on shift. Does a percentage rise mean more than the absolute change? And how should sex-specific thresholds and rapid rule-out pathways fit together?

Then we look beyond classical STEMI criteria for an occluded artery: posterior changes, de Winter's T waves, Wellens, and Sgarbossa in patients with known LBBB or ventricular pacing. We finish with MINOCA, unrecognised MI and a question that still divides clinicians: what should we do with suspected unstable angina when high-sensitivity troponins are negative?

Once again we'd love to hear any thoughts or feedback either on the website or via X @TheResusRoom!

Simon, Rob & James

This month we have three really clinically relevant papers that take us from a very common ED presentation, through an everyday diagnostic dilemma, and then right into a high-risk paediatric airway.

We start with abdominal pain in older adults and ask whether the history and examination are giving us as much reassurance as we think. The paper looks at how CT use, diagnostic yield, admission and surgery change with age - and whether we should think of geriatric abdominal pain as a distinct high-risk presentation.

Then move on to unexplained syncope and a large UK randomised trial of immediate 14-day ambulatory ECG monitoring. The didn't reduce recurrent syncope at one year, but it found substantially more clinically significant arrhythmias, found them earlier and led to more treatment. That leaves us with a really interesting question about the difference between diagnosing more disease and improving the outcome the patient actually experiences. What will it mean for our strategies moving forwards?

Finally, we look at paediatric emergency intubation through recorded video laryngoscopy. Which technical errors occur most often, which ones cluster around failure, and what can the airway coach spot early enough to change the attempt? As ever, we will take you through what the teams did, what they found, and whether any of it should change practice on your next shift.

Once again we'd love to hear any thoughts or feedback either on the website or via X @TheResusRoom!

Simon & Rob

We assess the pupils in almost every significantly unwell or injured patient - but how much are they really telling us? It is easy to document 'pupils equal and reactive' and move on, yet a changing pupil may be one of the earliest outward signs of a developing intracranial catastrophe. Equally, anisocoria in a completely well patient may be longstanding and entirely benign.

In this Roadside to Resus episode, we work through the anatomy and physiology of the pupillary light reflex before applying it to three important clinical situations: the blown pupil following a significant head injury, unequal or irregular pupils in a patient with a GCS of 15, and bilaterally fixed and dilated pupils in and following cardiac arrest, along with a deep dive into the evidence base.

We discuss how to decide which pupil is abnormal, the warning signs of third nerve palsy and Horner's syndrome, ocular and drug-related causes, and why serial change matters more than an isolated measurement. We also explore automated pupillometry, what the NPi can add, and why fixed pupils should never be used alone to determine futility or neurological prognosis.

Once again we'd love to hear any thoughts or feedback either on the website or via X @TheResusRoom!

Simon. Rob & James