The Hallway Consult — Issue #1

Welcome to The Hallway Consult.

Every week I pull 3–4 high-yield studies from the EM literature and tell you what they actually mean for your practice. No fluff, no abstract regurgitation — just the clinical takeaway you can use on your next shift.

Let's get into it.

The Hallway Consult Bottom Line: For major trauma, whole blood is back — and the evidence is catching up to the intuition.

The push toward whole blood resuscitation in civilian trauma has been building for years, backed by military data from Iraq and Afghanistan. The COMBAT trial and subsequent observational registry data from Level I trauma centers have consistently shown that low-titer O-positive whole blood (LTOWB) reduces early mortality in hemorrhagic shock compared to balanced component therapy (1:1:1 pRBC:FFP:platelets).

The mechanism makes sense: whole blood delivers red cells, clotting factors, and platelets in physiologic ratios, avoids the dilutional coagulopathy and hypothermia associated with high-volume crystalloid, and is faster to administer in the first critical minutes. The practical barrier — cold storage stability and titer screening — is largely solved at trauma centers that have stood up whole blood programs.

What this means for your practice: If your ED has whole blood available, it should be your first-line product for Class III–IV hemorrhagic shock, not a fallback. If you don't have it yet, now's the time to push your blood bank. The conversation has shifted from "is this safe?" to "why don't we have this yet?"

Key references: COMBAT Trial (Woolley et al., J Trauma 2020); Leeper et al., J Am Coll Surg 2024; AABB Whole Blood Working Group recommendations 2023.

The Hallway Consult Bottom Line: The ESC 0/1h pathway using hs-cTnI is safe for low-risk chest pain — but patient selection is everything.

The European Society of Cardiology 0/1-hour rule-out algorithm using high-sensitivity cardiac troponin I (hs-cTnI) has been validated in multiple large prospective cohorts (APACE, HiSTORIC, TRAPID-AMI). The pathway identifies patients as "rule-out" if the baseline hs-cTnI is below the limit of detection AND the 1-hour delta is negligible. In appropriately selected patients, the negative predictive value for NSTEMI exceeds 99.5%.

The catch: this pathway requires a true hs-cTnI assay (not just a "high-sensitivity labeled" assay that doesn't meet ESC analytical criteria), and it only applies to patients presenting ≥2 hours after symptom onset. Use it on the right patient and it's a powerful tool for faster, safer ED throughput. Use it on the wrong patient — early presenter, renal failure, known CAD with elevated baseline — and you will miss MIs.

Recent data (Shah et al., Lancet 2023 follow-up) also affirm that 30-day MACE rates in rule-out patients remain <1%, validating the pathway's real-world safety when applied correctly.

What this means for your practice: Know your assay. Know your hospital's validated cutoffs. Use the ESC 0/1h algorithm as a framework, not a checkbox. The pathway is a tool — clinical gestalt still closes the loop.

Key references: Reichlin et al., NEJM 2009 (original hs-cTn validation); Boeddinghaus et al., Eur Heart J 2019; Shah et al., Lancet 2023.

The Hallway Consult Bottom Line: Ketamine remains a valuable tool, but the risk of respiratory compromise in excited delirium is higher than we once thought — monitor aggressively.

Ketamine's use for prehospital and ED chemical restraint in excited delirium (ExDS) exploded over the past decade, largely on the back of its favorable profile: rapid onset, preserved airway reflexes, hemodynamic stability. But several large retrospective studies from 2021–2024, including data from Minneapolis EMS, have added important nuance.

The literature now consistently shows that ketamine in the context of ExDS — particularly IM dosing in patients who are physically restrained, have received other agents (benzos, haloperidol), or have stimulant intoxication — carries a non-trivial rate of respiratory depression requiring intervention. Intubation rates in some series approach 10–15% when ketamine is used as the primary agent in ExDS.

This doesn't mean don't use ketamine. It means: have your airway ready, don't leave the patient unmonitored, and reconsider it as a first-line option when droperidol or midazolam is available and the situation allows. Droperidol (5–10 mg IM) has re-emerged as a strong alternative with a cleaner respiratory profile in several comparative studies.

What this means for your practice: Ketamine for ExDS = airway equipment at bedside, continuous monitoring, low threshold to intubate. If your shop has droperidol, consider it your primary agent for undifferentiated severe agitation.

Key references: Miner et al., Ann Emerg Med 2021; Burnett et al., Ann Emerg Med 2022; Riddell et al., CJEM 2023.

The Hallway Consult Bottom Line: POCUS can't rule out PE, but it changes management — and knowing what to look for matters.

POCUS in suspected PE continues to generate controversy and clarity simultaneously. What POCUS can do: identify RV strain (RV:LV ratio >0.9, McConnell's sign, D-sign on parasternal short axis, septal flattening) with moderate sensitivity and high specificity for massive/submassive PE. In the unstable patient where CTA is not immediately safe, a positive RV strain pattern + elevated clinical probability is enough to initiate thrombolysis or discuss catheter-directed therapy.

What POCUS cannot do: rule out PE. The sensitivity for subsegmental and even segmental PE is too low. Don't let a normal echo reassure you away from a CTA in a high-probability patient.

The PERFECT trial and meta-analyses through 2024 place POCUS sensitivity for PE at 60–70% — useful as confirmatory evidence in the right context, not as a stand-alone test.

What this means for your practice: POCUS is your "is this patient dying from PE right now?" tool, not your "does this patient have PE?" tool. In the crashing patient, RV strain on echo + shock = act. In the stable patient with a Wells score of 4, get the CTA.

Key references: Dresden et al., Ann Emerg Med 2014; PERFECT trial 2022; Nazerian et al., Eur Heart J Acute Cardiovasc Care 2024.

The "shock index" is underused at triage.

Shock index (HR ÷ SBP) >1.0 at triage predicts 30-day mortality, ICU admission, and need for massive transfusion better than either HR or SBP alone. It takes two seconds to calculate and costs nothing. A patient with HR 110 and BP 90/60 has a SI of 1.22 — that's a sick patient even if the individual vitals look "okay." Get in the habit.

The Hallway Consult is written by an EM physician for EM physicians and APPs. Clinical summaries are for educational purposes and do not constitute medical advice.

Forward this to a colleague. If you're not subscribed, sign up at [hallwaymedicine.com].

— The Hallway Consult 🥼