The Hallway Consult — Issue #11: Renal Colic, Acute AF, and Hip Fracture Pain

Renal Colic Analgesia: Magnesium Looks Better Than Lidocaine as the Adjunct Move

Renal colic is one of those problems where the first move is usually clear and the second move often isn't. Most of us know the NSAID should come first. After that, practice gets messy fast: lidocaine, opioids, more NSAID, fluids, antiemetics, and a lot of clinical improvisation.

The 2024 Annals of Emergency Medicine trial by Toumia and colleagues is useful precisely because it asks a practical ED question. Adults aged 18 to 65 with suspected renal colic were randomized after receiving 75 mg intramuscular diclofenac to one of three adjuncts: IV magnesium sulfate, IV lidocaine, or placebo. The primary endpoint was a 50% or greater reduction in pain score at 30 minutes.

Magnesium came out ahead. A 50% or greater pain reduction at 30 minutes occurred in 81.7% of the magnesium group, compared with 72.9% of the lidocaine group and 71.8% of the placebo group. Rescue analgesia was also needed less often with magnesium than with placebo. Lidocaine did not separate itself nearly as well.

The important caveat is size of effect. This was a positive signal for magnesium, but not a magic trick. The authors noted that the pain-score difference was below accepted thresholds for clinical importance, which means the result should change your thinking more than it should create a reflex order.

That does not mean every renal colic patient now needs magnesium on arrival. It does mean the common idea that lidocaine is the obvious next step after an NSAID looks shakier when you put it head-to-head against a real alternative. If you are reaching for a second analgesic move after diclofenac, magnesium now looks like the more interesting option.

Bottom line: In ED patients with suspected acute renal colic already treated with intramuscular diclofenac, adding IV magnesium sulfate produced better pain relief than either IV lidocaine or placebo, while lidocaine did not clearly outperform placebo. The effect was modest, though, so this is an adjunct option rather than a new default..

Toumia M, Sassi S, Dhaoui R, et al. Magnesium Sulfate Versus Lidocaine as an Adjunct for Renal Colic in the Emergency Department: A Randomized, Double-Blind Controlled Trial. Ann Emerg Med. 2024;84(6):670-677.

Acute Atrial Fibrillation: RAFF4 Makes Vernakalant Harder to Ignore

Procainamide has had a long run as the respectable pharmacologic cardioversion choice in the ED. It is familiar, available, and backed by a lot of comfort if not a lot of excitement. Vernakalant has always had the reputation of being fast, but not necessarily enough head-to-head ED evidence to dislodge older habits.

RAFF4 changes that. In this 2025 randomized clinical trial from 12 tertiary care emergency departments in Canada, 350 patients with acute atrial fibrillation for whom rhythm control was a safe option were randomized 1:1 to IV vernakalant or IV procainamide. The primary outcome was conversion to sinus rhythm within 30 minutes of infusion completion.

Vernakalant won that comparison cleanly. Conversion within 30 minutes occurred in 62.4% of vernakalant patients versus 48.3% of procainamide patients, an adjusted absolute difference of 15.0%. Time to conversion was also much faster with vernakalant: 21.8 minutes versus 44.7 minutes. Fewer patients in the vernakalant group went on to attempted electrical cardioversion, and adverse events were described as mild, brief, and similar between groups.

RAFF4 is less a “change your order set tomorrow” trial for U.S. emergency physicians and more a reminder that procainamide’s familiar place in acute AF cardioversion is not unassailable. If vernakalant ever becomes available in your system, this is the head-to-head trial that makes it worth knowing.

That is the kind of result that actually matters in emergency practice. Faster conversion is not just a prettier number in the paper. It means fewer prolonged bed occupations, fewer handoffs to the next shift, fewer escalations to electricity, and potentially more same-visit discharge opportunities for the right patient.

Bottom line: In the RAFF4 randomized trial, intravenous vernakalant converted acute atrial fibrillation faster and more often than intravenous procainamide, with fewer patients going on to attempted electrical cardioversion and no obvious safety penalty.

Stiell IG, Taljaard M, Eagles D, et al. Vernakalant versus procainamide for rapid cardioversion of patients with acute atrial fibrillation (RAFF4): randomised clinical trial. BMJ. 2025;391:e085632.

Hip Fracture Pain: The Opioid-First Reflex Looks Increasingly Outdated

Hip fracture is one of the most predictable pain problems in emergency medicine, and we still often manage it like an afterthought. The standard pattern is familiar: IV opioid, maybe another one, wait, reposition carefully, and accept that the patient is going to spend the next few hours hurting.

The newer nerve-block literature keeps making that look lazy. In the 2026 American Journal of Emergency Medicine trial by Altunbaş and colleagues, ED patients with hip fracture were randomized in double-blind fashion to femoral nerve block or IV fentanyl. The reported result was not subtle: femoral nerve block produced superior analgesia, fewer side effects, and a lower need for rescue analgesia.

That matters because this is exactly the population where opioid side effects are costly. These are older patients, often frail, often delirium-prone, and often heading into a long preoperative wait. A strategy that improves pain while reducing rescue opioid requirements is not just a comfort win. It is a workflow win and probably a brain-preservation win too.

The real barrier now is not evidence. It is habit, training, and whether your department treats regional anesthesia like a normal emergency medicine skill or like a special occasion procedure.

Bottom line: In a 2026 randomized double-blind ED trial, femoral nerve block provided better analgesia, fewer side effects, and less rescue-opioid use than intravenous fentanyl for hip fracture pain.

Altunbas E, Kudu E, Unal E, Gunduz OH. Femoral nerve block vs IV fentanyl for hip fracture pain in the emergency department: A randomized double-blind clinical trial. Am J Emerg Med. 2026;99:359-364.

The Hallway Consult is built for EM clinicians who want the useful version of the literature. Forward it to a colleague if it helped.

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— The Hallway Consult team