EP-lab emergencies.

Acute hypersensitivity reactions in the EP lab usually come from contrast, antibiotics, or latex. Recognition fast, IM epinephrine first, the rest in parallel. Most cases respond to a single IM dose; biphasic reactions and refractory shock are the bad outcomes to anticipate.

Iodinated contrast reactions span a wide spectrum — from mild urticaria to anaphylactic shock. Most are mild and self-limited; some need IM epinephrine and full anaphylaxis management. Premedication protocols matter for patients with known history; recognition matters for the rest.

Tamponade in the EP lab usually progresses over minutes, not seconds. The team that recognizes it early — and acts before the patient deteriorates — does the patient an enormous favor. Triggers, signs, the ICE picture, and what to do in the first 90 seconds.

Defibrillating a patient with intracardiac catheters in place is the EP lab's bread-and-butter emergency. Pads in standard position, full energy, brief catheter management, sedation considerations — the steps that separate routine VF termination from a complicated event.

Bedside drainage of pericardial fluid for tamponade physiology — the EP lab's most time-critical procedure. ICE guidance preferred; subxiphoid approach with a Tuohy or pericardial needle, confirm with contrast or echo, leave a drain.

External pacing through chest pads — fast to start, painful when awake, and the bridge to transvenous pacing or a definitive intervention. Used when symptomatic bradycardia or high-grade AV block is causing hemodynamic compromise and a transvenous wire is not yet in.

Procedural sedation in the EP lab — propofol, midazolam, fentanyl, dexmedetomidine — has a narrow margin between adequate and excessive. Knowing when to reverse, when to bag, and when to intubate is the central airway skill on EP lab cases.

What's on the crash cart, what's in the room, and what's drawn up before the case for what kind of patient. ACLS adapted to the EP-lab context — where pacing wires, ablation catheters, anticoagulation, and ongoing sedation all change the equation.