Cardiology & Resuscitation
High-quality CPR
Compressions change survival. Push at 100–120/min, 2 to 2.4 inches (5–6 cm) deep for an adult, allow full recoil, and keep interruptions under 10 seconds. Switch compressors every 2 minutes. A pulse check takes no more than 10 seconds; if unsure, assume no pulse and start compressions.
Rhythm and medication sequence
Shockable rhythms are ventricular fibrillation and pulseless ventricular tachycardia: defibrillate as early as possible, resume compressions immediately, and give epinephrine 1 mg IV/IO after the second shock, then every 3–5 minutes. Nonshockable rhythms - asystole and PEA - get epinephrine as soon as access is available and no shocks. Amiodarone or lidocaine follows epinephrine in refractory VF/pVT. Treat reversible causes (the Hs and Ts) rather than stacking drugs.
ACS and peri-arrest
For suspected acute coronary syndrome: aspirin 324 mg chewed if not allergic or actively bleeding, nitroglycerin for chest pain with adequate blood pressure, and prompt transport to a PCI-capable facility. Nitro is contraindicated with hypotension, suspected right ventricular infarction, or recent phosphodiesterase inhibitor use.
Trap: AED prompts are not assessment - 'clear' means nobody is touching the patient, and you never delay compressions to reanalyze the rhythm.
Worked example: an adult collapses and the AED advises a shock. Deliver the shock, immediately resume compressions for 2 minutes, then reanalyze. Do not stop to check a pulse after the shock unless there is a sign of life.
Post-ROSC
Target an SpO2 of 94–99%, avoid hyperventilation, support blood pressure, and transport to a cardiac arrest center.