Claim the Room
The monitor blares. Fifteen people sprint in. There's no pulse, and the attending is a zip code away. Someone has to lead, out loud, immediately: "I am leading this code."
Why say it out loud: hospitals with the highest in-hospital cardiac arrest (IHCA) survival use a pit crew model, structured role assignments running in parallel, the way a NASCAR crew works a car.
The leader does not do compressions. The leader does not push meds. The leader thinks.
Stand at the foot of the bed. Be visible. Calm on the surface, working hard underneath.
Clear the Room and Assign Roles
Too many people is chaos. First order of business: anyone standing around either gets a job or leaves. Eye contact, name, task.
"Sarah, compressions." "Mike, airway." "Jen, med cart and timer." "Alex, recorder." "David, you're swapping in for compressions in 2 minutes." "Chris and Maria, you're my runners, stay right outside the door."
Everyone else: "Thank you for being here. We've got enough hands. If you want to help, rotate in for compressions. Otherwise please step out." Respectful. Clear.
Closed-Loop Communication
The most underrated skill in resuscitation. Leader: "Give 1 mg epi IV push." Nurse: "1 mg epi IV push, given." If nobody repeats it back, it didn't happen.
The counterintuitive part: the best-run codes are quiet. No side conversations. If someone has an idea, they walk over, say it at normal volume, and the leader announces the plan. Think air traffic control tower, not a stadium.
Chaos is not the same as effort. Calm is competence.
CPR Quality Is the Whole Game
Forget the drugs for a second. The single biggest determinant of survival is CPR quality.
- Rate: 100 to 120/min
- Depth: at least 5 cm, but under 6 cm. Yes, there is a ceiling.
- Full chest recoil
- Chest compression fraction: at least 60%, aim for 80% or higher
- Swap compressors every 2 minutes. Depth starts declining around 90 seconds, even when the compressor doesn't feel tired.
Lower the bed. Get a backboard underneath. Compressions on a mattress are compressions on a waterbed.
Epinephrine: Timing Matters
Epi 1 mg IV/IO every 3 to 5 minutes, roughly every other CPR cycle.
| Rhythm | Approach |
|---|---|
| Nonshockable (PEA/asystole) | Give epi early. Earlier epi tracks with better ROSC across the evidence. |
| Shockable (VF/pVT) | Prioritize defibrillation first. Epi comes after initial shocks fail. |
PARAMEDIC2 post-hoc analysis: epinephrine's benefit over placebo converges toward zero at roughly 20 minutes of pulselessness. Early epi matters because the window closes.
High-dose epinephrine has shown no survival benefit in randomized trials.
Calcium and Bicarbonate: the Sacred Cows
Both drugs are reached for reflexively during codes. Neither holds up when tested properly.
Calcium (COCA trial, Vallentin et al, JAMA 2021): stopped early for signal of harm. ROSC occurred in 19% of the calcium group versus 27% of placebo, RR 0.72 (95% CI 0.49 to 1.03). A trend toward harm, not benefit.
The 2020 and 2025 AHA guidelines: routine calcium is not recommended. Reserve it for confirmed hyperkalemia or calcium channel blocker overdose.
Sodium bicarbonate (BIHCA trial, Granfeldt et al, JAMA, published June 11, 2026): the first purpose-built RCT of bicarbonate in in-hospital cardiac arrest. 779 analyzed patients, up to 100 mmol of bicarbonate versus placebo, given after at least one epinephrine dose.
Sustained ROSC: 39% bicarbonate versus 37% placebo, no significant difference. 30-day survival and good neurologic outcome also did not differ significantly, though both numerically favored the bicarbonate group in this trial (12% vs 9.1% survival; 8.1% vs 5.4% good neuro outcome), a detail worth knowing even though the trial's bottom-line conclusion is correctly "no significant difference."
Bicarbonate is still given in roughly half of US in-hospital arrests despite this. Reserve it for hyperkalemia, tricyclic overdose, or known severe metabolic acidosis.
If you don't have a specific indication, leave both in the drawer.
Amiodarone vs Lidocaine
For shock-refractory VF/pVT, the ALPS trial found both drugs improved survival to hospital admission versus placebo, but neither definitively improved survival to discharge in the overall trial population.
In bystander-witnessed arrests specifically, both drugs did improve discharge survival.
Amiodarone given within 8 minutes of ALS team arrival improved both survival to discharge and functional outcome.
Both drugs have a narrow, time-dependent window. The 2025 AHA treats amiodarone and lidocaine as equivalent options. Pick one, give it early, move on.
Refractory VF: What's New
Still in VF after 3 shocks and amiodarone? The DOSE VF trial (NEJM 2022) tested two alternate defibrillation strategies against standard care.
| Strategy | Survival to discharge |
|---|---|
| Double sequential external defibrillation (DSED) | 30.4% |
| Vector-change (anterior-posterior pads) | 21.7% |
| Standard defibrillation | 13.3% |
Caveats from the 2025 AHA guideline: the benefit was concentrated in incessant VF (about 17% of enrolled patients), not recurrent VF. When analyzed by treatment actually received rather than intention-to-treat, the benefit was not significant. AHA 2025 rates the usefulness of both strategies as "not established" (Class 2b); ILCOR's softer wording is "may be considered." Not yet standard of care.
Practical move: if VF persists after 3 shocks, at minimum switch pad position to anterior-posterior. It's free, it's easy, and it has trial data behind it.
Think: The H's and T's
While CPR runs, the leader's real job is diagnosing why the patient arrested.
The H's: Hypovolemia, fluid and blood. Hypoxia, confirm the tube, check ETCO2. Hydrogen ion (acidosis), context-dependent bicarb. Hypo/hyperkalemia, point-of-care testing, empiric calcium if suspected. Hypothermia, check the temperature.
The T's: Tension pneumothorax, needle or finger thoracostomy. Tamponade, bedside echo. Toxins, lipid emulsion and specific antidotes. Thrombosis (coronary), STEMI workup toward the cath lab. Thrombosis (pulmonary), tPA, consider ECPR.
Fast POCUS during pulse checks, or TEE if available, is the fastest way to narrow this list in real time.
Cheat Sheet & Primary Sources
| # | Action |
|---|---|
| 1 | Announce leadership: "I'll be leading this code" |
| 2 | Clear the room, assign roles, extras rotate compressions or become runners |
| 3 | CPR quality: 100-120/min, ≥5 cm, full recoil, swap q2min |
| 4 | Rhythm check q2min: shockable → shock → resume CPR immediately |
| 5 | Epi 1 mg q3-5min: early for PEA/asystole, after failed shocks for VF |
| 6 | Amiodarone or lidocaine for refractory VF/pVT, give early |
| 7 | Think H's and T's, POCUS during pulse checks |
| 8 | Calcium/bicarb only for specific indications |
| 9 | Refractory VF: change pad vector (A-P), consider DSED |
| 10 | Closed-loop everything: if it wasn't repeated back, it wasn't heard |
Primary sources checked for this guide:
- AHA 2025 Part 4: Systems of Care. Circulation. 2025;152:S116-S148.
- AHA 2025 Part 7: Adult BLS. Circulation. 2025;152:S182-S218.
- AHA 2025 Part 9: Adult ALS. Circulation. 2025;152:S234-S280.
- AHA 2023 Focused Update on ACLS. Circulation. 2024;149:e254-e273.
- Granfeldt A, Kirkegaard BL, Vallentin MF, et al. Sodium Bicarbonate for In-Hospital Cardiac Arrest: A Randomized Clinical Trial (BIHCA). JAMA. Published online June 11, 2026.
- Vallentin MF, Granfeldt A, Meilandt C, et al. Effect of Intravenous or Intraosseous Calcium vs Saline on ROSC in Adults With OHCA (COCA trial). JAMA. 2021;326(22):2268-2276.
- Cheskes S, et al. Defibrillation Strategies for Refractory Ventricular Fibrillation (DOSE VF). N Engl J Med. 2022. PMID 36342151.
- Kudenchuk PJ, et al. Amiodarone, Lidocaine, or Placebo in Out-of-Hospital Cardiac Arrest (ALPS trial). N Engl J Med. 2016.
- Perkins GD, et al. A Randomized Trial of Epinephrine in Out-of-Hospital Cardiac Arrest (PARAMEDIC2). N Engl J Med. 2018. DOI 10.1056/NEJMoa1806842.
- Idris AH, Guffey D, Pepe PE, et al. Chest compression rates and survival following out-of-hospital cardiac arrest. Crit Care Med. 2015. PMID 25565457.
- Andersen LW, et al. In-Hospital Cardiac Arrest: A Review. JAMA. 2019. PMID 30910560.