Resources
Free references worth your time
Everything here is free to read. Guidelines first, then physiology, then the visual libraries we lean on for anatomy and ECGs.
Guidelines & consensus statements
Start here. These are the documents the exam and your unit protocols are ultimately derived from.
- Surviving Sepsis Campaign: International Guidelines 2021 (SCCM/ESICM)Fluids, vasopressor sequencing (norepinephrine first, add vasopressin, then epinephrine), MAP targets, and lactate-guided resuscitation.
- ESICM Guidelines on ARDS: definition, phenotyping and respiratory support strategies (2023)Current European guidance on HFNO, NIV, low tidal volume, PEEP, prone positioning, neuromuscular blockade and ECMO.
- A New Global Definition of ARDS (AJRCCM, 2024)Expands the Berlin definition to patients on high-flow nasal oxygen and adds SpO2/FiO2 criteria.
- SCAI SHOCK Stage Classification — 2022 Expert Consensus Update (JACC)Stages A–E of cardiogenic shock with bedside criteria; the language used in the pressor and hemodynamics modules.
- AACN Adult CCRN Certification — exam handbook and test planThe official blueprint this site is mapped to (revised exams launched November 12, 2025).
Physiology, free and rigorous
- Cardiovascular Physiology Concepts (Richard E. Klabunde, PhD)The clearest free explanations of receptor signaling, Frank–Starling, pressure–volume loops, and vascular tone. Companion to the textbook.
- Bers DM. Cardiac excitation–contraction coupling. Nature 2002The canonical review of calcium-induced calcium release, the ryanodine receptor and SERCA — the machinery every inotrope acts on.
- Grant AO. Cardiac ion channels. Circ Arrhythm Electrophysiol 2009Open-access walk through the ion channels behind each action potential phase.
- Life in the Fast Lane — Critical Care CompendiumConcise, referenced summaries of ventilation, hemodynamics and pharmacology topics.
- Deranged PhysiologyExhaustive, referenced physiology notes written for intensive care exams; excellent on ventilator mechanics and oxygen delivery.
Visual libraries
- Atlas of Human Cardiac Anatomy — University of Minnesota Visible Heart LaboratoriesFree videos and images of reanimated human hearts, plus tutorials on the conduction system, coronary system, valves, devices, congenital defects, echocardiography and physiology. Free for educational use with the UMN/Medtronic watermark and citation retained.
- UMN Atlas — Conduction System TutorialSA node to Purkinje fibers, with anatomy that maps directly onto the ECG intervals.
- UMN Atlas — Physiology TutorialCardiac cycle, pressure–volume relationships and the basis of the Frank–Starling mechanism.
- UMN Atlas — Coronary System TutorialCoronary anatomy to pair with ECG territory localization in the EKG module.
- UMN Atlas — Echocardiography TutorialStandard echo views, useful background for POCUS and VExUS content.
- Life in the Fast Lane — ECG LibraryThousands of annotated ECGs; the reference for bundle branch morphologies and OMI patterns.
- Dr. Smith's ECG BlogCase-based teaching from the group that developed the Occlusion MI paradigm.
Landmark trials cited across modules
- ARDS Network (ARMA), NEJM 2000 — 6 vs 12 mL/kg tidal volumeThe origin of lung-protective ventilation.
- Amato et al., NEJM 2015 — Driving pressure and survival in ARDSDriving pressure, not tidal volume or plateau pressure alone, best predicted survival.
- Gattinoni et al., Intensive Care Med 2016 — Mechanical powerUnifies tidal volume, driving pressure, flow, rate and PEEP into energy per minute.
- VASST, NEJM 2008 — Vasopressin vs norepinephrine in septic shockBasis for low-dose vasopressin as a catecholamine-sparing adjunct.
- ATHOS-3, NEJM 2017 — Angiotensin II for vasodilatory shockA third receptor system for refractory vasoplegia.
- SOAP II, NEJM 2010 — Dopamine vs norepinephrine in shockMore arrhythmias with dopamine; norepinephrine became first-line.
- DOREMI, NEJM 2021 — Milrinone vs dobutamine in cardiogenic shockNo difference in outcomes between the two inodilator strategies.
- Roca et al., AJRCCM 2019 — The ROX indexPredicting high-flow nasal cannula failure at the bedside.
- Beaubien-Souligny et al., Ultrasound J 2020 — VExUS grading systemHepatic, portal and intra-renal venous Doppler to grade venous congestion.
- Meyers et al., IJC Heart & Vasculature 2021 — OMI ECG findings vs STEMI criteriaThe evidence that STEMI criteria miss a large share of acute coronary occlusions.