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Clinical study aid

ACLS Review Notes

Review ACLS algorithms, medications, airway management, electrical therapy, team dynamics, and exam essentials.

For study only. Follow your current course materials, local protocols, and clinical guidance.

Quick reference
Shockable rhythmsImmediate defibrillation → CPR → Epinephrine → Amiodarone
Non-shockable rhythmsCPR → Epinephrine → Search H's & T's
BradycardiaAtropine → Pacing → Dopamine/Epinephrine
TachycardiaUnstable: cardioversion. Stable: adenosine (narrow) or amiodarone (wide).

Shockable Rhythms: VF/Pulseless VT Management

Priority: IMMEDIATE defibrillation - highest priority intervention for cardiac arrest survival

Energy Levels (Critical for Exam):

Defibrillation energy levels
Defibrillator Type Initial Shock Subsequent Shocks
Biphasic 120-200J Same or higher energy
Monophasic 360J 360J

Never delay defibrillation for IV access or intubation

Complete Algorithm Sequence:

Immediate CPR + defibrillation

Minimize pre-shock pause

Resume CPR immediately

After shock for 2 minutes (do NOT check pulse)

Rhythm check

<10 seconds every 2 minutes

Second shock

If VF/VT persists

Epinephrine 1mg IV/IO

After 2nd unsuccessful shock, then every 3-5 minutes

Third shock

If rhythm persists

Amiodarone 300mg IV/IO

After 3rd unsuccessful shock, then 150mg if needed

Consider advanced airway

After initial drugs given

Continue sequence

Until ROSC or termination of efforts

Critical Details:
  • Compression fraction should exceed 80% (minimize interruptions)
  • Switch compressors every 2 minutes (or sooner if fatigued)
  • Continuous compressions once advanced airway placed (no pauses for ventilation)
  • Consider dual sequential defibrillation if standard approach fails

Ventricular Fibrillation (VF) Rhythm

Ventricular Fibrillation (VF)

Ventricular Tachycardia (VT) Rhythm

Ventricular Tachycardia (VT)

Non-Shockable Rhythms: PEA and Asystole

Key Principle: No defibrillation - focus on high-quality CPR and reversible causes

Algorithm Sequence:

Immediate high-quality CPR

Minimize interruptions

Epinephrine 1mg IV/IO

As early as feasible, then every 3-5 minutes

Advanced airway

When feasible (after initial CPR cycles)

Aggressively search H's and T's

Throughout resuscitation

Consider ultrasound

To identify reversible causes

Critical Differences from Shockable:

  • Earlier epinephrine administration (no need to wait for failed shocks)
  • More focus on reversible causes (H's and T's analysis)
  • Consider termination if prolonged without reversible cause

Prognosis Factors:

  • Initial rhythm: PEA has better prognosis than asystole
  • ETCO2 <10mmHg after 20 minutes predicts poor outcome
  • No ROSC after 30 minutes with optimal care suggests futility

Asystole Rhythm

Asystole (Flat Line)

Bradycardia Algorithm

Assessment Framework:

Check for pulse and symptoms
Assess adequacy of perfusion
Identify underlying cause

STABLE Bradycardia (adequate perfusion):

  • Heart rate typically >50 bpm with adequate blood pressure
  • Monitor and observe
  • Treat underlying causes (hypothermia, drugs, electrolytes)
  • Prepare for deterioration

UNSTABLE Bradycardia (poor perfusion/symptoms):

  • Symptoms: Altered mental status, chest pain, hypotension, signs of shock
  • Heart rate typically <50 bpm or inadequate for clinical condition

Treatment Sequence:

Atropine 1mg IV/IO

Repeat every 3-5 minutes, maximum 3mg total

Mechanism: Blocks parasympathetic stimulation

Less effective in: Complete heart block, Mobitz Type II, transplanted hearts

If atropine ineffective or contraindicated:

Transcutaneous pacing (immediate if severe)

Dopamine infusion: 5-20 mcg/kg/min

Epinephrine infusion: 2-10 mcg/min

Expert consultation

For definitive management

Special Considerations:

  • Inferior MI: May respond better to atropine
  • Anterior MI: Often requires pacing
  • Beta-blocker/CCB overdose: May need high-dose insulin therapy

Tachycardia Algorithm

Assessment Framework:

Check pulse quality and blood pressure
Assess for symptoms of instability
Determine QRS width

(<0.12s narrow, ≥0.12s wide)

Evaluate rhythm regularity

UNSTABLE Tachycardia (immediate cardioversion):

  • Symptoms: Hypotension (SBP <90), altered mental status, chest pain, acute heart failure
  • Immediate synchronized cardioversion (don't delay for IV or sedation if critically unstable)

Energy Levels for Cardioversion:

Cardioversion energy levels for tachycardia
Rhythm Type Initial Energy
Narrow regular (SVT) 50-100J
Narrow irregular (A-fib) 120-200J
Wide regular (VT) 100J
Wide irregular Defibrillation dose (unsynchronized - treat as VF)

STABLE Tachycardia:

Narrow QRS (<0.12 seconds):
  • Regular narrow complex:
    1. Vagal maneuvers (if no contraindications)
    2. Adenosine 6mg IV rapid push → 12mg → 18mg if ineffective
    3. Beta-blockers or calcium channel blockers if adenosine fails
  • Irregular narrow complex (A-fib):
    1. Rate control: Beta-blockers, calcium channel blockers
    2. Anticoagulation if >48 hours or high stroke risk
Wide QRS (≥0.12 seconds):
  • Assume VT if unsure (treat as potentially lethal)
  • Amiodarone 150mg IV over 10 minutes
  • Procainamide alternative (if amiodarone unavailable)
  • Avoid adenosine in irregular wide complex
  • Expert consultation strongly recommended

Post-Cardiac Arrest Care (ROSC Protocol)

Immediate ROSC Management (first 20 minutes):

Confirm ROSC

Palpable pulse + measurable blood pressure

Optimize oxygenation

Target SpO2 92-98% (avoid hyperoxia)

Optimize ventilation

PETCO2 35-40 mmHg, 10 breaths/min

Treat hypotension

Maintain SBP ≥90 mmHg, MAP ≥65 mmHg

12-lead ECG immediately

Identify STEMI for emergent PCI

Advanced Post-ROSC Care:

  • Temperature management: 32-36°C × 24 hours (if comatose)
  • Avoid hyperthermia: Especially first 72 hours
  • Hemodynamic optimization: Target MAP 65-100 mmHg
  • Seizure management: Treat if present (EEG monitoring if available)
  • Glucose control: 144-180 mg/dL (avoid hypoglycemia)

Neuroprognostication:

  • Wait ≥72 hours after return to normothermia
  • Multimodal assessment: Clinical exam, imaging, electrophysiology
  • Avoid premature withdrawal of care

Epinephrine (Primary Cardiac Arrest Drug)

1mg IV/IO

Mechanism of Action:

  • Alpha-1 agonism: Vasoconstriction → ↑ coronary perfusion pressure → ↑ ROSC likelihood
  • Beta-1 agonism: ↑ heart rate, ↑ contractility, ↑ AV conduction
  • Beta-2 agonism: Bronchodilation (beneficial in respiratory arrest)

Dosing Protocols:

  • Cardiac arrest: 1mg IV/IO every 3-5 minutes (no maximum dose)
  • Bradycardia infusion: 2-10 mcg/min (titrate to effect)
  • Post-arrest hypotension: 2-10 mcg/min infusion
  • Endotracheal: 2-2.5mg in 10mL NS (if IV/IO unavailable)

Administration Details:

  • Follow with 20mL saline flush (ensures delivery to central circulation)
  • Use most proximal IV/IO access available
  • Continue until ROSC, decision to terminate, or advanced directive

Pharmacokinetics:

  • Onset: 1-3 minutes IV
  • Peak effect: 5-10 minutes
  • Half-life: 2-3 minutes
  • Metabolism: MAO and COMT in liver, kidney, other tissues
Important Considerations:
  • Limited evidence for improved survival to discharge
  • May increase ROSC rates without improving neurological outcomes
  • Higher doses not shown to be beneficial
  • Can worsen myocardial ischemia (↑ oxygen demand)

Amiodarone (Antiarrhythmic)

300mg IV/IO

Mechanism of Action:

  • Class III antiarrhythmic: Primarily blocks potassium channels
  • Also blocks: Sodium, calcium channels, alpha/beta receptors
  • Prolongs refractory period in atria and ventricles
  • Decreases automaticity and AV node conduction

VF/Pulseless VT Dosing:

  • First dose: 300mg IV/IO push (undiluted acceptable)
  • Second dose: 150mg IV/IO push if VF/VT persists
  • Maximum: 2.2g in 24 hours

Stable Wide-Complex Tachycardia:

  • Loading: 150mg IV over 10 minutes
  • May repeat: 150mg every 10 minutes as needed
  • Maintenance: 1mg/min × 6 hours, then 0.5mg/min × 18 hours

Post-ROSC Infusion Protocol:

  1. 360mg IV over 6 hours (1mg/min)
  2. 540mg IV over 18 hours (0.5mg/min)
  3. Total: 900mg over 24 hours

Administration Considerations:

  • Mix in D5W for infusions (not normal saline)
  • Use in-line filter for continuous infusions
  • Glass or polyolefin containers for >2 hour infusions (prevents drug absorption)
  • Central line preferred for continuous infusions (high osmolality)

Contraindications:

  • Sinus bradycardia without pacemaker
  • Second/third-degree heart block without pacemaker
  • Known hypersensitivity
  • Cardiogenic shock

Side Effects:

  • Hypotension (most common acute effect)
  • Bradycardia
  • QT prolongation (monitor for Torsades)
  • Pulmonary toxicity (with chronic use)

Lidocaine (Alternative to Amiodarone)

1-1.5mg/kg IV/IO

Mechanism of Action:

  • Class IB antiarrhythmic: Blocks sodium channels
  • Shortens action potential duration
  • Effective in ischemic tissue (preferentially blocks abnormal conduction)

VF/Pulseless VT Dosing:

  • Initial: 1-1.5mg/kg IV/IO push
  • Additional: 0.5-0.75mg/kg every 5-10 minutes
  • Maximum: 3mg/kg total dose

Post-ROSC Maintenance:

  • Infusion: 1-4mg/min (20-50 mcg/kg/min)
  • Reduce dose by 50% in heart failure, liver disease, age >70

Contraindications:

  • Complete heart block without pacemaker
  • Wolff-Parkinson-White syndrome with A-fib
  • Severe CHF
  • Cardiogenic shock
Toxicity Signs (Exam Important):
  • CNS effects: Confusion, slurred speech, seizures
  • Cardiovascular: Hypotension, bradycardia, asystole
  • Treatment: Supportive care, consider lipid emulsion for severe toxicity

Atropine (Anticholinergic)

1mg IV/IO

Mechanism of Action:

  • Competitive muscarinic receptor antagonist
  • Blocks parasympathetic stimulation of SA and AV nodes
  • Increases heart rate and AV conduction

Dosing for Bradycardia:

  • Dose: 1mg IV/IO push
  • Repeat: Every 3-5 minutes as needed
  • Maximum: 3mg total (full vagal blockade)
  • Minimum effective dose: 0.5mg (avoid paradoxical bradycardia)

Effectiveness Considerations:

  • Most effective: Sinus bradycardia, first-degree AV block
  • Less effective: Mobitz Type II, complete heart block
  • Ineffective: Transplanted hearts (denervated), infranodal blocks

Contraindications (Relative):

  • Narrow-angle glaucoma
  • Myasthenia gravis
  • Obstructive uropathy

Side Effects:

  • Tachycardia (expected effect)
  • Dry mouth, blurred vision
  • Confusion in elderly
  • Urinary retention

Adenosine (Purinergic Agonist)

6mg → 12mg → 18mg

Mechanism of Action:

  • Activates A1 adenosine receptors in AV node
  • Causes transient AV block (interrupts reentry circuits)
  • Very short half-life (10-30 seconds)

Dosing Protocol:

  • First dose: 6mg IV rapid push
  • Second dose: 12mg IV rapid push (if ineffective)
  • Third dose: 18mg IV rapid push (if needed)
Administration Technique (Critical):
  • Use most proximal IV (central > antecubital > hand)
  • Rapid push followed immediately by 20mL saline flush
  • Raise arm after injection (speeds central circulation)

Indications:

  • Stable narrow-complex SVT (regular)
  • Stable regular wide-complex tachycardia (if uncertain about diagnosis)
  • Diagnostic tool for wide-complex tachycardia

Contraindications:

  • Asthma/COPD (can cause bronchospasm)
  • Second/third-degree AV block without pacemaker
  • Sick sinus syndrome without pacemaker
  • Irregular wide-complex tachycardia (may precipitate VF)

Drug Interactions:

  • Dipyridamole: Potentiates effect (reduce dose)
  • Theophylline/caffeine: Antagonizes effect (may need higher doses)
  • Carbamazepine: Potentiates AV block

Expected Effects:

  • Transient asystole 3-15 seconds (warn patient)
  • Chest discomfort, dyspnea (brief)
  • Flushing, sense of impending doom

Other Critical ACLS Drugs

Vasopressin

40 units IV/IO once
  • No longer routinely recommended (replaced by epinephrine)
  • May substitute for first or second epinephrine dose

Magnesium Sulfate

2g (8 mEq) IV over 1-2 minutes
  • Primary indication: Torsades de Pointes
  • Also for: Suspected hypomagnesemia, digoxin toxicity
  • Can repeat: Once if needed

Calcium (Chloride preferred)

1g (10mL of 10% solution)
  • Indications: Hyperkalemia, calcium channel blocker overdose, hypocalcemia
  • Calcium chloride: 1g (10mL of 10% solution) IV push
  • Calcium gluconate: 3g (30mL of 10% solution) IV push
  • Do NOT mix with bicarbonate (precipitates)

Basic Airway Management

First-line airway maneuvers:

  1. Head-tilt chin-lift (no suspected spine injury)
  2. Jaw thrust (suspected cervical spine injury)
  3. Oropharyngeal airway (unconscious patients only)
  4. Nasopharyngeal airway (conscious/semiconscious patients)
Key Points:
  • Use jaw thrust if cervical spine injury suspected
  • OPA contraindicated in conscious patients (gag reflex)
  • NPA preferred for conscious/semiconscious patients

Bag-Mask Ventilation

Preferred initial approach:

  • Advantages: Immediately available, no intubation skills required
  • Technique: Two-person technique preferred (one seals mask, one bags)
  • Rate: 10-12 breaths/minute (1 breath every 5-6 seconds)
  • Volume: 500-600mL (watch for chest rise)
BVM Success Factors:
  • Proper mask seal - C-E grip technique
  • Two-person technique when possible
  • Avoid excessive ventilation (causes gastric distension)
  • Watch chest rise - indicator of adequate volume

Advanced Airway Options

Endotracheal Intubation:

  • Gold standard for definitive airway
  • Advantages: Protects against aspiration, allows precise ventilation
  • Disadvantages: Requires significant skill, interrupts CPR

Supraglottic Airways (SGA):

  • Examples: LMA, i-gel, King airway, Combitube
  • Advantages: Easier insertion, less interruption of CPR
  • Disadvantages: Less protection against aspiration
  • Equivalent outcomes to ETT in multiple studies
Advanced Airway Decision:
  • Consider SGA if intubation experience limited
  • ETT preferred for experienced providers
  • Don't delay compressions for prolonged airway attempts

Intubation Procedure

Pre-intubation Preparation:

  1. Pre-oxygenate with 100% O2 for 3-5 minutes if possible
  2. Position patient: "Sniffing position" (neck flexed, head extended)
  3. Prepare equipment: ETT, stylet, laryngoscope, suction, BVM
  4. Team coordination: Minimize CPR interruption

Intubation Technique:

  1. Insert laryngoscope from right side, sweep tongue left
  2. Advance blade to appropriate landmark (vallecula or epiglottis)
  3. Lift upward and forward (never lever on teeth)
  4. Visualize vocal cords
  5. Insert ETT through cords until cuff disappears
  6. Remove stylet and inflate cuff
  7. Confirm placement immediately
Intubation Limits:
  • Maximum attempt duration: 30 seconds
  • Maximum attempts: 3 (by experienced provider)
  • Resume CPR if unsuccessful

ETT Placement Confirmation

Primary Confirmation:

  • Continuous waveform capnography (most reliable)
  • PETCO2 >10 mmHg suggests tracheal placement
  • Persistent flat capnogram suggests esophageal placement

Secondary Confirmation:

  • Direct visualization of tube passing through cords
  • Bilateral breath sounds (auscultate at midaxillary line)
  • Absence of gastric sounds over epigastrium
  • Chest rise with ventilation
  • Condensation in ETT during exhalation

Continuous Monitoring:

  • Waveform capnography throughout resuscitation
  • Clinical assessment after any patient movement
  • Chest X-ray when feasible (tube tip 3-5cm above carina)
Gold Standard:
  • Continuous waveform capnography is most reliable
  • Never rely on single method - use multiple confirmations
  • Immediately remove if esophageal placement suspected

Post-Intubation Management

Ventilation Parameters:

  • Rate: 10 breaths/minute (1 breath every 6 seconds)
  • Tidal volume: 6-8mL/kg ideal body weight
  • PEEP: 5-10 cmH2O (avoid high pressures)
  • FiO2: Titrate to SpO2 92-98%

Continuous CPR:

  • No interruptions for ventilation once ETT placed
  • Asynchronous compressions and ventilations
  • Monitor for tube displacement

Rescue Airways (Last Resort):

  • Surgical Airway (Cricothyrotomy):
  • Indication: "Can't intubate, can't ventilate" scenario
  • Technique: Needle or surgical cricothyrotomy
  • High-risk procedure requiring surgical expertise
Post-Intubation Priorities:
  • Continuous monitoring - waveform capnography
  • Avoid hyperventilation - causes decreased ROSC
  • Maintain compressions - no interruptions for ventilations

Defibrillation (Unsynchronized)

Indications:

  • Ventricular fibrillation (VF)
  • Pulseless ventricular tachycardia (VT)
  • Unstable polymorphic VT (irregular wide complex)

Energy Selection:

  • Biphasic defibrillators: 120-200J initial, equal or higher subsequent
  • Monophasic defibrillators: 360J for all shocks
  • Unknown biphasic: Use 200J for all shocks

Defibrillation Technique:

  1. Confirm rhythm on monitor (not paddles)
  2. Charge defibrillator while CPR continues
  3. Clear area: "I'm charging, everyone clear"
  4. Visual check: Ensure no contact with patient
  5. Deliver shock: Firm pressure, both pads
  6. Resume CPR immediately (don't check pulse)

Pad/Paddle Placement:

  • Standard: Right upper chest, left lower chest
  • Alternative: Anterior-posterior (especially for A-fib)
  • Avoid implanted devices by >8cm if possible
Defibrillation Safety:
  • Remove patches/jewelry from contact area
  • Dry chest thoroughly - avoid burns
  • Ensure everyone clear before discharge
  • Resume CPR immediately - don't check pulse

Synchronized Cardioversion

Indications:

  • Unstable tachycardia with pulse
  • Stable A-fib/A-flutter (elective)
  • Stable SVT refractory to medications

Synchronization Process:

  1. Turn on sync mode (sync markers on R-waves)
  2. Confirm sync markers appear on QRS complexes
  3. Select energy level based on rhythm
  4. Charge and deliver (may require longer press)
  5. Turn OFF sync mode after each shock

Energy Levels by Rhythm:

Synchronized cardioversion energy levels
Rhythm Type Initial Energy
Narrow regular (SVT) 50-100J
Narrow irregular (A-fib) 120-200J biphasic
Wide regular (VT) 100J initial
Unstable polymorphic VT Defibrillation energy (unsynchronized)
Cardioversion Key Points:
  • Always check anticoagulation for elective procedures
  • Sedate conscious patients when time permits
  • Have atropine ready - may cause bradycardia
  • Turn off sync mode after each shock

Transcutaneous Pacing (TCP)

Indications:

  • Symptomatic bradycardia unresponsive to atropine
  • High-grade AV blocks (Mobitz II, complete)
  • Bradycardic arrest (not asystole)
  • Standby pacing in high-risk situations

TCP Procedure:

  1. Apply pacing pads: Anterior-posterior preferred
  2. Set initial rate: 60-80 bpm (higher if severe)
  3. Set initial output: Start at 0, increase gradually
  4. Identify capture: Pacing spike followed by QRS
  5. Set final output: Threshold + 10mA safety margin
  6. Confirm mechanical capture: Check pulse

Assessment of Capture:

  • Electrical capture: QRS after each pacing spike
  • Mechanical capture: Palpable pulse at set rate
  • Check femoral pulse (avoid carotid due to muscle stimulation)

TCP Settings & Safety:

  • Rate: Match clinical need (usually 60-80 bpm)
  • Output: Minimum required for consistent capture
  • Mode: Usually demand (paces only when needed)
  • Contraindications: Hypothermia, asystole, conscious patients
TCP Key Points:
  • Confirm mechanical capture - check femoral pulse
  • Provide analgesia/sedation for conscious patients
  • Anterior-posterior pad placement preferred
  • Not effective for asystole - focus on reversible causes

High-Performance Team Structure

Resuscitation Triangle Roles:

  1. Team Leader (directs overall care)
  2. Compressor (chest compressions)
  3. Airway Manager (ventilation and airway)

Additional Roles (larger teams):

  1. IV/Medication (vascular access and drugs)
  2. Monitor/Defibrillator (rhythm analysis and shocks)
  3. Recorder (documentation and timing)

Team Leader Responsibilities

Clinical Leadership:

  • Treatment decisions based on algorithms
  • Rhythm interpretation and shock decisions
  • Drug selection and timing
  • Decision to terminate resuscitation efforts

Team Management:

  • Role assignments and reassignments
  • Performance monitoring and feedback
  • Resource coordination (equipment, personnel)
  • Communication with family and receiving facilities

Situational Awareness:

  • Monitor team performance (CPR quality, drug timing)
  • Anticipate needs (prepare for algorithm branches)
  • Recognize complications (airway problems, IV issues)
  • Time awareness (duration of efforts, drug timing)

Effective Communication Strategies

Closed-Loop Communication:

  1. Command: "Give 1mg epinephrine IV"
  2. Acknowledgment: "1mg epinephrine IV" (repeat back)
  3. Action: Prepare and administer drug
  4. Confirmation: "1mg epinephrine given IV"

Clear Communication Principles:

  • Use specific terms (avoid "push some epi")
  • Speak loudly and clearly (overcome ambient noise)
  • Make eye contact when giving critical instructions
  • Use names when assigning tasks ("John, start compressions")

Information Sharing:

  • Brief team on patient condition and history
  • Announce rhythm changes clearly
  • Share time markers ("We're at 15 minutes")
  • Update on drug administration and response

High-Quality CPR Standards

Compression Parameters:

  • Rate: 100-120/minute (use metronome if available)
  • Depth: 5-6 cm (at least 2 inches, no more than 2.4 inches)
  • Recoil: Complete chest expansion between compressions
  • Position: Lower half of breastbone, heel of hand

CPR Quality Metrics:

  • Compression fraction >80% (minimize interruptions)
  • Pre-shock pause <10 seconds
  • Post-shock pause <10 seconds
  • No flow time minimized throughout

Team Performance:

  • Switch compressors every 2 minutes (or sooner if fatigued)
  • Smooth transitions during role changes
  • Continuous feedback on quality
  • Avoid leaning on chest between compressions

Constructive Intervention

Speaking Up Culture:

  • Any team member can voice concerns
  • Stop dangerous actions immediately
  • Suggest alternatives respectfully
  • Support team member who speaks up

Intervention Techniques:

  • "I need clarification..." (question approach)
  • "For safety, I recommend..." (suggest alternative)
  • "Let's pause and reassess" (if confused situation)

Team Leader Response:

  • Listen to concerns without defensiveness
  • Thank member for speaking up
  • Reassess situation based on input
  • Adjust approach if indicated

Debriefing and Improvement

Post-Event Debriefing:

  • What went well? (positive reinforcement)
  • What could improve? (constructive feedback)
  • What will we do differently? (action items)
  • Any system issues? (equipment, processes)

Continuous Quality Improvement:

  • Review CPR metrics if available
  • Analyze drug timing and appropriateness
  • Assess team communication effectiveness
  • Identify training needs

The H's (Hypo/Hyper Conditions)

1. Hypoxia

Recognition: Low SpO2, cyanosis, history of respiratory disease

Treatment: 100% oxygen, optimize ventilation, treat airway obstruction

Consider: Pneumothorax, pulmonary embolism, severe pneumonia

2. Hypovolemia

Recognition: History of bleeding, dehydration, flat neck veins

Treatment: IV fluid bolus (1-2L crystalloid), blood products if bleeding

Monitor: Response to fluid challenge, hemoglobin levels

3. Hydrogen ions (Acidosis)

Recognition: ABG pH <7.30, hyperventilation, diabetic history

Treatment: Hyperventilation, sodium bicarbonate (1 mEq/kg) if severe

Causes: DKA, renal failure, methanol/ethylene glycol poisoning

4. Hyperkalemia

Recognition: Peaked T waves, widened QRS, renal failure history

Treatment:

  • Calcium chloride: 1g IV (stabilizes membrane)
  • Insulin + D50: 10 units insulin + 1 amp D50
  • Albuterol: 10-20mg nebulized
  • Sodium bicarbonate: 1 mEq/kg IV
5. Hypokalemia

Recognition: U waves, flat T waves, diuretic use, diarrhea

Treatment:

  • Potassium chloride: 10-20 mEq/hr IV (central line preferred)
  • Magnesium replacement (hypokalemia resistant without Mg)
6. Hypothermia

Recognition: Core temperature <35°C (95°F), cold exposure

Treatment:

  • Active rewarming: Warm IV fluids, forced air warming
  • Continue CPR until rewarmed (30-32°C minimum)
  • "Not dead until warm and dead"

The T's (Toxins and Mechanical)

1. Tension Pneumothorax

Recognition: Unilateral decreased breath sounds, tracheal deviation, hypotension

Treatment:

  • Needle decompression: 14-16G, 2nd intercostal space, midclavicular line
  • Chest tube: Definitive management
  • Bilateral in arrest: Consider bilateral decompression
2. Tamponade (Cardiac)

Recognition: Beck's triad (elevated JVP, hypotension, muffled heart sounds)

Ultrasound: Pericardial effusion with collapse

Treatment: Pericardiocentesis (subxiphoid approach)

3. Toxins

Common causes: Beta-blockers, calcium channel blockers, tricyclics, opioids

Recognition: History, pill bottles, specific ECG changes

Treatment: Specific antidotes

  • Beta-blockers: Glucagon 5-10mg IV
  • Calcium channel blockers: Calcium chloride 1-3g, high-dose insulin
  • Tricyclics: Sodium bicarbonate
  • Opioids: Naloxone 0.4-2mg IV
4. Thrombosis - Pulmonary

Recognition: Right heart strain, hypoxia, risk factors (immobility, surgery)

Treatment:

  • Fibrinolytics: tPA 100mg IV or 1mg/kg
  • Consider ECMO if available
  • Anticoagulation post-ROSC
5. Thrombosis - Coronary

Recognition: ST elevation on ECG, chest pain history

Treatment:

  • Primary PCI preferred (<90 minutes)
  • Fibrinolytics if PCI unavailable (<30 minutes to treatment)
  • Antiplatelet therapy: Aspirin, P2Y12 inhibitor

Systematic Approach to H's and T's

During CPR:

  • Assign team member to consider reversible causes
  • Obtain history from family/EMS
  • Physical examination during pulse checks
  • Point-of-care ultrasound if trained
  • Laboratory studies as indicated

High-Yield Interventions:

  • Fluid bolus for suspected hypovolemia
  • Calcium chloride for suspected hyperkalemia
  • Needle decompression for suspected tension pneumothorax
  • Naloxone for suspected opioid overdose

Acute Coronary Syndrome (ACS) Recognition & Management

ACS Categories:

  1. STEMI: ST elevation ≥1mm in 2 contiguous leads or new LBBB
  2. NSTEMI: Elevated troponins without ST elevation
  3. Unstable Angina: ACS symptoms without troponin elevation

Initial Assessment (First 10 minutes):

  • 12-lead ECG within 10 minutes of arrival
  • History: Chest pain characteristics, radiation, associated symptoms
  • Physical exam: Signs of heart failure, hypotension
  • Risk stratification: TIMI score, GRACE score

STEMI Management:

  • Time-sensitive: Door-to-balloon <90 min, door-to-needle <30 min
  • Primary PCI preferred if available within 90 minutes
  • Fibrinolytic therapy if PCI unavailable

Fibrinolytic Contraindications:

  • Absolute: Active bleeding, stroke <3 months, intracranial pathology
  • Relative: Age >75, severe hypertension, recent surgery

Initial Medical Therapy (MONA):

  • Morphine: 2-4mg IV for pain (avoid if possible - may worsen outcomes)
  • Oxygen: Only if SpO2 <90% (avoid hyperoxia)
  • Nitroglycerin: 0.4mg SL q5min × 3 (avoid if hypotension)
  • Aspirin: 325mg chewed (unless allergic)

Additional ACS Therapies:

  • P2Y12 inhibitor: Clopidogrel, prasugrel, or ticagrelor
  • Anticoagulation: Heparin, enoxaparin, or bivalirudin
  • Beta-blockers: Metoprolol (avoid if heart failure/hypotension)
  • Statin: High-intensity (atorvastatin 80mg)

Stroke Recognition and Management

FAST Assessment:

  • Face: Facial droop (smile assessment)
  • Arms: Arm weakness (raise both arms)
  • Speech: Speech difficulties (repeat simple phrase)
  • Time: Time to call EMS

Additional Signs:

  • Sudden severe headache
  • Sudden vision loss
  • Sudden loss of balance/coordination
  • Sudden numbness (face, arm, leg)

Time Windows:

  • IV tPA: 0-4.5 hours from symptom onset
  • Endovascular therapy: 0-24 hours (selected patients)
  • "Time is brain" - every minute counts

Stroke Protocol:

  1. Activation: Stroke alert to hospital
  2. CT scan: Within 25 minutes of arrival
  3. Laboratory: Glucose, CBC, PT/INR, creatinine
  4. Blood pressure: Carefully managed (don't drop rapidly)
  5. Glucose: Treat if <60mg/dL

tPA Contraindications:

  • Recent stroke (<3 months)
  • Recent surgery (<14 days)
  • Active bleeding
  • Severe hypertension (>185/110 mmHg)
  • Platelets <100,000 or INR >1.7

Respiratory Arrest Management

Definition:

Absent or inadequate breathing with pulse present

Initial Management:

  1. Open airway: Head-tilt chin-lift or jaw thrust
  2. Provide ventilation: Bag-mask at 10-12 breaths/min
  3. Monitor pulse: Check every 2 minutes
  4. Prepare for intubation if prolonged

Ventilation Parameters:

  • Rate: 10-12 breaths/minute (1 breath every 5-6 seconds)
  • Volume: 500-600mL (watch chest rise)
  • Avoid hyperventilation: Can cause hypotension and gastric distension

Common Causes:

  • Opioid overdose: Naloxone 0.4-2mg IV/IN
  • Upper airway obstruction: Direct laryngoscopy, foreign body removal
  • Neuromuscular: Consider intubation early
  • Metabolic: Correct underlying cause

Progression to Cardiac Arrest:

  • Monitor closely: Pulse checks every 2 minutes
  • Prepare for CPR: If pulse disappears
  • Early intubation: Consider if cause unclear

Special Considerations:

  • Drowning: May have pulmonary edema
  • Drug overdose: Consider specific antidotes
  • Anaphylaxis: Epinephrine, steroids, antihistamines
  • Choking: Back blows, abdominal thrusts, direct removal

Key Algorithm Decision Points:

  1. Pulse present? → Determines CPR vs. supportive care
  2. Rhythm shockable? → VF/VT gets shock, PEA/Asystole gets epinephrine
  3. Stable vs. unstable? → Unstable gets immediate electrical therapy
  4. Wide vs. narrow? → Determines medication choices
  5. Regular vs. irregular? → Affects adenosine use

Drug Memory Aids:

  • "1-2-3" for Adenosine: 6mg → 12mg → 18mg
  • "3-1-5" for Amiodarone: 300mg → 150mg → 1.5mg/min infusion
  • "Every 3-5" for Epinephrine: 1mg every 3-5 minutes
  • "1mg every 3-5" for Atropine: 1mg every 3-5 minutes (max 3mg)
High-Yield Facts:
  • Most important intervention: High-quality CPR
  • Don't delay shocks for anything in VF/VT
  • Epinephrine earlier in non-shockable rhythms
  • Waveform capnography is gold standard for ETT confirmation
  • H's and T's must be considered in every arrest

Common Exam Scenarios:

  1. Witnessed VF: Immediate shock, then CPR
  2. Unresponsive, no pulse: Check rhythm, start appropriate algorithm
  3. Bradycardia with hypotension: Atropine, prepare for pacing
  4. Wide complex tachycardia: Assume VT if unstable
  5. Post-ROSC care: 12-lead ECG, avoid hyperoxia

Quality Measures:

  • Compression rate: 100-120/min
  • Compression depth: 5-6 cm
  • Compression fraction: >80%
  • Pre/post-shock pause: <10 seconds
  • Ventilation rate: 10 breaths/min with advanced airway
Remember:

ACLS is about systematic, algorithmic approaches. Know the algorithms, understand the physiology, and practice the skills. Good luck on your exam!

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