Advanced Cardiac Life Support (ACLS) Algorithms & Pharmacology

Initial Assessment & Scene Management

• Immediate priorities mirror Basic Life Support (BLS); ACLS simply layers advanced interventions on top.
• Consciousness check
– Tap & shout; absence of meaningful response implies need for further assessment.
• Pulse check (carotid for adults) ≤ 10\text{ s}.
• Respiratory check (look, listen, feel) simultaneously with pulse; agonal breaths count as apneic.
• Activate Emergency Response System (ERS) EARLY
– Public setting → call 911.
– Healthcare facility → “Code Blue.”
• Closed-loop communication = speaker gives a clear order → receiver repeats back → speaker confirms (prevents task overlap & omissions).

High-Quality CPR & Oxygenation

• If no pulse or only gasping respirations, BEGIN CPR IMMEDIATELY; do not await monitor or airway equipment.
• Compression details (review from BLS but required knowledge):
– Rate 100\text{–}120\;\text{min}^{-1}.
– Depth \approx 2\;\text{in} ( 5\;\text{cm} ) for adults.
– Full chest recoil; minimize pauses (

Defibrillation Cycle (Shockable Pathway: VF/VT)

• Allow device to analyze rhythm.
– Shockable → deliver recommended joules, then resume CPR immediately for 2\;\text{min}.
– Non-shockable → do not shock; proceed to medications & CPR.
• "Stand clear" statement protects team; visually confirm no one touching patient.
• Establish IV (preferred) or IO access while CPR is ongoing.
• Medication sequence:
– Epinephrine 1\;\text{mg IV/IO q3–5 min} (first dose can follow 2nd shock).
– Amiodarone 300\;\text{mg IV/IO push} for refractory VF/pVT; second dose 150\;\text{mg} after 3\text{–}5\;\text{min}.
• Alternate: Lidocaine 1\text{–}1.5\;\text{mg kg}^{-1}, then 0.5\text{–}0.75\;\text{mg kg}^{-1} q5\text{–}10\;\text{min}; max 3\;\text{mg kg}^{-1}.
– Magnesium sulfate 1\text{–}2\;\text{g IV/IO} for torsades de pointes (polymorphic VT with prolonged QT).
• Reassess with defibrillator every 2\;\text{min}; alternate between rhythm check and drug delivery.

Non-Shockable Pathway (Asystole / PEA)

• AED/monitor shows flat line or organized electrical activity without pulse.
• DO NOT SHOCK.
• Immediate steps:
– Resume CPR 2\;\text{min} cycles.
– Obtain IV/IO.
– Epinephrine 1\;\text{mg} every 3\text{–}5\;\text{min} (may shorten to 2\text{–}3\;\text{min} as slide indicates).
– Consider advanced airway & capnography.
• Re-evaluate for conversion to shockable rhythm each 2\;\text{min}.
• Persistent asystole/PEA after exhaustive reversible-cause search → consider terminating resuscitation.

Reversible Causes (H’s & T’s)

• Hypovolemia, Hypoxia, Hydrogen ion (acidosis), Hyper/Hypo-kalemia, Hypothermia.
• Tension pneumothorax, Tamponade (cardiac), Toxins, Thrombosis (pulmonary or coronary), Trauma.
• Treat concurrently; e.g., needle decompression for tension PTX, 50\%\;\text{MgSO}_{4} for torsades, bicarbonate for severe hyperK.

Pharmacology Deep Dive

• Epinephrine: non-selective adrenergic agonist ( (\alpha{1}, \alpha{2}, \beta{1}, \beta{2}) ).
– \alpha vasoconstriction → ↑ coronary & cerebral perfusion pressure.
– \beta_{1} → ↑ inotropy & automaticity (can facilitate VF).
– Post-push technique: flush with 20\;\text{mL} crystalloid & elevate limb 10\text{–}20\;\text{s} to speed central circulation.
• Amiodarone: class III but multi-class agent; slows phase 3 repolarization, blocks Na+, Ca++, & β receptors; long half-life (>40\;\text{d}).
• Lidocaine: class Ib Na+ blocker; useful when amiodarone unavailable or contraindicated.
• Procainamide: class Ia; avoid if CHF or prolonged QT.
• Sotalol: class II & III; give only if baseline QT normal.

Bradycardia With Pulse Algorithm

• Definition: HR <60\;\text{min}^{-1}; treat only if symptomatic.
• Initial assessment: airway, oxygen, monitor, IV, 12\text{-lead} if feasible.
• Signs of instability:
– Hypotension (e.g., \text{SBP}<90\;\text{mmHg}).
– Altered Mentation.
– Shock (cool, clammy, oliguria).
– Ischemic chest pain.
– Acute heart failure.
• If none → observe.
• If yes → Atropine first-line.
– Dose 1\;\text{mg IV bolus}; repeat q3\text{–}5\;\text{min}; max 3\;\text{mg}.
– Ineffective / unavailable → Dopamine infusion 5\text{–}20\;\mu\text{g kg}^{-1}\text{min}^{-1} or Epinephrine infusion 2\text{–}10\;\mu\text{g min}^{-1}.
• Expert consultation & transcutaneous pacing (TCP) if drugs fail or high-grade block.

Transcutaneous Pacing (TCP)

• Indications: severe symptomatic sinus brady, Mobitz II, third-degree AV block, new bundle branch, ventricular escape.
• Contraindications: asystole, severe hypothermia; relative—conscious patient w/o sedation.
• Procedure:
– Place anterior–posterior electrodes.
– Turn pacer ON.
– Set demand rate \approx 60\;\text{min}^{-1} (adjust by clinical response).
– Increase mA until capture (QRS with preceding pacing spike) + palpable pulse.
– Do not check carotid pulse during pacing (electrical artifact).

Tachycardia With Pulse Algorithm

• Types: sinus tachy, A-fib, A-flutter, AVNRT/SVT, monomorphic VT, polymorphic VT, wide-complex unspecific.
• Initial steps identical: airway, oxygen, monitor, IV.
• Assess for instability (same five signs as brady).
• Unstable → synchronized cardioversion (SCV).
– Narrow regular: 50\text{–}100\;\text{J}.
– Narrow irregular (A-fib): 120\text{–}200\;\text{J biphasic}.
– Wide regular: 100\;\text{J}.
– Wide irregular: unsynchronized (defibrillation) — treat like VF.
– Consider Adenosine 6\;\text{mg IV push} if QRS narrow & rhythm regular; second dose 12\;\text{mg}.
• Stable Tachycardia
– Wide QRS (≥0.12\;\text{s}) → antiarrhythmic infusion + expert help.
• Procainamide 20\text{–}50\;\text{mg min}^{-1} until arrhythmia suppressed, hypotension, QRS↑50\%, or max 17\;\text{mg kg}^{-1}.
• Amiodarone 150\;\text{mg over }10\;\text{min}; repeat if VT recurs; then 1\;\text{mg min}^{-1} × 6\;\text{h}.
• Sotalol 100\;\text{mg (1.5 mg kg}^{-1}) over 5\;\text{min}; avoid if baseline QT prolonged.
– Narrow QRS → vagal maneuvers, adenosine, β-blocker or Ca++-channel blocker.

Return of Spontaneous Circulation (ROSC) & Post-Cardiac Arrest Care

• Goals:
– Maintain \text{SpO}{2}>94\%. – Avoid hyperventilation: target \text{ETCO}{2} 35\text{–}40\;\text{mmHg}.
– Consider advanced airway & continuous capnography.
• Manage hypotension:
– Bolus 250\text{–}500\;\text{mL} isotonic crystalloid.
– Vasopressors (norepinephrine, epinephrine, dopamine) titrated to maintain \text{MAP}≥65\;\text{mmHg} or \text{SBP}≥90\;\text{mmHg}.
• 12-Lead ECG ASAP to detect STEMI; emergent coronary reperfusion if indicated.
• Temperature management (targeted 32\text{–}36^{\circ}\text{C} for 24\;\text{h}) decreases neurologic injury.

Ethical & Practical Considerations

• Early recognition & system response (Chain of Survival) dramatically improves survival.
• Termination of resuscitation: consider downtime, underlying disease, response to interventions, patient wishes/DNR.
• Team dynamics: role assignment, closed-loop, debriefing enhance outcomes.

Quick-Reference Numbers

• Chest compression fraction goal >80\%.
• Pulse check & rhythm analysis pause <10\;\text{s}.
• Drug flush volume 20\;\text{mL}.
• Epinephrine arrest dose 1\;\text{mg}; drip 2\text{–}10\;\mu\text{g min}^{-1} for brady.
• Dopamine drip 5\text{–}20\;\mu\text{g kg}^{-1}\text{min}^{-1}.
• Atropine max cumulative 3\;\text{mg}.
• Adenosine doses 6/12\;\text{mg} rapid IV push.

Connection to Previous Material

• Builds directly on BLS: CAB sequence, high-quality compressions, early defib.
• Pharmacology recalls autonomic nervous system physiology covered in pharmacodynamics lecture.
• ECG interpretation skills (rate, regularity, QRS width) integrate with earlier electrophysiology modules.

Real-World Relevance & Scenarios

• Out-of-hospital cardiac arrest (OHCA) survival climbs from