ACLS Exhaustive Study Notes and Supplementary Material

Supplemental Oxygen and Basic Airway Devices

• Oxygen administration is frequently required for patients presenting with acute coronary syndromes (ACS), pulmonary distress, or stroke.
• Supplemental oxygen delivery ranges from $21\%$ to $100\%$ depending on the device used.
• Nasal Cannula:
  • Classified as a low-flow administration system that adds oxygen to room air during inspiration.
  • Delivers an inspired oxygen concentration of up to $44\%$.
  • Increasing the flow by $1\,L/\text{min}$ (starting at $1\,L/\text{min}$ up to a limit of $6\,L/\text{min}$) increases inspired oxygen by approximately $4\%$.
  • High-flow nasal cannula systems can provide rates up to or exceeding $60\,L/\text{min}$ with oxygen concentrations up to $100\%$.
  • Requires the patient to have adequate spontaneous respiratory effort, tidal volume, and airway protective mechanisms.
  • Indications: Arterial oxyhemoglobin saturation $\le 94\%$ ($< 90\%$ for ACS patients or $92\%$ to $98\%$ for post-cardiac arrest), minimal respiratory problems, or inability to tolerate a mask.
• Simple Oxygen Face Mask:
  • Supplies low-flow oxygen to the nose and mouth.
  • Delivers $35\%$ to $60\%$ oxygen at flow rates of $6$ to $10\,L/\text{min}$.
  • A minimum flow of $6\,L/\text{min}$ is required to prevent rebreathing of exhaled carbon dioxide ($CO_2$) and maintain increased oxygen concentration.
• Venturi Mask:
  • Enables reliable and controlled delivery of oxygen concentrations from $24\%$ to $50\%$.
  • Adjustable settings: $24\%$, $28\%$, $35\%$, and $40\%$ at $4$ to $8\,L/\text{min}$; $40\%$ to $50\%$ at $10$ to $12\,L/\text{min}$.
  • Beneficial for patients with Chronic Obstructive Pulmonary Disease (COPD) who have chronic hypercarbia and mild-to-moderate hypoxemia.
  • High oxygen concentrations may produce respiratory depression in COPD patients by eliminating the hypoxemic stimulant effect on respiratory centers; however, oxygen should never be withheld in cases of severe hypoxemia.
• Face Mask with Oxygen Reservoir (Nonrebreathing Mask):
  • Consists of a mask with an attached reservoir bag into which a constant flow of oxygen enters.
  • Provides $95\%$ to $100\%$ oxygen at flow rates of $10$ to $15\,L/\text{min}$.
  • Indications: Seriously ill patients who are responsive and spontaneously breathing but require high oxygen concentrations; patients whom acute interventions might help avoid endotracheal (ET) intubation (e.g., acute pulmonary edema, COPD, severe asthma); and those being prepared for advanced airway management.

Basic Airway Management Techniques

• Mouth-to-Mask Breaths:
  • Using a pocket mask is ideal for a single rescuer because it allows breaths and compressions from the patient's side without constant repositioning.
  • The mask is sealed against the face using the bridge of the nose as a guide.
  • The head tilt–chin lift (or jaw thrust for suspected spinal injury) is used to open the airway while pressing the mask edges firmly for a seal.
  • Deliver each breath over $1$ second, enough to cause visible chest rise.
• Bag-Mask Ventilation:
  • The device includes a self-inflating bag and a nonrebreathing valve, used with a mask or advanced airway.
  • Two-rescuer ventilation is preferred: one rescuer opens the airway and seals the mask while the second squeezes the bag.
  • An adult ($1$ to $2\,L$) bag is used to deliver a tidal volume of approximately $500$ to $600\,mL$ ($6$ to $7\,mL/\text{kg}$) over $1$ second.
  • E-C Clamp Technique: Circle the thumb and index finger around the top of the mask (forming a "C") while using the third, fourth, and fifth fingers (forming an "E") to lift the jaw angle.
  • Potential for gastric inflation and subsequent complications exists when used without an advanced airway.

Advanced Airway Adjuncts

• Laryngeal Mask Airway (LMA):
  • A tube with a cuffed, mask-like projection at the end; an acceptable alternative to an ET tube.
  • Provides equivalent ventilation to ET tubes in $72\%$ to $97\%$ of patients.
  • Insertion does not require laryngoscopy or visualization of vocal cords.
  • Proper sizing: Generally, size $5$ for men and size $4$ for women.
  • Avoid overinflating the cuff to prevent pharyngolaryngeal injury or nerve damage.
• Laryngeal Tube:
  • A supraglottic device available in single- and dual-lumen versions.
  • Isolates the airway and reduces aspiration risk compared to bag-mask ventilation.
  • Insertion involves advancing the tube in the midline along the palate until resistance is felt.
• Esophageal-Tracheal Tube:
  • An invasive device with two inflatable balloon cuffs; it typically enters the esophagus but allows ventilation regardless of placement (esophageal or tracheal).
  • Two sizes: $37F$ (patients $4$ to $5.5$ feet tall) and $41F$ (patients over $5$ feet tall).
  • Contraindications: Responsive patients with gag reflex, age $\le 16$ years, height $\le 4$ feet, known esophageal disease, or caustic substance ingestion.
  • Confirming placement: Ventilation is first attempted through the blue (proximal) lumen; if no breath sounds are heard, the bag is moved to the white/clear (distal) lumen.
• Endotracheal (ET) Intubation:
  • A cuffed tube that maintains a patent airway, allows for suctioning, and provides a route for medications (Naloxone, Atropine, Epinephrine, Lidocaine).
  • ET drug doses are generally $2$ to $2.5$ times higher than IV/IO doses.
  • Proper Sizing: $7.5$ to $8.0\,mm$ internal diameter for adult males; $7.0$ to $7.5\,mm$ for adult females.
  • Procedure: Visualize the glottic opening using a laryngoscope (curved or straight blades), watch the tube pass the vocal cords, and inflate the cuff ($10$ to $12\,mL$).
  • Ventilation Rate: Once an advanced airway is in place, deliver $1$ breath every $6$ seconds during CPR while providing continuous chest compressions ($100$ to $120/\text{min}$).

Confirmation and Monitoring of ET Tube Placement

• Continuous Quantitative Waveform Capnography: The most reliable method for confirming and monitoring ET tube position. It identifies correct placement with high sensitivity and specificity.
• Capnometry: Provides a single quantitative readout of $CO_2$ concentration at a point in time.
• Exhaled (Qualitative) CO2 Detectors: Colorimetric devices that change color in the presence of $CO_2$. Acidic drugs like epinephrine can cause false positives.
• Esophageal Detector Devices (EDD):
  • Uses anatomical principles (vacuum vs. re-expansion) to determine tube location.
  • Can yield misleading results in morbid obesity, late pregnancy, or status asthmaticus.
• Physical Examination: Involves 5-point auscultation (gastric, left/right anterior lung, left/right midaxillary) and checking for equal chest expansion. Stomach gurgling indicates esophageal intubation.

ACLS Core Rhythms: Cardiac Arrest

• Ventricular Fibrillation (VF):
  • Characterized by chaotic, asynchronous ventricular depolarization. The heart "quivers" without cardiac output.
  • ECG Features: Rate/QRS unable to determine; amplitude described as fine ($2$ to $<5\,mm$), moderate ($5$ to $<10\,mm$), coarse ($10$ to $<15\,mm$), or very coarse ($>15\,mm$).
  • Clinical Signs: Disappearance of pulse, collapse, agonal gasps, or apnea.
• Pulseless Electrical Activity (PEA):
  • Organized electrical rhythms (excluding VF/pVT) that do not produce effective myocardial contraction.
  • H's and T's (Reversible Causes): Hypovolemia, Hypoxia, Hydrogen ion (acidosis), Hypo-/hyperkalemia, Hypothermia; Tension pneumothorax, Tamponade (cardiac), Toxins, Thrombosis (pulmonary/coronary).
• Asystole:
  • A "flat line" representing the total absence of ventricular electrical activity.
  • Occurs at the end of life, following massive shock, or due to severe ischemia/hypoxia.

ACLS Core Rhythms: Nonarrest Tachyarrhythmias

• Sinus Tachycardia:
  • Rate $>100/\text{min}$; normal response to exercise, pain, fever, or hypovolemia.
• Atrial Fibrillation (AF):
  • Irregularly irregular rhythm with multiple chaotic pathways through the atria (atrial rate $300$ to $400/\text{min}$).
• Atrial Flutter:
  • Classic "sawtooth" pattern; atrial rate $220$ to $350/\text{min}$.
• Supraventricular Tachyarrhythmias (SVT):
  • Regular, narrow-complex tachycardia, often exceeding $150/\text{min}$; P waves are usually hidden in T waves.
• Ventricular Tachycardia (VT):
  • Monomorphic: Same QRS shape in every complex; rate $120$ to $250/\text{min}$.
  • Polymorphic: Marked variation in QRS complexes; often deteriorates to VF.
  • Torsades de Pointes: Unique subtype showing a "spindle-node" pattern (amplitude increasing and then decreasing). Often caused by prolonged QT interval and hypomagnesemia.

ACLS Core Rhythms: Bradycardia and AV Block

• Sinus Bradycardia: Rate $<60/\text{min}$; symptomatic rates are generally $<50/\text{min}$.
• First-Degree AV Block: Fixed PR interval $>0.20$ seconds.
• Second-Degree AV Block Type I (Mobitz I/Wenckebach):
  • Progressive lengthening of the PR interval until a QRS complex is dropped.
• Second-Degree AV Block Type II (Mobitz II):
  • Constant PR interval followed by intermittent dropped QRS complexes; more likely to be infranodal (wide QRS).
• Third-Degree AV Block (Complete Block):
  • No relationship between P waves and QRS complexes (AV dissociation).
  • Escape rates: Ventricular escape $20$ to $40/\text{min}$; Junctional escape $40$ to $60/\text{min}$.

Automated External Defibrillator (AED) and Manual Defibrillation

• AED Operation:
  • Identify clinical signs: No response, absent/abnormal breathing, no pulse.
  • Universal steps: Power on, attach pads (8 years and older must use adult pads), clear patient for rhythm analysis, deliver shock if advised, resume CPR immediately.
  • Pad Placement: Anterolateral (default), anteroposterior, anterior–left infrascapular, or anterior–right infrascapular.
• Troubleshooting & Special Situations:
  • Hairy chest: Press pads firmly; if analysis fails, pull off pads to remove hair or shave if a razor is available.
  • Water: Wipe the chest; if in water, pull the patient out.
  • Pacemakers: Avoid placing pads directly over the implanted device lump.
  • Medication Patches: Remove and wipe the area before pad attachment.
• Manual Defibrillation Energy Levels:
  • Biphasic: Device-specific ($120$ to $200\,J$); if unknown, use maximal dose.
  • Monophasic: $360\,J$ for all shocks.
  • Clearing the patient: Announce "Clear" and perform a visual check; ensure no oxygen is flowing across the chest.

Medication Access: IV and IO Techniques

• Intravenous (IV) Access:
  • The antecubital vein is the preferred site during CPR.
  • Follow peripheral drugs with a $20\,mL$ bolus of flush solution and elevate the extremity for $10$ to $20$ seconds.
• Intraosseous (IO) Access:
  • Used as a rapid, reliable route when IV access is unavailable.
  • Sites: Proximal tibia (insertion site is $1$ or $2$ finger widths medial to the tibial tuberosity), humeral head, medial malleolus, sternum.
  • Contraindications: High-proximal fractures, osteogenesis imperfecta, previous attempt in the same bone, or overlying infection.
  • Confirmation: Correct placement is indicated by the needle standing without support and the aspiration of bone marrow/blood.

Acute Coronary Syndromes (ACS) Specifics

• Right Ventricular (RV) Infarction:
  • Often presents with symptomatic bradycardia and hypotension due to excess parasympathetic tone.
  • Treatment: Administer $250$ to $500\,mL$ normal saline boluses to increase filling pressures (Starling mechanism).
• AV Block in Inferior MI:
  • Common in right coronary artery events. Narrow-complex junctional escape rhythm at $40$ to $60/\text{min}$.
  • Asymptomatic patients are monitored; symptomatic patients receive Atropine ($1\,mg$ IV every $3$ to $4$ minutes, max $3\,mg$), TCP, or chronotropic infusions (Epinephrine $2$ to $10\,\mu g/\text{min}$, Dopamine $5$ to $20\,\mu g/\text{kg/min}$).

Ethical, Legal, and Professional Dimensions

• Resuscitation Success Rates:
  • Survival from EMS-treated cardiac arrest (any rhythm) is approximately $12\%$. In-hospital survival is about $24.8\%$.
  • Bystander-witnessed VF arrest survival in the US was $38.6\%$ (2014 data).
• Good Samaritan Laws:
  • Protect lay rescuers who attempt CPR in good faith. In Canada, provincial/territorial legislation (e.g., Manitoba's Defibrillator Public Access Act) provides immunity and mandates AEDs in high-traffic areas.
• Principle of Futility:
  • CPR is considered futile if there is a less than $1\%$ chance of survival. Resuscitation should not be started if there are signs of irreversible death (rigor mortis, decapitation, decomposition, dependent lividity) or a valid DNR.
• Termination of Resuscitation:
  • Physician-led decision in-hospital; out-of-hospital providers follow TR (Termination of Resuscitation) protocols.
  • Factors suggesting poor outcome: Absence of pupillary response or motor response to pain on day $3$ post-arrest.
• Advance Directives:
  • Includes living wills and DNR orders. "Allow Natural Death" (AND) is increasingly used to replace DNR to emphasize end-of-life comfort care.
• Organ and Tissue Donation:
  • Communities should optimize retrieval of organs from brain-dead post-arrest patients. Advanced planning requires coordination between ED/ICU staff and regional procurement programs.