Chapter 15 Paramedic Airway Lecture

Airway Introduction and Importance

• Establishing and maintaining a patent airway and ensuring effective oxygenation and ventilation are vital to patient care.
• The human body requires a constant supply of oxygen; failing to stabilize an airway compromises all subsequent care.
• Respiratory system role: brings in oxygen and eliminates carbon dioxide; vital organs fail to function properly if the airway/ventilation/oxygenation is interrupted.
• Failure to manage the airway is a major cause of preventable death in the prehospital setting.
• Core goals to focus on:
  • Early detection of airway problems
  • Rapid and effective intervention
  • Continual reassessment
• Appropriate airway management actions:
  • Open and maintain a patent airway
  • Recognize and treat obstructions
  • Assess ventilation and oxygenation status
  • Administer oxygen
  • Provide ventilatory assistance

Ventilation, Oxygenation, and Respiration

• Ventilation: physical act of moving air into and out of the lungs; two phases:
  • Inhalation (active, muscular part of breathing)
  • Exhalation (passive process)
• Ensure adequate ventilation at all times.
• Pathophysiology of respiration:
  • Disruption of pulmonary ventilation, oxygenation, and respiration causes immediate effects; must recognize and correct immediately.
  • Every cell requires a constant supply of oxygen to survive.
  • Perfusion: circulation of blood in adequate amounts to meet cellular needs.

Hypoxia and Airway Assessment

• Hypoxia: tissues and cells do not receive enough oxygen.
• Signs of hypoxia vary:
  • Early: restlessness, irritability, tachycardia, anxiety
  • Late: altered mental status, weak pulse, cyanosis
• Patient assessment: Airway evaluation is critical for quality care.
• Assessing airway:
  • Determine if airway is patent (airway patency checks):
  • Snoring
  • Vomitus draining from the mouth
  • Gurgling sound during breathing
  • Secretions pooling in the mouth may indicate a depressed or absent gag reflex.
• Adequate breathing indicators:
  • Patient is responsive, alert, able to speak
  • Rate between $12-20$ breaths/min
  • Adequate depth and regular pattern of inhalation/exhalation
  • Clear and equal breath sounds

Normal and Abnormal Breathing Patterns

• Normal respiratory rate ranges (as per Table 15-3):
  • Adults: $12-20$ breaths/min
  • Children (ages $1-12$ to $18$ years): $18$ breaths/min
  • Infants (ages $1 ext{ month} - 1 ext{ year}$): $30-53$ breaths/min
• Inadequate breathing patterns (abnormal):
  • Cheyne-Stokes respirations: gradually increasing rate and depth followed by gradual decrease with apnea; brainstem insult
  • Kussmaul respirations: deep, rapid respirations (common in diabetic ketoacidosis)
  • Biot (ataxic) respirations: irregular pattern with apnea; increased intracranial pressure
  • Apneustic respirations: prolonged inhalation with short exhalation; brainstem insult
  • Agonal gasps: slow, shallow, irregular or occasional gasps; may occur after cardiac arrest as brain signals attempt respiration
• Note: Abnormal respiratory patterns are important indicators of underlying pathology, requiring immediate evaluation and intervention.

Breath Sounds and Oxygenation Monitoring

• Assessment of breath sounds: auscultate with stethoscope; aim for clear, equal sounds bilaterally.
• Ventilation timing:
  • Normal inspiratory/expiratory (I/E) ratio: $ext{I:E} = 1:2$
  • Lower airway obstruction: expiratory phase prolonged; I:E may be $1:4 ext{ or } 1:5$
  • Tachypnea: expiratory phase shortened; I:E may approach $1:1$
  • Expiration may be short with tachypneic patients
• Pulse oximetry:
  • Pulse oximeter measures oxygen saturation of hemoglobin (Hb)
  • Normal SpO2: greater than 95 ext{%}
• Hemoglobin types and devices:
  • Oxyhemoglobin (HbO2)
  • Reduced hemoglobin
  • CO-oximeter determines HbO2 saturation (percentage of oxygenated Hb relative to total Hb)

End-Tidal CO2 and Capnography

• End-tidal CO2 (ETCO2) assessment:
  • Waveform capnography provides real-time CO2 information and a graphic waveform
  • Quantitative waveform capnography is recommended for monitoring initial and ongoing placement of advanced airway devices
  • Capnography indicates chest compression effectiveness and can detect return of spontaneous circulation (ROSC)
• Normal capnographic waveform features: contour, baseline, rate, and rise of CO2
• Waveform phases (nonintubated and intubated contexts):
  • Phase I (A-B): initial stage of exhalation
  • Phase II (B-C): expiratory upslope
  • Phase III (C-D): expiratory/alveolar plateau
  • Phase IV (D-E): inspiratory downstroke
• Abnormal capnographic waveforms and interpretations:
  • Hypoventilation: tall waveforms and high ETCO2
  • Hyperventilation: small waveforms and low ETCO2
  • Obstructions/bronchospasm, asynchronous breathing, and other patterns can appear (see visual references in course material)
• Uses of waveform capnography in nonintubated patients:
  • Assess underlying pathophysiology (e.g., pulmonary air trapping)
  • Gauge effectiveness of treatment

Airway Obstruction and Management

• Common causes of airway obstruction:
  • Foreign body
  • Tongue
  • Laryngeal edema
  • ETT out/not connected
  • Sudden loss of circulation
• Laryngeal spasm and edema:
  • Laryngeal spasm: spasmodic closure of vocal cords, completely occluding airway
  • Laryngeal edema: glottic opening narrows or closes; causes include epiglottitis, anaphylaxis, inhalation injury
  • Relieving strategies may include aggressive ventilation; forceful upward jaw pull; may require muscle relaxants; transport to hospital for evaluation
• Aspiration:
  • Increases mortality; can obstruct airway, damage bronchiolar tissue, introduce pathogens, impair ventilation
  • Ensure suction is readily available; administer supplemental oxygen
• Tongue obstruction (altered LOC):
  • Partial obstruction: snoring respirations
  • Complete obstruction: no respirations
  • Simple to correct with manual maneuvers
• Foreign body obstruction signs: choking, gagging, stridor, dyspnea, aphonia/dysphonia

Aspiration and Gastric Distension Management

• Aspiration consequences: airway obstruction, pulmonary damage, infection risk
• Aggressive airway management includes suction readiness and rapid sequence strategies when indicated
• Gastric distension risks with bag-valve mask ventilation:
  • Promotes regurgitation and aspiration risk
  • Pushes diaphragm upward, limiting lung expansion
  • Signs include abdominal distension and increased resistance to BVM ventilation
• Invasive gastric decompression:
  • Nasogastric tube: decomposes stomach and reduces intraabdominal pressure; decreases regurgitation risk
  • Orogastric tube: inserted via mouth; no nasal bleeding risk; safer with facial trauma; allows larger tubes

Oxygen Therapy and Delivery Devices

• Supplemental oxygen is indicated for any patient with potential hypoxia
• Indications for oxygen delivery:
  • Respiratory distress
  • Suspected or documented hypoxemia
  • Reassess frequently and adjust based on clinical condition and breathing adequacy
• Oxygen delivery devices:
  • Venturi mask: draws room air into the mask along with oxygen; can deliver 24 ext{%}, 28 ext{%}, 35 ext{%}, 40 ext{%} oxygen
  • Bag-mask device (BVM): used with oxygen; ensure chest rises and falls; if not, reposition head or insert airway; check for airway obstruction; manage gastric distension

Airway Assessment Tools and Techniques

• LEMON mnemonic for airway assessment:
  • Look externally: identify factors that could complicate intubation (short/thick necks, morbid obesity, dental conditions)
  • Evaluate 3-3-2 rule: three measurements to predict ease of laryngoscopy
• 3-3-2 evaluation:
  • 3: Mouth opening width > 3 fingers is ideal
  • 3: Mandible length > 3 fingers is ideal
  • 2: Distance from hyoid bone to thyroid notch is about 2 fingers
• Mallampati classification (oropharyngeal structures visible in upright seated patient):
  • Class I: entire posterior pharynx visible
  • Class II: posterior pharynx partially visible
  • Class III: only base of uvula visible
  • Class IV: no posterior pharyngeal structures visible
• Obstruction assessment and visualization considerations:
  • Note anything interfering with visualization or ET tube placement (foreign body, obesity, hematoma, masses)
  • Sniffing position is ideal for airway alignment; neck mobility problems common in trauma and elderly

Indications and Considerations for Endotracheal Intubation

• Indications:
  • Failure to maintain and protect airway
  • GCS score ≤ 8
  • Failure to ventilate or oxygenate despite CPAP, O2, BVM support
  • Anticipation of deterioration or potential laryngeal edema
• Complications and precautions:
  • Hypoxia with multiple attempts; limit each intubation attempt to ≤ 30 seconds
  • Equipment malfunction; test equipment at start of shift (blades and handle)
  • Risk of dental/soft tissue damage
  • Rough handling can cause airway injury; lift blade and handle as a unit; avoid using teeth as a fulcrum
  • Esophageal intubation and endobronchial intubation can cause life-threatening hypoxia or ventilation-perfusion mismatch
• Other side effects and considerations:
  • Recognition of airway displacement or dislodgement risks
  • Endotracheal intubation challenges require backup strategies and rapid decision-making

Preparing for Intubation: RSI and Sedation/Paralysis

• Rapid Sequence Intubation (RSI):
  • Safe, smooth, rapid sedation and paralysis followed immediately by intubation; generally used for patients unable to cooperate
• Preoxygenation:
  • Ensure adequate preoxygenation of all patients
  • If spontaneously breathing with adequate tidal volume: apply high-flow oxygen via nonrebreathing mask
  • If hypoventilating: assist ventilations with a bag-mask device and high-flow oxygen
• Premedication and airway prep:
  • Succinylcholine commonly used as paralytic; atropine sulfate should be available to reduce potential bradycardia
• Sedation and paralysis timing:
  • As soon as patient is sedated, administer paralytic; onset of paralysis should be complete within 2 minutes
  • Signs of adequate paralysis include: apnea, laxity of the mandible, loss of eyelash reflex
• Intubation procedure:
  • RSI is consistent with other intubation situations; if unable to intubate promptly, ventilate with 100% oxygen and reassess
  • If ventilating with BVM, ventilate slowly to avoid gastric insufflation
• Maintenance of paralysis and sedation:
  • Additional paralytics may be needed post-intubation; if a short-acting paralytic was given, follow with a nondepolarizing agent to maintain paralysis
  • If a long-acting paralytic is used, additional dosing is usually not necessary
• Modifications for unstable patients:
  • If oxygen saturation drops, ventilate more slowly
  • If hemodynamically unstable, reassess sedation approach

Airway Devices and Alternatives

• King LT Airway:
  • Latex-free, single-use, single-lumen device; supports positive pressure ventilation for apneic patients
• i-gel:
  • Suction-free supraglottic device that seals pharyngeal, laryngeal, and perilaryngeal structures while avoiding compression trauma
• SALAD (Suction Assisted Laryngoscopy and Airway Decontamination):
  • Technique used to manage airway contamination during intubation attempts

Endotracheal Tube and Accessories

• Endotracheal tube (ETT):
  • Flexible, translucent, single-lumen tube
  • Length: $12-32 ext{ cm}$; diameter: $2.5-9.0 ext{ mm}$
  • Proximal end has a standard $15 ext{ mm}$ adapter
  • Distal end can be cuffed or uncuffed (pediatric)
  • Pilot balloon reflects cuff inflation status
• Stylet:
  • Malleable, plastic-coated wire used to mold the ETT tip; should be recessed $1-2 ext{ cm}$ inside the tube to avoid airway injury
• 10 mL syringe:
  • Used to inflate the cuff to seal within the trachea; the air volume depends on tube size and patient
• Suction unit and securing device:
  • Suction for airway clearance; secure the ETT to prevent dislodgement
  • A bite block should be used to prevent biting and obstruction of airflow
• Verification of tube placement (minimum of three methods):
  • Direct visualization of the tube passing through the glottic opening
  • Bilateral breath sounds on ventilation with BVM
  • Capnometry or an esophageal detector device (EDD); capnometry is considered most reliable
• Landmarks for laryngoscopy:
  • Epiglottis and arytenoid cartilage visuals

Laryngoscope and Blades

• Laryngoscope has two parts: handle and blade
• Blade types:
  • Macintosh (curved blade): lifts the tongue and epiglottis indirectly by inserting into the vallecula, exposing the glottis
  • Miller (straight blade): lifts the epiglottis directly by placing under it to expose the glottis
  • Pediatric patients: Miller blade often preferred
• Blade assembly and light source:
  • Base of the blade attaches to the top of the handle; light source activated by lifting the blade
• Blade tip usage:
  • Curved blade into the vallecula to lift the epiglottis indirectly
  • Straight blade lifts the epiglottis directly

Endotracheal Tube Specifications and Confirmation

• Endotracheal tube details:
  • 12-32 cm length; 2.5-9.0 mm diameter
  • Standard 15 mm adapter at proximal end
  • Distal end may be cuffed or uncuffed (pediatric)
  • Pilot balloon indicates cuff status
• Stylet and suction use (see above)
• Securing and bite-block use (see above)
• Confirmation of tube placement (reiterated): visualization, bilateral breath sounds, and capnometry/EDD

Sedation, Analgesia, and Neuromuscular Blockade for RSI

• Sedation and analgesia goals:
  • Sedation reduces anxiety, induces amnesia, and decreases gag reflex
  • Undersedation risks poor cooperation and gagging; inadequate amnesia
  • Desired sedation level dictates dose
• Analgesics:
  • Fentanyl, alfentanil common; provide analgesia and some sedation
• Sedative-hypnotics:
  • Benzodiazepines: diazepam, midazolam; provide muscle relaxation, anxiolysis, antiseizure effects, and anterograde amnesia
  • Potential side effects: respiratory depression and mild hypotension
  • Flumazenil: benzodiazepine antagonist
• Ketamine (dissociative anesthetic):
  • Rapid acting, short duration; analgesic properties; can facilitate intubation
• Etomidate (Amidate):
  • Hypnotic-sedative; fast-acting, short duration; minimal effect on heart rate, blood pressure, and intracranial pressure (ICP)
  • Notable side effects: myoclonic movements
• Opioids for analgesia in RSI:
  • Fentanyl, alfentanil; risk of respiratory/CNS depression; naloxone as antagonist
• Neuromuscular blocking agents (NMBAs):
  • Paralytics paralyze skeletal muscles; do not affect level of consciousness
  • Two main categories: depolarizing and nondepolarizing
• Depolarizing NMBA:
  • Succinylcholine (sux): rapid onset; depolarizing agent; fasciculations may occur; contraindications in certain conditions
• Nondepolarizing NMBA:
  • Vecuronium, Pancuronium, Rocuronium: block acetylcholine receptors without depolarizing the muscle fiber
  • Do not use before airway is secured

RSI Dosing (Table 15-15) and Examples

• Succinylcholine (depolarizing): $1-2 ext{ mg/kg}$ IV push (initial dose); repeat dosing based on response
• Vecuronium bromide (nondepolarizing): initial $0.1-0.2 ext{ mg/kg}$ IV push; maintenance 0.8-1.2 mg/kg every 45-60 minutes; pediatric initial 0.1-0.3 mg/kg IV/IO; maintenance 0.01-0.015 mg/kg IV push
• Pancuronium bromide (nondepolarizing): initial $0.06-0.1 ext{ mg/kg}$ IV push; repeat every 30-60 minutes as needed; pediatric: 0.04-0.1 mg/kg slow IV/IO
• Rocuronium bromide (nondepolarizing): initial $0.6-1.2 ext{ mg/kg}$ IV/IO; pediatric: 0.6-1.2 mg/kg IV/IO
• Abbreviations: IV = intravenous; the table notes defasciculating dose concepts for succinylcholine
• Note: These agents are presented in summary form; exact dosing should follow local protocols and patient factors

RSI Considerations and Modifications

• Preoxygenation and induction considerations for unstable patients:
  • If oxygen saturation drops, ventilate slowly and adjust
  • If hypotensive or otherwise unstable, tailor sedation/analgesia to maintain hemodynamic stability
• RSI process remains similar; ensure rapid ventilation if intubation is not immediately possible
• Role of fast-acting paralysis to facilitate rapid airway control while minimizing aspiration risk

King LT and i-gel Airways

• King LT airway:
  • Latex-free, single-use, single-lumen airway
  • Provides positive pressure ventilation for apneic patients
• i-gel airway:
  • Supraglottic airway that seals pharyngeal, laryngeal, and perilaryngeal structures
  • Designed to avoid airway compression trauma

SALAD Technique

• SALAD: Suction Assisted Laryngoscopy and Airway Decontamination
• Technique used when airway contamination is suspected or present during laryngoscopy

Quick Practical Summary and Ethical Considerations

• In the prehospital setting, airway management decisions can be life-saving and time-critical; minimize delays and avoid repeated unsuccessful attempts
• Always prepare equipment and confirm function before use; know the steps for confirmation of tube placement and be prepared with backup strategies
• Ethical practice emphasizes rapid, decisive action when indicated, while balancing patient safety, airway protection, and minimizing harm from aspiration or hypoxia
• Continuous reassessment is essential: monitor SpO2, ETCO2, chest rise, breath sounds, and patient responsiveness; adjust therapy accordingly