Module 2: Airway Management and Ventilation

Section 1: Advanced Airway Anatomy and Physiology

1.1 Detailed Anatomy of the Upper Airway

• Nasal Cavity

  • Functions: Warming, humidifying, filtering air.

  • Structures: Nares, septum, turbinates, sinuses.

• Oral Cavity

  • Structures: Lips, teeth, tongue, hard and soft palates.

  • Importance in airway management: Alternative route for ventilation and intubation.

• Pharynx

  • Nasopharynx: Behind nasal cavity; contains adenoids, Eustachian tube openings.

  • Oropharynx: Behind oral cavity; includes tonsils, base of tongue.

  • Laryngopharynx (Hypopharynx) : Extends from hyoid bone to esophagus; pathway for food and air.

• Larynx

  • Functions: Airway protection, phonation.

  • Cartilages:

    • Thyroid Cartilage: Prominent "Adam's apple."

    • Cricoid Cartilage: Only complete cartilaginous ring; landmark for cricothyrotomy.

    • Epiglottis: Leaf-shaped flap that prevents aspiration during swallowing.

  • Vocal Cords

    • Abduction and adduction control airflow and sound production.

  • Intrinsic Muscles

    • Control tension and position of vocal cords.

  • Glottic Opening

    • Narrowest part of the adult airway.

1.2 Detailed Anatomy of the Lower Airway

• Trachea

  • Extends from cricoid cartilage to carina.

  • Composed of C-shaped cartilaginous rings.

  • Lined with ciliated epithelium for mucus clearance.

• Bronchi and Bronchioles

  • Mainstem Bronchi: Right is wider, shorter, and more vertical—aspirated objects more likely here.

  • Lobar and Segmental Bronchi: Branch into each lung lobe.

  • Bronchioles: Lack cartilage; smooth muscle controls diameter.

  • Terminal Bronchioles: Lead to alveolar ducts.

• Alveoli

  • Site of gas exchange.

  • Surfactant reduces surface tension, preventing collapse.

  • Alveolar-capillary membrane facilitates diffusion of oxygen and carbon dioxide.

1.3 Physiological Considerations

• Mechanics of Ventilation

  • Inspiration: Diaphragm contracts, thoracic cavity expands, negative pressure draws air in.

  • Expiration: Passive process; diaphragm relaxes, positive pressure expels air.

• Gas Exchange

  • Oxygen Transport: Bound to hemoglobin (~98%), dissolved in plasma.

  • Carbon Dioxide Transport: Dissolved in plasma, as bicarbonate, bound to proteins.

• Oxygen-Hemoglobin Dissociation Curve

  • Factors shifting the curve:

    • Right Shift: Decreased affinity (↑ temperature, ↑ CO₂, ↑ H⁺, 2,3-DPG).

    • Left Shift: Increased affinity (↓ temperature, ↓ CO₂, ↓ H⁺).

• Age-Related Anatomical Differences

  • Pediatrics

    • Larger tongue relative to mouth.

    • Narrow nasal passages.

    • Higher, more anterior glottic opening.

    • Floppier epiglottis.

    • Narrowest point at cricoid cartilage.

  • Geriatrics

    • Decreased lung elasticity.

    • Increased chest wall rigidity.

    • Diminished cough reflex.

Section 2: Airway Assessment

2.1 Predicting Difficult Airway

• Mallampati Classification

  • Classes I-IV based on visibility of oropharyngeal structures.

  • Class I: Full visibility of tonsils, uvula, and soft palate.

  • Class IV: Only hard palate visible.

• LEMON Law

  • Look externally: Facial trauma, large incisors, beard, or moustache.

  • Evaluate 3-3-2 Rule:

    • 3 fingers mouth opening.

    • 3 fingers thyromental distance.

    • 2 fingers distance from hyoid bone to thyroid notch.

  • Mallampati score.

  • Obstruction: Obesity, foreign bodies, swelling.

  • Neck mobility: Limited in trauma or arthritis.

• Thyromental Distance

  • Distance between the thyroid notch and mentum (chin).

  • Less than 6 cm (three fingerbreadths) may indicate a difficult airway.

2.2 Detection of Airway Compromise

• Signs of Partial Airway Obstruction

  • Stridor.

  • Snoring.

  • Gurgling.

  • Hoarseness.

• Signs of Complete Airway Obstruction

  • Inability to speak or cough.

  • Universal choking sign.

  • Cyanosis.

  • Loss of consciousness.

• Assessment of Breathing

  • Rate: Tachypnea, bradypnea, apnea.

  • Effort: Use of accessory muscles, nasal flaring, retractions.

  • Pattern: Cheyne-Stokes, Kussmaul respirations.

  • Skin Color: Pallor, cyanosis.

• Airway Patency Check

  • Look: Chest rise and fall.

  • Listen: Air movement at mouth and nose.

  • Feel: Air movement on cheek.

Section 3: Basic Airway Management Review

3.1 Manual Maneuvers

• Head-Tilt/Chin-Lift

  • Contraindicated in suspected cervical spine injury.

• Jaw-Thrust Maneuver

  • Use when cervical spine injury is suspected.

  • Technique:

    • Kneel at patient's head.

    • Place fingers behind angles of mandible.

    • Lift upward, displacing jaw forward.

• Recovery Position

  • Lateral recumbent to maintain airway in patients with decreased consciousness but adequate breathing.

3.2 Airway Adjuncts

• Oropharyngeal Airway (OPA)

  • Indications: Unconscious patients without gag reflex.

  • Contraindications: Conscious patients, intact gag reflex.

  • Insertion Techniques:

    • Adults: Insert upside down, rotate 180°.

    • Pediatrics: Use tongue depressor, insert right side up.

• Nasopharyngeal Airway (NPA)

  • Indications: Semiconscious patients with intact gag reflex.

  • Contraindications: Basilar skull fracture, nasal trauma.

  • Insertion Technique:

    • Lubricate, bevel toward septum, insert into larger nostril.

3.3 Suctioning

• Equipment

  • Rigid (Yankauer) and flexible catheters.

  • Portable suction devices.

• Techniques

  • Pre-oxygenate patient.

  • Limit suctioning to 10-15 seconds.

  • Apply suction on withdrawal in a circular motion.

Section 4: Advanced Airway Techniques

4.1 Endotracheal Intubation (ETI)

4.1.1 Indications and Contraindications

• Indications

  • Inability to maintain airway patency.

  • Failure to protect airway (e.g., absent gag reflex).

  • Failure to ventilate adequately.

  • Anticipation of clinical deterioration.

• Contraindications

  • Complete airway obstruction (alternative methods required).

  • Severe facial trauma requiring surgical airway.

4.1.2 Equipment Preparation

• Basic Equipment

  • Laryngoscope handle and blades (Macintosh and Miller).

  • Endotracheal tubes (ETT) in various sizes.

  • Stylet.

  • Syringe (10 mL for cuff inflation).

  • Suction device.

  • Bag-valve-mask (BVM) with oxygen source.

  • End-tidal CO₂ detector (capnography).

• Additional Equipment

  • Magill forceps.

  • Lubricant.

  • Tape or securing device.

  • Alternative airway devices as backup.

4.1.3 Laryngoscope Blades

• Macintosh Blade (Curved)

  • Fits into vallecula.

  • Lifts epiglottis indirectly.

• Miller Blade (Straight)

  • Directly lifts epiglottis.

  • Preferred in pediatric patients.

4.1.4 Procedure

• Preparation

  • Ensure all equipment is ready and functioning.

  • Position patient in "sniffing" position (unless contraindicated).

  • Pre-oxygenate with 100% oxygen for 3-5 minutes if possible.

• Visualization

  • Open patient's mouth using scissor technique.

  • Insert laryngoscope blade to the right of the tongue.

  • Sweep tongue to the left.

  • Advance blade until epiglottis is visualized.

• Identifying Landmarks

  • Epiglottis: Leaf-shaped structure.

  • Vocal Cords: Pearly white bands.

  • Arytenoid Cartilages: Posterior landmarks.

• Insertion of Endotracheal Tube

  • Pass ETT through vocal cords.

  • Advance tube 2-3 cm beyond cords.

  • Typical depth: 21 cm at teeth for females, 23 cm for males.

• Securing the Tube

  • Inflate cuff with required air volume (usually 5-10 mL).

  • Confirm placement before releasing hold on tube.

  • Secure with tube holder or tape.

4.1.5 Verification of Tube Placement

• Primary Methods

  • Direct Visualization: Seeing tube pass through vocal cords.

  • Auscultation: Bilateral breath sounds, absence of gastric sounds.

  • Chest Rise and Fall: Symmetrical movement.

• Secondary Methods

  • End-Tidal CO₂ Detection

    • Colorimetric Device: Color change indicating CO₂.

    • Capnography: Waveform provides continuous monitoring.

  • Condensation in Tube

• Troubleshooting

  • If unilateral breath sounds (right mainstem intubation), withdraw tube 1-2 cm and reassess.

  • If no confirmation of placement, remove and ventilate with BVM before reattempting.

4.1.6 Complications

• Immediate

  • Hypoxia due to prolonged attempts.

  • Esophageal intubation.

  • Trauma to teeth, airway structures.

  • Vomiting and aspiration.

• Delayed

  • Tube displacement.

  • Infection.

  • Tracheal stenosis from prolonged cuff pressure.

4.2 Rapid Sequence Intubation (RSI)

4.2.1 Indications

• Need for immediate airway control in patients with intact gag reflex.

• Combative or uncooperative patients requiring airway intervention.

4.2.2 Medications

• Sedatives (Induction Agents)

  • Etomidate: Rapid onset, minimal hemodynamic effects.

  • Midazolam: Sedative, can cause hypotension.

  • Ketamine: Provides sedation and analgesia, maintains airway reflexes.

• Paralytics

  • Depolarizing Agent:

    • Succinylcholine: Rapid onset, short duration.

    • Contraindications: Hyperkalemia, neuromuscular disorders, crush injuries, burns >24 hours old.

  • Non-Depolarizing Agents:

    • Rocuronium, Vecuronium: Longer duration.

4.2.3 Procedure Steps

• Preparation

  • Ensure all equipment and medications are ready.

  • Assign roles to team members.

• Preoxygenation

  • 100% oxygen to fill functional residual capacity.

• Pretreatment (If applicable)

  • Consider medications to mitigate response (e.g., lidocaine, atropine).

• Induction

  • Administer sedative agent.

• Paralysis

  • Administer paralytic once sedation confirmed.

• Intubation

  • Proceed with intubation as per standard technique.

• Post-Intubation Management

  • Secure tube, confirm placement.

  • Initiate mechanical ventilation.

  • Provide ongoing sedation and analgesia.

4.3 Alternative Airway Devices

4.3.1 Supraglottic Airway Devices

• King LT Airway

  • Single-lumen device with cuff seals.

  • Sizes based on patient height.

  • Insertion: Blindly inserted into esophagus, cuff inflated.

• Laryngeal Mask Airway (LMA)

  • Sits over laryngeal inlet.

  • Various sizes; cuff inflated to seal.

  • Limited protection against aspiration.

• I-Gel Airway

  • Non-inflatable, gel-like cuff.

  • Easier insertion, minimal trauma.

4.3.2 Indications and Contraindications

• Indications

  • Difficult or failed intubation.

  • Airway management during cardiac arrest.

  • Short-term airway management when intubation not feasible.

• Contraindications

  • Intact gag reflex.

  • High risk of aspiration.

  • Severe airway obstruction below glottis.

4.3.3 Insertion Techniques

• Lubricate device.

• Position head appropriately.

• Insert device along the hard palate until resistance is felt.

• Inflate cuff if applicable.

• Confirm placement with chest rise, breath sounds, and capnography.

4.4 Surgical Airway Management

4.4.1 Needle Cricothyrotomy

• Indications

  • Cannot intubate, cannot ventilate scenario.

  • Upper airway obstruction.

• Equipment

  • Large-bore (12-14G) IV catheter.

  • High-pressure jet ventilation system or modified BVM.

• Procedure

  • Palpate cricothyroid membrane between thyroid and cricoid cartilages.

  • Clean site aseptically.

  • Insert needle at 45-degree angle caudally while aspirating.

  • Confirm air aspiration, advance catheter over needle.

  • Secure catheter, connect to ventilation device.

• Complications

  • Hypercarbia due to inadequate ventilation.

  • Barotrauma.

  • Subcutaneous emphysema.

4.4.2 Surgical Cricothyrotomy

• Indications

  • Severe maxillofacial trauma.

  • Airway obstruction not relieved by less invasive means.

• Procedure Overview

  • Incision through skin and cricothyroid membrane.

  • Insertion of tracheostomy tube or ETT.

  • Ventilation and verification as with intubation.

• Complications

  • Bleeding.

  • Injury to surrounding structures.

  • Infection.

Section 5: Ventilation Management

5.1 Mechanical Ventilation

5.1.1 Indications

• Patients who are intubated requiring controlled ventilation.

• Respiratory failure unresponsive to non-invasive methods.

5.1.2 Transport Ventilators

• Types

  • Pneumatically powered.

  • Electronically controlled.

• Settings

  • Tidal Volume (Vt) : Typically 6-8 mL/kg of ideal body weight.

  • Respiratory Rate (RR) : Adjusted based on patient's needs.

  • FiO₂ (Fraction of Inspired Oxygen) : 21-100%, usually start at 100% then titrate.

  • PEEP (Positive End-Expiratory Pressure) : Generally 5 cm H₂O to prevent alveolar collapse.

5.1.3 Ventilation Modes

• Assist-Control (A/C) : Delivers set volume/pressure with each breath; patient can trigger additional breaths.

• Synchronized Intermittent Mandatory Ventilation (SIMV) : Delivers mandatory breaths synchronized with patient's efforts.

• Pressure Support Ventilation (PSV) : Augments spontaneous breaths with set pressure.

5.1.4 Monitoring and Adjustments

• Peak Inspiratory Pressure (PIP)

  • High PIP may indicate obstruction, bronchospasm, or kinks.

• Alarms

  • High pressure, low pressure, apnea alarms must be monitored.

• Waveforms

  • Flow, volume, pressure waveforms aid in troubleshooting.

5.1.5 Complications

• Barotrauma: Over-distension leading to pneumothorax.

• Hypoventilation/Hypoventilation: Adjust settings as needed.

• Ventilator-Associated Pneumonia (VAP) : Minimize duration on ventilator.

5.2 Non-Invasive Ventilation

5.2.1 Continuous Positive Airway Pressure (CPAP)

• Indications

  • Acute pulmonary edema.

  • COPD exacerbations.

  • Sleep apnea.

• Contraindications

  • Respiratory arrest.

  • Unconsciousness.

  • Facial trauma.

  • Vomiting.

• Procedure

  • Apply mask snugly.

  • Start with low pressures (5 cm H₂O), titrate up.

  • Monitor for improvement.

5.2.2 Bilevel Positive Airway Pressure (BiPAP)

• Indications

  • Similar to CPAP but allows separate inspiratory (IPAP) and expiratory (EPAP) pressures.

• Advantages

  • Provides ventilatory support and reduces work of breathing.

5.3 Ventilation Strategies

• Obstructive Lung Disease (Asthma, COPD)

  • Avoid high tidal volumes.

  • Prolonged expiratory phase to prevent air trapping.

  • Low respiratory rates.

• Restrictive Lung Disease

  • Higher respiratory rates with lower tidal volumes.

• Acidosis

  • Increase minute ventilation to "blow off" CO₂.

Section 6: Capnography

6.1 Understanding Capnography

• Capnometry vs. Capnography

  • Capnometry: Numeric reading of CO₂.

  • Capnography: Numeric and graphical representation (waveform).

6.2 Phases of Capnography Waveform

• Phase I (Baseline)

  • Inspiratory baseline; should be near zero.

• Phase II (Expiratory Upstroke)

  • CO₂ from alveoli mixes with dead space air.

• Phase III (Expiratory Plateau)

  • Reflects alveolar CO₂ level.

• Phase 0 (Inspiratory Downstroke)

  • Inhalation begins; CO₂ level drops to baseline.

6.3 Clinical Applications of Capnography

• Verification of Intubation

  • Continuous waveform confirms correct tube placement.

• Monitoring Ventilation

  • Changes in EtCO₂ reflect ventilation status.

    • Hyperventilation: Decreased EtCO₂.

    • Hypoventilation: Increased EtCO₂.

• Circulatory Status

  • Sudden loss of EtCO₂ may indicate circulatory collapse.

• During CPR

  • EtCO₂ levels correlate with cardiac output.

  • Levels above 10 mmHg suggest adequate compressions.

  • Sudden increase may indicate ROSC.

• Metabolic Monitoring

  • Elevated EtCO₂ in cases of hypermetabolic states (fever, seizures).

  • Decreased EtCO₂ in metabolic acidosis (e.g., DKA).

6.4 Capnography Waveform Patterns

• Bronchospasm

  • Shark-fin appearance due to prolonged expiration.

• Rebreathing CO₂

  • Elevated baseline; waveform does not return to zero

• Leak in Ventilator Circuit

  • Irregular waveforms

Section 7: Airway Decision-Making and Critical Thinking

7.1 Assessing the Need for Advanced Airway

• Indications for Intubation vs. Alternative Airways

  • Consider patient condition, difficulty of intubation, and resources.

• Risk Assessment

  • Weigh risks of procedures against benefits.

7.2 Airway Algorithms

• Difficult Airway Algorithm

  • Structured approach to managing anticipated and unanticipated difficult airways.

  • Includes backup plans (LMA, surgical airway).

• Failed Airway Algorithm

  • Steps to take after unsuccessful intubation attempts:

    • Reattempt with adjustments.

    • Use alternative devices.

    • Consider waking the patient if safe.

    • Prepare for surgical airway.

7.3 Environmental Considerations

• Limited Space

  • Adapt techniques in confined areas.

• Lighting Conditions

  • Ensure adequate illumination or use devices with built-in lights.

• Noise and Distractions

  • Maintain focus and clear communication with team.

Section 8: Putting It All Together - Case Studies

8.1 Case Study 1: Respiratory Failure in Asthma

• Scenario

  • 22-year-old female with severe asthma attack, unresponsive to nebulized treatments, increasing fatigue.

• Assessment

  • Rapid shallow breathing, diminished breath sounds, accessory muscle use.

  • EtCO₂ rising, indicating hypoventilation.

• Actions

  • Decide on advanced airway management due to impending respiratory failure.

  • Prepare for intubation, consider the potential for difficult airway due to bronchospasm.

  • Use medications that minimize bronchial irritation.

  • Post-intubation, adjust ventilator settings to allow for longer expiratory phase.

8.2 Case Study 2: Trauma Patient with Airway Obstruction

• Scenario

  • 35-year-old male with facial trauma after motor vehicle collision, bleeding profusely, gurgling sounds.

• Assessment

  • Airway compromised due to blood and swelling.

  • Limited visualization of landmarks.

• Actions

  • Suction airway promptly.

  • Attempt to maintain airway with basic maneuvers.

  • Predict difficult airway; prepare alternative devices.

  • If unable to intubate, consider supraglottic airway.

  • Prepare for possible surgical airway if obstruction persists.

Mastering airway management and ventilation is essential for paramedics, as airway compromise can have immediate life-threatening consequences. This module has provided an in-depth exploration of advanced airway techniques, ventilation strategies, and the critical thinking required to make informed decisions in complex situations. Continuous practice and staying updated with current guidelines will enhance your proficiency and confidence in managing airways effectively.