Airway Management in Children

Anatomical & Physiological Differences - Little Lungs, Big Deal

• Head: Large occiput (neck flexion).
• Tongue: Relatively large, prone to obstruction.
• Larynx: Higher (C3-C4 infants), anterior.
  • Epiglottis: Long, narrow, U-shaped/omega (Ω), angled posteriorly.
• Narrowest Point: Cricoid ring (functionally, subglottis) in children < 8-10 yrs.

  ⭐ The narrowest part of the pediatric airway is the cricoid cartilage (subglottis), unlike the glottis in adults. This makes them prone to subglottic stenosis/edema.

• Trachea: Shorter ($4-5 \text{ cm}$ neonate), narrower, more compliant.
• Nares: Obligate nasal breathers (up to 3-5 months).
• Chest Wall: Highly compliant; ribs horizontal; diaphragmatic breathing.
• Physiology:
  • ↑$V\text{O}_2$ (Oxygen consumption): $6-8 \text{ mL/kg/min}$.
  • ↓FRC (Functional Residual Capacity) relative to $V\text{O}_2$ demand.
  • ↑Closing volume (may exceed FRC → atelectasis).
  • Rapid desaturation during apnea (due to ↓FRC, ↑$V\text{O}_2$).

Airway Equipment & Techniques - Tiny Tools, Top Tactics

• Masks: Anatomical, transparent, minimal dead space. Sizes 00-5.
• Airways:
  • OPA (Guedel): Mouth corner to mandible angle.
  • NPA: Nose tip to tragus. Diameter ≈ ETT ID.
• Laryngoscope Blades:
  • Miller (straight): Sizes 00-1. Neonates/infants (direct epiglottis lift).
  • Macintosh (curved): Sizes 1-3. Older children (vallecula).
  • 📌 Miller for Miniatures, Mac for Mature.
• Endotracheal Tubes (ETT):
  • Uncuffed (Age < 8 yrs): $ID (mm) = (Age/4) + 4$.
  • Cuffed (preferred, monitor pressure < 20-25 cm H₂O): $ID (mm) = (Age/4) + 3.5$.
  • Depth (oral, cm): $ID \times 3$ OR $(Age/2) + 12$.
  • ⭐ > Cuffed ETTs are preferred in most pediatric patients (except neonates) for reliable ventilation, reduced aspiration risk, and less OR pollution, if cuff pressure is monitored (< 20-25 cm H₂O).
• Supraglottic Airways (SGA): LMA (sizes 1-2.5 for < 30kg), i-gel.
• Techniques:
  • Positioning: "Sniffing" (older children); neutral/shoulder roll (infants).
  • ETT Confirmation: EtCO₂ (gold standard), bilateral air entry, chest rise.

Difficult Airway & Extubation - Crisis Control, Clear Exit

Difficult Airway

• Prediction: 📌 LEMON (Look, Evaluate 3-3-2, Mallampati, Obstruction, Neck mobility). Note syndromes (Pierre Robin, Treacher Collins).
• Equipment: Correct size blades (Miller 00-2, Mac 1-3), ETTs (cuffed/uncuffed, formulas: cuffed $ (Age/4)+3.5 $, uncuffed $ (Age/4)+4 $), LMAs, stylet, bougie, VL, FOB.
• Management: Follow difficult airway algorithm. Key: maintain oxygenation.

Extubation

• Safe Criteria: Awake, alert, commands; adequate spontaneous ventilation; intact airway reflexes; stable; normothermic; TOF > 0.9.
• Deep Extubation: Select cases (e.g., ↓airway reactivity). Risks: laryngospasm, aspiration.
• Complications & Management:
  • Laryngospasm: 100% O₂, PPV, jaw thrust. 📌 Larson's maneuver. If persistent: Propofol 0.5-1 mg/kg IV; Suxamethonium 0.1-0.5 mg/kg IV or 4-5 mg/kg IM.
  • Post-extubation stridor: Humidified O₂, nebulized epinephrine, steroids.

⭐ In children, the narrowest part of the airway is the cricoid cartilage (functionally), unlike adults where it's the glottis. This makes them prone to subglottic stenosis and post-extubation stridor.

High‑Yield Points - ⚡ Biggest Takeaways

• Pediatric larynx: higher (C3-C4), more anterior, challenging laryngoscopy.
• Epiglottis: long, floppy, omega-shaped, more horizontal.
• Narrowest part: cricoid cartilage (subglottis) until ~8-10 years.
• Trachea: shorter, narrower, ↑ risk of mainstem intubation/extubation.
• Infants: obligate nasal breathers (first 3-5 months).
• Uncuffed ETTs common; cuffed ETTs need pressure monitoring and leak test.
• ETT size (uncuffed): (Age/4) + 4; (cuffed): (Age/4) + 3.5.