1. Pediatric Airway Management: An Update
HANY EL-ZAHABY, MD
Anesthesia, Ain Shams University

2. Five Cardinal Anatomical Features of Infant’s Larynx
1- Higher Larynx
Acute angulation between plane of tongue & plane of glottis makes exposure difficult ►straight blade ►exaggerated by mandibular hypoplasia (Pierre Robin syndrome).

3. 2- Relatively Larger Tongue: Obstructs airway
Obligate nasal breathers
Difficult to manipulate & stabilize with laryngoscopic blades

4. 3- Anteriorly Angulated Vocal Cords:
The anterior attachment of vocal cords are lower than posterior attachment ► difficulty in nasal intubations where “blindly” placed ETT lodges in the anterior commissure rather than in the trachea.

5. 4- Differently Shaped Epiglottis
Infant epiglottis ohmega (Ώ) shaped and angled away from axis of trachea More difficult to lift an infant’s epiglottis with laryngoscopic blade

6. 5- Funnel shaped larynx
The only complete ring
Narrowest part of infant’s larynx is the cricoid cartilage: Tight fitting ETT may cause edema. Uncuffed ETT preferred for patients < 8 years old

7. Respiratory Physiology Obligate nasal breathers
Immaturity of coordination between respiratory efforts and oropharyngeal motor/sensory input.
During quiet respiration, the tongue rests against the roof of the mouth.

8. Respiratory Physiology Respiratory Parameters
High metabolic rate (5-8 ml/kg/min)
Tidal volume (6-7 ml/kg/min)
High respiratory rate (40-60 breaths/min)
High alveolar ventilation (130 ml/kg/min)
Lung compliance is less while chest wall compliance is more than those in adults {reduced FRC and atelectasis} ►PEEP.

9. Respiratory Physiology Tracheal and Bronchial Function
Infant's larynx, trachea, and bronchi are highly compliant and hence more subject to distention and compression forces
The intrathoracic trachea is subject to stresses that are different from those in the extrathoracic portion

10. Respiratory Physiology Dynamic Airway Obstruction
Normal inspiratory
stretch/collapse
(crying)
Dynamic collapse
at inlet
Bronchiolitis/asthma

11. Respiratory Physiology Work of Breathing
The work of breathing is needed to overcome the chest wall compliance and the resistance of the airways.
The WOB per kilogram is similar to adults.
The nasal passages account for 25% of the total resistance to airflow in a neonate, compared with 60% in an adult. In infants, most resistance to airflow occurs in the bronchial and small airways ► respiratory failure with bronchiolitis.
Long, small ETT, obstructed ETT, narrowed airway ► increased WOB ► increased oxygen consumption ► increases oxygen demand.

12. Change in work of breathing after placement of an appropriate endotracheal tube
in extremely low birth weight infants (<1000 g), premature infants (1500 g),
full-term infants, children, and adults

13. Respiratory Physiology Effect of Edema on WOB

14. Respiratory Physiology Type I Muscle Fibers
Unable to sustain increased WOB for long periods

15. Evaluation of the Upper Airway (History)
URTI
Snoring (adenoidal hypertrophy, obstructive sleep apnea)
Croupy cough (subglottic stenosis, TEF repair, F.B.aspiration)
Inspiratory stridor (subglottic stenosis or web, laryngomalacia, macroglossia, extrathoracic F.B. or extrathoracic tracheal compression)
Hoarse voice (laryngitis, vocal cord palsy, papillomatosis, granuloma)
Asthma
Repeated pneumonias
Previous anesthetic problem

16. Evaluation of the Upper Airway (Physical Examination)
Facial expression
Nasal flaring
Mouth breathing
Color of mucous membranes
Retractions (suprasternal, intercostal, subcostal)
Respiratory rate
Voice change
Mouth opening
Size of mouth
Size of tongue and its relationship to other pharyngeal structures (Mallampati)?

17. Loose or missing teeth.
Size and configuration of palate.
Size and configuration of mandible (side view).
Location of larynx in relation to the mandible.
Presence of inspiratory stridor :epiglottitis, croup, extrathoracic foreign body.
Both inspiratory and expiratory stridor: aspirated foreign body, vascular ring, or large esophageal foreign body.
Prolonged expiration: lower airway disease?
Baseline oxygen saturation in room air.

18. Bilateral microtia (ear deformity easily notable) is associated with mandibular hypoplasia & difficulty in visualizing the laryngeal inlet (42%) & with unilateral microtia (2.5%).
Are there congenital anomalies that may fit a recognizable syndrome? The finding of one anomaly mandates a search for others.

19. Evaluation of the Upper Airway (Diagnostic Testing)
X-ray, MRI and CT.
Radiologic airway examination in a child with a compromised airway must be undertaken only when there is no immediate threat to the child's safety and only in the presence of skilled and appropriately equipped personnel able to manage the airway.
Endoscopic evaluation (flexible fiberoptic endoscopy)
Arterial blood gas analysis (chronic airway obstruction with respiratory acidosis)

20. Causes of Difficult Airway Congenital Anomalies Tumors Infection Musculoskeletal Problems

21. Encephalocele
Hallermann-Streiff S.
Pierre Robin S.
Bilateral Cleft Palate
Achondroplasia
Down S.

22. Crouzon S.
Seckel S.
Treacher Collins S.
Goldenhar S.
Apert S.
Nager S.

23. Mucopolysaccaridosis
Type IH (Hurler)
Type 1 H/S (Hurler-Scheie)
Type II Hunter
Type III (Sanfilippo)

24. Tumors Infection Cystic hygroma Hemangioma of tongue, pharynx Teratoma
Retropharyngeal abscess
Epiglottitis
Laryngotracheobronchitis
(subglottic croup)
Ludwig’s angina
Adenotonsillitis, abscess, hypertrophy ( obstructive sleep apnea)
Scleroderma
Laryngeal web

25. Musculoskeletal Problems
Ankylosis of jaw, cervical spine
Unstable or dislocated cervical vertebrae
Wired jaw
Cervical cord tumor
Halo traction apparatus
Facial trauma, fractures, laceration, burns

26. Techniques to Open the Airway Head tilt- Chin lift - Jaw Thrust – Oropharyngeal Airway

27. Hazards: long, bleeding 30%, intracranial placement
Techniques to open the Airway
Nasopharyngeal Airway
Size
Hazards: long, bleeding 30%, intracranial placement

28. Aligning of the Upper Airway Axes ( More than 6 Years Old)
Three-axes theory?

29. Ventilation Techniques Multi-handed Mask Ventilation

30. Tracheal Intubation Laryngoscopic Blade Sizes
Macintoch
Miller
Age -
Preterm
Neonate 1
Neonate-2 Yrs 2
2-6 Yrs
6-12 Yrs 3
>12 Yrs

31. Tracheal Tube Sizes Insufflation Pressure ? Muscle Relaxants?
Insertion length
(Alveolar ridge)
Size (mm ID)
Age
6-9 cm
2.5
3.0
Preterm 1000g
Preterm g
10 cm
Neonate-6 Month
11 cm
6 Month – 1 Yr
12 cm
1-2 Yrs
age (yrs)/2 + 12
age (yrs)/4 + 4
Beyond 2 Yrs

32. Micro-cuff ETT
More anatomical fit
Sealing at low pressures
More distal position
Greater permeability for nitrous oxide
For neonates ≤3 kg and infants ≤1 year, ID 3.0-mm
For children 1 to 2 years of age, ID 3.5-mm
For children ≥2 years, ID (mm) = age/
Post-intubation croup was 0.4% (2/500 children)

33. LMA: Reusable Classic, Disposable Unique, ProSeal
Silicone
Softer, deeper mask bowl, bite block, improves stability
PVC
Silicone

34. LMA sizes Largest TT (mm ID) Maximum cuff volume (ml)
(Least effective volume)
Patient’s weight
Mask size
3.5 4
1-5 kg 1
4.0 7
5-10 kg
1.5
4.5 10
10-20 kg 2
5.0 14
20-30 kg
2.5
6.0, non-cuffed 20
> 30 kg 3

35. Special Techniques for Intubation Rigid Laryngoscopy The retromolar, paraglossal, or lateral approach to rigid laryngoscopy utilizing a straight blade.

36. Optimal External Laryngeal Manipulation (OELM)
OELM is particularly helpful for infants & children with immobile or shortened necks.
Either by an assistant or the laryngoscopist.
Intubation Guides

37. Lighted Stylet Light Wand

38. Glidescope Video Laryngoscope

39. Intubation through LMA (Blind)

40. Fibreoptic Intubation through LMA

41. Fibreoptic Assisted Intubation

42. Percutaneous Cricothyrotomy

44. Percutaneous needle cricothyrotomy provides only a mean for oxygen insufflation and does not reliably provide adequate ventilation.
If glottic or subglottic pathology is not suspected, LMA placement to establish ventilation may be appropriately attempted first.

45. Retrograde Intubation

46. Awake approach?
Sedation?
General anesthesia (inhalation/IV)?
“Assisted spontaneous ventilation during inhaled anesthesia is the preferred technique when abnormal airway anatomy is present”.

47. Rules “To avoid trouble one must be prepared for trouble”
“Have an IV access & experienced assistant”
“Do what you masters”
“Have definitive plan A, but have plan B & C”

48. Rules “Use your common sense”
“ Do not continue to do the same thing and expect different results’’
“Easier comes first”
“Each difficult intubation is a different”

49. Difficult Airway Cart Oropharyngeal/nasopharyngeal airways
Laryngosopic blades TT
Stylets
LMA
Fiberoptic laryngoscope
PC cricothyrotomy kit
Jet ventilation eq.
TT exchangers
Exhaled CO2 detectors
Experienced assistance
IV access

51. Incomplete Airway Obstruction
Apply gentle positive pressure
Improved
No improvement
Eliminate noxious stimulus,
+ concentration of volatile anesthetic
IV thiopentone/propofol, stabilize &
resume anesthetic
No improvement
Improved
No improvement
Stabilize + resume anesthetic
IV succinylcholine + atropine
Ventilate with 100% oxygen + ETT
Roy WL, Lerman J, Anaesthesia 1988:35, 93

52. Complete Airway Obstruction
Jaw thrust, ventilate with 100% oxygen
No improvement +
no IV access
Improvement
Eliminate noxious stimulus,
+ concentration of
volatile anesthetic
Intubate immediately without
relaxant
No improvement +
IV access
Call for help
spray cords with lidocaine,
intubate
Succinylcholine +
atropine +
intubate
Ventilation 100% oxygen
Ventilate + intubate
Start CPR, cricothyrotomy

53. Extubation of Difficult Intubation Patient
Facial Grimacing

54. Documentation
1.Whether or not mask ventilation was attempted and, if there was a special maneuver needed?
2.Any difficulty with intubation?
3.What Special technique that was required for successful intubation?  
4.What special technique that was not helpful for intubation?
5. What grade of laryngoscopic view of laryngeal structures during rigid laryngoscopy?

55. Conclusion
Successful management of the difficult airway depends on prediction, preparation, maintenance of good oxygenation and ventilation, and the use of familiar tools by experienced physician.

56. THANK YOU