15.3.2 Lower Resp Tract Infection

Question 1

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Answer 1

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Question 2

Paediatric upper airway

Answer 2

Slide 4
- More likely to obstruct upper airway
- More difficult to intibate- several levels, tongue, glottis
- Carefult to avoid subglottic injury following intubation
- Increased risk of upper airway obstruction
- More difficult endotracheal intubation
- Risk of subglottic injury with endotracheal intubation

Question 3

Airway obstruction

Answer 3

• from outside (glands, blood vessels)
• inside airway (FB, mucus)
• thickening of airway wall

Question 4

Airway inspiration and expiration physiology

Answer 4

Slide 7 & 8

Question 5

Upper airway obstruction signs

Answer 5

• Causes turbulent airflow - noise
• Snoring: vibration of pharyngeal soft tissue; implies partial upper airway obstruction
• Stridor: indicative of obstruction in larynx or trachea (extrathoracic airways) – mainly inspiratory
• Wheeze: narrowing of intrathoracic airways – mainly expiratory

Question 6

Child vs Adult narrowest part in Larynx / Airway

Answer 6

Adult = vocal cords
Child = cricoid

Question 7

Physiology: effect of oedema

Answer 7

Slide 11

Question 8

Stridor: Obstruction of extra thoracic airways

Answer 8

Where is the lesion?
- Level of obstruction?
What is the lesion?
- Differential diagnosis of cause at that level
- Age of child
➡️Young child: congenital
➡️Older child: acquired
- Duration of stridor: acute vs chronic

Classification + causes
Acute - Acquired
- ALTB (CROUP)
- FB
- epidlottitis
- bacterial tracheitis
- retrophyryngeal abscess
continue on slide 14

ACUTE: Acquired
Viral croup (ALTB)
 : Foreign body

CHRONIC
Congenital: Laryngomalacia (young child, onset early)
Acquired: Subglottic stenosis

Question 9

Viral Croup

Answer 9

• Most common cause parainfluenza 1-3
• Previously well child
• Age 6 months – 5 years, most commonly in 2nd year
• Preceding URTI, mild fever
• Barking cough, hoarse, inspiratory stridor
• start as resp stridor then increases in severity

Question 10

Grading

Answer 10

• Grade 1: Inspiratory stridor
• Grade 2: Inspiratory and expiratory stridor
• Grade 3: Inspiratory and expiratory stridor, pulsus paradoxus, active expiration
• Grade 4: Severe obstruction, cyanosis, apathy, pre-terminal (EMERGENCY)

Question 11

Differential diagnosis of stridor

Answer 11

• Other causes of croup (bacterial; post-intubation)
• Foreign body
• Epiglottitis
• Bacterial tracheitis
• Retropharyngeal abscess
• Trauma

Question 12

STRIDOR: Foreign Body

Answer 12

• Sudden onset of stridor
• History of choking (sometimes pt don’r remember or don’t want to tell their parents)
• Consider if non-resolving stridor
• Radio-opaque FB on X-ray of neck
• Rx: bronchoscopy & remove FB

Question 13

STRIDOR: Epiglottis

Answer 13

• Aetiology: Haemophilus Influenzae type b
• Acutely ill, usually older child
• Fever, soft voice, low-pitched stridor
• Sits upright, protects airway, dysphagia
• EMERGENCY!!
• Total airway obstruction may occur without warning
• Thumb sign??? (lateral chest X-ray)

Question 14

STRIDOR: Retropharyngeal abscess

Answer 14

• Bacterial infection: strep pyogenes; staph aureus; anaerobes
• Enlarged, suppurating glands in retropharyngeal space
• Child previously well
• Clinical presentation: ill child, high fever, dysphagia, opisthotonus, stridor
• Diagnosis: swelling in pharynx; XR neck: widened retropharyngeal space
• Rx: IVI antibiotics: cefuroxime
  Surgical drainage

Question 15

STRIDOR: Bacterial Tracheitis

Answer 15

• Pseudomembrane formation in trachea and larynx
• Toxically ill child
• Aetiology: Staph aureus and Haemophilus influenzae
• Clinically: acutely ill child, high fever, coughing up thick sticky sputum
• Diagnosis: clinical, bronchoscopy
• Rx: Airway if indicated
  IVI antibiotics: cefuroxime

Question 16

STRIDOR: Diphtheria

Answer 16

• Unimmunised children
• White membrane over pharynx, larynx

Question 17

STRIDOR: Trauma

Answer 17

Post-intubation stridor

Question 18

CHRONIC EXTRATHORACIC AIRWAY OBSTRUCTION: Laryngomalacia

Answer 18

• Excessive supraglottic tissue sucked into laryngeal opening
• Inspiratory obstruction
• Symptoms begin at about 2 weeks of age
• NOT FROM BIRTH!!
• Changes with position
• Improves with time, usually resolves by about 2 years of age

Question 19

Other chronic causes of stridor

Answer 19

• < 4 months (congenital subglottic stenosis)
• Sudden onset (foreign body)
• Toxically ill, drooling, dysphagia (epiglottitis, retropharyngeal abscess)
• Previous intubation (acquired subglottic stenosis)
• Repeated episodes (spasmodic croup, gastrooesophageal reflux)
• Oral thrush (Candida infection, ?AIDS)
• immune compromised children have to think of other things

Question 20

SNORING:(STERTOR) OROPHARYNGEAL OBSTRUCTION (OPO)

Answer 20

• Obstructive apnoea: cessation of airflow at nose and mouth despite respiratory efforts
• Obstructive sleep apnoea or oropharyngeal obstruction: partial airway obstruction (snoring) to complete apnoea
• Central apnoea: cessation of airflow unaccompanied by respiratory effort

Question 21

SNORING: Obstructive sleep aponea syndrome (OSAS)

Answer 21

• Disturbed relationship between factors maintaining airway patency and components of upper airway load promoting collapse
• Important factors:
  ➡️Anatomy
  ➡️Adenoids / tonsils
  ➡️Muscle tone

Pathogenesis
Slide 34

Clinical features
- Difficult breathing with recession
- Restless sleep with frequent arousal
- Snoring
➡️Snoring > 3 months requires regular follow up for adverse effects
➡️Snoring every night > 6 months requires Rx

Complications
Sleep disturbance
- Developmental delay
- Failure to thrive
- Learning difficulties
- Restless sleep, sleepwalking, nightmares
Hypoxia
- Death
- Brain damage
- Pulmonary hypertension
- Cardiac arrhythmias
- Cardiac failure
- Behavioural disorders