1. TBL: Acute Respiratory Distress and Acute Respiratory Infections in Children
Tom Kovesi M.D. F.R.C.P.(C), Pediatric Respirologist, Professor (Pediatrics), Children’s Hospital of Eastern Ontario, University of Ottawa
Matthew Bromwich M.D. F.R.C.S.(C), Pediatric Otolaryngology - Head and Neck Surgery, Assistant Professor (Surgery), Children’s Hospital of Eastern Ontario, University of Ottawa
Unit 1 – TBL: Stridor and Acute Respiratory Infections in Children – Drs Bromwich and Kovesi

2. Objectives
Explain why respiratory infections are common, and serious, in children.
List reasons why children are more susceptible to respiratory infections.
Recognize underlying conditions that may predispose children to respiratory tract infections.
Identify the causative organism(s), presentation of, diagnosis of, and treatment of common pediatric respiratory infections
respiratory tract infections: Epiglottitis, Croup, Pertussis, and Bronchiolitis, Bacterial Pneumonia,Viral Pneumonia and Mycoplasma Pneumonia
Describe the differences between sturtor, inspiratory stridor and expiratory wheezing.
Develop an approach to determining the cause of respiratory distress associated with stridor or wheezing in children and recognize important non"infectious causes of stridor, such as laryngomalaica.
Identify life"threatening pediatric airway emergencies based on history and physical examination.
Unit 1 – TBL: Stridor and Acute Respiratory Infections in Children – Drs Vaccani and Kovesi

3. Smaller airway size in infants
Predisposing Factors for Respiratory Infections (1): Endogenous Factors
Smaller airway size in infants
Develop more respiratory distress when airways narrowed during infections
Less developed (and experienced) immune system (especially premature infants)
Underlying diseases - cystic fibrosis, primary Ciliary dyskinesia, congenital & acquired immune deficiency, Gastroesophageal Reflux
Congenital anomalies - cardiac (pulmonary edema), neurological handicaps (aspiration)

4. Predisposing Factors (2): Environmental Factors
Crowding, poverty, poor access to health care & immunizations
Malnutrition
Day care
Environmental tobacco smoke exposure
Smoking in older children & teens
Air pollution
Indoor Air Pollution
Biomass fuel heaters in developing world
Aspirated foreign bodies
Pieces of toys, nuts, pieces of food, cut corners of plastic milk bags

5. From The Airway To The Airspace
Laryngomalacia
Supraglottis
Epiglottitis
Epiglottis
Croup
Subglottis
Pertussis
Bronchi
Bronchiolitis
Bronchioles
Pneumonia
Alveoli

6. Anatomical locations for Respiratory Distress in Children
Infectious
Oropharynx
Peritonsillar cellulitis/abscess
Retropharyngeal abscess
Larynx
Epiglottitis
Croup
Lower Airway
Bronchiolitis
Pertussis
Pneumonia
Tuberculosis
Nasal Cavity
Anterior/Midnasal stenosis
Choanal atreasia
Adenoid Hypertrophy
Oral Cavity
Tonsillar Hypertrophy
Glossoptosis
Pierre-Robin Sequence
Larynx
Laryngomalacia
Vocal cord paralysis
Subglottic stenosis
Trachea
Tracheomalacia
Unit 1 – TBL: Stridor and Acute Respiratory Infections in Children – Drs Vaccani and Kovesi

7. Assessing Respiratory Disease in Children (3)
Respiratory rate
Retractions
Tracheal tug
Intercostal retractions
Subcostal retractions
Accessory muscle use
Sternocleidomastoid
Paradoxical respirations
Level of consciousness
Cyanosis
Pulsus paradoxicus

8. Bronchoscopy and Suspension

9. Anatomic: Bronchoscopy

10. Bronchoscopy

11. Most common congenital cause of stridor
Laryngomalacia:
Most common congenital cause of stridor
Congenital collapse of tissue into airway from above vocal cords
Several potential causes:
Short aryepiglottic folds,
Arytenoid prolapse,
Omega-shaped epiglottis
Maybe… abnormal development of neural control of larynx in babies
Usually starts prior to 2 weeks of age
Progresses for first few months of life
Slow improvement after this time
Usually all symptoms have gone by 18 months of age
Very rarely – severe with apnea, failure to thrive, feeding difficulties
May need surgery
Unit 1 – TBL: Stridor and Acute Respiratory Infections in Children – Drs Vaccani and Kovesi

12. Symptoms of Laryngomalacia
Inspiratory stridor
Stridor is not constant
intermittent
variable intensity
Increases with agitation and feeding
Decreases with neck extension or prone
Normal cry
Noisier asleep

13. Arytenoid Prolapse
A cause of laryngomalacia

14. Omega Epiglottis
A cause of Laryngomalacia

15. Treatment of Laryngomalacia
Expectant – wait for it to get better!
Medical:
Treat GERD if present (commonly associated)
Surgical-supraglottoplasty (excision of floppy supraglottic tissues)
Pre-op
Post-op

16. Other Causes of Stridor in Children
Congenital
Airway Hemangioma
Airway Webs
Acquired
Subglottic Stenosis
Most often: Post-intubation
Laryngeal Papillomatosis
Foreign Body
Vocal Cord Paralysis
Unilateral or bilateral
Unit 1 – TBL: Stridor and Acute Respiratory Infections in Children – Drs Bromwich and Kovesi

17. Vocal cord paralysis
Etiologies – most often, acquired:
Iatrogenic ( most common)
Post cardiac surgery
Prolonged neonatal intubation: scarring
Brainstem Disorders
Thoracic Masses and compression of recurrent laryngeal nerve
Idiopathic

18. Two types of vocal cord paralysis
Unilateral: one cord paralyzed
Usually asymptomatic from respiratory point of view
Able to create adequate airway opening
Voice changes
Watch for aspiration
Bilateral: both cords paralyzed
Unable to create adequate airway
80% require trach within first year
50% resolve after 1 year with no surgical intervention
Significant inspiratory stridor
Increased risk of aspiration
Marked respiratory distress is often seen
Permanent surgical correction an option after 1-2 years of age

19. Tracheomalacia Congenital
Causes expiratory wheeze; biphasic wheeze if severe
Severe cases can cause:
Apnea
Feeding Difficulties
Failure to thrive
Recurrent Pneumonias (reduced mucociliary clearance)
Associated with:
Other congenital anomalies (cardiac, vascular rings)
GERD
Tracheomalacia.

20. Foreign Bodies in the Airway
Most common in toddler and preschool children
Most often (but not always) – witnessed history of choking on something, with facial duskiness
Presentation
Asphyxia – large airway
Respiratory distress
Persistent Pneumonia
Chronic cough
Persistent wheeze
Asymptomatic
Whenever significant suspicion, needs a rigid bronchoscopy!
Peanut in Airway.
Peanut

21. Retropharyngeal Abscess
Retropharyngeal lymph nodes drain adenoids and nasopharynx, and can get infected, resulting in abscess formation
Usual cause: Group A, β-haemolytic Streptococci
Generally children < 2 years of age, following upper respiratory tract infection, tonsillitis, otitis, adenitis
Can occur in older children from penetrating injury posterior wall of pharynx (lollipop, fishbones)
Symptoms: fever, sore throat, difficulty and/or pain swallowing, difficulty breathing, stridor, muffled voice, gurgling breathing
Signs: mass in posterior wall of pharynx, (generally unilateral), hyperextended neck, enlarged cervical lymph nodes
Diagnosis: enlarged retropharyngeal space on lateral neck X-ray; CT neck
Normal width retropharyngeal space in child < 15 years is < 7 mm
Treatment: surgical incision & drainage of abscess, intravenous Penicillin

22. Retropharyngeal Abscess
Rules (Length of Retropharyngeal Space) Normal: - 7mm at C mm C-6 kids - 22mm C-6 adults OR: >1/2 Vert Body

23. Retropharyngeal Abscess

24. Epiglottitis
Bacterial infection of supraglottic structures - epiglottis and aryepiglottic folds
Age years
Caused by Hemophilus influenzae type b;
Rare since HiB (Hemophilus influenza type b) vaccination.
Symptoms progress rapidly:
severe pain in throat leads to difficulty and avoidance of swallowing, causing drooling
dyspnea,
muffled cough and voice,
high fever,
anxious expression,
child tends to sit leaning forward
Risk for epiglottis sticking to laryngeal structures causing complete airway obstruction and asphyxia
Similar symptoms caused by Bacterial Tracheitis (severe bacterial infection of the trachea with necrotic tissue & pus, caused by Staphylococcus aureus, and occasionally by Haemophilus influenzae)

25. Lateral Views of the Larynx
Diagnosis:
lateral neck X-ray under medical supervision (“thumb sign” epiglottis, thickened aryepiglottic folds)
DO NOT examine throat with tongue depressor or upset the child
Normal
Epiglottitis

26. Epiglottitis

27. Treatment of Epiglottitis
Controlled intubation by experienced physician (emergency tracheostomy set available)
Then - culture epiglottis
Treat with IV Cefuroxime
(2nd generation Cephalosporin, covers Haemophilus influenzae)
Note: Bacterial tracheitis is diagnosed by bronchoscopy.
Treatment:
Intubation
Intravenous Cloxacillin, Vancomycin, or Cefuroxime
SWITCH AFTER THIS SLIDE

28. Croup (Viral Laryngotracheobronchitis)
Age 3 months - 5 years
Causes:
Parainfluenza virus type III (most common)
Influenza virus,
Respiratory syncytial virus (RSV)
Symptoms - dramatic!
Coryza,
Loud, barky cough
Lots of stridor
Hoarseness
Fever
Cyanosis if severe
Worse at night
Seasonality: especially fall & spring

29. Anterior views of the Larynx

30. Oral Steroids (occasionally, nebulized budesonide)
More on Croup
Diagnosis:
Usually clinical
If X-ray done, AP film of neck (“steeple sign”)
Normal child may have a “steeple sign” if X-ray done in full inspiration
Treatment:
Oxygen if needed
Oral Steroids (occasionally, nebulized budesonide)
Nebulized epinephrine if stridor at rest (to reduce swollen tissues)
Observe 2h afterwards for recurrence
Traditionally: Cool mist (but not effective in studies)

31. Pertussis (Whooping Cough)
The only true “bronchial infection” in children
Children get “bad colds” or bronchopneumonia (visible on CXR); Otherwise, as children aren’t heavy smokers, “bronchitis symptoms” are invariably viral
Caused by Bordetella pertussis (85% of cases; occasionally Bordetella parapertussis or Adenovirus can cause similar symptoms)
Vaccine-preventable, but Pertussis vaccination about 90% effective
Older whole-cell vaccine was less effective, more side effects, and vaccine effectiveness wanes over time; Adults remain a reservoir, spreading infection back to children
New acellular vaccine now in widespread use
Infection and toxin production assist bacterial adhesion and lead to cell necrosis, leads to severe dysfunction of cough receptors

32. Pertussis (Whooping Cough): Symptoms
Catarrhal phase - coryza, mild cough - lasts about a week
Paroxysmal phase - severe paroxysms of coughing, leading to facial plethora, vomiting
In older children, an inspiratory “whoop” at the end of a paroxysm of coughing.
Paroxysms of coughing can cause apnea in small infants.
Lasts 6 weeks
Convalescent phase - cough gradually abates, but re-activates with viral colds (never as bad as the initial episode) for up to a year
Catarrhal Phase
Paroxysmal Phase
Severity
Convalescent Phase
Time

33. Pertussis (Whooping Cough): Diagnosis and Treatment
Nasopharyngeal aspirate (culture or PCR), serologic testing
Chest x-ray shows bronchopneumonia pattern
Occasionally, severe lymphocytosis (“leukemoid pattern”)
Treatment:
Macrolide antibiotics shortens the period of infectivity, but affects the cough only when given during the catarrhal phase
Macrolides are also used to prophylax close contacts.
Cough remedies have no effect
Casey PA. Altitude treatment for whooping cough. BMJ May 18;302(6786):1212.

34. Bronchiolitis Viral infection of the bronchioles Causes:
RSV (most common)
Less often:
Influenza
Parainfluenza virus
Rhinovirus
Adenovirus, Metapneumovirus, Bocavirus
Pathology:
Viral infection causes intense inflammation, edema, mucous production, and mucosal shedding of the bronchiolar epithelium
Small-airways narrowing or obstruction leads to hyperinflation due to gas-trapping and areas of atelectasis
Bronchospasm may occur
May have contiguous spread into interstitium, causing an interstitial pneumonia

35. Bronchiolitis: Symptoms and Diagnosis
coryza and fever,
followed by respiratory distress (tachypnea, retractions), wheezing, cough;
Cyanosis and lethargy if severe
Diagnosis:
Nasopharyngeal aspirate for viral culture or rapid testing (immunofluoresence assay)
Chest radiograph shows:
hyperinflation,
bronchial wall thickening.
If associated viral pneumonia:
atelectasis,
interstitial infiltrates

36. Bronchiolitis X-ray Note: Hyperinflation Bronchial wall thickening
Patchy atelectasis

37. Bronchiolitis: Treatment
Oxygen
Extra fluids
30-50% respond to bronchodilators (2-agonists, nebulized epinephrine)
Role of oral steroids controversial – most studies do not support their use

38. Bronchiolitis - Prognosis
Lower respiratory tract involvement during RSV infection associated with anti-RSV IgE (as opposed to anti-RSV IgG) antibodies
Infants genetically predisposed to producing anti-viral IgE antibodies likely to develop other atopic diseases, so 50% infants with RSV bronchiolitis will later have asthma
Severe bronchiolitis (especially adenovirus) in aboriginal children may lead to permanent lung damage, including permanent scarring of the bronchioles (bronchiolitis obliterans) and bronchiectasis

39. Pneumonia (General) Incidence (per 1000) Typical Atypical
Lobar Pneumonia
Bronchopneumonia
Due to bacteria: most often Strep pneumoniae, Haemophilus influenzae
Atypical
Interstitial Pneumonia
Due to:
Viruses
Mycoplasma
Children also get:
Nosocomial Pneumonia
Opportunistic infections (immunocompromised children)
Tuberculosis
Commonest in 1st year of life

40. Diagnosing Pneumonia in Children
Chest radiograph, CBC
Blood culture
Nasopharyngeal cultures for viruses, mycoplasma
Serology: Mycoplasma, Chlamydia, viruses
TB skin test
In severe cases: Bronchoscopy, Pleural fluid culture
CT Scan, Ultrasound Chest can identify and characterize complications (lung abscess, empyema)

41. Lobar Pneumonia
Classic consolidation of one or more lobes, with alveolar spaces being filled with fluid, pus, and fibrin, with eventual organization and consolidation
Symptoms:
Onset with URI in infants. May follow influenza, measles (developing world)
Rapid development high fever,
lethargy,
dyspnea,
hacking cough ± sputum production
headache,
abdominal pain
Physical exam: classical signs pneumonia:
crackles,
reduced air entry,
dullness
± meningismus
Signs pleural effusion (if present)

42. Lobar Bacterial Pneumonia: X-ray and Organisms
CXR:
lobar consolidation occupying one or more lobes
+/- parapneumonic effusion, empyema
Common organisms:
Streptococcus pneumoniae
Haemophilus influenzae
Group A Streptococcus
Staphylococcus aureus

43. Right Middle Lobe - Lobar Pneumonia - Chest X-ray

44. Bronchopneumonia
Patchy areas of consolidation near bronchi, often throughout one or in multiple lobes
Suppurative neutrophilic exudate fills bronchi, bronchioles, and adjacent alveolar spaces
Chest X-ray shows patchy infiltrates next to major bronchi
Typically follows URI.
Symptoms:
Fever, chills
Cough
Chest Pain (older children)
Fatigue
Shortness of Breath, Rapid Shallow Breathing
Sputum (older children)
Signs: difficulty breathing, productive cough, crackles
Causes: Streptococcus pneumoniae, Hemophilus influenzae, β-haemolytic Strep Group A

45. Complicated Pneumonia
Bacterial pneumonia can be complicated by:
Pleural Effusion
Parapneumonic Effusion (Transudate)
Empyema (Exudate) – suppurative material and bacteria accumulating in pleural space
Lung Abscess
Necrosis and breakdown of lung tissue into cavities filled with pus and air (air-fluid level)
Pneumatocele
Necrosis of breakdown of lung tissue producing air-filled cavity only
Necrotizing Pneumonia
Combination of empyema, consolidation, and multiple lung abscesses within the consolidated lung
Symptoms: rapid progression respiratory distress, cyanosis, shock

46. The Key Bacteria (1)
Streptococcus pneumoniae (“Pneumococcus”)
Overwhelmingly the commonest cause of pneumonia in children
½ of cases are lobar, ½ are bronchopneumonia
commonest cause of parapneumonic effusions, empyema, and necrotizing pneumonia in children
Hemophilus influenzae
3/4 of cases are lobar
80% cases children < 2 years of age
typable Hemophilus influenzae less common since vaccination
75% are complicated by pleural effusion
High extra-pulmonary complication rate: meningitis, epiglottitis, septic arthritis

47. Infants, malnourished children (developing world)
The Key Bacteria (2)
Group A Streptococcus
Generally children > 5 years of age
1/3 have antecedent strep throat.
Often follows varicella, influenza, measles
¾ of cases are bronchopneumonia, ¼ are lobar
Severe pneumonia; massive pleural effusion in at least 2/3 cases
Staphylococcus aureus
Infants, malnourished children (developing world)
Lobar or segmental infiltrates
Severe pneumonia;
massive pleural effusion & empyema (75%)
pneumothorax (40%)
pneumatoceles (45%)
lung abscesses

48. Mycoplasma Pneumonia Cause: Mycoplasma pneumoniae
Rare before 4 years of age; commoner in children over 5 years of age and very common in adolescents and young adults
Symptoms:
Usually - gradual onset fever, headache, malaise, myalgias, dry cough, sore throat, abdominal pain
Occasionally - sudden onset, sputum production may occur
Crackles in 75%.
Diagnosis:
CXR:
peribronchial infiltrates, patchy atelectasis most common;
interstitial infiltrates may be seen
Other diagnostic tests:
serology
PCR or culture of respiratory specimens
Cold agglutinins fairly sensitive but not specific

49. Mycoplasma Interstitial Pneumonia - Chest X-ray

50. More on Mycoplasma Pneumonia
Complications common:
Arthritis
Hemolytic anemia
Meningitis
Treatment:
Macrolide antibiotic (erythromycin, clarithromycin, or azithromycin)
Chlamydia pneumoniae causes a similar infection in children, associated with a single, subsegmental lesion

51. Viral Pneumonia
Common organisms: RSV, Influenza, Parainfluenza, Adenovirus
Pathology:
Organisms spread contiguously from upper respiratory tract to lower, causing epithelial necrosis, sloughing, and mucous hypersecretion, causing hyperinflation and areas atelectasis.
Alveolar involvement leads to interstitial mononuclear cell infiltrates & edema
Symptoms:
URI
anorexia,
respiratory distress,
cough,
fever,
cyanosis
Wheezing is common
Chest radiograph:
Hyperinflation
bronchopneumonic/peribronchial infiltrates, interstitial infiltrates, patchy areas of atelectasis,
Treatment: fluids, oxygen

52. Pneumonia – an Ounce of Prevention
Influenza – influenza vaccination available in Ontario for people 6 months and older
Overall, 30% reduction in influenza deaths in Ontario
Strep Pneumoniae:
90 serotypes, 23 account for 85-90% of invasive disease
7-valent protein-conjugated pneumococcal vaccine given at 2, 4, 6, 15 months
Use resulted in 35% reduction in hospitalization for pneumonia in American children
23-valent polysaccharide vaccine for children 2 years and over
For high-risk children with underlying disease
Re-vaccinate in about 5 years
Haemophilus influenzae type b (HiB):
Protein-conjugated HiB vaccine given at 2, 4, 6, 18 momths
Use resulted in 99.7% reduction in invasive Haemophilus influenza disease (including epiglottitis) in American children
No effect on non-typable Haemophilus influenzae, Haemophilus species

53. Bacterial Pneumonia: Treatment
Mild-Moderate Pneumonias (Outpatient therapy)
Children 1 – 4 years: amoxicillin +/-clavulinic Acid, 2nd-generation cephalosporin (cefuroxime)
Children 5-18 years: macrolide (clarithromycin, azithromycin) if broncopneumonia, amoxicillin if lobar pneumonia
Severe Pneumonia (Inpatient therapy)
IV 2nd-generation cephalosporin (cefuroxime)
IV Ceftriaxone or Vancomycin for Penicillin-resistant Pneumococci
IV cloxacillin for staphylococcus; vancomycin if Methicillin-resistant
Pleural effusions or pneumothorax:
Drain with a chest tube if moderate-large
Video-assisted Thoracoscopic Surgery (VATS) or fibrinolytics (TPase) by chest tube if thick/loculated empyemas
Pneumatoceles generally resolve on their own