A 12-month-old infant is admitted to your ICU with bronchiolitis.

a) List five differential diagnoses that should be considered (30% marks)

b) List five signs of severity in bronchiolitis. (30% marks)

c) List four risk factors for severe bronchiolitis. (10% marks)

d) List the available supportive therapies. (30% marks)

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College Answer

Any five of: 

  • Bacterial pneumonia
  • Recurrent viral triggered wheezing in atopic children (but too young for a diagnosis of asthma)
  • Chronic lung disease of ex-prematurity (broncho-pulmonary dysplasia)
  • Occult congenital heart disease or cardiac failure
  • Foreign body aspiration
  • Congenital vascular rings
  • Aspiration pneumonia due to gastro-oesophageal reflux

Any five of:                                             

  • Tachypnoea
  • Nasal flaring
  • Grunting
  • Subcostal or intercostal recession
  • Tracheal tug
  • Use of accessory muscles
  • Apnoeic episodes
  • Hypoxia on pulse oximetry

Any four of:            

  • Ex prematurity
  • Less than 12 weeks old
  • Chronic Lung Disease
  • Upper airway disease
  • Congenital heart disease
  • Immunodeficiency
  • Neurological disease
  • Smokers in the household
  • Crowded households
  • Attending day-care
  • Older siblings

                d)                                                             

Mild disease:

  • continue feeding, comfort

More severe disease:

  • Nasogastric feeding and/or iv fluids
  • High flow humidified fresh gas by nasal cannulae (titrated FiO2, FGF 1-2 L/kg/min)
  • Non-invasive CPAP
  • Intubation rarely required

Discussion

a) 

The whole table of differentials for respiratory failure in children is reproduced below. However, there are specific broncholitis mimics which need to be mentioned, as they also present with wheeze. 

These are:

  • Asthma
  • Recurrent viral-triggered wheezing
  • Bacterial pneumonia
  • Chronic lung disease of ex-prematurity (or some other sort of chonic lung disease)
  • Foreign body aspiration
  • Aspiration pneumonia
  • Congenital heart disease with heart failure
  • Vascular rings (eg. pulmonary artery slings)

Causes of respiratory failure in children, more broadly:

Category Neonates Young children
Vascular
  • Congenital heart defect
  • Vascular rings and slings
  • Pulmonary haemorrhage
  • Progression of congenital heart disease
  • Rheumatic fever
Infectious
  • Neonatal pneumonia
  • Bronchiolitis
  • Pneumonia
  • Croup
Neoplastic  
  • Intrathoracic solid tumours; lymphoma and neuroblastoma
Drug-induced  
  • Accidental ingestion of respiratory depressant, eg. opiate of some sort
Idiopathic
  • Transient tachypnoea of newborn
 
Congential
  • ARDS of prematurity
  • Congenital heart defect
  • Laryngo/tracheo/bronchomalacia
  • Pulmonary hypoplasia
  • Gastroschisis and omphalocele
  • Neuromuscular and skeletal disorders
  • Diaphragmatic hernia
  • Chronic neuromuscular conditions
Autoimmune  
  • Asthma
  • Anaphylaxis
Traumatic
  • Meconium aspiration syndrome
  • Diaphragmatic palsy (post cardiothoracic surgery)
  • Pneumothorax
  • Inhaled foreign body 
Metabolic
  • Metabolic acidosis
  • Decreased LOC due to some sort of metabolic coma 

b)

Clinical signs of severity in bronchiolitis:

  • Tachypnoea (over 70)
  • Nasal flaring
  • Grunting
  • Subcostal or intercostal recession
  • Tracheal tug ("suprasternal resession")
  • Use of accessory muscles
  • Apnoeic episodes
  • Hypoxia on pulse oximetry (less than 90%)
  • Head bobbing
  • Decreased level of consciousness

c) Risk factors for severe bronchiolitis:

  • Ex prematurity
  • Low birth weight
  • Less than 12 weeks old
  • Bronchopulmonary dysplasia of ex-prematurity
  • Anatomical defects of the upper airways
  • Hemodynamically significant congenital heart disease
  • Immunodeficiency
  • Neurological disease
  • Smokers in the household
  • Crowded households
  • Attending day-care
  • Older siblings
  • Concurrent birth siblings
  • High altitude 

d) Supportive therapies in the management of bronchiolitis:

  • Airway:  
    • Assess the need for intuibation (rarely required)
    • Nasal suctioning to clear upper airway (not deep nasopharyngeal, but rather shallow nasal suctioning)
    •  
  • Ventilation:
    • Just oxygen to begin with
    • Aim for sats of over 90%
    • CPAP or HFNP may be the next step of escalation. With infants, maximum flow rate is about L/min. 
    • Invasive mechanical ventilation may be required, but HFNP frequently prevents the need for this.
    • Respiratory distress will escalate whenever the child is handled; the key to respiratory success is to minimise handling and to group all routine cares so that the child gets long breaks between distressing events.
    • Apnoeas may be helped by caffeine or aminophylline
  • Advanced strategies to improve gas exchange
    • ​Nebulised hypertonic saline 
    • Nebulised surfactant
    • Heliox
    • ECMO
    • None of these are strongly based in any sociaety recommendations, and sucess is mainly known from case reports
  • Circulation:
    • ​IV maintenance fluids and resuscitation of dehydration
    • Assessment for any coexisting cardiac disease with TTE
  • Electrolytes
    • Watch for SIADH: apparently that is one of the possible complications
  • Nutrition
    • Nasogastric feeding to make up for recent deficit
  • Antibiotics
    • ​Routine use of IV antibiotics is not indicated
    • Ribavirin has been trialled, and is also not recommended for routine treatment of RSV
      infection but may be considered in select immunocompromised individuals
    • Palivizumab, a humanized monoclonal antibody (IgG) directed against RSV, may be used in at-risk populations for prevention (eg. premature infants during RSV season).
  • Strategies which have been trialled and which clearly do not work:
    • Nebulised bronchodilators
    • Montelucast
    • Corticosteroids (no evidence of benefit, and may even increase the duration of viral shedding)
    • Chest physiotherapy (probably no benefit)
    • Caffeine or aminophylline (they were supposed to decrease the risk of apnoeas, but they do not seem to work)
    • However, it must be mentioned that the trials of all these interventions excluded the "severe" category of patients.

References

References

Plint, Amy C., et al. "Epinephrine and dexamethasone in children with bronchiolitis." New England Journal of Medicine 360.20 (2009): 2079-2089.

Lowell, Darcy I., et al. "Wheezing in infants: the response to epinephrine." Pediatrics 79.6 (1987): 939-945.

Ralston, S. L., A. S. Lieberthal, and H. C. Meissner. American Academy of Pediatrics Subcommittee on Diagnosis and Management of Bronchiolitis. "Clinical practice guideline: the diagnosis, management, and prevention of bronchiolitis". Pediatrics 134.5 (2014): e1474-e1502.

Osvald, Emma Caffrey, and Jane R. Clarke. "NICE clinical guideline: bronchiolitis in children." Archives of disease in childhood-Education & practice edition (2015): edpract-2015.

Alansari, Khalid, et al. "Caffeine for the Treatment of Apnea in Bronchiolitis: A Randomized Trial." The Journal of pediatrics (2016).