Respiratory Distress– keeping it simple
- A-B-C-D-E
- airway: foreign body / choking / vomitus / obtundation
- breathing: oxygen (NC / FM / NRB) ± nasal CPAP / BiPAP
- circulation: IVF 4-2-1 rule (cc/kg/hr)
- disability:
- exposure:
- Non-invasive respiratory support
- mechanical ventilation
Back to Basics
Stridor
Stridor is a sign of upper airways obstruction.
Causes of stridor
Acute Stridor
- Acute infections
- Acute Laryngotracheobronchitis (croup)
- Epiglottitis
- Retropharyngeal and peritonsillar abscess
- Diphtheria
- Angioneurotic oedema
- Non-infectious
- Laryngeal foreign body – sudden onset followed by wheezing
Chronic Stridor
- Congenital
- Laryngeal
- Laryngo-tracheomalacia (“floppy larynx”) – heard in the first few days of life
does not interfere with feeding / sleeping
- Laryngo-tracheomalacia (“floppy larynx”) – heard in the first few days of life
- Subglottic stenosis
- Vocal cord palsy
- Laryngeal webs
- Cysts upper and lower airway
- Laryngeal cleft
- Laryngeal papillomata
- Tracheal
-
- Vascular ring
- Tracheal stenosis
-
- Laryngeal
- Acquired
- Subglottic stenosis (post-intubation)
Upper Airway Obstruction
Traditionally, it was important to be able to clinically differentiate between croup and epiglottitis. In geographical regions were infant immunisation against Haemophilus influenza is routine, epiglottitis is now rarely seen.
Causes of Upper Airways Obstruction
- Viral Laryngotracheobronchitis (LTB)
- Spasmodic – associated with asthma (no preceding viral illness)
- Membranous – Staphylococcus and H. influenza (rare)
- Foreign Body
- Epiglottitis
Croup vs Epiglottitis
Croup is characterised by a low-grade fever and runny nose prodrome with symptoms commonly developing during the night when the child wakes with a characteristic “barking” or “sea-lion” cough. Sternal and suprasternal retraction is usually absent at rest but may develop during exertion. Inspiratory or even expiratory stridor at rest is usually an indication for admission for supplemental oxygen, nebulised adrenaline, and oral prednisone (or dexamethasone), and monitoring for signs of hypoxia which may suggest the need for nasotracheal intubation.
Epiglottitis is a bacterial infection of the epiglottis in which acute respiratory obstruction can be precipitated simply by lying the child on their back. It is traditionally taught to be confirmed by a “thumb” sign on a lateral airways film, the swollen epiglottis causing such a swollen silhouette against the surrounding darker air on a radiograph. Epiglottitis is always a severe airway and always needs admission for intubation and systemic antibiotics (with blood cultures). Intravenous Cefotaxime brings improvement within 24-48 hours and is usually continued for about 5 days.
Croup
Croup is heralded by a low-grade fever and runny nose prodrome and is a self-limiting viral infection that runs the course of 4-5 days of generally mild upper airway (laryngeal) obstruction.
The reasons for admission in croup are:
- Acute onset
- Worsening respiratory difficulty (stridor at rest)
- Young age
- Uncertain diagnosis
- Previous underlying abnormality e.g. BPD
Signs of Hypoxia
- Restlessness
- Tachycardia
- Tachypnoea
- Cyanosis
Bronchopulmonary Dysplasia
- Post-neonatal ventilation lung disease – especially seen if still on oxygen after a month
- CO2
- Barotrauma (airway pressure)
- Time
- Radicals / peroxide
- Recurrent airway obstruction + associated problems
Treatment:
- Home oxygen (eventually improve)
- Bronchodilators
- Antibiotics
- Admission
Acute Cough
Infections:
- URTI
- Croup
- Epiglottitis
- Acute bronchitis – viral, pertussis, mycoplasma
- Pneumonia
Non-infectious:
- Asthma
- Foreign body / aspiration
Ask about feeding, important in any respiratory problem: “how sick (how much vomit)?”; did they aspirate?
Look for:
- nasal flare
- respiratory rate
- colour
- accessory muscles of respiration
- recessions / tracheal tug
- cough and type
- breath sounds
- comparing each side of the chest for differences
- prolonged expiration
- inspiratory crepitations (bronchiolitis)
- (watch for transmitted noise with upper airway secretions)
Chronic Cough – causes by Age
Infancy (under 1 year)
- Congenital malformations – tracheomalacia, branchial cysts
- Congenital and neonatal infections
- Viral pneumonitis – rubella, cytomegalovirus
- Chlamydial pneumonia
- Aspiration – milk, gastric contents, saliva
Preschool (1 to 5 years)
- Inhaled foreign body
- Suppurative lung disease
- Chronic atelectasis
- Bronchiectasis (clubbing occurs late)
- Cystic fibrosis (clubbing occurs early)
- Bronchitis associated with chronic upper respiratory tract disease
School-age (5 to 15 years)
- Cigarette smoking
- Mycoplasma pneumoniae infection
- Nervous or psychogenic cough – honking cough
- Do not cough when asleep
- Overt / covert anxiety by parents regarding cough
- No evidence of underlying disease
Common to all age groups
- Recurrent viral bronchitis
- Asthma (bronchiolitis in younger)
- Pertussis
Investigating the Child with a Chronic Cough
- CXR: ? inspiratory and expiratory ± lateral neck film
- Barium swallow
- Rarely bronchoscopy / bronchography or angiography
- Mantoux Test
- PEF, Spirometry, Blood gases
- Immunological function tests, in the very ill
As a rule of thumb, upper airway obstruction causes more of a tracheal tug and sternal retraction while lower airway obstruction causes more intercostal and subcostal recession, although there is significant overlap, especially in more severe disease. Pertussis and laryngeal foreign body often cause cyanotic spells, vomiting, and interfere with feeding.
Wheezing in Infants (0-1 Year)
- Obstruction of small airways
- Acute viral bronchiolitis
- Aspiration – especially in developmentally delayed, GORD
- Asthma – episodic
- Bronchopulmonary dysplasia
- Cystic fibrosis
- Obstruction larger airways
- Congenital airway malformations – e.g. tracheomalacia
- Vascular malformations – e.g. vascular rings (aortic or branches)
- Mediastinal cyst, tumours
Toddler / Preschool Wheeze (1-5 Years)
- Small airways obstruction
- Asthma
- Acute viral bronchiolitis – not often diagnosed in > 1-year-old
- Suppurative lung disease / bronchiectasis
- Cystic fibrosis
- Chronic aspiration
- Adenoviral pneumonia
- Post-infectious (mycoplasma) viral
- Obstruction large airways
- Inhaled foreign body
- Ingested foreign body
- Mediastinal masses – especially hilar nodes
Causes of Wheeze in Schoolchildren / adolescents
- Obstruction small airways
- Asthma – majority
- Mycoplasma pneumoniae infection – commonest CAP in > 5 years old
- Suppurative lung disease / bronchiectasis
- Obstruction large airways
- Inhaled foreign bodies
- Mediastinal masses / tumour
- Bronchial adenoma
- α-1-antitrypsin deficiency
- Wheeze / stridor
- Functional
- Foreign Body
With respect to suspicion of inhaled foreign body:
Inspiratory and Expiratory CXR
- Trachea: no difference between inspiratory / expiratory films (no change in air)
- Main bronchus: Expiratory
- Affected side stays inflated
- Opposite side deflates
- Mediastinal shift away from lesion
A convincing history of choking of sudden onset and respiratory distress warrants bronchoscopy even if the CXR is normal.
Community Acquired Pneumonia (CAP)
Respiratory rate
Check the respiratory rate over 30 seconds to 1 minute:
- If > 40 in the first year of life, be suspicious
- If > 50 in the first year of life, be quite suspicious
- If > 60 in the first year of life, there is a problem
Note that the respiratory rate increases by 2-3 breaths/min for every 1°C rise in temperature.
Normal Resting Respiratory Rates (RR)
Age (Years): RR (breaths per minute)
- 0-1: 25-35
- 1-2: 25-30
- 2-3: 22-28
- 3-4: 21-24
- 4-5: 21-25
- 5-6: 20-24
- 6-7: 18-24
- 7-8: 18-22
- 8-9: 18-22
- 9-10: 17-21
- 10-11: 17-21
- 11-12: 16-22
- 12-13: 16-21
- 13-14: 16-21
- 14-15: 15-20
- 15-16: 14-20
- 16-17: 14-20
- 17-18: 13-20
From both fed, sleeping and fasting, awake children. (A. Iliff and V A Lee. Pulse rate, respiratory rate, and body temperature of children between two months and eighteen years of age. Child Dev, 23:237, 1952).
Foreign Body
Peak incidence: 1-2 years of age
Often choking event is short lived with apparent resolution and then later re-emergence of symptoms including cough, wheeze, and respiratory distress.
Any case with a suspicious story including a history of choking followed by cough, dyspnoea, fever, or any abnormal physical or chest radiographic findings requires bronchoscopy as > 40% of children will have a foreign body present.
Radiographic changes
- Normal lung fields extend to ribs 9-11 posteriorly and ~ rib 7 anteriorly: if more, consider hyperinflation.
- Younger children tend to aspirate into their upper lobes, while lying on their back
- Older children tend to aspirate into their lower lobes
- An “elephant trunk” sign of GORD should prompt a consideration of aspiration, as it represents widening of the cardio-oesophageal junction
- Patchy, non-specific changes + hyperinflation: think bronchodysplasia
- Hyperinflation of single lobes occurs with foreign body obstruction
The young baby with acute respiratory problems – an aide memoire
Modern Medicine of Australia, December 1987, p. 72
Differential Diagnosis
Commoner infective causes
- Coryza and other upper respiratory tract infections
- Any pyrexial illness
- Pertussis (during epidemics)
- Croup
- Bronchiolitis
- Pneumonia
Non-infective causes (all uncommon and needing referral)
- Congenital heart disease
- Obstruction with a foreign body
- Acidosis, e.g. due to a renal or general metabolic cause
- Congenital laryngeal or chest conditions e.g. laryngomalacia or right diaphragmatic hernia
Assessment
This is with a view to diagnosis and decisions over referral and treatment.
History:
- Is the difficulty interfering with feeding?
- How long has the baby been distressed?
- Could the baby have inspired a foreign body?
- What are the personal and social resources of the family: can they cope with this illness and follow instructions?
- How has the baby’s weight progressed on their chart? A recent crossing of centiles downwards is a poor sign.
Examination:
- The baby’s general appearance; robust or thin and wasted?
- Colour of the baby; pink, pale or cyanosed? (examine the tongue in babies of colour)
- Signs of infection: coryza, malaise, temperature, inflamed conjunctiva, lymphadenopathy?
- Assessment of degree of distress
- Tachypnoea
- Moderate: 30-45 / min
- Severe > 50 / min
- Dyspnoea
- Moderate: flaring of nostrils, some chest indrawing
- Severe: marked chest indrawing
- Stridor? If present do not examine the throat
- Added chest sounds? Generalised wheeze (bronchiolitis) or focal signs (pneumonia)
- Heart murmur? Anything more than a short systolic murmur makes congenital heart disease likely.
- Heart failure? (due to severe respiratory infection more often than heart disease). Never easy to judge in a baby. More useful signs are: sever tachypnoea (see above); a tachycardia over 180; liver edge 3 cm or more below the ribs.
- Tachypnoea
Instructions for parents managing a baby with an infective respiratory illness
Check your child every three to four hours, including through the night. Consult a doctor urgently if:
- Breathing problems prevent feeding
- Your child becomes very sleepy
- Your child cries for more than three hours and cannot be comforted
I have summarised the assessment and management of breathing and airway emergencies, available here for download as a pdf. The guide is appropriate for those working in primary care in rural or remote locations.
Breathing (and Airway) Emergencies in Children
The article is from my Paediatric Lecture Notes, Westmead Hospital, University of Sydney, 1992. The pdf file is my own.