Crianças com dificuldades respiratórias

Children frequently present with respiratory problems to general practitioners. The importance of these conditions is highlighted by the fact that they account for 20-35% of acute paediatric admissions and are the fifth most common cause of death in children between the ages of 1 and 14 years in the UK.

This article focuses on identifying the sick child and suggests underlying diagnoses.

Identifying the sick child^{1 2}

Veja também Criança doente e febril, Exame pediátrico e História e exame do sistema respiratório.

História

• Establish what the parent or carer is worried about.

• Note what symptoms there are and how long they have been going on for.

• Specifically find out about recent activities suggesting foreign body ingestion (make no assumptions relating to a young baby's age: an older toddler may try to 'feed' the new baby) and anaphylactic reaction:

• Specifically find out about past respiratory disease:

• Complete a usual paediatric history, including birth history and immunisations. Enquire about smokers in the house (relatives, frequent visitors as well as people who live there) as part of a social history.

Exame

• General observations.

• Respiratory system:

Signs of respiratory distress

• Assess chest expansion and auscultate: beware of the silent chest (this means that very little air is going in and out and may be a pre-terminal sign). Pulse oximetry should show an oxygen saturation close to 100% in normal healthy children breathing air. Acute severe asthma is defined by an SpO₂≤92%, respiration rate raised and the child being unable to talk in normal sentences.

• Other systems - these need assessing to gauge to what extent the respiratory distress has affected them:
  

  • Cardiac system - tachycardia is generally seen (the heart rate should roughly be four times the normal respiratory rate) - eg, pulse ≥140 beats per minute (bpm) (2-5 years) or ≥150 bpm (≥5 years old) in acute severe asthma. NB: bradycardia occurs in the presence of severe or prolonged hypoxia and is a pre-terminal sign.

  • Skin colour - pallor occurs initially. Cianose is a late and pre-terminal sign.

  • Agitation ± drowsiness. This may be difficult to assess and the parents will need to be consulted in the case of the very young child or baby.

Etiologia

Respiratory distress may result from:

• Laryngomalacia: common cause of stridor in infants. Stridor and noisy breathing may indicate varying degrees of respiratory compromise. Conservative management with feeding upright, anti-reflux therapy, and close observation of symptoms are generally all that is necessary for most affected infants. Only a small minority require surgical intervention.⁵

• Foreign body ingestion.

• Laryngeal oedema: anafilaxia, inhalation injury.

• Upper respiratory tract infection: epiglotite, crupe, retropharyngeal abscess.

• Lower respiratory tract causes: asthma, bronquiolite and bronchitis, pneumonia, Aquelas devido a doença primária dos vasos arteriais pulmonares. See also Infecção do trato respiratório inferior em crianças.

• Refluxo gastroesofágico na infância.

Clinical clues to alternative diagnoses other than asthma in wheezy children.⁴ Veja também Sibilância em crianças.

Perinatal and family history:

• Symptoms present from birth or perinatal lung problem: cystic fibrosis, chronic lung disease of prematurity, ciliary dyskinesia, developmental lung anomaly.

• Family history of unusual chest disease: cystic fibrosis, neuromuscular disorder.

• Severe upper respiratory tract disease: defect of host defence, ciliary dyskinesia.

Symptoms and signs:

• Persistent moist cough: cystic fibrosis, bronchiectasis, protracted bacterial bronchitis, recurrent aspiration, host defence disorder, ciliary dyskinesia.

• Excessive vomiting: gastro-oesophageal reflux (with or without aspiration).

• Paroxysmal coughing bouts leading to vomiting: pertussis.

• Dysphagia: swallowing problems (with or without aspiration).

• Breathlessness with light headedness and peripheral tingling: dysfunctional breathing, panic attacks.

• Inspiratory stridor: tracheal or laryngeal disorder.

• Abnormal voice or cry: laryngeal problem.

• Focal signs in chest: developmental anomaly, post-infective syndrome, bronchiectasis, tuberculosis.

• Finger clubbing: cystic fibrosis, bronchiectasis.

• Failure to thrive: cystic fibrosis, host defence disorder, gastro-oesophageal reflux.

Investigations:

• Focal or persistent chest radiological changes: developmental lung anomaly, cystic fibrosis, post-infective disorder, recurrent aspiration, inhaled foreign body, bronchiectasis, tuberculosis.

Gestão

This will be guided by the degree of respiratory distress and the underlying diagnosis:

• Life-threatening respiratory distress warrants immediate initiation of life support measures and immediate ambulance transfer to hospital.

• Children with moderate-to-severe respiratory distress should be referred to the local paediatric team.

• Where the decision is made to treat the child at home, parental education is important, with safety-netting so that the parent knows when to consult again. In some cases a review appointment might be usefully booked, which can be cancelled if the child has improved.

Lembre-se

• Almost all severely ill (or injured) children will benefit from high-concentration oxygen therapy. The only small group of infants to be careful with are those with duct-dependent congenital heart disease.

• It is usually counterproductive to make an unwilling child wear an oxygen mask. Avoid any other action that may agitate the child (which worsens the respiratory distress) unless the child is critically ill. Most of the assessment and initiation of treatment can be done with the child in their parent's arms.

• Do not put anything (including a thermometer) in the mouth of a child with stridor as this may precipitate complete respiratory obstruction and can be fatal if the underlying diagnosis turns out to be epiglottitis.