Perioperative Respiratory Complications in Paediatrics

Perioperative respiratory complications:

Risk Assessment

Patient factors:

  • Age
    ↑ in prematurity, and ↓ by ~11% per year of age.
  • ↑ Airway reactivity
    • Atopy
      • Asthma
        Major risk factor for bronchospasm and laryngospasm. Key features:
        • Wheezing during exercise
        • Nocturnal dry cough
        • Eczema
          Present or past.
      • FHx of two or more relatives with asthma, eczema, or rhinitis
    • Eczema
    • Recent URTI
      Major risk factor for laryngospasm if within last 6/52, though first 2/52 are highest risk period.
      • Croup is especially high risk
    • Passive smoke exposure
  • Fever ⩾38°C
  • Systemically unwell
  • Coarse crepitations

Anaesthetic factors:

  • Premedication with midazolam
  • Use of volatiles:
    • Bronchospasm: Desflurane > Sevoflurane > Isoflurane
    • Sevoflurane associated with more laryngospasm than propofol maintenance (but equivalent bronchospasm) Compared with sevoflurane.
  • Use of lignocaine
    Effect is disputed and may vary depend on method of administration.
  • Airway devices and depth of anaesthesia
    Safest options to reduce laryngospasm involve minimising laryngeal and tracheal stimulation. Consider:
    • Use of facemask
      Equivalent bronchospasm risk to LMA, but significantly reduced laryngospasm.
    • Use of LMA
      With deep removal.
    • If intubating:
      • Awake removal of ETT
      • Use of cuffed (compared with uncuffed) ETT
        Also reduces post-operative stridor.

Surgical factors:

  • Nature of surgery
    ENT surgery more likely.
  • Airway intervention

Management

Factors favouring proceeding:

  • Frequent URTIs
  • “As well as baseline”
  • Long waiting list
  • Social and emotional burden of presentation
    • Difficulty of parents getting to hospital
  • Team experience
  • ENT surgery
  • Able to perform extended monitoring

Factors favouring cancellation:

  • Parental concerns
  • Age < 1 year
  • Prematurity
  • Respiratory comorbidity
  • Airway surgery
  • Requires endotracheal intubation

Post-Extubation Stridor/“Croup”

Post-operative laryngeal oedema due to irritation from ETT. It:

  • Can be disastrous
  • Occurs in young children due to airway diameter
    • 1-4 years
    • Infants ⩽1 at particular risk
  • Presents as stridor and coughing
  • Requires immediate treatment with:
    • Humidified oxygen
      FiO2 >0.5.
    • Resuscitation
    • Light sedation
      Aim to reduce distress without ↓ respiratory drive.
    • Nebulised adrenaline
      0.5ml/kg of 1:1,000, up to 5mg total.
    • Steroids
      Dexamethasone 0.5-1mg/kg.
    • Reintubation
      If ongoing deterioration or hypoxia
    • Tracheostomy
      If upper airway obstruction worsens.
  • Rebound may occur at ~2 hours

References

  1. von Ungern-Sternberg BS, Boda K, Chambers NA, Rebmann C, Johnson C, Sly PD, et al. Risk assessment for respiratory complications in paediatric anaesthesia: a prospective cohort study. The Lancet. 2010 Sep;376(9743):773–83.
  2. Parnis SJ, Barker DS, Van Der Walt JH. Clinical predictors of anaesthetic complications in children with respiratory tract infections: CLINICAL PREDICTORS OF ANAESTHETIC COMPLICATIONS. Pediatric Anesthesia. 2001 Jan 26;11(1):29–40.