Cyanotic Episodes in Congenital Heart Disease

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  • See also

    Intranasal fentanyl
    Recognition of the seriously unwell neonate and young infant
    Resuscitation of the seriously unwell child

    Key points

    1. Most cyanotic episodes in children with congenital heart disease (CHD) are self-limiting
    2. The child should be comforted by the parent, clinicians should use a minimal handling approach with targeted examination
    3. Prolonged episodes may be life threatening and require active treatment with oxygen and opiates
    4. Early involvement of senior staff and specialist advice is important in prolonged episodes


    • Cyanotic episodes in children with congenital heart disease (also known as hypercyanotic spells, hypoxic spells or “tet spells”) are acute episodes of cyanosis or exaggerated cyanosis compared to the child’s baseline. They most often occur in children with Tetralogy of Fallot and pulmonary atresia
    • Cyanotic episodes are due to an imbalance between pulmonary and systemic vascular resistance with decreased pulmonary flow, and increased right to left shunting of blood
    • Most commonly occur between 2-6 months of age
    • Usually occur during times of stress, for example when unwell with an infection, when upset or upon waking
    • Most episodes are self-limiting



    • Known history or evidence of structural heart disease
    • Severe cyanosis (more than usual)
    • Hyperpnoea
    • Precipitating factors eg distress, prolonged crying, dehydration, intercurrent illness
    • Lethargy, altered conscious state
    • In older children, there may be a history of squatting episodes


    • Minimal handling approach with limited and gentle examination to avoid distressing child
    • Degree of cyanosis compared to baseline – apply oxygen saturation monitoring
    • Assess hydration and perfusion
    • Auscultate for murmur if able


    Initial management

    • Aim to calm the child because distress can worsen or prolong cyanotic episodes
    • Minimal handling approach, child remaining with parent as much as possible
    • Place child in knee to chest position to increase systemic vascular resistance

    Cyanotic Episodes in Congenital Heart Disease

    Knee to chest position lying supine

    Cyanotic Episodes in Congenital Heart Disease

    Knee to chest position held upright

    Cyanotic Episodes in Congenital Heart Disease

    Post-episode management


    • Consider performing after episode has resolved to avoid distressing child
    • Guided by possible precipitating factors
    • An ECG is also helpful in excluding an arrhythmia


    • Monitor to ensure resolution of cyanotic episodes, and that child is not sedated due to opiate administration
    • Discuss with Cardiology regarding ongoing observation and management

    Consider consultation with local paediatric team when

    Child present with cyanotic spells requiring treatment

    Consider transfer when

    Child requiring ICU admission or review by Cardiology

    For emergency advice and paediatric or neonatal ICU transfers, see Retrieval Services

    Consider discharge when

    The child is back to baseline, not sedated and consultation with Cardiology has occurred

    Parent information

    Tetralogy of Fallot Spells

    Last updated November 2022

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