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Key messages

  • Central cyanosis affects 3-4 per cent of all newborns and may indicate significant disease.
  • Infants with central cyanosis where sepsis is suspected should be commenced on parental antibiotics early until further investigation.
  • Echocardiography is the gold standard for the assessment of congenital heart disease in infancy.
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    Please note that all guidance is currently under review and some may be out of date. We recommend that you also refer to more contemporaneous evidence in the interim.

    Cyanosis is characterised by a blue discolouration of the tissues caused by reduced haemoglobin levels.

    Central cyanosis affects 3-4 per cent of all newborns and is a marker of significant disease.

    Causes of cyanosis

    The causes are varied but may include:

    Echocardiography is the gold standard for assessing  congenital heart disease in infancy.

    Infants with central cyanosis where sepsis is suspected should be commenced on parental antibiotics early until further investigation is possible.

    Differentiating PPHN from duct dependent pulmonary cardiac lesions can be very difficult; if uncertainty exists PG infusion is generally the safest option for transport.

    Differential diagnosis of a cyanosed infant


    Breathing pattern

    Right and left sao2 difference


    Severe metabolic acidosis

    Response to 100% O2
    (discuss with cardiologist)

    Primary pulmonary disease Tachypnoea, grunting and recession No difference No ↑ PaO2
    and SaO2
    Cardiac Tachypnoea, slow/deep breathing +/-
    (usually 5-10%)
    Normal or  Present No significant change
    PPHN* Tachypnoea, recession and grunting may be present > 10-15% Normal or  +/- +/-
    Sepsis Respiratory distress may be present No difference Normal or  +/- Moderate PaO2 or SaO2

    * PPHN = persistent pulmonary hypertension of the newborn

    • History and presentation may allow the cause to be easily identified.
    • Often, differentiating cause is difficult without echocardiography especially in infants with relatively little respiratory distress.
    • Echocardiography is the gold standard for the assessment of congenital heart disease in infancy.
    • Transporting infants with severe cyanosis is difficult whatever the aetiology and stabilisation prior to transport is particularly important.
    • Fortunately, with adequate stabilisation, the overall transport-related mortality in infants with suspected cardiac disease is 0.7 per cent.

    General approach to the cyanotic infant

    Assess the history

    Physical examination

    • Check vital signs for respiratory distress and signs of sepsis.
    • Four limb BP - an upper to lower limb systolic difference of > 10 mmHg is significant and may be suggestive of Coarctation of the aorta.
    • Hypotension in a cyanotic infant is a serious finding.
    • Listen for murmurs.


    • Include FBE, BGL, U&Es, calcium, blood cultures, septic screen.
    • Confirm central cyanosis with arterial blood gas (ABG) in room air if possible; a sample from the right arm (preductal) is the best site.
    • Correct metabolic acidosis and systemic hypo perfusion if present with fluid boluses and bicarbonate (only if adequate ventilation established).
    • Consult with PIPER on 1300 137 650.

    Hyperoxia test (HT)

    100 per cent FiO2 into headbox for > 10 min:

    • Monitor SaO2.
    • Repeat ABG
      • PaO2 > 100 mmHg or SaO2 increase by 15 per cent: likely pulmonary disease
      • PaO2 < 70 mmHg, rise by < 30 mmHg or SaO2 unchanged: cardiac cause or PPHN likely.
    • Total anomalous pulmonary venous drainage (TAPVD) and hypoplastic left heart syndrome may respond.
    • Pulmonary disease with a massive intrapulmonary shunt may not respond.

    Limitations of HT

    • HT is not as reliable as an echocardiogram and is not as important as resuscitation and attendance to cardiorespiratory support, especially if acidosis or respiratory distress is present.
    • HT has many limitations especially when only saturations are measured and not arterial PaO2 and should only be used in conjunction with a thorough clinical assessment.
    • There is a risk of hyperoxia.

    Other assessments and treatment

    • Assess right and left sided SaO2 for any ductal difference
    • CXR and ECG if possible
    • Intubation and paralysis if significant distress
    • Two IV lines ideally or UVC
    • Parental antibiotics (preferably after blood cultures taken)
    • Prostaglandin E1 infusion if duct dependent cardiac disease is suspected
    • Consider inotrope support to maintain BP/improve cardiac contractility
    • Infants should be transferred to a Level 6 unit with paediatric cardiology and cardiac surgery facilities readily available

    Differential diagnosis


    Consult sepsis for more detail but note the following:

    • Sepsis with a low output state may cause:
      • poor pulses
      • severe metabolic acidosis
      • blunted response to HT
      • absent respiratory distress (if no primary lung pathology).
    • Differentiating the infant in severe septic shock from other causes of cyanosis is very difficult and no safe clinical measures exist. Thus, generally all infants with central cyanosis should be commenced on parental antibiotics early until further investigation is possible.

    Persistent pulmonary hypertension of the newborn (PPHN)

    Consult PPHN for more detail but note:

    • PPHN results from an altered pulmonary vasoreactivity and increased pulmonary vascular resistance, causing a right to left ductal shunt.
    • Most infants present with respiratory distress and cyanosis.
    • Usually the infant is tachypnoeic, shows labile oxygenation and has evidence of right ventricular strain (prominent right ventricle impulse and tricuspid regurgitation murmur).
    • There is usually a pre and post-ductal difference of 10-15 per cent in SaO2 and 10-15 mmHg PaO2. Despite this a degree of clinical variability exists depending on the severity, stage of disease and underlying pathology.
    • If PPHN is suspected hyperventilation for 10 minutes is a useful clinical test when other investigative options are unavailable.
    • Infants with PPHN show improved oxygenation (PaO2 increasing by > 30 mmHg) when pH is raised to 7.55. Prolonged hyperventilation is not recommended due to the cerebral effects of prolonged hypocapnia.
    • Differentiating PPHN from duct-dependent pulmonary cardiac lesions can be very difficult; if uncertainty exists a PG infusion is generally the safest option for transport and infants with PPHN may show some improvement on infusions of 50-60 nanog/kg/min.

    Cardiac causes

    Issue to note about cardiac causes for cyanosis:

    • Generally an infant with cyanosis and a murmur has a high probability of a cardiac cause.
    • Absence of peripheral pulses further raises this probability.
    • Infants presenting with cyanosis due to a cardiac cause have a high probability of a duct dependent lesion involving either of the following conditions.

    Duct-dependent pulmonary circulation

    • critical pulmonary stenosis
    • transposition of the great arteries.

    Presenting with:

    • cyanosis
    • tachypnoea without respiratory distress
    • adequate perfusion initially.

    Duct-dependent systemic circulation (critically obstructed systemic circulation)

    • coarctation of the aorta
    • hypoplastic left heart syndrome
    • critical aortic stenosis.

    Presenting with:

    • cardiac failure with systemic hypoperfusion
    • poor or absent peripheral pulses
    • increasing metabolic acidosis
    • cyanosis may not develop until the latter stages of the clinical course.

    Management of cardiac causes

    Aim to maintain adequate tissue perfusion and duct patency rather than correcting the cyanosis.

    Minimise pulmonary blood flow:

    • moderate PEEP (4-6 cm H20)
    • ventilate in air if possible
    • aim for a CO2 of 37-45 mmHg
    • SaO2 75-85 per cent.

    Maximise tissue perfusion with:

    • fluid resuscitation (saline 10ml/kg boluses)
    • low-dose inotropes (dopamine/dobutamine), see shock
    • sodium bicarbonate if BE > -10 (dose (mmol) = BE *wt/4).

    Consider muscle relaxants, sedation and respiratory ventilation if the infant is distressed.

    Achieve ductal patency with prostaglandin E1.

    Prostaglandin E1 (PG) infusion

    When to give prostaglandin E1 (PG) infusion

    Give prostaglandin E1 (PG) infusion in these situations:

    • In a cyanotic infant in whom cardiac disease is suspected there should be a low threshold for starting PG following consultation with PIPER.
    • Even in a stable infant the risk of withholding PG is usually greater than the risks associated with PG due to the risk of rapid clinical deterioration when the duct closes, especially in a transport environment.
    • There is evidence that infants with suspected duct dependent cardiac lesions transported with prostaglandin have better outcomes than those in which prostaglandin is withheld. The overall risk to the infant is low.
    • There are no true contraindications to PG but infants with TAVPD may worsen on PG.
    • If the diagnosis is uncertain a trial of PG for 30-60 minutes with repeat ABG may be warranted and will usually outweigh the risks of delaying treatment.


    Dosage guidelines include the following:

    • When the duct is still open the priority is to prevent further loss of patency.
    • A starting dose of 10 nanogram/kg/min infusion in 5 per cent dextrose or normal saline is adequate.
    • If no improvement in SaO2 then increase dose by 10 nanogram/kg/min increments up to 50 nanogram/kg/min until SaO2 improves.
    • Prostaglandin can be given via a peripheral line or UVC.
    • Infants in extremis will usually have a closed duct and a higher starting dose of 100 nanogram/kg/min will be required to reopen the duct.
    • When saturations improve then dose can be decreased to a dose to maintain ductal patency.

    See the Drug Calculator

    Side effects of prostaglandin E1 (PG) infusion

    Most frequent side effects include:

    • fever 12 per cent
    • apnoea 12 per cent
    • flushing 10 per cent
    • hypotension
    • tachycardia.

    Apnoea rarely occurs at 10 ncg/kg/min and is not an indication to decrease the dose if the infant is responding clinically.

    Ensure adequate respiratory support.

    The likelihood of apnoea is very high at a dose of 100 ncg/kg/min and most infants on this dose should have ventilatory support.

    Close observation is mandatory following commencement of PG infusion and assisted ventilation,volume expansion or inotrope infusion are frequently required.

    Who to intubate?

    The threshold to intubate an infant on a PG infusion will be lower in a transport or remote setting. Factors to consider:

    • presence of apnoea
    • the distance to the receiving hospital
    • gestation of the infant
    • clinical state of the infant (metabolic acidosis, shock, severe distress and tachypnoea)
    • high PG dose required to achieve ductal patency.

    In a stable infant with a PG responsive ductal lesion transport without intubation maybe appropriate.

    Conversely, it would generally be appropriate to electively intubate an infant requiring high dose PG (although these infants usually require respiratory support for other reasons).

    More information



    • Penny DJ, Shekerdemian LS. Management of the neonate with symptomatic congenital heart disease. Arch Dis Child Fetal Neonatal Ed 2001; 84: F141 - F145.
    • Hellstrm-Westas L et al. Long-distance transports of newborn infants with congenital heart disease. Pediatr Cardiol 2001; 22: 380-384
    • Buck ML. Prostaglandin E1 treatment of congenital heart disease: use prior to neonatal transport. DICP Ann Pharmacother 1991; 25: 408 - 9
    • Barry PW, Ralston C. Adverse events occurring during interhospital transfer of the critically ill. Arch Dis Child 1994; 71: 8-11
    • Jaimovich DG, Vidyasagar D (Ed). Handbook of pediatric and neonatal transport medicine. Ch 8. 2nd Ed. 2002. Hanley & Belfus. Pp 93 - 125
    • Myung K Park. Pediatric cardiology for practitioners. 3rd Ed. 1996. Mosby-Year Book (St Louis)

    Get in touch

    Centre of Clinical Excellence - Women and Children
    Safer Care Victoria

    Version history

    First published: June 2017

    Last web update: October 2018

    Review by: June 2020


    Page last updated: 17 Feb 2021

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