Neonatal respiratory distress

01OverviewDefinition, clinical context and the essential points that orientate the chapter.

Breathing difficulty in a newborn is a final common pathway rather than one diagnosis. Lung immaturity, retained fluid, aspiration, infection, air leak, maladaptation of pulmonary circulation, cardiac disease and congenital anatomy can look similar initially.

At transition, aeration lowers pulmonary vascular resistance and replaces placental gas exchange. Failure of aeration or persistent high pulmonary pressure creates hypoxaemia, bradycardia and right-to-left shunting.

Respiratory distress syndrome is primarily surfactant deficiency in preterm lungs. Increased surface tension collapses alveoli at end-expiration, reduces compliance and functional residual capacity, and produces worsening work of breathing.

Transient tachypnoea reflects delayed absorption of fetal lung fluid, particularly after prelabour caesarean birth. It should improve, whereas worsening oxygen need, shock or systemic illness argues for another cause.

Meconium aspiration can obstruct airways, cause chemical pneumonitis, inactivate surfactant and precipitate air leak or persistent pulmonary hypertension. Routine tracheal suction is not recommended solely for meconium; support ventilation according to NLS.

Persistent pulmonary hypertension of the newborn causes high pulmonary vascular resistance and right-to-left ductal or atrial shunting. Hypoxaemia can be labile and disproportionate to radiographic lung disease.

Early-onset infection may present only with grunting, oxygen need or apnoea. Risk factors inform suspicion, but clinical illness itself is sufficient to trigger investigation and empirical treatment.

Respiratory support is a dose. Pressure, volume, oxygen and ventilation targets should be prescribed, monitored and reduced when possible because both insufficient support and treatment-related injury matter.

Communication with parents should explain uncertainty and trajectory: a working diagnosis may change as response, imaging, cultures and echocardiography clarify physiology.

Key points

Respiratory distress is tachypnoea, recession, grunting, nasal flaring, cyanosis or apnoea; rate alone does not describe severity.
Stabilise temperature, airway, breathing, circulation and glucose before pursuing a perfect diagnosis. Attach preductal saturation and use ECG when resuscitation is needed.
Gestation and onset organise the differential: preterm early distress suggests RDS; term caesarean birth suggests transient tachypnoea; meconium suggests aspiration.
RDS results from surfactant deficiency and usually worsens over the first hours with low-volume granular lungs and increasing oxygen or pressure need.
Transient tachypnoea follows delayed fetal-lung-fluid clearance, usually causes mild early tachypnoea and improves within 24–72 hours; it remains a diagnosis of exclusion.
First-line respiratory support for spontaneously breathing preterm babies is CPAP where clinically appropriate; invasive ventilation is reserved for failure or another indication.
Give surfactant early to a preterm baby who needs invasive ventilation for RDS; use a minimally invasive method in suitable babies who do not need an endotracheal tube for other reasons.
After stabilisation, target SpO2 91–95% in preterm babies. In term babies prescribe an individual target and investigate cyanosis rather than reflexively using prolonged 100% oxygen.
A preductal-postductal difference supports ductal shunting but does not by itself distinguish persistent pulmonary hypertension from structural heart disease; urgent echocardiography is definitive.
Treat the cause: antibiotics for suspected infection, drainage for tension pneumothorax, prostaglandin through a specialist pathway for duct-dependent disease, and pulmonary-hypertension support in intensive care.
Repeated blood gases, oxygen exposure and radiographs should answer a clinical question; use the least injurious support compatible with effective gas exchange.
Failure to improve as expected should reopen the differential, including airway obstruction, air leak, congenital anomaly, cardiac disease, metabolic acidosis and neurological depression.

02AetiologyUnderlying causes, associations and risk factors, with why each one matters.

Pulmonary transition and immaturity

Surfactant deficiency, retained fetal lung fluid and immature respiratory drive cause RDS, transient tachypnoea and apnoea.

Inflammation and aspiration

Bacterial infection, meconium, blood or gastric contents can injure small airways and alveoli and impair surfactant.

Airway and structural disease

Choanal obstruction, oesophageal atresia, diaphragmatic hernia, lung malformation and pneumothorax impair ventilation through distinct mechanical routes.

Cardiovascular and systemic causes

PPHN, congenital heart disease, shock, anaemia, acidosis, hypoglycaemia and neurological depression can present with cyanosis or tachypnoea.

03PathophysiologyThe causal sequence from the underlying abnormality to symptoms and harm.

1
Alveolar collapse
Low surfactant raises surface tension, reducing compliance and functional residual capacity and creating clinically important intrapulmonary shunt.
2
Fluid retention
Delayed epithelial sodium-mediated absorption leaves interstitial and alveolar fluid, reducing respiratory compliance until physiological clearance occurs after birth.
3
Pulmonary vascular shunting
Persistently high pulmonary resistance drives deoxygenated blood across ductal or atrial pathways and produces labile hypoxaemia.
4
Treatment-related injury
Excess volume, pressure and oxygen amplify inflammation, air leak and arrested lung development, especially in immature lungs.

04Clinical features and red flagsSymptoms, examination findings, patterns of presentation and time-critical warnings.

Respiratory examination

Count respiratory rate over a full minute and assess recession, grunting, nasal flare, symmetry, breath sounds, air entry, posture, tone and ability to feed.

Perinatal context

Record exact gestation, mode of birth, labour, membrane rupture, maternal fever or antibiotics, antenatal scans, steroids, meconium, resuscitation and time symptoms began.

Preductal and postductal oxygenation

Measure preductal right-hand saturation; add a postductal foot reading when cyanosis, pulmonary hypertension or duct-dependent cardiac disease is possible.

Systemic physiology

Assess heart rate, pulses, capillary refill, blood pressure, temperature, glucose, urine and neurological state because shock or metabolic disease may drive tachypnoea.

Anatomical clues

Look for a scaphoid abdomen, displaced heart sounds, dysmorphism, copious secretions, abdominal distension and unequal chest movement that point beyond common lung disease.

Support trajectory

Trend oxygen concentration, pressure requirement, carbon dioxide and work of breathing; the direction of travel is more informative than a single respiratory rate.

Red flags requiring action

Apnoea, gasping, falling heart rate, reduced respiratory effort or altered responsiveness signals exhaustion and need for ventilation rather than observation.
Sudden asymmetric chest movement, unilateral reduced breath sounds, cardiovascular collapse or abrupt oxygen deterioration raises tension pneumothorax.
Persistent central cyanosis, weak femoral pulses, shock or a large preductal-postductal saturation difference raises congenital heart disease or persistent pulmonary hypertension.
A scaphoid abdomen, displaced heart sounds or antenatal diaphragmatic abnormality suggests congenital diaphragmatic hernia; avoid bag-mask inflation.
Temperature instability, poor perfusion, hypotonia, feed intolerance or maternal infection risk with respiratory signs raises neonatal sepsis and requires timely antimicrobials.
Bilious secretions, copious frothy saliva or inability to pass an orogastric tube suggests oesophageal atresia or another surgical airway-feeding disorder.

05InvestigationsWhat to request, why it matters and how to interpret it.

Investigation order

Read from the initial assessment onwards. Tests may run in parallel in urgent care; first-line, preferred, confirmatory, definitive and gold-standard labels appear only when the chapter explicitly states them.

01
First-line: preductal pulse oximetry and continuous cardiorespiratory monitoringFirst stepFirst line
Why
Quantify oxygenation and deterioration while initial support is delivered.
Interpretation and limitations
Use neonatal transition targets during resuscitation; after stabilisation NICE recommends 91–95% for preterm babies. Verify waveform and probe site before acting on an implausible reading.
02
Blood gas with glucose and lactate
Why
Assess ventilation, oxygenation, acid-base status, perfusion and metabolic contribution.
Interpretation and limitations
Rising carbon dioxide with fatigue suggests ventilatory failure; metabolic acidosis may indicate shock, sepsis or congenital heart disease and should not be treated as a lung diagnosis alone.
03
Chest imaging
Why
Assess lung volume and pattern, air leak, aspiration, congenital anomaly and tube or line position.
Interpretation and limitations
Low-volume granular change supports RDS; fluid in fissures or hyperinflation may support TTN, but radiographic appearances overlap and must fit gestation and trajectory.
04
Sepsis evaluation
Why
Detect bloodstream or focal infection when risk factors or clinical indicators are present.
Interpretation and limitations
Obtain blood culture before antibiotics when this does not delay treatment, use serial CRP according to NICE, and do not exclude infection through one reassuring result.
05
Confirmatory test: echocardiographyConfirmatory
Why
Define anatomy, ventricular function, ductal shunting and pulmonary pressures when cardiac disease or PPHN is suspected.
Interpretation and limitations
A saturation differential is a clue, not a diagnosis; echocardiography distinguishes pulmonary hypertension from duct-dependent or mixing cardiac lesions.
06
Targeted lung ultrasound or transillumination
Why
Support rapid recognition of air leak or lung-fluid patterns where local expertise exists.
Interpretation and limitations
A clinically tensioned pneumothorax is treated immediately and must not wait for confirmatory imaging.

06Differential diagnosisRealistic alternatives and the features that help distinguish them.

Respiratory distress syndrome or TTN

Gestation, delivery, early trajectory, pressure need and imaging together distinguish surfactant deficiency from retained fetal lung fluid.

Infection or aspiration

Systemic illness, maternal risk, meconium and focal radiographic changes support pneumonia, sepsis or aspiration but overlap is substantial.

PPHN or congenital heart disease

Severe cyanosis, abnormal pulses, shock or differential saturations requires urgent specialist echocardiographic definition of the underlying cardiovascular physiology.

Airway, air leak or congenital anomaly

Asymmetry, absent air entry, abnormal abdomen, secretions or failure to pass a tube directs rapid anatomical assessment.

07ManagementImmediate care, first-line treatment, alternatives and escalation.

01ImmediateStabilise physiologyFirst stepA newborn has respiratory distress or cyanosis.

1Warm, position, assess breathing and heart rate and call neonatal help.
2Apply preductal oximetry, support airway and breathing with blended oxygen and CPAP or ventilation as indicated.
3Check glucose and gas while examining rapidly for tension pneumothorax, diaphragmatic hernia, shock and congenital heart disease.

02PretermRDS pathwayA preterm baby has progressive early distress and needs oxygen or pressure.

1Use early CPAP for a spontaneously breathing baby when appropriate.
2EscalationEscalate pressure and oxygen against response; intubate for apnoea, failure or severe disease.
3Give early surfactant when invasive ventilation is required and consider minimally invasive surfactant in a suitable spontaneously breathing baby.

03HypoxaemiaCardiac and pulmonary vascular assessmentCyanosis is severe, labile or disproportionate, or pulses/perfusion are abnormal.

1Compare preductal and postductal saturations and review blood pressure, pulses, gas and radiograph.
2DefinitiveSeek urgent neonatal-cardiology input and definitive specialist echocardiography.
3Optimise ventilation, lung recruitment, temperature, glucose, perfusion and acid-base status; specialist therapies depend on confirmed physiology.

04ReassessmentFailure to improveSupport requirement rises or the expected course does not occur.

1Check equipment, airway position, secretions and air leak first.
2Reconsider infection, cardiac disease, PPHN, aspiration, congenital anomaly, anaemia and metabolic or neurological causes.
3EscalationEscalate level of care and obtain focused imaging and specialist assessment without delaying life-saving treatment.

Key medicines and prescribing safety1 treatment · regimens, roles and cautions

Surfactant replacement for neonatal respiratory distress syndrome; use early when a preterm baby requires invasive ventilation and by a minimally invasive technique in suitable spontaneously breathing babies.

Poractant alfa intratracheal surfactant

Initial 100–200 mg/kg, equivalent to 1.25–2.5 mL/kg of the 80 mg/mL preparation, given endotracheopulmonarily as soon as possible after diagnosing RDS. If required, give further 100 mg/kg doses about 12 hours apart; maximum cumulative dose 300–400 mg/kg according to the SmPC and neonatal protocol.

Administer only by trained neonatal clinicians with full monitoring and ventilation capability. Confirm tube position, anticipate transient bradycardia or desaturation and rapid compliance change, and reduce oxygen and pressures promptly. Follow the exact product and unit protocol.

08ComplicationsImportant consequences, why they occur and why they matter clinically.

Air leak and pulmonary haemorrhage

Severe disease and positive pressure may lead to acute cardiorespiratory collapse requiring immediate bedside recognition and intervention.

Bronchopulmonary dysplasia

Persistent inflammation and disrupted lung development can create prolonged oxygen need and important later respiratory morbidity in childhood.

Hypoxic brain and organ injury

Untreated respiratory failure or shock compromises cerebral, renal, cardiac and gut perfusion and can cause permanent injury.

Therapy toxicity

Hyperoxia, hypocarbia, volutrauma, infection from invasive devices and medicine adverse effects can compound the initial disease.

09Monitoring and follow-upTreatment response, safety checks and longer-term review.

Continuously monitor heart rate, respiratory rate, preductal saturation, oxygen concentration and support settings; prescribe alarm limits and targets.
Repeat work of breathing, air entry, perfusion, temperature and neurological state after every significant intervention.
Trend blood gases according to severity and mode of support, avoiding unnecessary sampling and large swings in carbon dioxide.
After surfactant, anticipate rapid improvement in compliance and reduce ventilator pressure and oxygen promptly to avoid volutrauma or hyperoxia.
Monitor for pneumothorax, pulmonary haemorrhage, hypotension, infection, feeding intolerance and evolving bronchopulmonary dysplasia.
Record cumulative oxygen and ventilation exposure, and review readiness to wean at every senior assessment.
Ensure hearing, neurodevelopmental, respiratory and cardiac follow-up reflects the underlying diagnosis and intensity of neonatal care.

10Special situationsVariants, exceptions and circumstances that change the usual approach.

Ventilation precedes oxygen

When a newborn is apnoeic or bradycardic, lung inflation and effective ventilation restore heart rate; oxygen alone cannot ventilate unexpanded lungs.

A normal radiograph is not reassurance

Critical congenital heart disease and early pulmonary hypertension may cause profound cyanosis with little primary lung shadowing.

TTN should improve

Retained lung fluid usually resolves over 24–72 hours; worsening support need should trigger diagnostic review rather than repeated reassurance.

Surfactant changes mechanics quickly

Compliance may improve within minutes, so ventilator pressures and oxygen must be actively reduced against measured response.

Right hand is preductal

A right-hand probe samples blood before the ductal insertion; either foot is postductal and helps demonstrate shunting.

11Common pitfallsFrequent interpretation and management errors.

01
Do not observe an exhausted or apnoeic baby because the respiratory rate is no longer high.
02
Do not begin chest compressions before establishing effective lung inflation in neonatal resuscitation.
03
Do not use prolonged unblended 100% oxygen outside the specific resuscitation indication.
04
Do not delay decompression of a clinically tensioned pneumothorax for radiography.
05
Do not give mask ventilation when congenital diaphragmatic hernia is suspected.
06
Do not call worsening respiratory disease transient tachypnoea merely because birth was by caesarean section.
07
Do not exclude sepsis with a single normal CRP or absence of maternal fever.
08
Do not interpret preductal-postductal saturation difference as proof of PPHN without echocardiography.