Respiratory distress and failure in children

Respiratory distress and respiratory failure are common manifestations of critical illness in children. The initial evaluation should include pediatric vital signs assessment based on age, especially since respiratory rates vary between neonates, infants, toddlers, preschoolers, school-aged children, and adolescents. Child-specific clinical signs of respiratory distress include retractions, grunting, and nasal flaring. In patients with undifferentiated respiratory distress or failure, it is helpful to initially categorize the illness into one of four common phenotypes based on clinical presentation: upper airway obstruction (e.g., stridor), lower airway obstruction (e.g., wheezing), parenchymal lung disease (e.g., crackles), or disordered breathing control (e.g., irregular or absent respirations). Notable underlying causes include croup, foreign body aspiration (FBA), anaphylaxis, bronchiolitis, asthma exacerbation, pneumonia, pulmonary edema, acute respiratory distress syndrome (ARDS), seizures, traumatic brain injury (TBI), poisoning, and neuromuscular conditions.

Initial respiratory support must begin in tandem with clinical and diagnostic evaluation. Bedside tests such as pulse oximetry, end-tidal CO₂ (EtCO₂) monitoring, portable chest x-ray (CXR), lung POCUS, and blood gas analysis are used to determine the severity of respiratory compromise and rapidly identify underlying conditions that cannot be diagnosed clinically. Management includes pediatric airway management, oxygen therapy for children, emergency therapies (e.g., naloxone, epinephrine, bronchodilators, maneuvers to dislodge an aspirated foreign body), and mechanical ventilation in children. These treatments may be integrated into broader management or resuscitation algorithms for children and require specialized approaches, equipment, and/or expertise. Neonates require dedicated resuscitation protocols and respiratory support strategies due to their unique physiology.

See also “Airway obstruction” and “Wheezing.” For adults, see “Respiratory failure and arrest” and “Dyspnea.”

This article focuses on the airway and breathing components of the ABCDE approach in children with respiratory distress and/or respiratory failure and arrest. Respiratory arrest is the primary cause of cardiac arrest in children and informs BLS in infants and children and pediatric modifications to advanced life support.^[1]

See “Respiratory distress and failure in neonates” for causes specific to newborns. See also “Causes of hypoxemia” and “Causes of hypercapnia.”

Upper airway obstruction

• Croup
• Upper airway FBA
• Anaphylaxis
• For a more comprehensive list, see "Causes of airway obstruction."

Although the central airway is defined as a lower airway structure, the presentation and management of central airway obstruction resemble that of upper airway obstruction.

Lower airway obstruction

Typically refers to conditions that obstruct the distal airways, impairing ventilation and oxygenation

• Asthma exacerbation
• Bronchiolitis
• Lower airway FBA
• For more comprehensive lists, see:
  • "Etiology of wheezing"
  • "Common causes of wheezing in all ages"
  • "Causes of acute wheezing in children"

Parenchymal lung diseases

Conditions that affect lung parenchyma (e.g., respiratory bronchioles, pulmonary alveoli), thereby impairing gas exchange and lung compliance and leading to V/Q mismatch

• Pneumonia in children
• ARDS
• Pulmonary edema
  • Acute heart failure in children
  • Cholinergic poisoning
• Aspiration pneumonitis
• Pulmonary hemorrhage
  • Trauma (e.g., blunt chest trauma)
  • Vasculitis (e.g., granulomatosis with polyangiitis, microscopic polyangiitis)
  • See "Causes of hemoptysis" for details.
• Interstitial lung disease

Disordered breathing control

Conditions that cause altered respiratory drive and/or respiratory muscle weakness

• CNS injury or disease
  • TBI
  • Intracranial hemorrhage (e.g., subarachnoid hemorrhage, intracerebral hemorrhage)
  • Meningitis
  • Encephalitis
• Neuromuscular weakness
  • Muscular dystrophies
  • Myasthenic crisis
  • Guillain-Barré syndrome
  • See "Weakness and paralysis" for details.
• Metabolic acidosis that causes respiratory compensation
  • Diabetic ketoacidosis in children
  • Lactic acidosis (pediatric sepsis, shock, hypoxia)
  • Uremic acidosis (acute kidney injury, chronic kidney disease)
  • Toxic ingestions (salicylates, methanol, ethylene glycol)
  • Inborn errors of metabolism
• Poisoning in children
  • Opioid overdose
  • Sedative-hypnotic drug overdose
  • Carbon monoxide poisoning
  • Cyanide poisoning
• Congenital central hypoventilation syndrome

Vital signs

See “Pediatric vital signs” for normal heart rate and blood pressure ranges in children.

Respiratory rate (RR)

Oxygen saturation in children

• Normal SpO₂ for most children is 95–100%.
• Exceptions include:
  • Children with cyanotic congenital heart defects
  • Neonates in the first few minutes of life (see "Normal preductal neonatal SpO₂") ^[6]
• Oxygen desaturation usually occurs more rapidly in children than in adults. ^[7][8]
• For diagnostic considerations, see "Pulse oximetry in children."
• For therapeutic goals, see "SpO₂ targets in children."

Abnormal breathing patterns

• Kussmaul breathing
• Cheyne-Stokes breathing
• Ataxic breathing
• Obstructive breathing (prolonged expiratory phase)

Clinical features of abnormal gas exchange

• Oxygenation
  • See “Clinical features of hypoxemia.”
  • See “Pulse oximetry in children.”
• Ventilation
  • See “Clinical features of hypercapnia.”
  • See “EtCO₂ in children”

Clinical features of respiratory distress in children

• Clinical features of respiratory distress: The following signs occur more commonly in neonates, infants, and young children.
  • Retractions: a sign of increased WOB in which indrawing of the skin and soft tissue is visible around bony structures of the neck and/or thorax during inspiration
    • Suprasternal retractions: retractions visible above the sternal notch
    • Subcostal retractions: retractions visible below the lowest ribs
    • Intercostal retractions: retractions visible between the ribs
  • Grunting
    • A sign of respiratory distress that involves closing the glottis during expiration
    • Effectively increases positive end-expiratory pressure (PEEP) to keep airways open
  • Nasal flaring: wider opening of the nostrils during inspiration
  • Other signs of increased WOB
• Clinical features of partial airway obstruction
• Clinical features of poisoning (e.g., cholinergic toxidrome, clinical features of carbon monoxide toxicity) may be present.
• Associated signs (e.g., fussiness, crying, irritability, feeding difficulty)

Clinical features of respiratory failure in children

Typically preceded by signs of respiratory distress

• Clinical features of complete airway obstruction
• Apnea
• Cyanosis
• Respiratory muscle fatigue
• Clinical features of poisoning may be present, e.g.:
  • Sedative-hypnotic toxidrome
  • Opioid toxidrome
• Altered mental status or coma

Increasing WOB suggests respiratory distress; decreasing WOB despite worsening oxygenation suggests respiratory muscle fatigue and impending respiratory failure and is a life-threatening emergency that requires immediate intervention.

Provide respiratory support in tandem with clinical evaluation, bedside diagnostic workup, and, when applicable, components of a broader resuscitation algorithm (e.g., PALS, ATLS, neonatal resuscitation).

• Obtain a full set of pediatric vital signs, including pulse oximetry in children.
• Rapidly determine phenotype (i.e., upper airway obstruction, lower airway obstruction, parenchymal lung disease, disordered breathing control) based on general appearance and vital signs (see "Overview" for details).
• Begin pediatric airway management with basic airway maneuvers.
• Administer rescue breaths immediately if respiratory arrest is apparent.
• Begin oxygen therapy for children if indicated.
• For causes that can be diagnosed clinically, administer time-sensitive therapies (e.g., epinephrine, naloxone, maneuvers to dislodge an aspirated FB).
• Obtain bedside diagnostic tests (e.g., portable CXR, lung POCUS in children) to identify underlying causes if clinical evaluation is equivocal.
• Obtain rapid diagnostics (e.g., capillary blood gas, PEFRs) to help determine the severity of respiratory distress or failure and monitor the response to treatment.
• If indicated, perform pediatric advanced airway management and pediatric mechanical ventilation without delay.

General principles

• Respiratory distress and respiratory failure are clinical diagnoses.
• Bedside imaging can help diagnose some underlying causes (e.g., pneumonia, pulmonary edema, pneumothorax, pleural effusion, blunt thoracic trauma).
• Other bedside tests are typically used to determine the severity of respiratory compromise and response to treatment and/or to help identify underlying causes of clinically diagnosed conditions.
• Some underlying conditions may require confirmatory diagnostics, but these are usually performed after stabilization.

Pulse oximetry in children ^[9]

Interpret SpO₂ in the context of the overall clinical picture.

Emergency indications ^[9]

• Respiratory illnesses
• Other critical illnesses (e.g., shock, trauma)
• Monitoring (e.g., during procedural sedation or when using HFNC) ^[10]
• Neonates: See “Causes” in “Respiratory distress and failure in neonates.”

Closely monitor SpO₂ in critically ill children as both hypoxemia and hyperoxemia are potentially fatal to them. ^[11]

Method ^[9]

• Use size-appropriate adhesive sensors to maximize adherence and accuracy.
• Select a sensor location based on age, measurement reliability, and comfort.
  • Neonates: palms or soles preferred
  • Other children: fingertips, toes, earlobes, nose, or forehead preferred
• Ensure proper calibration of sensor systems to age and size.

Consider sensor placement on the earlobe or forehead in children with poor peripheral perfusion. ^[9]

Interpretation

• Consider the effects of the following on interpretation: ^[9]
  • Motion artifacts
  • Poor peripheral perfusion (especially on extremity readings)
  • Darker skin color ^[12]
• When SpO₂ is 100%, pulse oximetry cannot reliably differentiate between normoxia and hyperoxemia. ^[13]
• For normal values, see "SpO₂ in children."
• For therapeutic goals, see "SpO₂ targets in children."

Commercially available pulse oximeters consistently overestimate SpO₂ in Black and other dark-skinned infants and children, especially those with hypoxia. ^[12]

EtCO₂ in children ^[14]

• Indicated to confirm ET tube placement in children. ^[1][3]
• Consider for prehospital and interfacility transport of critically ill children. ^[1]
• Other clinical applications include: ^[14]
  • Real-time evaluation of CPR efficacy ^[3]
  • Monitoring during:
    • Mechanical ventilation
    • Procedural sedation
    • Patient transportation ^[3]
• Interpret levels according to age, weight, and clinical condition under specialist guidance. ^[14]

Do not use EtCO₂ levels to guide decision-making for termination of resuscitation in children. ^[3]

Laboratory studies

Blood gas analysis in children ^[15][16]

• Goals: to identify hypoxemic respiratory failure, hypercapnic respiratory failure, mixed respiratory failure, and related acid-base disorders
• Method: capillary blood gas (CBG), venous blood gas (VBG), arterial blood gas (ABG)
• Capillary blood gas ^[15]
  • Obtained via pricking the fingertip or heel with an automated lancet
  • Sampling is easier, safer, and more comfortable with nonpharmacological pain management.
  • Reasonable alternative to ABG to measure pH and pCO₂
  • Significantly underestimates pO₂
  • Accuracy is affected by changes in body temperature, peripheral perfusion, and blood pressure.
• ABG analysis
  • More accurate than VBG and CBG
  • ABG sampling is more invasive, painful, and prone to complications.
  • Typically avoided in children when possible
  • Required if P/F ratio measurement is indicated (e.g., for ARDS)

In children, consider less invasive methods (i.e., CBG or VBG) to assess ventilation and acid-base disturbances; SpO₂ is a more reliable noninvasive measure of oxygenation. Consider more invasive ABG sampling if an accurate measure of pO₂ is required to guide management (e.g., patients with poor peripheral perfusion).

Other laboratory studies

• Respiratory viral panel
• COVID-19 testing
• Depending on clinical suspicion
  • Diagnostics for neuromuscular weakness
  • Toxicology screen
  • Anemia workup

X-rays

Typically performed as a portable, bedside study in children with moderate to severe respiratory distress or failure who require hospitalization

• CXR indications ^[16]
  • Respiratory distress or failure due to pediatric pneumonia
  • Suspected pleural disease (e.g., pneumothorax, hemothorax, pleural effusion)
  • Lower airway FBA
  • Initial evaluation of thoracic trauma
  • Asthma exacerbation with suspected complications (e.g., pneumothorax, pneumomediastinum)
  • Severe bronchiolitis or suspected complication (e.g., pneumonia, pneumothorax) ^[17]
  • Suspected cardiogenic pulmonary edema (e.g., congenital heart disease, acute heart failure) or pediatric ARDS ^[18][19]
• Lateral neck x-ray indications: suspected upper airway obstruction that cannot be diagnosed clinically (e.g., epiglottitis)
• Characteristic findings
  • CXR findings of pneumonia
  • Imaging findings of pneumothorax
  • CXR findings in foreign body aspiration
  • CXR findings in bronchiolitis
  • Neck x-ray
    • Croup: steeple sign
    • Epiglottitis: thumbprint sign

CXR is not routinely required in stable children with wheezing (e.g., due to mild or moderate asthma exacerbations or nonsevere, uncomplicated bronchiolitis). ^[17][20][21]

Lung POCUS in children ^[16][22]

• Indication: undifferentiated respiratory distress or respiratory failure in emergency settings
• Technique: See “Lung POCUS.”
• Findings
  • Pediatric pneumonia
    • Ultrasound findings of lung consolidation (i.e., shred sign, tissue-like sign, sonographic air bronchograms)
    • See “Lung ultrasound in pneumonia.”
  • Alveolar-interstitial syndrome
    • Abnormal pleural line
    • > 3 B-lines per intercostal space
    • See “POCUS in AHF.”
  • Pneumothorax: absent lung sliding
  • Bronchiolitis
    • Small (< 1–1.5 cm) areas showing sonographic signs of lung consolidation in subpleural tissue
    • Abnormal pleural line
    • Multiple confluent B-lines
    • Occasionally, POCUS findings of pleural effusion or POCUS findings of pneumothorax
  • COVID-19
    • Abnormal pleural line
    • Sonographic signs of lung consolidation
    • Scattered confluent B-lines
    • POCUS findings of pleural effusion
  • Lung contusion
    • Focal increase in B-lines
    • Findings similar to alveolar interstitial syndrome

Advanced imaging ^[16]

• CT chest
  • Generally, CT chest is limited in children to limit radiation exposure following the ALARA principle.
  • Clinical applications
    • Second-line imaging in trauma (e.g., for operative planning)
    • Pneumonia in immunocompromised children and/or with suspected complications (e.g., lung abscess, bronchopleural fistula)
    • Suspected pulmonary embolism or pulmonary infarct
    • High clinical suspicion of lung disease or airway obstruction despite equivocal x-ray and lung POCUS findings
• MRI chest: usually reserved to evaluate for specific underlying conditions (e.g., cystic fibrosis) and conducted after initial stabilization and imaging
• Bronchoscopy ^[23]
  • Limited use as it is invasive and prone to complications
  • Most often used in the removal of a lower airway FB
  • Other indications (after initial stabilization) include advanced testing or therapies, such as:
    • Bronchoalveolar lavage
    • Bronchial or lung biopsy
    • Bronchial stenting

This section pertains to general management of respiratory distress and failure in children; see also "Initial management."

General principles

• Management of respiratory failure in children is often a key component of broader resuscitation algorithms. See:
  • “CPR in infants and children.”
  • “Unresponsive patient with suspected FBA.”
  • “Treatment of drowning.”
  • “Trauma in children.”
  • “C-spine injury in children.”
• Respiratory decompensation can occur rapidly in children. ^[24]
• Prioritize noninvasive interventions whenever possible (e.g., HFNC or NIPPV instead of invasive mechanical ventilation).
• Balance proactive respiratory support against the risks of overtreatment (e.g., oxygen toxicity, complications of mechanical ventilation).

Cardiac arrest in children is more commonly caused by respiratory failure than primary cardiac conditions. ^[1]

Airway management in children

• Pediatric airway characteristics create difficult airway management conditions. ^[8]
• Optimize basic airway maneuvers first (e.g., airway opening maneuvers). ^[1]
• Use Broselow tape to estimate:
  • Appropriate airway equipment sizes
  • Dosages for intubation induction agents
• Adjust technique according to age and cause of airway obstruction.
• See “Neonatal respiratory support” for details on neonates.
• See also “Initial management of airway obstruction.”

Difficult airway management is often required in children. Call pediatric anesthesia or ENT for help early.

If possible, avoid interventions that can worsen airway obstruction or edema (e.g., by increasing crying or agitation). ^[25]

Basic airway maneuvers in children

• Use the head-tilt/chin-lift as an airway opening maneuver preferentially unless C-spine injury in children is suspected.
• If C-spine injury in children is suspected, use the jaw thrust maneuver first; only use the head-tilt/chin-lift if jaw thrust is unsuccessful.
• See also "Foreign body aspiration."

Advanced airway management in children ^[1][3][7]

• Intubation
  • Consider apneic oxygenation to extend safe apnea time.
  • Prioritize videolaryngoscopy or flexible fiberoptic intubation over direct laryngoscopy.
  • Cuffed ET tubes are typically preferred in infants and children.
  • Avoid cricoid pressure during intubation.
  • Consider atropine as premedication to prevent bradycardia. ^[3]
  • Confirm ET tube placement with capnography or capnometry.
  • See “Neonatal endotracheal intubation” for details on neonates.
• Failed intubation: Use a supraglottic airway device for rescue ventilation.
• Emergency surgical airway
  • Avoid surgical cricothyrotomy in neonates, infants, and preschoolers.
  • If required, perform needle cricothyrotomy and jet ventilation in this age group.
  • See “Cricothyrotomy contraindications” for details.

Anticipate a difficult airway in neonates and infants even if they have no classic risk factors for a difficult airway. ^[7]

Oxygen therapy in children ^[10]

Tailor the oxygen therapy modality and SpO₂ target to the patient's age, airway anatomy, underlying condition, and severity of respiratory distress or failure.

• Indications
  • Respiratory distress with hypoxemia; SpO₂ thresholds vary by clinical condition.
    • Bronchiolitis: < 90% ^[26]
    • Asthma: < 94%
  • Spontaneous pneumothorax
  • Carbon monoxide poisoning
  • See "Short-term oxygen therapy" for other indications.
• Modalities: optimal modality depends on disease severity and patient factors
  • Basic oxygen delivery systems (e.g., nasal cannula, simple face mask oxygen, nonrebreather mask)
  • Advanced systems (e.g., HFNC)
  • Heliox
  • Hyperbaric oxygen therapy
• SpO₂ targets in children
  • Undifferentiated respiratory distress: Tailor to the individual. ^[10][27][28]
  • Bronchiolitis: 90–97% ^[10]
  • Oxygen therapy in asthma: ≥ 94% ^[13][20]
  • Postcardiac arrest: Tailor to the underlying condition and wean to 94–99%. ^[1][3]
  • Critically ill patients (e.g., mechanically-ventilated): Consult PICU and tailor to the individual. ^[29][30]
  • Neonates: Target normal preductal neonatal SpO₂.

Avoid hyperoxemia in critically ill children to prevent oxygen toxicity. ^[31]

Rescue breathing

• Indications ^[1]
  • Pulselessness
  • Respiratory failure
    • Inadequate respiratory effort in a child with a pulse
    • Respiratory arrest (e.g., due to opioid overdose)
• Technique: See "Bag-mask ventilation."
  • Children with a pulse: Target 20–30 breaths per minute.
  • Pulseless children with an advanced airway device: Target 20–30 breaths per minute.
  • Pulseless children without an advanced airway device: Ventilation rates and ratios depend on the cardiac arrest algorithm.
    • See “BLS in infants and children.”
    • See "Neonatal resuscitation."

Begin rescue breathing with bag-mask ventilation in children with in-hospital cardiac arrest without an advanced airway device in place.

Avoid hyperventilation when providing rescue breaths to children in cardiac arrest to prevent hemodynamic compromise. ^[3]

Mechanical ventilation in children

Noninvasive positive pressure ventilation (NIPPV) ^[32]

• Indications include: ^[32]
  • Impending respiratory failure (e.g., due to bronchiolitis, asthma exacerbation, pulmonary edema, pediatric pneumonia, or acute chest syndrome)
  • Prevention of intubation in selected patients (e.g., those with neuromuscular weakness, cystic fibrosis, restrictive lung diseases, do-not-intubate order)
  • Long-term management of chronic or recurrent respiratory failure (e.g., sleep apnea, neuromuscular diseases, bronchopulmonary dysplasia)
• Modalities: CPAP, BiPAP
• Considerations
  • Use interfaces appropriate to patient size, anatomy, and developmental stage.
  • Tailor initial parameters, adjustments, and alarms to individual patient needs in consultation with a specialist.
  • Suspect treatment failure and prepare for intubation if tachypnea and hypoxemia do not resolve within 1–6 hours. ^[32]
  • See “NIPPV” in “Mechanical ventilation” for more information.

Invasive mechanical ventilation ^[32]

• Indications include:
  • Respiratory failure that is severe, rapid onset, and/or refractory to NIPPV
  • Airway compromise
  • Refractory shock
  • Pediatric ARDS ^[33]
• Ventilator modes in children: Select in consultation with a specialist; follow local PICU or NICU protocols.
  • Traditional modes include volume control ventilation and pressure support ventilation.
  • In some PICU and NICU settings, nontraditional modes (e.g., high-frequency oscillatory ventilation) may be used. ^[32]
• Ventilator settings in children: Set and adjust in consultation with a specialist.
  • Based on ideal body weight and tailored to individual needs (similarly to ventilation strategies in adults)
  • Adjusted to avoid complications of mechanical ventilation, such as ventilator-induced lung injury (e.g., barotrauma) and patient-ventilator dyssynchrony

Emergency medications

Early administration of critical medications can prevent the need for aggressive respiratory support.

• Racemic epinephrine for croup
• IM epinephrine for anaphylaxis
• Bronchodilators for asthma exacerbation
• Naloxone for opioid overdose

Foreign body aspiration (FBA)

• Maneuvers to dislodge the aspirated FB (e.g., back blows, abdominal thrusts)
• Emergency airway procedures for FBA
• CPR in infants and children
• See “Acute management checklist for FBA.”

Drowning ^[34]

• Prioritize pediatric airway management (e.g., airway opening maneuvers) and ventilation (i.e., rescue breathing) during BLS in infants and children.
• Cardiac arrest
  • Begin CPR with rescue breathing before obtaining or applying an automated external defibrillator.
  • Administer oxygen during or after resuscitation.
• See also “Acute management checklist for drowning.”

Respiratory distress and failure in neonates

Causes

• Neonatal respiratory distress syndrome (caused by surfactant deficiency)
• Apnea of prematurity
• Transient tachypnea of the newborn
• Persistent pulmonary hypertension of the newborn
• Meconium aspiration syndrome
• Pulmonary hypoplasia
• Congenital diaphragmatic hernia
• Neonatal sepsis
• Neonatal pneumonia

Management

See "Neonatal resuscitation" for details.

• Algorithms
  • Initial neonatal assessment
  • Initial neonatal resuscitation
  • Advanced neonatal resuscitation
• Respiratory support
  • Initial neonatal airway interventions
  • Neonatal oxygen therapy
  • Neonatal CPAP
  • Neonatal positive-pressure ventilation
  • Neonatal endotracheal intubation

Normal preductal oxygen saturation in newborns varies in the first 10 minutes after birth.