Pediatric respiratory failure develops when the rate of gas exchange between the atmosphere and the blood is unable to match the body’s metabolic demands. Acute respiratory failure remains an important cause of morbidity and mortality in children. Cardiac arrests in children frequently result from respiratory failure. See the image below.
Bilateral airspace infiltrates on chest radiograph film secondary to acute respiratory distress syndrome that resulted in respiratory failure.
Signs and symptoms
Patients may be lethargic, irritable, anxious, or unable to concentrate. Children with respiratory distress commonly sit up and lean forward to improve leverage for the accessory muscles and to allow for easy diaphragmatic movement. Children with epiglottitis sit upright with their neck extended and head forward while drooling and breathing through their mouth.
The respiratory rate and quality can provide diagnostic information, as exemplified by the following:
Bradypnea: Most often observed in central control abnormalities
Tachypnea: Fast and shallow breathing is most efficient in intrathoracic airway obstruction; it decreases dynamic compliance of the lung
The patient should also be evaluated for the following:
Stridor (an inspiratory sound)
Wheezing (an expiratory sound)
Decreased breath sounds (eg, alveolar consolidation, pleural effusion)
Paradoxical movement of the chest wall
Accessory muscle use and nasal flaring
Cardiovascular signs in patients with respiratory failure can include the following:
Tachycardia and hypertension: May occur secondary to increased circulatory catecholamine levels
Gallop: Suggestive of myocardial dysfunction leading to respiratory failure
Bradycardia: Age-specific bradycardia associated with decreased or shallow breathing and desaturations indicates the need for emergent positive-pressure ventilation
See Clinical Presentation for more detail.
Blood and pulmonary studies
Arterial blood gas (ABG) measurement: Can be used to define acute respiratory failure
Complete blood count (CBC): Polycythemia suggests chronic hypoxemia
Electrolyte abnormalities: Hypokalemia, hypocalcemia, and hypophosphatemia can impair muscle contraction
Alveolar-arterial oxygen difference ([A-a]DO2): In children, (A-a)DO2 is normally 5-10
PaO2/ fractional concentration of inspired oxygen (FiO2): Indicates gas exchange
Oxygen index: (PaO2 x FiO2/mean airway pressure) x 100
Dead-space volume to tidal gas volume (VD/VT)
Intrapulmonary shunt fraction (Qs/Qt)
Common radiographic findings associated with respiratory failure include the following:
Focal or diffuse pulmonary disease (eg, pneumonia, acute respiratory distress syndrome [ARDS])
Bilateral hyperinflation (eg, asthma)
Asymmetrical lung expansion suggesting a bronchial obstruction
Bronchoalveolar lavage and lung biopsy
Bronchoalveolar lavage (BAL) is performed to identify a specific infectious pulmonary pathogen; it can also be used to isolate lipid-laden macrophages (suggestive of recurrent aspiration) or pulmonary hemorrhage.
Lung biopsy may be indicated if BAL does not reveal a pathogen and is also helpful in the diagnosis of sarcoidosis and other granulomatous conditions.
See Workup for more detail.
For partial upper-airway obstruction (eg, from anesthesia or acute tonsillitis), place a nasopharyngeal airway to provide a passageway for air. An oropharyngeal airway can be used temporarily in the unconscious patient.
For extrathoracic airway obstruction, as in croup, the following measures may be helpful:
Inspired humidity: To liquefy secretions
Heliox (helium and oxygen gas mixture): To decrease the work of breathing
Racemic epinephrine 2.25% (an aerosolized vasoconstrictor)
Systemic corticosteroids: To decrease airway edema
Nebulized hypertonic (3%) saline
Lung and respiratory pump support
Oxygen therapy: Supplemental oxygen is the initial treatment for hypoxemia
Humidified high-flow nasal cannula therapy (HHFNC): May be effective in the treatment of some neonatal respiratory conditions
Continuous positive airway pressure (CPAP): May be indicated if lung disease results in severe oxygenation abnormalities
Noninvasive positive-pressure ventilation (NPPV): To decrease the work of breathing and provide adequate gas exchange
Conventional mechanical ventilation: For acute hypercapnia and severe hypoxemia
Inverse ratio ventilation: A nonphysiologic pattern for breathing
Airway pressure release ventilation (APRV): A form of inverse-ratio ventilation that allows the patient to breathe spontaneously throughout the ventilatory cycle
High-frequency oscillatory ventilation (HFOV): Improves the occurrence and treatment of air-leak syndromes associated with neonatal and pediatric acute lung injury; research suggests, however, that it may lead to poorer outcomes than conventional mechanical ventilation in pediatric acute respiratory failure
Adjunctive therapies for severe hypoxemia
Prone positioning: Reduces compliance of the thoracoabdominal cage by impeding the compliant rib cage
Inhaled nitric oxide (NO): Potential benefit of NO is to improve ventilation-to-perfusion matching by enhancing pulmonary blood flow to well-ventilated parts of the lung
Exogenous surfactant: Improves respiratory mechanics and oxygenation in neonatal respiratory distress syndrome (RDS)
Extracorporeal life support (ECLS): Therapy in which blood is removed from the patient, passed through an artificial membrane where gas exchange occurs, and returned to the body by either the arterial (venoarterial [VA]) or venous (venovenous [VV]) system