Emergency evaluation and immediate management of acute respiratory distress in children
Author:
Debra L Weiner, MD, PhD
Section Editor:
Gary R Fleisher, MD
Deputy Editor:
James F Wiley, II, MD, MPH
Contributor Disclosures
All topics are updated as new evidence becomes available and ourpeer review processis complete.
Literature review current through:Oct 2016.|This topic last updated:Nov 24, 2014.
INTRODUCTION—Respiratory distress is one of the most common chief complaints for which children seek medical care. It accounts for nearly 10 percent of pediatric emergency department visits and 20 percent of hospitalizations [1].
Respiratory distress in children, particularly neonates and infants, must be promptly recognized and aggressively treated because they may decompensate quickly. Factors that contribute to rapid respiratory compromise in children include smaller airways, increased metabolic demands, decreased respiratory reserves, and inadequate compensatory mechanisms as compared to adults. Respiratory arrest is the most common cause of cardiac arrest in children and outcomes are poor for patients who develop cardiopulmonary arrest as the result of respiratory deterioration [2-5].
The initial assessment and stabilization of children with respiratory and circulatory distress including airway management techniques, rapid sequence intubation (RSI), causes of respiratory compromise in children, and conditions causing respiratory distress in newborns are discussed separately:
●(See"Initial assessment and stabilization of children with respiratory or circulatory compromise".)
●(See"Basic airway management in children".)
●(See"Emergency endotracheal intubation in children".)
●(See"Rapid sequence intubation (RSI) in children".)
●(See"Causes of acute respiratory distress in children".)
●(See"Overview of neonatal respiratory distress: Disorders of transition".)
DIFFERENTIAL DIAGNOSIS—The differential diagnosis of acute respiratory distress in children is discussed in detail separately (table 1). (See"Causes of acute respiratory distress in children".)
EVALUATION—The evaluation of a child with acute respiratory distress includes determining the severity, as well as the underlying cause. Tachypnea and in neonates, infants, and young children, retractions, are hallmarks of respiratory distress. Respiratory distress may manifest as inadequate respiratory effort, most often in those who have tired from attempts to compensate for respiratory compromise, those with underlying neuromuscular disease and those with disordered control of breathing (eg, bronchiolitis, opioid overdose). Tachypnea and decreased respiratory effort can lead to respiratory failureand/orarrest and the child with inadequate respiratory effort is often at more immediate risk.
The emergency evaluation of the child with respiratory distress must first determine the severity of respiratory distress and the need for emergent intervention. Features of the history and physical examination will ideally localize the source as well as suggest the etiology and direct initial treatment (table 2). Ancillary studies can then be performed as indicated to confirm the diagnosis and guide management (table 3). The clinical features and evaluation of specific conditions that cause acute respiratory distress in children are discussed separately. (See"Causes of acute respiratory distress in children".)
Regardless of etiology, the initial management of respiratory distress in children requires immediate evaluation and supportive care of airway, breathing, and circulation. For some conditions, specific interventions (ie, bronchodilator therapy for asthma or decompression of a pneumothorax) may rapidly relieve symptoms. With prompt aggressive treatment of respiratory distress and its underlying cause, most children with respiratory distress recover uneventfully.
Initial rapid assessment—The pediatric assessment triangle (PAT) focuses initial evaluation on appearance, breathing, and circulation for acutely ill or injured children to quickly identify conditions that require immediate intervention. The PAT is reviewed separately. (See"Initial assessment and stabilization of children with respiratory or circulatory compromise", section on 'Pediatric assessment triangle'.)
Features of the PAT that are specific to children with acute respiratory distress include (see'General observation'below):
●Appearance– Restlessness, anxiety and combativeness are early manifestations or air hunger or hypoxia. Somnolence and lethargy are indicative of severe hypoxia, hypercarbia,and/orrespiratory fatigue.
●Breathing– The initial response to respiratory compromise is usually tachypnea. Abnormal airway sounds (eg, stridor, wheezing), increased accessory muscle use, and positioning to maximize airway opening (eg, “sniffing” position, “tripod” position) are other indicators of respiratory compromise. As respiratory distress progresses, respiratory rate often decreases and the pattern of respirations becomes irregular. These are ominous signs. Without intervention, respiratory arrest quickly ensues.
●Circulatory status– Pallor, ashen color, and cyanosis are concerning findings that may indicate hypoxemia, but may also be observed in patients with shock.
Conditions that require immediate, life-saving interventions include (table 4):
●Complete or rapidly progressing partial upper airway obstruction
●Tension pneumothorax
●Cardiac tamponade
●Respiratory failure
Throughout this evaluation, every reasonable effort must be made to keep the child calm and comfortable, since anxiety and crying can substantially increase the work of breathing in young children by decreasing upper airway diameter and increasing metabolic demand for oxygen [6]. The child should be positioned or allowed to maintain the position that best supports their respiratory effort.
History—A detailed history should be obtained once the child's condition is stabilized. (See"Initial assessment and stabilization of children with respiratory or circulatory compromise", section on 'Initial stabilization'.)
Helpful historical information includes:
●Trauma– A history of recent trauma suggests specific diagnoses, such as pneumothorax, pulmonary contusion, flail chest, cardiac tamponade, intraabdominaland/orcentral nervous system injury.
●Change in voice– Many children with acute upper airway pathology will have a change in voice (either muffled or hoarse). In comparison, those with lower airway processes have a normal voice.
●Onset and duration of symptoms– The abrupt onset of gagging or choking suggests upper airway conditions, such as an aspirated foreign body, allergy, or irritant exposure. A child who suddenly complains of chest pain may have a pneumothorax.
An infant who gradually develops tachypnea and retractions may have asthma, bronchopulmonary infection, or heart failure.
●Associated symptoms– Fever suggests an infectious etiology. Fever itself can result in an increase in respiratory rate of three to seven breaths per minute per degree centigrade above normal [7,8]. A child with tachypnea without fever, URI symptoms, or cough may be compensating for a metabolic acidosis. A complaint of abdominal pain may indicate a gastrointestinal process (ie, appendicitis or bowel obstruction), diaphragmatic irritation from a pneumonic condition (as can occur with basilar pneumoniaand/orpleural effusion), or a metabolic abnormally (ie, ketoacidosis from diabetes).
●Exposures– Exposure to specific infections, toxins (including medications, substances of abuse, biologic, chemical or nuclear agents), or allergens may suggest an etiology for respiratory distress.
●Previous episodes– Information regarding previous episodes of respiratory distress, including treatments that have been used and their effect, may guide interventions. As an example, an infant or young child who is wheezing, and has not been diagnosed with asthma, may have had previous episodes of wheezing that responded to bronchodilators
●Underlying medical conditions– Respiratory distress may be an acute manifestation of a process associated with a specific chronic medical condition (ie, acute chest syndrome in a child with sickle cell disease) or a complication of a chronic condition (ie, pneumothorax in a patient with asthma). (See"Causes of acute respiratory distress in children", section on 'Acute on chronic diseases'.)
●Family history– Family history of inheritable conditions (including asthma, cardiac disease, diabetes mellitus) may give clues to possible undiagnosed etiologies of respiratory distress.
Physical examination—The initial physical examination of the child with severe respiratory distress should be completed rapidly, focusing on the respiratory and cardiovascular systems, but recognizing that other organ system processes may be the etiology of respiratory distress [9].
After rapid assessment of airway, breathing and circulation, vital signs, including pulse oximetry, and actual or estimated weight, should be obtained. Side port capnography, is helpful in detecting hypercarbia. Once the child is stabilized, the clinician should perform a complete physical examination.
General observation—The following observations suggest severe respiratory distress:
●Mental status– Agitation and combativeness suggest early air hunger or hypoxia, while somnolence and lethargy are manifestations of severe hypoxemia or hypercarbia.
●Position of comfort– To maximize airway patency, a child with upper airway obstruction may sit upright and assume the "sniffing position" (neck flexed, head mildly extended) to align the airway axes and improve airflow (picture 1). With lower airway disease, the child may assume a “tripod position”, ie, sitting up and leaning forward on outstretched hands.
●Cyanosis– Cyanosis is generally a late finding in children with hypoxemia. It is seen most often in those who have low cardiac output in addition to low arterial oxygen saturation. Severely anemic patients (hemoglobin <5g/dL)may not manifest cyanosis despite severe hypoxemia.
●Drooling, dysphagia– Inability to handle secretionsand/orswallow are signs of oropharyngeal or laryngotracheal obstruction.
Vital signs—Respiratory rate, heart rate, blood pressure, temperature, and oxygen saturation give clues to the presence and etiology of respiratory distress.
●Respiratory rate– Normal respiratory rate varies by age (table 5). Tachypnea is one of the most important findings in children with respiratory disease. Tachypnea may also occur due to fever, activity, crying, cardiac disease, and metabolic acidosis. For example, increases in respiratory rates of three to seven breaths per minute per degree Celsius above baseline have been reported in response to fever [7,8]. For children <12 months of age the compensatory increase may be as high as 7 to 11 breaths per minute per degree Celsius above baseline (See"Causes of acute respiratory distress in children", section on 'Causes'.)
Apnea and bradypnea in neonates and infants with respiratory disease is usually the result of respiratory muscle fatigue. In neonates, particularly premature neonates central immaturity is a common cause of apnea. In young infants, apnea may be the initial manifestation of bronchiolitis or pertussis. Other causes of apnea in infants and young children include head trauma, including abusive head trauma from shaking, severe metabolic acidosis, and poisoning.
●Heart rate– Tachycardia due to increased sympathetic tone is commonly present in children with respiratory distress. With prolonged respiratory distress, tachycardia may reflect dehydration due, at least in part, to feverand/ortachypnea. Bradycardia in a hypoxemic child is a late and ominous sign that often signals impending cardiopulmonary arrest.
●Pulsus paradoxus– Pulsus paradoxus with >10 mmHg of the normal decrease in blood pressure during inspiration, correlates with degree of airway obstruction. Pulsus paradoxus occurs as the result of accentuated swings in pleural pressure between inspiration and expiration. It also occurs when hyperinflation of the lungs limits inspiratory filling, and therefore left ventricular stroke volume of the heart and in patients with cardiac tamponade. Although not specific, the presence of pulsus paradoxus is an important indicator of severe respiratory distressand/ordecreased cardiac output. Accurate measurement of pulsus paradoxus is often difficult in young children. (See"Cardiac tamponade", section on 'Pulsus paradoxus'.)
●Oxygen saturation– A resting room air oxygen saturation ≤97 percent by pulse oximetry is abnormal in full-term infants and children although this measurement should not be considered in isolation in any individual patient [10]. Values ≤90 percent indicate significant tissue hypoxemia. Patients with oxygen saturations between 90 and 95 percent who are also tachypneic may also be hypoxemic.
Oxygen saturation measurement may be falsely low due to the following (see"Pulse oximetry in adults"and"Pulse oximetry in adults", section on 'Troubleshooting sources of error'):
•Probe removal by the patient, improper placement, or motion artifact
•Poor peripheral perfusion
•Severe anemia (hemoglobin <5g/dL)
•Hypothermia
•Venous congestion
•Fingernail polish
Breathing—A detailed assessment of breathing is imperative in children with respiratory distress and consists of inspection, abnormal sounds, auscultation, palpation, and percussion.
●Inspection– Some of the most valuable information regarding the severity and etiology of respiratory distress is obtained by careful observation noting:
•Respiratory pattern– Rate, depth and rhythm of respiration may provide a clue to the etiology of respiratory distress:
-Rapid, shallow breathing with prolonged exhalation is typically seen with air trapping, as occurs with asthma bronchiolitis or airway foreign body beyond the carina. It may also result from chest or abdominal pain or chest wall dysfunction.
-Kussmaul respirations (deep, regular, sighing breaths that may be rapid, slow, or normal in rate) suggest metabolic acidosis, particularly diabetic ketoacidosis.
-Cheyne-Stokes respirations (respirations with increasing then decreasing depth and rate alternating with periods of apnea) occur as the result of central nervous system immaturity in otherwise normal neonates, particularly during sleep. This pattern can also be seen in neonates, infants, and children with inadequate cerebral perfusion, brain injury, increased intracranial pressure, and central narcotic depression.
-Ataxic respirations (breaths of irregular depth interrupted irregularly by periods of apnea) suggest central nervous system infection, injury, or drug-induced depression.
-Thoracoabdominal dissociation or paradoxical breathing (chest collapses on inspiration, while abdomen protrudes) is a sign of respiratory fatigue or muscle weakness.
•Tracheal deviation– Tracheal deviation is a key finding in tension pneumothorax. Air accumulation displaces the trachea to the side opposite the pneumothorax. Tracheal deviation may also be seen in patients with pulmonary emphysema, unilateral effusion, or a thoracic mass.
•Accessory muscle use–Accessory muscle use is an important indicator of respiratory distress in infants and children.
-Nasal flaring, exaggerated opening of the nostrils during inspiration, is a subtle form of severe accessory muscle use that is commonly seen in neonates and infants.
-Head bobbing, extension of the head and neck during inhalation and falling forward of the head during exhalation, is less common than other manifestations of accessory muscle use and is also most likely to be seen in neonates infants.
-Retractions of the muscles of the chest wall result from high negative intrathoracic pressure generated by increased respiratory effort. Supraclavicular and suprasternal retractions are usually indicative of upper airway obstruction, but may be seen with severe lower airway processes. Intracostal and subcostal retractions are indicators of lower airway obstruction but can be seen in severe upper airway obstruction. Mild retractions may be normal in neonates and infants. Severe retractions of more than one muscle group indicate significant distress [11].
-Abdominal breathing, characterized by thoracoabdominal dissociation, in which the chest collapses and the abdomen protrudes on inspiration, may be normal in neonates and infants, but young children or in patients with poor muscle tone is concerning for respiratory muscle fatigue.