Respiratory Emergencies in Children: Croup, Epiglottitis and Foreign Body Aspiration
Respiratory failure is the most common cause of cardiopulmonary arrest in children. Acute obstruction of the airway is a common cause of emergency department visits. About 50% of Emergency Department visits for children less than 3 years of age are for upper respiratory infections; a subgroup of these patients may present with a respiratory emergency. Patients in respiratory distress need prompt assessment to recognize potential causes and to start appropriate management so as to obtain the best possible outcome. General assessment skills that will help the clinician recognize different conditions include, but are not limited, to the following parameters:
Three medical conditions can result in respiratory emergencies due to airway obstruction; these conditions are Croup, Epiglottitis and Foreign Body Aspirations. Croup is the most common cause of infectious airway obstruction in children from age 6 months to 4 years. It affects approximately 18 per 1000 children in this age group, with peak frequencies between 1 -2 years. Croup is caused by different viruses; in order of frequency they are parainfluenza, influenza, RSV, and adenovirus. This infection happens more frequently during early fall and winter. A patient with the typical clinical presentation will have symptoms suggestive of an upper respiratory tract infection for several days, usually preceding the classical triad of barking cough (seal cough), hoarse voice and inspiratory stridor. In severity this disease can be mild to severe. As many as 30% of children will need hospitalization due to airway obstruction. In assessing the degree of disease severity look for the presence of tachypnea, increased work of breathing and stridor. The Westley croup score can be used to assess disease severity and response to treatment. This score takes the following parameters into account - level of consciousness, cyanosis, retractions, air entry, stridor. Each parameter scores 0 (absent or normal), 1 (mildly abnormal), 2 (moderately abnormal), or 3 (severely abnormal). It is recommended that patients with scores of >e;3 be treated. Patients should be kept under observation until scores are <2. Biphasic stridor, increased respiratory effort, tachypnea and hypoxemia are signs of Respiratory Failure and these patients represent an airway emergency. They need prompt treatment and continuous observation until improvement. For many years the mainstay of treatment for croup has been:
Recently, the manufacturers (Sanofi-aventis Canada, Inc) have decided to halt production of epinephrine in racemic form (Vaponephrine). Therefore, within a short period of time it will not be available for emergency room use in the Maritimes. The pharmacy at the IWK Children's Hospital in Halifax recommends as a substitution L-epinephrine at a 1-mg/milliliter concentration (1:1000) at the following doses:
Dilute dose in 2-3 ml of 0.9% NaCl and deliver via nebulizer Patients that are stable (Westley scores <e;2) and are eating and drinking appropriately can be sent home. Parents should be instructed about how to recognize signs of respiratory distress and if these signs recur, the parents should return the child to the emergency room for reassessment. One of the hallmarks of moderate croup is the decrease in symptoms when the child is brought into the night air. Parents might try bringing the child into the cool night air if symptoms recur. If the symptoms do not decrease, this would be an added indication for bringing the child back to medical attention. Epiglottitis is a serious life threatening infection due to cellulitis of the supraglottic structures that results in an airway emergency. Before the Haemophilus influenzae B vaccine was widely used most of the infections were caused by Haemophilus influenzae, type B. Currently, in patients that are fully immunized, the causes include non B types of Haemophilus influenza, streptococcus pneumonia and streptococci groups A, B, and C. Its incidence is approximately 1.3 per 100 000 children <5 years of age. Clinically epiglottitis characterized by the following symptoms: sore throat, high fever, muffled voice, and inability to swallow. On physical exam patients have a toxic appearance, look anxious, drool and may have inspiratory stridor. When the patients are in severe respiratory distress they will sit with a slight forward inclination and support themselves with their arms extended as if in a "tripod" As well they will hold their heads as if they are "sniffing". Remember the 4 "D's of severe respiratory distress: Dyspnea, Drooling, Dysphagia and Dysphonia. The diagnosis of epiglottitis is based clinically on signs and symptoms. Diagnosis can be confirmed by direct inspection of supraglottic tissue, however, this inspection should be performed only by a physician who can manage a difficult intubation should this situation arise following the examination. Intubation is done usually by emergency endoscopy in the OR to secure the airway and to take cultures. Priority management includes avoiding anxiety provoking procedures (IV, blood tests, X rays) and trying to keep the patient calm. Patients need constant monitoring. Regular investigations include CBC and differential as well as blood cultures. Lateral neck X ray may show the "thumb sign". Antibiotic treatment includes second or third generation cephalosporins given intravenously. Foreign body aspiration is a worldwide health problem. Although there are not enough studies to document the real frequency, it is known that 50% of all cases happen in children that are <18months. Foods are the usual cause. The type of food will vary from country to country. In the past the mortality rate was as high as 50%. However, since the use of bronchoscopy has become more widely available, the mortality rate has decreased to <1%. It is important to recognize that to make the diagnosis of foreign body aspiration (FBA) you need a high index of suspicion. A history of sudden onset of cough or a choking or gagging episode is highly suggestive of FBA. Some reports described witnessed events in up to 89% of cases. It is quite rare to see foreign body aspiration without the history of a choking episode. However, these episodes can happen when the parents are not present, such as when the child is at day care or playing at a friend's house. They may not be reported to parents. Therefore to make the diagnosis of foreign body aspiration you may need to generate a history from all the adult caretakers of the child. Some patients with aspiration may present with persistent localized wheezing or a story of recurrent pneumonias in the same location in the lung. Once again, a high index of suspicion is required to avoid missing the diagnosis. On examination patients may have stridor or wheezing, depending on the location and size of the foreign body. If the obstruction is high it might cause severe hypoxemia. Patients may show abnormal chest movement and on auscultation you may find decreased breath sounds or focal areas of wheezing. Although there is a predisposition for foreign bodies to lodge in the right lung, they can also be seen in the left lung, so that localization should not decrease your suspicion if there's been a substantial choking episode. Diagnosis can be confirmed by CXR if the object is radio-opaque. At times the diagnosis is not confirmed until a therapeutic bronchoscopy is done to treat airway obstruction. Treatment consists of removal of the foreign body and antibiotics if signs of infection are present. - Oliva Ortiz-Alvarez MSc. MD. FRCP(C) Thanks to Dr. Walter Robinson, Head Department of Respirology at the IWK Children's Hospital in Halifax, Nova Scotia, Canada for reviewing the draft copy of this article. References:
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