| Chapter 11: | The Infant |   |
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Common Respiratory Diseases of Children
Croup (Laryngotrachealbronchitis--LTB)
Croup is the name given to a group of inflammatory diseases that primarily affect infants and children. The most common manifestation of croup is laryngotracheitis, which is the result of a viral organism, with approximately 75% of all cases involving parainfluenza virus. The remaining 25% are caused by RSV, influenzas, and mycoplasma pneumonia.
The onset of laryngotracheitis is much like that of a common cold, complete with runny nose, fever, cough, and upper airway congestion. The symptoms available for diagnosis of croup present much slower (usually 3-4 days) than is seen in the epiglottis. The patient awakes in the night with a tight, barky cough, and has upper airway stidor on inspiration and expiration. There is also a degree of distress relative to the amount of airway obstruction. A-P x-rays show the narrowing of the airway at the larynx level, and the trachea on the x-rays of these patients has been described as being shaped like an hourglass, a pencil, and a steeple.
Laryngotreacheobronchitis is the name given to a bacterial superinfection of laryngotracheitis, and it involves the upper airway structures and then progresses to the bronchial airways and structures. Spasmodic croup is an apparent allergic response that results in the sudden onset of a barky cough, shortness of breath, and stridor. The patient with spasmodic croup is typically healthy, with no signs of upper respiratory infection. The distinguishing feature can be seen in some familial history of spasmodic croup.
The treatment of croup varies according to its severity, with mild cases being successfully monitored and treated at home with room humidifiers, hydration, and close observation. However, more serious signs such as retractions, increased respiratory rate or nasal flaring are indicators for the need of medical intervention. Since croup has a viral origin, nebulized racemic epinephrine (0.2 to 0.5 ml mixed with 2.5 ml saline) is used because it causes local vasoconstriction on the swollen subglottic tissues and reduces the edema.
If this treatment fails to eliminate the stridor, the patient needs to be hospitalized, with medication nebulizer treatments continued as needed every 1-2 hours to relieve the airway occlusion. Weaning treatments would be applied every 4-6 hours after symptoms subside. While croup is not usually considered life-threatening, any disease that causes swelling of the airway requires close monitoring for signs of worsening condition. Croup patients, therefore, should be monitored for breath sounds, respiratory rate, and the presence of retractions at four-hour intervals until airway swelling subsides.
Epiglottitis
This is an acute inflammatory disease of infants and children that affects not only the epiglottis, but also the surrounding aryepiglottic folds and arytenoid cartilages. While there are several viruses that can cause epiglottitis, it is generally considered to be bacterial in nature with most cases being caused by type b Hemophilus influenzae. Unlike LTB, epiglottitis is a life-threatening disease requiring prompt diagnosis and treatment.
There is a rapid onset with moderate to severe respiratory distress, sore throat, possibly high-pitched stridor with drooling, and difficulty in swallowing. Mortality from epiglottitis is due to blockage of the trachea by swollen, inflamed tissues leading to asphyxiation. The rapid onset of tracheal blockage makes intubation extremely difficult, and the probability of anoxic brain damage becomes more pronounced.
Because of its fulminant nature, the treatment of epiglottitis needs to be handled as an emergency. First priority should be given to the establishment of an airway, either by intubation or tracheostomy, until the swelling has subsided.
Following the establishment of an airway, treatment of the infection involves administration of antibiotics such as chloramphenicol and ampicillin. The inflammation of the epiglottic usually can be eliminated within 24-36 hours, at which time the patient may be extubated. If paralyzation is necessary, mechanical ventilation may be employed since the otherwise healthy lung requires very low pressures, rates, and FIO2s to maintain ventilation.