Table of Characteristics of the Croup Syndromes
Characteristic | Viral Croup | Spasmotic Croup | Acute Infectious Laryngitis |
Age | 3mo.-5 years | 1-3 years | All ages |
Organism | Parainfluenza type 1 | Viral Allergic | Influenza |
Incidence | Common | Common | Common |
Clinical Presentation | Gradual onset Mild URI Barky cough Low fever | Abrupt onset at night No URI No fever | Gradual onset Hoarseness Cough |
Physical Exam | Inspiratory stridor | Inspiratory stridor | Erythematous pharynx |
Treatment | Humidification Racemic epinephrine | Humidification | Humidification Rest Voice |
Causes:
The parainfluenza viruses (I, II, III) are responsible for as many as 80% of croup cases, with parainfluenza I accounting for most episodes and for 50-70% of hospitalizations. One study revealed 18,000 additional croup hospitalizations in years with a high prevalence of that virus.
Other causes of croup include adenovirus, respiratory syncytial virus (RSV), measles, some enteroviruses, metapneumovirus, and influenza A and B. Influenza A is associated with severe disease.
Mycoplasma pneumoniae has been implicated in a few cases.
Lab Studies:
· The diagnosis of croup is largely clinical, based on the presenting history and physical examination findings.
· Laboratory test results rarely contribute to the diagnosis. The CBC count is usually nonspecific, although the WBC count and differential may reveal a viral pattern. Identification of specific viruses is also not typically necessary but may be useful in determining isolation needs or, in the case of influenza A, deciding whether antiviral therapy is indicated.
Imaging Studies:
· Plain films can verify a presumptive diagnosis or exclude other disorders, such as aspirated foreign body, epiglottitis, bacterial tracheitis, or retropharyngeal abscess. Plain films should not be used as the only means of making a diagnosis. The posterior-anterior chest radiograph classically reveals a steeple sign, which signifies subglottic narrowing, while the lateral view may reveal a distended hypopharynx during inspiration. However, these findings are not observed in as many as 50% of children with croup. At the same time, a steeple sign may be observed in patients without croup, representing a false positive.
Other Tests:
· Pulse oximetry: While pulse oximetry findings are within normal limits in most patients, such monitoring is helpful to assess the degree of respiratory compromise.
Procedures:
· Laryngoscopy is required only in unusual circumstances (e.g., the course of illness is not typical or the child has symptoms that suggest an underlying anatomic or congenital disorder).
Medical Care:
A child who is mildly ill with croup may be cared for at home and usually recovers in 3 to 4 days. The child should be made comfortable, given plenty of fluids, and allowed to rest because fatigue and crying can worsen the condition. Home humidifying devices (for example, cool-mist vaporizers or humidifiers) may reduce drying of the upper airways and ease breathing. The humidity can be raised quickly by running a hot shower to steam up the bathroom. Carrying the child outside to breathe cold night air may also open the airways significantly—something parents often discover when the child's breathing returns to normal by the time they arrive at the hospital.
Children who do not respond to these measures need to be taken to the hospital. Children with increasing or continuing difficulty in breathing, rapid heart rate, fatigue, or bluish skin discoloration need to be hospitalized.
ED treatment depends upon the degree of distress. For example, the child who presents with only a croupy cough may require nothing more than parental reassurance, and the parents may just need education regarding the course of the disease.
· The first rule of management is to keep the child as comfortable as possible, allowing the patient to remain in a parent's arms and avoiding unnecessary interventions.
· The current cornerstones of treatment are glucocorticoids and nebulized epinephrine. While steroids have proven beneficial in mild-to-severe illness, epinephrine is typically reserved for patients in moderate-to-severe distress. Although a child who is sufficiently symptomatic to receive epinephrine may be discharged after 3-4 hours of observation, anyone receiving epinephrine should also be given steroids.
· ADRENALIN given in a nebulizer and corticosteroids given by mouth or injection. These drugs help shrink swollen tissue in the airways. Children who improve with these treatments may be sent home, although children with more severe cases should remain in the hospital. Antibiotics are used only in the rare situation when a child with croup also develops a bacterial infection. Rarely, a ventilator is needed. Fortunately, the vast majority of children with croup recover completely.
Drug Category:
Corticosteroids - Steroids are thought to decrease airway edema via their anti-inflammatory effect. In mild disease, steroids have been proven to reduce the number of children returning to the ED for further treatment. In moderate-to-severe disease, they improve croup scores within 12-24 hours and decrease hospitalization rates. Most trials have used dexamethasone at 0.6 mg/kg (IM or PO), but oral doses as low as 0.15 mg/kg are effective. PO and IM routes appear equally beneficial. Inhaled steroids have also demonstrated efficacy, with most trials utilizing budesonide. However, according to most authors, the relative ease, speed, and cost of administration make systemic steroids preferable to nebulized formulations.
Drug Name | Dexamethasone (Decadron) -- Dexamethasone exerts beneficial effect via anti-inflammatory action in which laryngeal mucosal edema is decreased. Onset of action occurs within 6 h for PO and IM. Long pharmacodynamic effect of 36-56 h. |
Pediatric Dose | 0.15-0.6 mg/kg PO/IM as a single dose; not to exceed 10 mg/dose |
Drug Name | Budesonide (Pulmicort Respules) -- Corticosteroids exert beneficial effect via anti-inflammatory action in which laryngeal mucosal edema is decreased. |
Pediatric Dose | 2 mL (0.5 mg) of solution inhaled via nebulizer |
Precautions | Prolonged use may increase the systemic absorption of corticosteroids; hypothalamic-pituitary axis suppression; hyperglycemia; glycosuria |
Drug Category:
Nebulized vasoconstrictors -- Epinephrine stimulates alpha- and beta2-receptors. It constricts the precapillary arterioles, thus decreasing airway edema. Because of the potential adverse effects of tachycardia and hypertension, it is reserved for children with moderate-to-severe disease. The effects of epinephrine are transient: most trials show alleviation of symptoms for no more than 2 h. However, in recent years, patient discharge after 3-4 hours of observation has become acceptable as long as they have no stridor at rest, normal air entry, normal color, normal consciousness, and have received a dose of steroids.
Drug Name | Epinephrine, racemic (microNefrin) 2.25% -- Causes adrenergic stimulation, which constricts precapillary arterioles, thus decreasing capillary hydrostatic pressure. This leads to fluid resorption from the interstitium and improvement in the laryngeal mucosal edema, although its beta2 activity leads to bronchial smooth muscle relaxation. |
Pediatric Dose | Administer 2.25% solution for nebulization (dose according to weight listed below) mixed with 3 mL saline: <20 kg: 0.25 mL 40 kg: 0.5 mL >40 kg: 0.75 mL May repeat q20-30min |
Contraindications | Documented hypersensitivity; angle-closure glaucoma; obstruction of ventricular outflow, as in tetralogy of Fallot |
Precautions | Adverse effects include tachycardia (discontinue if heart rate >200 bpm), dysrhythmias, palpitations, hypertension, tremor, agitation, nausea, vomiting, headache; |
Drug Name | Epinephrine (Adrenalin) -- Stimulates alpha-, beta1-, and beta2-adrenergic receptors, which results in bronchodilatation, increased peripheral vascular resistance, hypertension, increased chronotropic cardiac activity, and positive inotropic effects. Causes alpha-adrenergic receptor–mediated vasoconstriction of edematous tissues, thus reversing upper airway edema. |
Pediatric Dose | 5 mL (5 mg) of 1:1000 solution diluted in 2 mL saline administered via nebulization; may repeat q20-30min |
Precautions | Caution in cardiovascular disease, tachycardia (especially with HR >200 bpm), diabetes mellitus, |
Further Inpatient Care:
Hospital admission is advised if, after optimal ED management, the child exhibits the following:
· Cyanosis, hypoxia, or both
· Depressed sensorium
· Moderate respiratory distress
· Stridor at rest
· Progressive symptoms
· Poor oral intake, dehydration, or both
· Hospital admission is also advised if the child is young or if the family is unable to properly care for the child at home or cannot return to the ED if needed.
· Hospital care is largely supportive, including careful monitoring, supplemental oxygen as needed, and rehydration.
Complications:
· Complications are rare. In most series, fewer than 5% of children who present with croup require hospitalization, and fewer than 2% of those who are hospitalized are intubated. Death occurs in approximately 0.5% of intubated patients.
· Bacterial superinfection may result in pneumonia or tracheitis.
· Pulmonary edema and pneumothorax have also been reported.
7.THE CONTENT OF PRACTICAL WORK.
The practical work begins with the examination of the summarized knowledge of the students on the theme of present practical works. Students initiate with self-contained work in unit: carry out the daily observation of the patients, fill in the history cases, master practical skills, work in a room for medical procedures. During the time of patients examination (student's care) students are presented all manipulations which are carried out to children. During self-work students carry out sanitary - educational work.
During the time allocated on self-work students study the visual stuff offered by the teacher, manuals. The teacher all time monitors activities of students, helps them in development of the most difficult practical skills, analysis of supervised patients. The teacher checks quality of a writing, registration of a case history, a substantiation of diagnoses, timeliness of a writing of the stage, and diagnostic epicrisises. After the end of self-work the students discuss the theme of practical work, the thematic patient.
At the end of practical work sums up, the teacher exposes evaluations to students, they receive tasks for the following practical work.
8. RECOMMENDED LITERATURE
Basic:
1. Uchaykin V.F. “Manual of infectious diseases in children”. Moscow, 2001.
2. Ogay E.A. “Manual of infectious diseases in children”. Almaty, 2000.
3. Nisevich N.I. and Uchaykin V.F. “Infectious diseases in children”. Moscow, 1990
4. Ivanova V.V. “Infectious disease in children” Moscow 2002
Additional:
1. Zubic T.M., Ivanov K.S. “Differentials of infectious diseases” St-Petersburg 1991.
2. Vasilyev V.S. “Practice of inflectionist” Minsk, 1993.
3. AAP: Mumps. In: Red Book: Report of the Committee on Infectious Diseases. 26th ed. Elk Grove Village, Ill: American Academy of Pediatrics; 2003: 439-443.
4. Cherry JD: Mumps Virus. In: Feigin RD, Cherry JD, eds. Textbook of Pediatric Infectious Disease. 2nd ed. Philadelphia, Pa: WB Saunders; 1998: 2075-2083.
5. Long SS: Diphtheria. In: Behrman RE, Kliegman R, Jenson HB, eds. Nelson Textbook of Pediatrics. 16th ed. WB Saunders Co; 2000:817-20.