The Wheezing child
Wheezing is continuous musical sound produced by the forcible expulsion of air through a narrow airway, primarily the smaller bronchi and bronchioles. It is heared mostly during expiration as a result of airway obstruction.Causes of Acute wheezing in Children
Asthma Bronchiolitis Bronchitis Laryngotracheobronchitis Bacterial tracheitis Foreign body aspiration Esophageal foreign bodyRecurrent or persistant wheeze
Functional abnormalitiesStructural abnormalities
Asthma
Tracheo-bronchomalacia
Gastroesophageal reflux
Vascular compression/rings
Recurrent aspiration
Tracheal stenosis/webs
Cystic fibrosis
Cystic lesions/masses
Immunodeficiency
Tumors/lymphadenopathy
Primary ciliary dyskinesia
Cardiomegaly
Bronchopulmonary dysplasia
Retained foreign body (trachea or esophagus)
Bronchiolitis obliterans
Pulmonary edema
Vocal cord dysfunction
Interstitial lung disease
Bronchiolitis:
Bronchiolitis is an acute inflammatory condition of the bronchioles that is usually caused by a viral infection. RSV is responsible for more than 50% of cases. Other agents include parainfluenza, adenovirus, rhinovirus, and Mycoplasma. there is no evidence of a bacterial cause for bronchiolitis and bronchiolitis is rarely followed by bacterial superinfection.Bronchiolitis is more common in boys, in those who have not been breastfed, and in those who live in crowded conditions. Risk is higher for infants with young mothers or mothers who smoked during pregnancy.
pathology:
Clinical presentationsGradually, respiratory distress develops, with paroxysmal wheezy cough, dyspnea, and irritability. The infant is often tachypneic, which can interfere with feeding. Apnea may be more prominent early in the course of the disease, particularly with very young infants (<2 mo old) or former premature infants.
On examination
the lack of audible wheezing is not reassuring if the infant shows other signs of respiratory distress. Poorly audible breath sounds suggest severe disease with nearly complete bronchiolar obstructionDiagnostic Evaluation
The diagnosis of acute bronchiolitis is clinical, particularly in a previously healthy infant presenting with a 1st-time wheezing episode during a community outbreak. Chest radiography can reveal hyperinflated lungs with patchy atelectasis. Chest radiographs only done in children who appear ill, are experiencing clinical deterioration, or are at high risk (eg, those with underlying cardiac or pulmonary disease).Viral testing (polymerase chain reaction, or viral culture) is helpful if the diagnosis is uncertain.(but not in uncomplicated cases) The white blood cell and differential counts are usually normal.
Treatment
The mainstay of treatment is supportive. cool humidified oxygen for hypoxia. sitting with head and chest elevated at a 30-degree angle with neck extended. Frequent suctioning of nasal and oral secretions.
If there is any risk for further respiratory decompensation, the infant should not be fed orally but be maintained with parenteral fluids. High-flow nasal cannula therapy can reduce the need for intubation in patients with impending respiratory failure.
Bronchodilators & Corticosteroids are not recommended. Antibiotics have no value.
PROGNOSISInfants with acute bronchiolitis are at highest risk for further respiratory compromise in the 1st 72 hr after onset of cough and dyspnea. The case fatality rate is <1%, with death attributable to apnea,respiratory arrest, or severe dehydration. Mean duration of illness is 14 days Severe lower respiratory tract infection at an early age has been identified as a possible risk factor for the development of asthma.
PREVENTION:
Prevention Meticulous hand hygiene is the best measure to prevent nosocomial transmission. administration of palivizumab(an intramuscular monoclonal antibody to the RSV), before and during RSV season reduce severity and incidence of acute bronchiolitis.Palivizumab indicated for children born at <29-wk completed gestation or those with significant heart disease or chronic lung disease of prematurity, through the 1st or 2nd yr of life. Prophylaxis may be considered in infants with neuromuscular disease and immunocompromised states.
ACUTE BRONCHITIS
Acute bronchitis often follow a viral upper respiratory tract symptomes (coryza,low grade fever,malaise,sorethroat) It is more common in the winter. Most common cause is viral.The child presents with nonspecific upper respiratory symptoms for 3 to 4 days followed by frequent,dry hacking cough, which may or may not be productive. Chest pain may be a prominent complaint in older children and is exacerbated by coughing. Mild fever, malaise,sorethroat,wheezing.
Cough and sputum gradualy abate and total duration of illness about 2 weeks. On examination:coarse and fine crackles and scattered high-pitched wheezing.
Chest radiographs are normal or may show increased bronchial markings. High fever and Respiratory distress is unlikely in Acute Bronchitis and should raise suspision of Pneumonia.
Treatment
The disease is selflimited,and antibiotics,is not indicated. Cough suppressants can relieve symptoms but can also increase the risk of suppuration and inspissated secretions and, therefore, should be used with caution and only in children above 4 years. Antihistamines dry secretions and are not helpful. expectorants not indicated. Acetaminophen or ibuprofen for fever. Plenty of fluid.Differential diagnosis:
Disorders With Cough as a Prominent Finding: Asthma Bronchopulmonary dysplasia Cystic fibrosis Tracheomalacia or bronchomalacia Ciliary abnormalities Gastroesophageal reflux Airway compression (such as a vascular ring or hemangioma) Congenital heart disease Immunodeficiency Tuberculosis Sinusitis Tonsillitis or adenoiditis Bordetella pertussis Mycoplasma pneumoniae Foreign body aspiration, tracheal or esophagealPneumonia
What is pneumonia?Inflammation of the lung parenchyma Causative agents include bacteria, viruses, fungi is the leading infectious cause of death globally among children younger than 5 yr.
Etiology
Neonates(<3 wk): Group B streptococcus, Escherichia coli, Streptococcus pneumoniae, Haemophilus influenzae. 3 wk-3 mo: RSV, rhinoviruses, influenza, adenovirus, S.pneumoniae, H.influenzae. if patient is afebrile,consider Chlamydia trachomatis.
4 mo-4 yr: RSV,rhinovirus, influenza viruses, adenovirus, S. pneumoniae, H. influenzae, Mycoplasma pneumoniae, group A streptococcus≥5 yr: Mycoplasma. pneumoniae, S. pneumoniae, H. influenzae , influenza viruses, adenovirus
Staph pneumonia: mainly bellow 1 year, follow influenza virus infection, pneumatocele, empyema. Pneumococcus: consolidation, empyema. Group A streptococci: diffuse lung involvement & interstitial pneumonia. Aspiration pneumonia: mixed anaerobes. Mycoplasma & chlamydia: adolescents. Nosocomial infection: staph & gram negative. Cystic fibrosis: pseudomonus
Neonates & immunocompramized: HSV & CMV Measles: rash,coryza,conjunctivitis. Fungal pneumonia:immunocompramized. Mycobact.:endemic area, HIV Eosinophilic pneumonitis: Ascaris
CLINICAL MANIFESTATIONS
Usually preceded by several days of symptoms of an upper respiratory tract infection,like rhinitis and cough. Tachypnea (most consistant clinical manifestation of pneumonia). grunting intercostal, subcostal, and suprasternal retractions,nasal flaring. Cyanosis in severe infection(mainly in infants) Fever( low grade in viral pneumonia) Cough and chest pain in older child Nausea, vomiting, abdominal pain(lower lobe pneumonia)Auscultation of the chest may reveal crackles and ronchi in early stage. With the development of increasing consolidation or complications of pneumonia such as pleural effusion or empyema, dullness on percussion is noted and breath sounds may be diminished. Hepatomegaly may be seen because of downward displacement of the diaphragm secondary to hyperinflation of the lungs.
Sudden onset of symptomes and rapid worsening is characteristic of bacterial pneumonia.
DIAGNOSISchest radiograph (posteroanterior and lateral views) Viral pneumonia is usually characterized by hyperinflation with bilateral interstitial infiltrates and peribronchial thickening. Confluent lobar consolidation is typically seen with pneumococcal pneumonia. the film may also show a complication such as a pleural effusion or empyema.
Viral pneumonia
Bacterial pneumonia
peripheral white blood cell (WBC) count can be useful in differentiating viral from bacterial pneumonia. In viral pneumonia, the WBC count can be normal or elevated but is usually not higher than 20,000/mm3, with a lymphocyte predominance. Bacterial pneumonia is often associated with an elevated WBC count, in the range of 15,000-40,000/mm3, and granulocyte predominance.definitive diagnosis of a viral pneumonia rests on the isolation of the virus in respiratory tract secretions or serology. The definitive diagnosis of a bacterial infection requires isolation of an organism from the blood, pleural fluid, or lung.
Blood culture in bacterial pneumonia is positive in 10% of cases and only done if no improvement or in complicated cases require hospitalizations. ASO & anti Dnase B titer used to diagnose group A streptococcal pneumonia. Cold agglutinin titer greater than 1:64 may be helpful to diagnose mycoplasma pneumonia but nonspecific.
Recurrent pneumonia is defined as 2 or more episodes in a single year or 3 or more episodes ever, with radiographic clearing between occurrences. An underlying disorder should be considered if a child experiences recurrent pneumonia.
Causes of Recurrent pneumonia
HEREDITARY DISORDERS Cystic fibrosis Sickle cell disease DISORDERS OF IMMUNITY Bruton agammaglobulinemia Common variable immunodeficiency syndrome Severe combined immunodeficiency syndrome Chronic granulomatous disease DISORDERS OF CILIA Immotile cilia syndrome Kartagener syndrome ANATOMIC DISORDERS Pulmonary sequestration Lobar emphysema Gastroesophageal reflux Foreign body Tracheoesophageal fistula (H type) Bronchiectasis Aspiration (oropharyngeal incoordination)
Treatment
Treatment of suspected bacterial pneumonia is based on the causative agent, age and clinical appearance of the child. For mildly ill children who do not require hospitalization, high doses of amoxicillin (80-90 mg/kg/24 hr) is given. alternatives include cefuroxime axetil and amoxicillin/clavulanate.For school-age children with suspected M. pneumoniae or C. pneumoniae , a macrolide antibiotic as azithromycine is given. clarithromycin or doxycycline (for children 8 yr or older) are alternatives.
empiric treatment of suspected bacterial pneumonia in a hospitalized child with ampecillin or penicillin G(in children who are fully immunized against H. influenzae type b and S. pneumoniae and are not severely ill). otherwise ceftriaxone or cefotaxime should be used. If clinical features suggest staphylococcal pneumonia (pneumatoceles ,empyema), vancomycin or clindamycin is add.
In suspected viral pneumonia, no need for antibiotics unless there is deterioration that may signal superimposed bacterial infection.
Continue antibiotic Rx until child is afebrile for 72 hr and not less than 10 days.Outpatient therapy for uncomplicated pneumonia for 5-7 days.oral zinc(10 mg/day for <12 mo, 20 mg/day for ≥12 mo) reduces mortality among children with severe pneumonia.
Indications for Hospitalization
Age <6 mo Multiple lobe involvement Immunocompromised state Toxic appearance Moderate to severe respiratory distress Hypoxemia ( SPO2 less than 90% at room air) Sickle cell anemia with acute chest syndrome. Complicated pneumonia(empyema,abcess,effusion) Vomiting or inability to tolerate oral fluids or medications No response to appropriate oral antibiotic therapy Social factors.Causes of poor response to Rx:
complications, such as empyema bacterial resistance nonbacterial etiologies such as viruses or fungi foreign body, or mucous plugs. preexisting diseases such as immunodeficiencies, ciliary dyskinesia, cystic fibrosis. 6) congenital airway malformation(cystic adenomatoid malformation)
Complications of pneumonia:
Pleural effusion, empyema, abscess, bronchopleural fistula, extrapulmonary infection (meningitis, arthritis, pericarditis, osteomyelitis, endocarditis), hemolytic uremic syndrome, or sepsis.S. aureus, S. pneumoniae, and S. pyogenes are the most common causes of parapneumonic effusions and empyema. Pleural fluid should be sent for Gram stain, and bacterial culture as this may identify the bacterial cause of pneumonia.
A pleural fluid WBC count with differential may be helpful if there is suspicion for pulmonary tuberculosis or a noninfectious etiology for the pleural effusion, such as malignancy. Large effusions should typically be drained, particularly if the effusion is purulent (empyema) or associated with respiratory distress.