بسم الله الرحمن الرحيم. respiratory system : objectives common cold :...

بسم الله الرحمن الرحيم

 Respiratory System

::ObjectivesObjectives Common cold Common cold : etiology ,clinical : etiology ,clinical features , features , treatment, complications.treatment, complications.Acute Pharyngitis &TonsillitisAcute Pharyngitis &Tonsillitis: : Etiology , Cl /F, Dx Etiology , Cl /F, Dx investigations ,treatment ,complicatioinvestigations ,treatment ,complications .ns .StridorStridor: Differential diagnosis.: Differential diagnosis.Acute infetious upper airway Acute infetious upper airway obstructionsobstructions..CroupCroup :DDx Cl/F, management. :DDx Cl/F, management.Acute epiglottitis Acute epiglottitis : Etiology , Cl /F , : Etiology , Cl /F , Management.Management.Wheezy Child Wheezy Child : DDx.: DDx.BronchiolitisBronchiolitis : Etiology ,Cl /F, : Etiology ,Cl /F, Investigations, DDx, Investigations, DDx, Treatment ,ComplicationsTreatment ,Complications..

PneumoniaPneumonia: Etiology , Cl/F, : Etiology , Cl/F,

Investigations,Investigations, DDx, Treatment, DDx, Treatment, Complications.Complications.Cystic FibrosisCystic Fibrosis: Pathology : Pathology Cl/F ,Dx ,complications ,Rx.Cl/F ,Dx ,complications ,Rx.AsthmaAsthma: Etiology& Pathology, : Etiology& Pathology, Cl/F ,Pattern, Drugs Cl/F ,Pattern, Drugs Acute Acute AsthmaAsthma :Definition ,Diagnosis ,Treatment. :Definition ,Diagnosis ,Treatment.Foreign Body Aspiration Foreign Body Aspiration ;Diagnosis & ;Diagnosis & TreatmentTreatment..

The Common Cold

The common cold is a viral illness in which the symptoms of rhinorrhea and nasal obstruction are prominent; systemic symptoms and signs such as myalgia and fever are absent or mild. It is often termed rhinitis but includes self-limited involvement of the sinus mucosa and is more correctly termed rhinosinusitis.

Most common pathogens associated with the common cold are the rhinoviruses.Rarely it is caused by influenza, PIV, RSV ,or adenovirus.

CLINICAL

MANIFESTATIONS

The onset of common cold symptoms typically occurs 1–3 days after viral infection. .The 1st symptom noted is frequently sore

or “scratchy” throat, followed closely by nasal obstruction and rhinorrhea.Cough is associated with ≈30% of colds and usually begins after the onset of nasal symptoms.The usual cold persists for about 1 wk., although 10% last for 2 wk.

A change in the color or consistency of the secretions is common during the course of the illness and is not indicative of sinusitis or bacterial super infection.

Influenza viruses, RSV, and adenoviruses are more likely than rhinoviruses or coronaviruses to be associated with fever and other constitutional symptoms

TREATMENTThe management of the common cold consists primarily of symptomatic treatment

COMPLICATIONS: Otitis media.

Sinusitis. Exacerbations of asthma.

Acute Pharyngitis & Tonsillitis

Etiology

.Viruses: (adenoviruses, coronaviruses, enteroviruses, rhinoviruses, respiratory syncytial virus [RSV], Epstein-Barr virus [EBV], herpes simplex virus [HSV],) .

Bacteria : (GABHS) .

CLINICAL MANIFESTATIONS

Streptococcal pharyngitis: onset is often rapid with prominent sore throat, fever, and absence of cough. Headache and gastrointestinal symptoms (abdominal pain, vomiting) are frequent. The pharynx is red, and the tonsils are enlarged and classically covered with a yellow, blood-tinged exudate. There may be petechiae on the soft palate and posterior pharynx, and the uvula may be red, and swollen. The anterior cervical lymph nodes are enlarged and tender. The incubation period is 2–5 days. Some patients demonstrate the additional stigmata of scarlet fever.

Viral pharyngitis: Onset is more gradual, and symptoms more often include rhinorrhea, cough, and diarrhea. A viral etiology is suggested by the presence of conjunctivitis, coryza, hoarseness, and cough .

DiagnosisThe goal of specific diagnosis is to identify GABHS infection

Throat culture .Antistreptococcal antibodies .

Treatment

Early antibiotic therapy hastens clinical recovery by 12–24 hr . The primary benefit of treatment is the prevention of acute rheumatic fever, which is almost completely successful if antibiotic treatment is instituted within 9 days of illness. Antibiotic therapy should be started immediately without cultureimmediately without culture 1.for children with symptomatic pharyngitis and a positive rapid streptococcal antigen test. 2. clinical diagnosis of scarlet fever 3. household contact with documented streptococcal pharyngitis 4. past history of acute rheumatic fever . 5.or a recent history of acute rheumatic fever in a family member

Penicillin VPenicillin V : :given bid or tid given bid or tid for 10 days: 250 mg/dose for 10 days: 250 mg/dose for children and 500 for children and 500 mg/dose for adolescents mg/dose for adolescents and adults. and adults. Oral Oral amoxicillinamoxicillin A once-daily 750 A once-daily 750 mg dose of amoxicillin mg dose of amoxicillin given orally for 10 days may given orally for 10 days may be as effective as 250 mg of be as effective as 250 mg of penicillin given tid for 10 penicillin given tid for 10 daysdays..

Single intramuscular dose of benzathine penicillin (600,000 U for children <27 kg [60 lb]; 1.2 million U for larger children and adults) ensures compliance and provides adequate blood levels for more than 10 days.

Erythromycin (erythromycin ethyl succinate 40 mg/kg/day divided bid, tid, or qid orally for 10 days) is recommended for patients allergic to β-lactam antibiotics

Complications and Prognosis : Viral: otitis media. GABHS: Early complications : local suppuration( e.g. parapharyngeal abscess). Late non suppurative (RF&GN)

Stridor, a harsh, medium-pitched, inspiratory sound associated with obstruction of the laryngeal area or the extra thoracic trachea, is often accompanied by a croupy (barking) cough and hoarse voice. Acute Stridor is usually due to: Croup(acute laryngotracheobronchitis). Foreign body. Trauma. Recurrent Stridor is usually due to: Allergic (spasmodic) croup. Laryngomalacia.

Others: (hypocalcemia, hysteria…) Persistent Stridor is usually due to: Laryngomalacia. Tracheomalacia. Foreign body. Subglottic tracheal stenosis.Extrinsic masses (e.g. mediastenal mass, vascular ring…_)

 Infectious Upper Airway Obstruction

ETIOLOGY AND EPIDEMIOLOGY. Viral agents: The parainfluenza viruses (types 1, 2, and 3) account for ≈75% of cases; other viruses associated with this disease include influenza A and B, adenovirus, respiratory syncytial virus (RSV), and measles. Age: 3 mo to 5 yr, with the peak in the 2nd yr of life. The incidence of croup is higher in males; it occurs most commonly in the late fall and winter but may occur throughout the year. Recurrences are frequent.

CLINICAL MANIFESTATIONS

Starts as upper respiratory tract infection (rhinorrhea, pharyngitis, mild cough, and low-grade fever for 1–3 days) ; then the signs and symptoms of upper airway obstruction become apparent. The child develops the characteristic “barking” cough, hoarseness, and inspiratory stridor. Symptoms are characteristically worse at night and often recur with decreasing intensity for several days and resolve completely within a week. Agitation and crying greatly aggravate the symptoms and signs. The child may prefer to sit up in bed or be held upright. Older children usually are not seriously ill. Other family members may have mild respiratory illnesses with laryngitis.

Rarely, the upper airway obstruction progresses and is accompanied by an increasing respiratory rate; nasal flaring; suprasternal, infrasternal, and intercostal retractions (signs of respiratory distress); and continuous stridor.

The child who is hypoxic, cyanotic, pale, or obtunded needs immediate airway management

X- Ray:Croup is a clinical diagnosis and does not require a radiograph of the neck. Radiographs of the neck may show the typical subglottic narrowing or “steeple sign” of croup on the posteroanterior view . Radiographs should be considered only after airway stabilization in children who have an atypical presentation or clinical course. Radiographs may be helpful in distinguishing between severe laryngotracheobronchitis and epiglottitis, but airway management should always take priority.

Spasmodic Croup. Spasmodic croup occurs most often in children 1–3 yr of age and is clinically similar to acute laryngotracheobronchitis, except that the history of a viral prodrome and fever in the patient and family are frequently absent. The cause is viral in

some cases, but allergic and psychological factors may be important in others.

Usually starts at night, the child awakens with a characteristic barking cough, stridor, and respiratory distress and appears anxious and frightened. The patient is usually afebrile. Usually, the severity of the symptoms diminishes within several hr. Such episodes may recur several times. Spasmodic croup may represent more of an

allergic reaction to viral antigens than direct infection, although the pathogenesis is unknown.

DIFFERENTIAL DIAGNOSIS.

Acute Epiglottitis

Foreign Body

Diphtheria

Bacterial Tracheitis

Angioedema

COMPLICATIONS. 1. Complete Airway Obstruction & Suffocation.

2 .Extension of the infectious process to, the middle ear, the terminal bronchioles or the pulmonary parenchyma. 3. Complications of tracheotomy

TREATMENT

Airway Management. This may include:

Mist therapy (cold or hot).

Nebulized Racemic Epinephrine (0.25-0.75 ml of 2.25% in 3 ml normal saline) every 20 min.

as required . Dexamethasone 0.6mg/kg single

dose oral or im. Antibiotics are not indicated in viral croup. Helium-Oxygen mixture (Heliox) in

severe cases .

Most patients can be treated at home.

Children with croup should be hospitalized for any of the following: 1.progressive stridor or severe stridor at rest 2.respiratory distress 3.hypoxia & cyanosis 4.depressed mental status 5.poor oral intake 6.the need for reliable observation. These children may require

intubation or tracheostomy.

Acute Epiglottitis

A potentially lethal condition is caused by H.influenzae type b in children 2-4 yr old characterized by an acute potentially fulminating course of high fever, sore throat, dyspnea, and rapidly progressing respiratory obstruction. Often, the otherwise healthy child suddenly develops a sore throat and high fever. Within a matter of hours, the patient appears toxic, with dysphagia, and breathing is labored. Drooling is usually present and the neck is hyperextended in an attempt to maintain the airway. The child may assume the tripod position, sitting upright and leaning forward with the chin up and mouth open while bracing on the arms. Stridor is a late finding and suggests near-complete airway obstruction.. The barking cough typical of croup is rare. Usually, no other family members are ill with acute respiratory symptoms.

DiagnosisRequires visualization of a large, “cherry red” swollen epiglottis by laryngoscopy .

This should never be attempted until facilities for

immediate intubation are ready. For patients in whom diagnosis is not certain and are not in severe respiratory

distress a lateral X-ray film of the neck may show (thumb

sign).

Complications:Pneumonia, cervical lymphadenitis, otitis media, or, rarely, meningitis or septic arthritis can occur in the course of epiglottitis.

TREATMENT

Epiglottitis is a medical emergency and warrants immediate treatment with an: 1. Artificial airway in an operating room or intensive care unit. 2.Oxygen 3.Cultures of blood, epiglottic surface, and, in selected cases, cerebrospinal fluid should be collected after airway stabilization. 4.Antibiotics Ceftriaxone, cefotaxime, or a combination of ampicillin and sulbactam should be given parenterally pending culture and susceptibility reports. Antibiotics should be continued for 7–10 days. Chemoprophylaxis is recommended with Rifampicin 20 mg/kg/24hr (Max 600mg /day) for all household contacts if there is any contact (<48 mo) without complete immunization against H. influenzae type b .

The Wheezy The Wheezy ChildChild

Wheezing in infantsWheezing in infantsViral: Respiratory Syncytial Viral: Respiratory Syncytial Virus(RSV),adenovirus,..Virus(RSV),adenovirus,..Asthma.Asthma.Anatomic abnormalitiesAnatomic abnormalities bronchomalacia bronchomalacia vascular ring vascular ring congenital lobar emphysema congenital lobar emphysema foreign body foreign body TE fistula(H type) TE fistula(H type) GER GERCystic fibrosisCystic fibrosisImmunodeficiencyImmunodeficiencyCardiac e.g. (heart failure)Cardiac e.g. (heart failure) . .

ACUTE BRONCHIOLITIS

Bronchiolitis is the commonest serious respiratory infection of infancy: 2-3% of all infants are admitted to hospital with the disease each year during annual winter epidemics; 90% are aged 1-9 months (bronchiolitis is rare after 1 year of age). Respiratory syncytial virus (RSV) is the pathogen in 80% of cases. Human metapneumovirus is a recently identified virus causing respiratory symptoms in children, and with the other respiratory viruses(PIV,Adenovirus &rarely Mycoplasma) account for the remainder .

There is no evidence of a bacterial cause for bronchiolitis, although bacterial pneumonia is sometimes confused clinically with bronchiolitis and bronchiolitis is rarely followed by bacterial superinfection.

Coryzal symptoms precede a dry cough and increasing breathlessness. Wheezing is often, but not always, present. Feeding difficulty associated with increasing dyspnea is often the reason for admission to hospital. Recurrent apnea is a serious complication, especially in young infants .

sharp, dry coughssub costal and intercostals recessionhyperinflation of the chestprominent sternumliver displaced downwards fine end-inspiratory crepitationshigh-pitched wheezes - expiratory > inspiratorytachycardiacyanosis or pallor .

Investigations RSV can be identified rapidly on nasopharyngeal secretions demonstrating binding of a fluorescent antibody.

A chest X-ray shows hyperinflation of the lungs due to small airways obstruction, air trapping and often focal atelectasis.

Blood gas analysis, which is required in only the most severe cases, shows lowered arterial oxygen and raised CO2 tension.

Differential Diagnosis:Differential Diagnosis:1.1.AsthmaAsthma :is recurrent , with :is recurrent , with personal or family history of personal or family history of atopy ; there may be atopy ; there may be eosinophilia in blood or eosinophilia in blood or respiratory secretions ; and respiratory secretions ; and respond well to respond well to bronchodilators.bronchodilators.2.2.BronchopneumoniaBronchopneumonia..3.3.Acute pulmonary edemaAcute pulmonary edema..

Management This is supportive. Humidified oxygen is delivered via nasal cannulae or into a head box; the concentration required is determined by pulse oximetry. The infant is monitored for apnea. Mist, antibiotics and steroids are not helpful. Nebulized bronchodilators, such as salbutamol or ipratropium, though often used, have not been shown to reduce the severity or duration of the illness. Nebulized epinephrine may be more effective.

Fluids may need to be given by nasogastric tube or intravenously. Mechanical ventilation is required in about 2% of infants admitted to hospital.

Corticosteroids are not recommended in previously healthy infants with RSV

Ribavirin, an antiviral agent administered by aerosol, has been

used for infants with congenital heart disease or chronic lung disease.

Antibiotics have no value unless there is secondary bacterial

pneumonia. There is no support for RSV

immunoglobulin administration during acute episodes of RSV

bronchiolitis.

PrognosisMost infants recover from the acute infection within 2 weeks. However, as many as half will have recurrent episodes of cough and wheeze. Rarely, usually following adenovirus infection, the illness may result in permanent damage to the airways (Bronchiolitis obliterance).

Prevention

A monoclonal antibody to RSV (palivizumab) given monthly by intramuscular injection) reduces the number of hospital admissions in high-risk preterm infants(with broncho- pulmonary dysplasia). Its use is limited by cost and the need

for several injections .

Pneumonia

Incidence Pneumonia is highest in infancy, remains relatively high in childhood, is low in adults and increases again in old age.

Pneumonia is caused by a variety of viruses and bacteria, although in half of cases no causative pathogen is identified. Viral pneumonia tends to peak during autumn and winter, while bacterial pneumonia exhibits less seasonal fluctuation .

ETIOLOGY

The pathogens causing pneumonia vary according to the child's age :

Newborn - organisms from the mother's genital tract, particularly group B Streptococcus, but also Gram-negative enterococci.Infants and young children - respiratory viruses, particularly RSV, are most common, but bacterial infections include Streptococcus pneumoniae or Haemophilus nfluenzae. Chlamydia trachomatis can also cause pneumonia at this age. An infrequent but serious cause is Staph. aureus.Children over 5 years - Mycoplasma pneumoniae, Streptococcus pneumoniae and Chlamydia pneumoniae are the main causes. Mycobacterium tuberculosis should be considered at all ages .

Clinical features

Fever and difficulty in breathing are the commonest presenting symptoms, usually preceded by an upper respiratory tract infection. Other symptoms include cough, lethargy, poor feeding and an 'unwell' child. Localized chest, abdominal, or neck pain is a feature of pleural irritation and suggests

bacterial infection .

Examination reveals tachypnoea, nasal flaring and chest indrawing. Chest hyperinflation and wheeze are more suggestive of viral or mycoplasma infection. There may be end-inspiratory respiratory coarse crepitations over the affected area, but the classic signs of consolidation with dullness on percussion, decreased breath sounds and bronchial breathing over the affected area are frequently absent. Oxygen saturation readings may be

decreased .

DIAGNOSIS

The chest radiograph confirms the diagnosis of pneumonia and may

indicate a complication such as a pleural effusion or empyema .

Viral pneumonia is usually characterized by hyperinflation with bilateral interstitial infiltrates and peribronchial cuffing (Bronchopneumonia).Confluent (lobar) consolidation is typically seen with pneumococcal pneumonia

Chest X-ray may confirm the diagnosis but cannot differentiate between bacterial and viral pneumonia.A chest X-ray showing cavities containing fluid and air (pneumatocele) is characteristic of staphylococcal pneumonia .

A small proportion of pneumonias are associated with a parapneumonic effusion, where there may be blunting of the costophrenic angle on the chest X-ray). Ultrasound of the chest will distinguish between parapneumonic effusion and empyema.

Nasopharyngeal aspirate is useful to identify viral causes .

The 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 a predominance

of granulocytes

A large pleural effusion, lobar consolidation, and a high fever at the onset of the illness are also suggestive of a bacterial

etiology

The definitive diagnosis of a viral infection rests on the isolation of a virus or detection of the viral genome or antigen in respiratory tract secretionsThe definitive diagnosis of a bacterial infection requires isolation of an organism from the blood, pleural fluid, or lung. Culture of sputum is of little value in the diagnosis of pneumonia in young children. Blood cultures are positive in only 10% of children with pneumococcal pneumonia.

TREATMENT

Most cases can be managed at home .

Indications for admission include oxygen saturations <93%, severe tachypnoea and difficulty breathing, grunting, apnoea, not feeding or family unable to provide appropriate care.

General supportive care should include analgesia for pain, and oxygen for hypoxia. Fluids should be given if necessary, ensuring that an excessive volume is not given because of potential inappropriate ADH secretion .

Treatment of suspected bacterial pneumonia is based on the presumptive cause and the clinical appearance of the

child .For mildly ill children who do not require hospitalization, amoxicillin is recommended. In communities with a high percentage of penicillin-resistant pneumococci, high doses of amoxicillin (80–90 mg/kg/24 hr)for 7-10 days, should be prescribed. Therapeutic alternatives include cefuroxime axetil or amoxicillin/clavulanate. For school-aged children and in those in whom infection with M. pneumoniae or C. pneumoniae (atypical pneumonias) is suggested, a macrolide antibiotic such as azithromycin is an appropriate choice. In adolescents, a respiratory fluoroquinolone (levofloxacin, gatifloxacin, moxifloxacin, gemifloxacin) may be considered for atypical pneumonias.

The empirical treatment of suspected

bacterial pneumonia in a hospitalized child requires an approach based on the clinical manifestations at the time of presentation. Parenteral cefuroxime (150 mg/kg/24 hr), cefotaxime, or ceftriaxone is the mainstay of therapy when bacterial pneumonia is suggested.

If clinical features suggest staphylococcal pneumonia (pneumatoceles, empyema), initial antimicrobial therapy should also include vancomycin or clindamycin.

Up to 30% of patients with known viral infection may have coexisting bacterial pathogens. Therefore, if the decision is made to withhold antibiotic therapy based on presumptive diagnosis of a viral infection, deterioration in clinical status should signal the possibility of superimposed bacterial infection and antibiotic therapy should be initiated.

Parapneumonic effusions usually resolve with appropriate antibiotics, but the small proportion that develop an empyema require drainage of the fluid, either by placement of a chest tube and installation of intrapleural urokinase to break down any intrapleural septations, or by surgery.

COMPLICATIONS.

Complications of pneumonia are usually the result of direct spread of bacterial infection within the thoracic cavity (pleural effusion, empyema, pericarditis) or bacteremia and hematologic spreadMeningitis, suppurative arthritis, and osteomyelitis are rare complications of hematologic spread of pneumococcal or H. influenzae type b infection.

Cystic fibrosis

Cystic fibrosis (CF) is the commonest life-limiting inherited condition in Caucasians. CF is an autosomal recessive disease. In Caucasians the carrier rate is 1 in 25, with 1 in 2500 affected births. The disease is much less common in other ethnic groups. A gene located on chromosome 7 codes for the protein called cystic fibrosis transmembrane regulator (CFTR), which is defective in CF. CFTR is a cyclic AMP-dependent chloride channel blocker. The gene mutation affects the severity of disease, and life expectancy. Identification of the gene mutation involved within a family allows prenatal diagnosis and carrier detection in the wider family .

In CF, the abnormal ion transport across the

epithelial cells of the exocrine glands of the respiratory tract and pancreas results in increased viscosity of secretions. Abnormal function of the sweat glands results in excessive concentrations of sodium and chloride in the sweat (60-125mmol/L in cystic fibrosis, 10-30 mmol/L in normal children). This forms the basis of the essential diagnostic

procedure, the sweat test, in which

sweating is stimulated by pilocarpine iontophoresis. The sweat is collected into a special capillary tube or absorbed onto a weighed piece of filter paper.. Thick and viscid mucus is not the only basis of the pathogenesis of CF. Abnormality of the CFTR also affects inflammatory processes and defence against infection .

Clinical features

Infancy Infancy Meconium Ileus In Newborn PeriodMeconium Ileus In Newborn Period Prolonged Neonatal Jaundice Prolonged Neonatal Jaundice Failure To Thrive Failure To Thrive Recurrent Chest Infections Recurrent Chest Infections Malabsorption , Steatorrhea Malabsorption , Steatorrhea

NewbornNewborn Diagnosed through newborn screeningDiagnosed through newborn screening

Young childBronchiectasisRectal prolapseNasal polypSinusitis

Older child and adolescent Allergic bronchopulmonary aspergillosis (ABPA) .

Diabetes mellitus (often not insulin-dependent) .Cirrhosis and portal hypertension .

Distal intestinal obstruction (DIOS, meconium ileus equivalent).

Pneumothorax or recurrent haemoptysis .Sterility in males .Increasing psychological problems.

Clinically, most children with CF will present with malabsorption and failure to thrive from birth, accompanied by recurrent or persistent chest infections. In the lungs, viscid mucus in the smaller airways predisposes to chronic infection, initially with Staph. aureus and H. influenzae and subsequently with Pseudomonas aeruginosa. This leads to damage of the bronchial wall, bronchiectasis and abscess

formation.. On examination there is hyperinflation of the chest due to air trapping, coarse inspiratory crepitations and/or expiratory wheeze. With established disease, there is finger clubbing. Ultimately 95% of patients with CF will die of respiratory failure .

The sweat test, using pilocarpine iontophoresis to collect sweat and chemical analysis of its chloride content, is the standard approach to diagnosis.More than 60 mEq/L of chloride in sweat is diagnostic of CF when 1 or more other criteria are present.

TREATMENT

With regular treatment, most infants and children with CF should have no respiratory symptoms, and often have no abnormal sign. From diagnosis, children should have

physiotherapy at least twice a day, aiming to clear the airways of secretions. In younger children parents are taught to perform airway clearance at home using chest percussion and postural drainage. Older patients perform controlled deep breathing exercises and use a variety of physiotherapy devices for airway clearance.

Continuous prophylactic oral antibiotics (usually flucloxacillin), with additional rescue oral antibiotics for any increase in respiratory symptoms or decline in lung function. Persisting symptoms or signs require prompt and vigorous intravenous therapy to limit lung damage, usually administered for 14 days via a peripheral venous

long line

Nutritional management Dietary status should be assessed regularly. Pancreatic insufficiency is treated with oral enteric-coated pancreatic replacement therapy taken with all meals and snacks. Dosage is adjusted according to clinical response. A high-calorie diet is essential, and dietary intake is recommended at 150% of normal.. Most patients require fat-soluble vitamin supplements .

 Childhood Asthma

Asthma is a chronic inflammatory condition of the lung airways resulting in episodic airflow obstruction affecting 15-20% of children and the incidence is increasing.Asthma is considered to be a common clinical presentation of intermittent, recurrent wheezing and/or coughing, resulting from different airways pathologic processes underlying different types of asthma.

there are 2 main types of there are 2 main types of childhood asthma: (1) recurrent childhood asthma: (1) recurrent wheezing in early childhood, wheezing in early childhood, primarily triggered by common primarily triggered by common viral infections of the respiratory viral infections of the respiratory tracttract (2) chronic asthma associated (2) chronic asthma associated with allergy that persists into with allergy that persists into later childhood and often later childhood and often adulthoodadulthood . .

Types of Childhood AsthmaTypes of Childhood Asthma

Pathophysiology Asthma results in chronic inflammation of the airways involving eosinophils, lymphocytes, mast cells and neutrophils. The inflammation causes widespread but variable airflow obstruction, with bronchoconstriction, mucosal oedema and excessive mucus production. The airflow obstruction is often reversible, either spontaneously or with treatment, and is associated with an increase in airway responsiveness to a variety of stimuli such as exercise, cold air or

allergen exposure .

Examination of the chest is usually normal between attacks. In long-standing asthma there may be hyperinflation of the chest, generalized expiratory wheeze and a prolonged expiratory phase. Onset of the disease in infancy may result in Harrison's sulci. Evidence of eczema should be sought, as should examination of the nasal mucosa for allergic rhinitis. Growth is normal unless the asthma is extremely severe. The presence of a wet cough or sputum production, finger clubbing, or poor growth suggests a more severe condition such as cystic

fibrosis or bronchiectasis.

Diagnosis

The diagnosis of asthma in children should be suspected in any child with wheezing on more than one occasion, ideally heard on auscultation by a health professional, and distinguished from transmitted upper respiratory noises. In practice, the diagnosis is usually made on a history of recurrent wheeze, with exacerbations usually precipitated by viral respiratory infections.

The pattern of asthma should be assessed by asking :How frequent are the symptoms?

How much school has been missed due to asthma?

Are sport and general activities affected by the asthma?

How often is sleep disturbed by asthma?

How severe are the interval symptoms between exacerbations?

Causes of recurrent wheeze in infancy Transient early wheezingNon-atopic wheezing in the preschool childIgE-mediated wheezing (atopic asthma)Recurrent aspiration of feedsCystic fibrosisCow's milk protein allergyInhaled foreign bodyCongenital abnormality of lung, airway or heartIdiopathic

Investigations:Investigations:Usually diagnosis is clinical and Usually diagnosis is clinical and no no investigation is required. investigation is required. 1.Skin prick 1.Skin prick :may be done for common :may be done for common allergens to allergens to identify possible offending allergens. identify possible offending allergens. 22.CXR.CXR: Usually normal. May help to : Usually normal. May help to exclude other conditions.exclude other conditions.3.3.Peak Expiratory Flow Rate(PEFR) Peak Expiratory Flow Rate(PEFR) in in school aged school aged Asthma results in Asthma results in increased variability in peak flow increased variability in peak flow (Diurnal, day to day & (Diurnal, day to day & MOST MOST IMPORTANTLY bronchodilator IMPORTANTLY bronchodilator responsiveness by (10-15%) which is responsiveness by (10-15%) which is very valuable for diagnosisvery valuable for diagnosis). ).

Management

The aim of management is to allow the child to lead as normal a life as possible by controlling symptoms and preventing exacerbations, optimizing pulmonary function, while minimizing treatment and side-effects .

Drug Bronchodilators: β2-agonists

(relievers) Salbutamol Terbutaline

Anticholinergic : Ipratropium bromide Preventative/prophylactic treatment

Inhaled steroids Budesonide

Beclometasone Fluticasone

Mometasone Long-acting β2-bronchodilators Salmeterol , Formoterol Methylxanthines Theophylline Leukotriene inhibitors Montelukast Oral steroids Prednisolone

Bronchodilator therapy Inhaled β2-agonists are the most commonly used and most effective bronchodilators. Short-acting β2-agonists (often called relievers) such as salbutamol or terbutaline have a rapid onset of action, are effective for 2-4 hours, and have few side-effects. They are used as required for increased symptoms, and

in high doses for acute asthma attacks. In contrast, long-acting β2 -agonists (LABAs) such as salmeterol or formoterol are effective for 12 hours and are used in conjunction with regular inhaled corticosteroids. They are not used in acute asthma, and should not be used without an inhaled corticosteroid. Long-acting β2-agonists are useful in exercise-induced

asthma .

Ipratropium bromide, an anticholinergic bronchodilator, is sometimes given to young infants when other bronchodilators are found to be ineffective, or in the treatment of severe acute .asthma

Inhaled steroids Prophylactic drugs are effective only if taken regularly. Inhaled steroids (often called preventers) are the most effective inhaled prophylactic therapy. They decrease airway inflammation, resulting in decreased symptoms, asthma exacerbations and bronchial hyperactivity. They are increasingly used in conjunction with an inhaled long-acting β2-agonist. They have no clinically significant side-effects when given in conventional licensed doses. They can produce systemic side-effects, including impaired growth, adrenal suppression and altered bone metabolism, when

high doses are used .

Oral leukotriene receptor antagonists such as montelukast are helpful as add-on therapy when inhaled steroids with a LABA fail to control symptoms .Slow-release oral theophylline is

an alternative. However it has a high incidence of side-effects (vomiting, insomnia, headaches, poor concentration) and blood levels need to be monitored, so it is now rarely used in children.

Oral prednisoloneusually given on alternate days to minimise the adverse effect on height, is required only in severe persistent asthma where other treatment has failed.

Antibiotics are of no value in the absence of a bacterial infection and neither cough medicines nor decongestants are

helpful .

Allergen avoidance and other non-pharmacological

measures: Complete avoidance of allergens is difficult.Complementary medicine is probably useless .

Parents should be advised against cigarette smoking.

Exercise-induced asthma Some children's asthma is brought on only by vigorous exercise. With appropriate treatment asthma should not restrict exercise, and there are many elite athletes with asthma. For most, a short-acting β2-agonist bronchodilator taken immediately before exercise is sufficient, but if there are more marked symptoms a LABA taken in conjunction with an inhaled steroid will give greater

protection .

Acute asthma

Clinical features are :Wheeze and tachypnoea (respiratory rate >50 breaths/min in children 2-5 years, >30 breaths/min in children 5 or overIncreasing tachycardia (>130 beats/min in children aged 2-5 years, >120 beats/min in children 5 or over).The use of accessory muscles and chest recessionThe presence of marked pulsus paradoxus.If breathlessness interferes with talking, the attack is severe.Cyanosis, fatigue and drowsiness are late signs, indicating life-threatening asthma; this may be accompanied by a silent chest on auscultation as little air is being exchanged.

However, the severity of an acute asthma may be underestimated by clinical examination alone. Therefore :

Arterial oxygen saturation should be measured with a pulse oximeter in all children presenting to hospital with acute asthma. Oxygen saturations <92% in air imply severe or life-threatening asthma.Measurement of the peak expiratory flow rate should be routine in school-age children.

A severe exacerbation of asthma that does not improve

with standard therapy is

termed Status Asthmaticus

TreatmentTreatment 1.1.supplemental oxygensupplemental oxygen2.2.Inhaled salbutamolInhaled salbutamol 0.03 0.03 ml/kg (Min 0.5ml/dose ml/kg (Min 0.5ml/dose &Max 1ml/dose) &Max 1ml/dose) 3. REASESS after 20 min3. REASESS after 20 min..

Salbutamole (oral) 0.2 Salbutamole (oral) 0.2 mg /kg/6hr. mg /kg/6hr. Oral prednisolone 1-2 Oral prednisolone 1-2 mg/kg/day for 5 days. mg/kg/day for 5 days. Re-examine after few daysRe-examine after few days..

If there is good response (mild) If there is good response (mild) discharge discharge HOME onHOME on

If the respnos was If the respnos was partial(moderate partial(moderate ::attack)attack)Keep in hospital .Keep in hospital .Add Hydrocortisone Add Hydrocortisone 5mg/kg/6hr. iv5mg/kg/6hr. ivSalbutamol nebulizer (same Salbutamol nebulizer (same dose) /20 min for one hour. dose) /20 min for one hour. REASESSREASESS..

If good response send home If good response send home (as (as previously).previously).If limited (or no )response If limited (or no )response THEN:THEN: Admit to ICU Admit to ICUCardiorespiratory monitor.Cardiorespiratory monitor.O2 to maintain POO2 to maintain PO22>92%>92%Nebulized salbutamol (same Nebulized salbutamol (same dose)dose)Nebulized ipatropium bromideNebulized ipatropium bromideHydrocortison (5mg/kg/6hr) ivHydrocortison (5mg/kg/6hr) iv

Other drugs that may be Other drugs that may be considered in severe cases: considered in severe cases:

AminophyllinAminophyllin 5mg/kg 5mg/kg loading dose followed by loading dose followed by 1mg/kg/hr infusion.(if the pt 1mg/kg/hr infusion.(if the pt had received theophyllin had received theophyllin shortly before admission omit shortly before admission omit the loading dose). the loading dose). Side effects include Side effects include vomiting ,arrhythmias ,hypotenvomiting ,arrhythmias ,hypotension, seizures, and death).sion, seizures, and death).

Magnesium sulphate Magnesium sulphate 50mg/kg over 30-60 min. 50mg/kg over 30-60 min.

infusion(Max dose 2 gm.)infusion(Max dose 2 gm.) > >

Close monitoring of clinical status, hydration, and oxygenation are essential elements of immediate management. A poor response to intensified treatment in the 1st hour suggests that the exacerbation will not remit quickly.

Rarely, a severe asthma exacerbation in children results in respiratory failure, and intubation and mechanical ventilation become necessary.

Foreign Bodies of the Airway

Can be life threatening Can be life threatening eventeventLarge objects may cause Large objects may cause complete obstruction.complete obstruction.Symptoms depend on Symptoms depend on site ,size site ,size duration , and type of F.B. duration , and type of F.B. Commonest age is 1 -3 Commonest age is 1 -3 yearsyears..

Signs of upper airway Signs of upper airway obstructionobstruction::Respiratory Respiratory distress ,cough , stridor distress ,cough , stridor hoarseness ,wheeze ,and hoarseness ,wheeze ,and cyanosis.cyanosis.Signs of lower airway Signs of lower airway obstructionobstruction: Cough, : Cough, recurrent infections , recurrent infections , asthma like symptoms not asthma like symptoms not responding to treatment, responding to treatment, hemoptysis and hemoptysis and bronchiectasisbronchiectasis . .

A positive history must never be ignored. A negative history may be misleading. Choking or coughing episodes accompanied by wheezing are highly suggestive of an airway foreign body. Since nuts are the most common bronchial foreign body, the physician specifically questions the toddler's parents about nuts. If there is any history of eating nuts, bronchoscopy is carried out promptly.

Posteroanterior and lateral chest radiographs are standard in the assessment of infants and children suspected of having aspirated a foreign object. The abdomen is included. A good expiratory posteroanterior chest film is most helpful. During expiration, the bronchial foreign body obstructs the exit of air from the obstructed lung, producing obstructive emphysema (air trapping) with persistent inflation of the obstructed lung and shift of the mediastinum toward the opposite side

ApproachSuspected F.B in upper airwayAssess &ResuscitateIf pt is in respiratory distress and unable to speak or cry complete airway obstruction is likely and the risk is high . Heimlech maneuver may be done. If the child can speak then this method is contraindicated because it may dislodge the F.B. to more dangerous place.Send the pt to endoscopy.If lower airway obstruction is suspected ,stabilize the pt (ABC) and send for brochoscopy.

TREATMENT

The treatment of choice for airway foreign bodies is prompt endoscopic removal with rigid instruments. Bronchoscopy is deferred only until preoperative studies have been obtained and the patient has been prepared by adequate hydration and emptying of the stomach. Airway foreign bodies are usually removed the same day the diagnosis is 1st considered.