Fa Associated Professor Pediatric Department. Bronchiolitis -LRT disease common in infant resulting inflammatory obstruction of small airway -By age of.

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Associated Professor Pediatric Department

Bronchiolitis

-LRT disease common in infant resulting inflammatory obstruction of small airway

-By age of 2 years (1-3 mo.)-Winter- early spring

-Infants with respiratory distress , tachypnea and wheez

Acute bronchiolitis : Etiology

Viral infection • RSV>50% • Parainfluenza – adenovirus – mycoplasma • Human meta-pneumovirus & bocavirus (primary or

co-infection) • Sometime confused clinically with bacterial

pneumonia but it rarely followed by bacterial super-infection • Pertussis may be co-infection • In co-infection ; is more severe

Acute bronchiolitis : Epidemiology

In USA 100.000 children < 1y/o are hospitalized annually (RSV)

rate: -Day care center- survival of premature baby

Acute bronchiolitis: Epidemiology • More common in:- - boys – not breast fed- crowded condition- - younger mother smoked during pregnancy

• Source of infection: older family member with URI

• Older children tolerate bronchiolar edema

Acute bronchiolitis : Pathogenesis• Bronchiolar obstruction (edema- mucus- cellular

debris) • Airflow is inversely proportional to th 4th power of

radius • Resistance is increased in inspiration < expiration:

air trapping & over inflation • If obstruction become complete: atelectasis • V/Q mismatch: hypoxemia: then hypercapnia

Pathophysiology

Not all infected infant develops LRTI Smaller airway Diminished lung function Eosinophil degranulation , ECP IgE

Chemokine IL8 , MIP1α- RANTES (regulated

on activation, normal T cell expressed and secreted)

IFNδ, leukotriene

Acute bronchiolitis : Clinical manifestation- Exposure to URI- Sign of URI- Diminished appetite and fever 38.5-39 (T range:

subnormal or markedly elevated)- Gradually resp distress- cough – wheez-irritable –

interfere with feeding- Apnea may be prominent (age < 2mo or premature) - Might fine crackles or overt wheeze - Prolong Exp- Decrease breath sound severe disease- Liver & spleen ( hyperinflated)

Acute bronchiolitis Dx• Previously healthy infant with first-time wheezing

in outbreak • CXRay hyperinflated with patchy atelectasis • WBC: Nl• PCR – IF – Culture (if dx is uncertain or for

epidemiologic purpose) • Trial of bronchodilator reverse asthma &

occasionally bronchiolitis but can worsen bronchial malacia

CX ray: hyper inflation, patchy atelectasis, 10% nl

bilateral hyperinflation (most evident on the lateral), with increased perihilar, peribronchial, and interstitial thickening .

bilateral suprahilar ill-defined opacities

Acute bronchiolitis Df Dx

-Asthma – CF – congenital malformation – F.B. – GER – trauma & tremor - Cardiogenic asthma(pul. Congestion)

Acute bronchiolitis : Treatment Admission: -hypoxia – inability to take oral feeding – extreme tachypneaRisk factor for severe disease:- age < 12 wk- – preterm - – CVD - – pul- – ID

Acute bronchiolitis : TreatmentSupportive Cool humidified oxygen in all hypoxemic infant • No sedative (Resp. drive) • Head & chest elevated (30o) + neck extended • Aspiration due to tachypnea (NG feeding), in severe forms& need intubation: NPO

• Trial of bronchodilator (further therapy is individualized)

Acute bronchiolitis : Treatment

• Frequency suctioning of nasal and oral secretions often provides relief of distress or cyanosis

• - CS (parenteral, oral on inhaled) have been used (conflicting studies)

• Ribavirin (aerosal): in CHD – CLD• Antibiotic have no value unless co-infection

of bacteria

Acute bronchiolitis : Treatment

- No support RSV Ig during acute episode in healthy children.

- Nebulizer E and Dexamethasone is not currently recommended.

- Nebulized hypertonic saline (some benefit)

Bronchiolitis Obliterance

• Chronic • Hydrochloride –Nitric oxide –sulphur oxide • Rhuematoid arthritis• SLE• GVHD• Lung transplant• Steven Jhonson• Adenovirus 7 & 21• RSV – parainfluenza -Mycoplasma

Bronchiolitis Obliterance

• Ill, cough ,fever,dyspnea, wheez • Wax and wane• Weeks to months• Chronic lung disease in 60%

DX : Bronchiolitis Obliterance

• Persistent wheez after transplant or viral or mycoplasma infection

• Unilateral or patchy Hyperlucency -Hyperinflation - atelectasis

• V/P scan• Bronchoscopy• Chest CT• Lung biopsy

Bronchiolitis Obliterance

Histology Hypertrophy -disorganizing

Destruction, Fibrosis Oblitration of termainal bronchiol and

dilation of distal bronchiol