Bronchiolitis Bronchiolitis fa Dr. S. Alyasin 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

peribronchial, and interstitial thickening. 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 tachypnea Risk factor for severe disease: age < 12 wk – preterm – CVD – pul – ID

Acute bronchiolitis : Treatment Supportive 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