Broncho pulmonary dysplasia(bpd)

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Text of Broncho pulmonary dysplasia(bpd)

  • 1. Bronchopulmonary Dysplasia (BPD)Dr Varsha Atul Shah

2. Back ground Develops in neonates treated with O2 & PPV . Originally described by Northway in 1967 usingclinical , radiographic & histologic criteria . Bancalari refined definition using ventilationcriteria , O2 requirement @ 28days to keepPaO2>50mmhg & abnormalities in chest x ray . 3. Back ground Shennan proposed in 1988 criteria of O2requirement @ 36 weeks corrected GA . Antenatal steroids , early surfactant Rx &gentle modes of ventilation minimizeseverity of lung injury . 4. Pathophysiology Multifactorial Major organ systems - lungs & heart Alveolar stage of lung development - 36wks GAto 18 months post conception Mechanical ventilation & O2 interferes withalveolar & pulmonary vascular development inpreterm mammals . Severe BPD Pulmonary HT & abnormalpulmonary vascular development . 5. Stages of BPD Defined by Northway in 1967 Stage 1 - similar to uncomplicated RDS Stage 2 - pulmonary parenchymal opacitieswith bubbly appearance of lungs Stage 3 & 4 areas of atelectasis ,hyperinflation & fibrous sheaths Recently CT & MRI of chest reveals moredetails of lung injury 6. Frequency of BPD Dependent on definition used in NICU . Using criteria of O2 requirement @ 28 daysfrequency range from 17% - 57% . Survival of VLBW infants improved withsurfactant Actual prevalence of BPD hasincreased . 7. Mortality/Morbidity of BPD Infants with severe BPD Increased risk ofpulmonary morbidity & mortality within thefirst 2 years of life . 8. Pulmonary Complications ofBPD Increased resistance & airway reactivityevident in early stages of BPD along withincreased FRC . Severe BPD Significant airwayobstruction with expiratory flow limitations& further increased FRC secondary to airtrapping & hyperinflation 9. Volume trauma & Barotrauma Rx of RDS surfactant replacement , O2 ,CPAP & mechanical ventilation . Increased PPV required to recruit all alveolito Px atelectasis in immature lungsLunginjuryInflammatory cascade . Trauma secondary to PPV-Barotrauma VolumetraumaLung injury secondary toexcess TV from increased PPV . 10. Volume trauma &Barotrauma Severity of lung immaturity & effects ofsurfactant deficiency determines PPV . Severe lung immaturityAlveolar numberis reducedincreased PP transmitted todistal bronchioles . Surfactant deficiencysome alveolicollapse while others hyper inflate . 11. Volume trauma &Barotrauma Increased PPV to recruit allalveoliCompliant alveoli & terminalbronchioles ruptureleaks air in tointerstiumPIEIncrease risk of BPD Using SIMV compared to IMV in infants