新生兒呼吸窘迫綜合征（NRDS）英文課件

1、Neonatal Respiratory Distress Syndrome (NRDS)Tongji HospitalNeonatal Respiratory Distress Syndrome (NRDS)or: Hyaline Membrane Disease (HMD)Most common cause of respiratory failure in the first daysOccurring in 12% of newborn infants (GA 2628w, 50%, 3031w, less than 2025%)Mortality 50% at 20 yrs ago,

2、 Survive 8090% nowHigh risk: IDM, GA37w, multi preg., C-section, asphyxia, cold stress, history of prior affected, male or white infantsLow risk: chronic or pregnancy-associated hypertension, maternal opiate addiction, PROM, antenatal corticosteroidLung Development Embryonic Lung Development Fetal L

3、ung Development (Pseudoglandular, Canalicular, Terminal Saccular) Postnatal Lung DevelopmentEmbryonic Lung Development primitive lungmain bronchilobar bronchisegmental bronchi Fetal Lung DevelopmentPseudoglandular Stage 7th 16th weekPrimitive bronchial treeTerminal bronchiolesFetal Lung DevelopmentC

4、analicular Stage 16th 24th weekTerminal Saccular Stage 24th 36th weekRespiratory bronchioles Transitory saccules and ductsPostnatal Lung DevelopmentPostnatal Development birth 8 yearAlveolar periodSecondary alveolar septaAlveolar ducts and alveoliFunction of Pulmonary SurfactantDecrease alveolar sur

5、face tension, reduce respiratory workMaintain alveoli inflation and functional residual capacity Accelerate lung fluid absorption, reduce alveolar effusionPathogen Opsonization, alveolar macrophage activation Effects: improve oxygenation, ameliorate ventilation/perfusion anti-inflammation Fluid surf

6、ace tension Pressure (P) = 2xsurface tension()radius (r)Etiology and Pathophysilogy Surfactant lowers the surface tension of alveolar membrane Pulmonary immaturity results in surfactant deficiency Alveoli collapse at the end of expiration leads to respiratory failure Surfactant deficiency can arise

7、after asphyxia/shock and acidosisPathologyatelectasis, pulmonary edema, vascular congestion, hemorrhage, generalized capillary leak and mucosal necrosis leads to the small air filled terminal airways, the respiratory bronchioles and alveolar ducts, being surrounded by collapsed alveoli filled with d

8、ebris in a near uniform distribution (hyaline membranes)Laboratory Findings Respiratory and metabolic acidosis Phospholipid (PL)/ Sphingomyelin (S) 0.6, PaO250mmHg or TcSO285% Pressure: 410cm H2O, flow 5L/min, 32C, humidity 100%Conventional Mechanical Ventilation (CMV) Indication: PaO250mmHg or TcSO

9、270mmHg; or frequent apnea Complication: PAL (pulmonary air leak) BPD (bronchopulmonary dysplasia; or CLD) RLF (retrolental fibroplasia) VAP (ventilator-associated pneumonia)PreventionCareful maternal care and fetal monitoringAvoidance of asphyxia and infection at birthMaternal glucocorticoids (betamethasone, 12mgX2, im, 24h apart, dexamethasone, 6mgX4, im, 6h apart) Preventive use of surfactant The