1. 新生儿呼吸窘迫综合征 新生儿呼吸窘迫综合征 Respiratory Distress Syndrome ( RDS ) 中南大学儿科学教研室 陈平洋 第七章第九节

2. Purpose To be familiar with etiology （病因） and mechanism （发病机制） To master clinical manifestation （临 床表现） and differential diagnosis （鉴别诊断） To master prevention and treatment

3. Summary NRDS （新生儿呼吸窘迫综合征） is primarily developmental deficiency in the amount of pulmonary surfactant ( PS, 肺表面活性物质 ), at the air- liquid interface of the lung RDS frequently referred to as hyaline membrane disease (HMD, 肺透明膜 病 )

4. Summary RDS is a disease primarily of the premature infant （未成熟儿） Pulmonary hyaline membranes （肺透 明膜） and atelectasis （肺不张） are findings at autopsy （尸体解剖）

5. Etiology and Mechanism PS production and /or release by type II alveolar cells （ II 型肺泡细胞） PS appears in the amniotic fluid （羊 水） between 28 ～ 32 weeks Mature levels of PS are usually present after 35 weeks

6. PS ↓ → surface tension （表面张力） ↑ → atelectasis （肺不张） → hypoxia （低氧血 症） and acidosis （酸中毒） → p a vasoconstriction （肺动脉收缩） → right– to-left shunting （右向左分流） → ischemic injury （缺血性损伤） to the vascular bed → effusion of proteinaceous material （ 蛋白样物质） → pulmonary hyaline membrane （肺透明膜） → hypoxia and acidosis ↑↑

9. Who Is Risk baby? The incidence is inversely proportional to gestational age （胎龄） <28 wk: 60% ～ 80% of infants 32 ～ 34 wk: 15% ～ 30% of infants >37 wk: 5% of infants Infants of diabetic mothers （糖尿病母 亲之婴儿）

10. Clinical Manifestations The infant with RDS is mostly premature Respiratory distress （呼吸窘迫） usually begin 2 to 6 hours after birth dyspnea （呼吸困难）, cyanosis （发 绀）, and an expiratory grunt （呼 气性呻吟）

11. The clinical manifestation is progressive worsening （进行性加重） Uncomplicated （无并发症） cases are characterized by worsening of the disease for 2 ～ 3 d with recovery at 72 hr

12. 胃液泡沫稳定试验 1 ml of gastric juice （胃液） with an equal volume of 95% ethanol （酒精） → shake 15 sec → static state 15 sec Fetal lung maturity ： （＋） RDS ： （ - ）

13. Radiologic Features Ground glass （毛玻璃样） with air bronchograms （支气管充气征 ) As the disease progresses, the lung may become white-out lung ( 白肺 )

15. Treatment 一. Specific therapy 1. Surfactant replacement （表面活性物 质替代） The mammalian （哺乳动物） surfactant is currently preferred PS should be given under conditions of adequate mechanical ventilation （机械通气）

16. 2.Continuous positive airway pressure (CPAP, 持续气道压力 ) CPAP may be administered by nasal prongs （鼻塞）, mechanical ventilation( 机械通气） 3.Closure of the patent ductus arteriosus （ PDA ） PDA should be closed, either with indomethacin （消炎痛） therapy or with surgery

17. 二. Supportive management 1. Maintain a neutral thermal temperature( 中性温度 ) 2. Administer adequate fluids and electrolytes （水、电解质） Prevent fluid overload 3. Correct acid-base disturbances （酸碱失衡）

18. CPAP by nasal prongs

19. Prevention 1. Prevent premature labor （早产） 2. Predict the risk of RDS by testing of amniotic fluid ： lecithin/sphingomyelin ( L/S, 卵磷 脂 / 鞘磷脂 ) ratio 〉 2.0, indicates fetal lung maturity

20. 3. Accelerate fetal lung maturation( 加快 胎肺成熟） Administration of dexamethasone （地 塞米松） to women 48hr before delivery 4. Administration of a first dose of PS （肺表面活性物质） into the trachea of infants immediately after birth or during the first 24hr of life

21. Differential diagnosis( 鉴别诊断 ) 1. Meconium pneumonitis （胎粪性肺炎） Gestational age fullterm infant （足月儿） Etiology Hypoxia （缺氧） History Clinical manifestations Radiologic features Meconium –stained amniotic fluid （胎粪性羊 水） Signs appear with in minuts of birth, barrel-shaped chest （ 桶状胸）, Prolonged expiration, and rales （罗音） may be audible. Hyperinflation （肺气肿）, irregular, streaky densities with areas of atelectasis （肺不张）, Pneumothorax （ 气胸 ）

22. 2. Infectious pneumonia Gestational age Etiology History Clinical manifestations Radiologic features Each Gestational age （各胎龄） Bacteria, virus and other microbe Infection,Prolonged rupture of membranes （早破水 ）,URI （上呼吸道 感染） May occur at any time with nasal obstruction （鼻塞）, coughing （咳 嗽）,Tachypnea （呼吸急促 ） The sign is indefinite

23. Pneumomediastinum Pneumonia （纵隔积气） （肺炎）