新生儿呼吸窘迫综合征.ppt

Neonatal Respiratory Distress Syndrome NRDS新生儿呼吸窘迫综合征
Pediatric department of First Affiliated Hospital of Shantou university medical college
Lin Niyang
Definition
定义
Etiology
病因
Pathogenesis
发病机制
Clinical manifestation
临床表现
Assistant examination
辅助检查
Diagnosis
诊断
Differential diagnosis
鉴别诊断
Therapy
治疗
Prevention
预防
Definition
Hyaline membrane disease, HMD
Deficiency of pulmonary surfactant,PS
Pulmonary alveoli collapse at the end of expiration
Progressively aggravated respiratory distress shortly after birth
Mainly in preterm infant
Higher incidence rate with smaller gestational age
Infant of DM mother, cesarean section, the second baby of twins
Etiology
PS are secreted by type II epithelial cells of pulmonary alveoli.
Dipalmitoyllecithin(DPPC) is the main substance.
Surfactant protein(SP)
PS are produced from 18~20w till 35~36w when lung is mature.
Etiology
PS cover the inner surface of pulmonary alveoli, which can:
decrease alveolar surface tension
prevent alveoli collapse at the end of expiration
keep functional residual capacity(FRC)
keep stable pulmonary alveolus pressure
decrease fluid exude from capillary to pulmonary alveoli
Etiology
Preterm birth
pH of body fluid, body temperature, volume of pulmonary blood flow and hormone can influence PS secretion.
Asphyxia, hypothermia, placenta previa, placental abruption and hypotension of mother, which can influence blood flow of fetus.
High level insulin of IDM may resist the promotion effect of adrenal cortex hormone to PS synthesis
Pathogenesis
PS deficiency
alveolar surface tension↑
alveolus collapse and pliance↓
work at inspiration↑difficulty at alveolus opening
tidal volume↓
alveolar ventilation↓
CO2 retention
respiratory acidosis
V/A↓
hypoxia
metabolic acidosis
Alveolar permeability↑
interstitium edema
fibrin deposition in the inner surface of alveoli
eosinphilic hyaline membrane
gas diffusion disorder
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Clinical manifestation
Respiratory distress 2~6h after