Respiratory Distress Syndrom

Respiratory Distress Syndrome in infant

Illustrations Definition Causes,incidence,and risk factors Symptoms Complications Signs and tests Treatment Prognosis

Illustrations The major features of the lungs include the bronchi, the bronchioles and the alveoli. The alveoli are the microscopic blood vessel-lined sacks in which oxygen and carbon dioxide gas are exchanged.

Definition Respiratory distress syndrome is one of the most common lung disorders in premature infants. The condition makes it hard to breathe

Neonatal respiratory distress syndrome (NRDS) is caused by a deficiency in pulmonary surfactant (PS) and is one of the main reasons of neonatal mortality.

from 34 to 37 weeks gestation, the cells in the alveoli normally produce a substance called surfactant

surfactant is kind of phosphatide and produced by the type Ⅱalveolar cells . reduces the surface tension of fluids that coat the lungs so the air sacs can expand at birth and the infant can breathe normally.

Causes,incidence,and risk factors Causes When an infant is born prematurely(<32 weeks), their lungs have not produced the necessary amount of surfactant.Without surfactant, the lungs can not inflate, resulting in RDS. The lack of this chemical causes the alveolar to collapse and prevents the child from breathing properly. Symptoms usually appear shortly after birth and slowly become more severe.

Incidence • The incidence of RDS declines with degree of maturity at birth. • It occurs in 60 % of babies born at less than 28 weeks' gestation, 30% of those born at 28 to 34 weeks, and less than 5% of those born after 34 weeks. • In 2003, the RDS mortality rate (per 100,000 live births) among African Americans was 43.7, versus 16.8 among whites--a difference of more than 62 percent.

Risk factors  Prematurity  Diabetes  acidosis

in the mother

Symptoms  Onset

Usually less than 2-5 hours after birth Increases in severity from 24 to 48 hours Then, gradual improvement after 48-72 hours  Abnormal retraction of chest wall  Cyanosis  Expiratory grunting  Increased respiratory rate

Complications Sepsis  Hemorrhage :Pulmonary hemorrhage ,Intracranial 

hemorrhage

 pneumothorax

(collapse of lung)  bronchopulmonary dysplasia: may develop as a result of oxygen toxicity, high pressures delivered to the lungs during mechanical ventilation or the severity of the condition itself.

Signs and tests A

blood gas analysis shows low oxygen and acidosis.  A chest x-ray indicates respiratory distress (the lungs develop a characteristic "ground glass" appearance).  Lung function studies may be necessary.  Blood cultures and a sepsis work-up are usually done to rule out infection and sepsis as a cause of the respiratory distress.

Treatment  Glucocorticoids:

on 48h before birth, 5mg,tid,im×2 days  Supportive therapy  High oxygen and humidity concentrations  Assisted ventilation  Exogenous surfactant via trachea : 60-100mg/kg

Prognosis  The

condition may persist or worsen for 2 to 4 days after birth with improvement thereafter. Some infants with severe respiratory distress syndrome will die.

 Long-term

complications may develop as a result of oxygen toxicity, high pressures delivered to the lungs, the severity of the condition itself, or periods when the brain or other organs did not receive enough oxygen.