急性呼吸窘迫综合征

ACUTE RESPIRATO ISTRESS SYNDROME

急性呼吸窘迫综合征(Acute RepiratoryDistress Syndrome)略语为ARDS,系自1950年Tenkin首先提出的休克肺发展而来,后发现多种原因均可导致本征的发生,在1967年由Ashbaugh提出呼吸窘迫综合征这一名称,国内多赞成这一名词术语。为区别婴儿缺乏肺表面活性物质导致的透明膜形成的呼吸困难,称为成人呼吸窘迫综合征(Adult Respiratory DistressSyndrome),但不如急性呼吸窘迫综合征较为确切。

Since Tenken proposed for the first time in 1950. the term lung shock, acute respiratory dis-tress syndrome has developed and many causes has been found to be responsible for ARDS. The morta-lity of this syndrome though has been re-duced, it still has a death rate of 35-40%. ARDS may be induced by shock of various causes, trauma ( including major operations ) burns, inhalation of poisonous gases, dissemi-nated intravascular coagulation, drowning, drug over-dosing, severe infections, etc. The diagnosis of ARDS had been described in the criteria stipulated by the Three railure Conference held in 1 979, as summarized in Table. Table Diagnosis of ARDS L Clinical Manifestation Laboratory Examination Stage respiratory rate respiratory distress hypoxia physical Puimonary sign Puimonary X-ray PH PaO, kPa Pa07 kPa A?aDO, kPa QS/QT nig % 1 sign 1 air inspiration air inspiration >7.45 8-9 >4.0 1 20-30 yes no no no or pure oxygen <4.7 pure oxygen 7-15 normal inspiration inspiration 47-60 > 13 I air inspiration air inspiralion >7.45 7-8 >8.0 11 >30 more no no no or pure oxygen <4.0 pure oxygen 16-20 normal inspiration inspiration <47 >27 rri >35 markedly Serious yes diffused wet rale in both lungs diffused spot or reticular shadows >7.35 or normal air inspiration 5-7 pure oxygen inspiration <20 lowered or recovered air inspiralion pure oxygen inspiration >40 21-25 markedly diffused shadows air inspiration <5 air inspiration >33 IV >40 serious and marked wet rale in both fused in <7.25 pure oxygen >6.() pure oxygen >26 irregular lungs patch inspiration inspiration > 53 Etiology and Mechanism: 1 Direct Causes of Lung Injury. a, Oxygen intoxication, b. Accidental inhalation of gastric content, c. Miscellaneous, radiation injury, inhalation of poisonous gases, etc. 2. Body Fluid Factors Responsible for Lung Injury. Histamin. 5-HT, bradykinin, prostaglandin ( including thromboxane TX A2), endotoxin, fibriongen degradation products, etc. 3. Inhibition of ReticuloendotheHal System and Lack of Fibronectin. 4. Lung Injury Caused by Blood Cell Constituents. Polymorphonuclear neutrophiie, blood platelet. 5. Insufficient Lung Perfusion. 6. Lung Injury Complicated with Abnormal Blood Coagulation disseminated intravascular coagulation, over-dose of banked-blood transfusion. 7. Fat Embolism and Lipacidemia. fat embolism in diaphyses and fat embolism caused by multiple fracture. 8. Neurogenic Lung Injury. fulminant respiratory failure may occur after central nerve injury. 9. Miscellaneous. Prevention and Treatment of ARDS: Once ARDS occurred, the prognosis may not be good. Treatment of ARDS is a difficult and complicated task. Prevention and early treatment are very important. For patients with severe trauma and shock, the following are major points for attention: 1. Rapid restoration of blood volume after shock. 2. The patients are urged to do deep breathing. 3. Frequent change of posture. 4. Standard filter should be used for those more than 4 units of blood transfusion are needed. Obsolete banked梑lood should not be used. 5. Nutrition Supply. 6. Too quick infusion should be controlled. 7. Prolonged inhalation of oxygen should be controlled. 8. Prevention of accidental inhalation of gas-tric content. Two Major Links in Treating ARDS. 1. Assisted oxygen supply to maintain suffi-cient oxygenation of the tissue and to sup-port the recovery of the injured lung. 2. Take active measure to pervent life threat-ening complications. A. Oxygen Supply and Mechanical Ventilation. For oxygen supply, catheter, rhinobyon and mask can be used at the early stage. If hypoxia can not be alleviated, mechanical ventilation is needed 1. Mechanical ventilation ( see the whole text). 2. Choice of assisted breathing and externally controlled breathing. The first choice is assisted breathing. Externally controlled breathing is needed when 1, severe respiratory