西安交通大学医学院呼吸系统疾病课件 Respiratory Failure.pptVIP

Respiratory Failure Respiratory department Chen Mingwei Definition Respiratory failure is a functional disorder caused by any condition that severely affects the lungs’ ability to maintain arterial oxygenation or carbon dioxide (CO2) elimination with PO260mmHg or and CO250mmHg under circumstances as at sea level, with silent respiration indoor and excluding others related. It may be acute or chronic, depending on then the process develops withy important pathogenic, physiologic, and therapeutic distinctions. Respiratory failure, whether acute or chronic, is a frequently encountered medical problem and a major cause of death in the world. Chronic obstructive lung disease (COPD), which ends in death from respiratory failure, is the only chronic disease that continues to show a yearly increase in mortality. More than 70% of the deaths in patients with pneumonia are attributed to respiratory failure. For acute respiratory failure (ARF) not preceded by disease or systemic illness, short-term survival is 85%. Etiology Any causes that can bring about respiratory dysfunction may lead to the respiratory failure. Common diseases include in the clinic: 1. Obstruction of the airways due to inflammation, spasm, tumor, foreign body may result in hyperventilation, or with ventilation/perfusion mismatch resulted from uneven gas distribution, and then hypoxia and hypercarbia occurred. 2. Lung diseases including severe pneumonia, pulmonary edema, or fluid in the lungs, can be the source of respiratory failure. Also, it can often be a result of heart disease; respiratory distress syndrome; pulmonary fibrosis and other scarring diseases of the lung; radiation exposure; burn injury when smoke is inhaled; and widespread lung cancer. All of the diseases can cause the outcome like numbers of alveoli become less, diffusion decreases, lung compliance weaken, and ventilation/perfusion mismatch. Therefore hypoxia or with hypercarbia occurred. 3. Pulmonary vascular disorders