呼吸衰竭RespiratoryFailure英文.pptxVIP

呼吸衰竭RespiratoryFailure英文第1页/共39页 RESPIRATORY FAILURE“inability of the lung to meet the metabolic demands of the body. This can be from failure of tissue oxygenation and/or failure of CO2 homeostasis.” 第2页/共39页 RESPIRATORY FAILUREDefinition Respiration is gas exchange between the organism and its environment. Function of respiratory system is to transfer O2 from atmosphere to blood and remove CO2 from blood.Clinically Respiratory failure is defined as PaO2 60 mmHg while breathing air, or a PaCO2 50 mmHg.第3页/共39页 Respiratory system includes: CNS (medulla) Peripheral nervous system (phrenic nerve) Respiratory muscles Chest wall Lung Upper airway Bronchial tree Alveoli Pulmonary vasculature 第4页/共39页 Potential causes of Respiratory Failure第5页/共39页 HYPOXEMIC RESPIRATORY FAILURE(TYPE 1)PaO2 60mmHg with normal or low PaCO2 ? normal or high pHMost common form of respiratory failureLung disease is severe to interfere with pulmonary O2 exchange, but over all ventilation is maintainedPhysiologic causes: V/Q mismatch and shunt第6页/共39页 HYPOXEMIC RESPIRATORY FAILURE CAUSES OF ARTERIAL HYPOXEMIA 1. ?FiO2 2. Hypoventilation (? PaCO2) Hypercapnic 3. V/Q mismatch Respiratory failure (eg.COPD) 4. Diffusion limitation ? 5. Intrapulmonary shunt - pneumonia - Atel