常见的ICU病人困难脱机的原因及处理对策13.ppt

ICU病人困难脱机的原因及处理对策 撤机 撤机（weaning）是一个缓慢、逐渐地降低呼吸支持的过程，20%-30%的患者出现撤机困难，有的患者甚至出现严重的呼吸机依赖，总的来说用来撤机的时间约占整个机械通气时间的40%，而在某些特殊的疾病状态下（如COPD）撤机时间可占总通气时间的60%左右。 撤机 快速撤机：几个小时内成功撤机 缓慢撤机：需要几天、几周的撤机技术 COPD，高龄或虚弱，ARDS 困难撤机：呼吸机依赖或脑损伤或神经肌 肉病变 困难撤机标准（Weaning Failure Criteria） MAP change 20mmHg Pulse rate chang 20bpm PaCO2 increae 10-20mmHg PaCO2 decreae 10-20mmHg or SpO2 90% despite increasing FiO2 to 45% PH 7.30 Frequency 30-40bpm 困难撤机的表现 呼衰的病理生理学 困难脱机的常见原因 FAILURE TO WEAN OFF VENTILATOR: CAUSES - 1 Respiratory: - Use wider bore artificial airway – ET tube / tracheostomy - Treat bronchospasm adequately - Improve lung compliance by removing excess fluid (“wet lungs”) by using diuretics if volume overloaded / congestive cardiac failure is the cause. - Cardiovascular: left ventricular dysfunction - pulmonary oedema (backward failure) - inability of the cardiovascular system to provide the increase in delivery of oxygen needed by the respiratory muscles during weaning (forward failure) Appropriate therapy (diuretics / vasodilators / inotropes) Wean the inotropes only after successful weaning from mechanical ventilatory support. Haemoglobin must also be optimized 8g% 10g% with myocardial ischemia / cerebral ischemia FAILURE TO WEAN OFF VENTILATOR: CAUSES - 2 Neurological: -brain stem dysfunction due to trauma, hypoxia or infection, critical illness polyneuropathy -intermediate syndrome due to organophosphorus insecticides Fluid Balance: Positive cumulative fluid balance is associated with failure to wean and a negative fluid balance was predictive of a successful weaning in a recent study. Infection: any sepsis and/or respiratory infection should have resolved FAILURE TO WEAN OFF VENTILATOR: CAUSES - 3 Drugs - st