1、 呼吸过程呼吸过程 外呼吸（肺通气和肺换气）外呼吸（肺通气和肺换气） 气体在血液中的运输气体在血液中的运输 内呼吸（组织换气）内呼吸（组织换气）呼吸全过程呼吸全过程呼吸衰竭呼吸衰竭 (Respiratory failure) concept & classification 2. Respiratory failure is a syndrome in which the respiratory system fails in one or both of its gas exchange functions: oxygenation and carbon dioxide eliminatio
2、n. In practice, respiratory failure is defined as a PaO2 value of less than 60 mm Hg while breathing air or a PaCO2 of more than 50 mm Hg. PO2Hb氧饱和度（）氧饱和度（） hypoxemic respiratory failure） a PaO2 of less than 60 mm Hg with a normal or low PaCO2. Cause of：Edema, Vascular disease, Chest Wall & Pleural
3、disease.hypercapnic respiratory failure） a PaO2 low 60 mm Hg and PaCO2 of more than 50 mm Hg. Cause of：Airway obstruction, Neuromuscular disease. 通气障碍通气障碍换气障碍换气障碍 一、一、（ventilatory disorders） 呼吸运动呼吸运动 平静呼吸平静呼吸吸气吸气：膈肌、肋间外肌收缩：膈肌、肋间外肌收缩主动主动呼气呼气：膈肌、肋间外肌舒张：膈肌、肋间外肌舒张被动被动 用力呼吸用力呼吸呼、吸均主动呼、吸均主动吸气吸气：膈肌、肋间外肌、胸锁
4、：膈肌、肋间外肌、胸锁 乳突肌、斜角肌收缩乳突肌、斜角肌收缩呼气呼气：肋间内肌、腹肌：肋间内肌、腹肌 肺栓塞、氧中肺栓塞、氧中毒、毒气中毒毒、毒气中毒肺泡表面活性肺泡表面活性物质合成物质合成型肺泡上皮受损型肺泡上皮受损 肺纤维化、肺实变、肺不张肺纤维化、肺实变、肺不张 肺泡表面肺泡表面张力张力肺组织顺应性肺组织顺应性肺泡通气量肺泡通气量呼衰呼衰肺水肿、肺水肿、急性胰腺炎急性胰腺炎肺泡表面活性物肺泡表面活性物质分解、消耗质分解、消耗 胸腔大量积液、张力性 气胸、严重的腹水、肝脾肿大肺泡扩张受限胸廓顺应性下降胸廓畸形、胸膜纤维化、胸腔积液、肋骨骨折胸壁的弹性阻力 肺泡扩张的阻力肺顺应性 肺有效通气
5、量呼吸衰竭限制性通气不足Obstruction is located in the airway inside the thorax： expiratory dysneaObstruction is located in the airway outside the thorax： inspiratory dysnea + 。胸内压胸内压=肺内压肺内压 - 肺回缩力肺回缩力=大气压大气压 - 肺回缩力肺回缩力 = - 肺回缩力肺回缩力吸气末：吸气末：-5 -10 mmHg ； 呼气末：呼气末：-3 -5 mmHg用力吸气：用力吸气：-30 -80 mmHg；用力呼气：；用力呼气：110 mmH
6、gThe diffusion impairment is characterized by a disruption in the exchange of O2 or CO2 or both across the alveolar-capillary membrane.气体弥散速度取决于：气体弥散速度取决于：肺泡膜两侧的气体分压差、肺泡膜两侧的气体分压差、气体的分子量和溶解度、气体的分子量和溶解度、肺泡膜的面积和厚度。肺泡膜的面积和厚度。 弥散障碍时的血气变化弥散障碍时的血气变化 V Q V / Q. The dysfunction of gas exchange can arise secondary to ventilation /perfusion mismatching. 呼衰呼衰 （increased of anatomical shunt ） ARDS 名词解释名词解释思考题思考题
