Wong Frankie W H
Clinical Neuroscience Unit, Foothills Medical Centre, Calgary, Alberta.
Dynamics. 2007 Fall;18(3):16-8.
Human physiology changes are often amplified in disease states and may be altered when a patient is mechanically ventilated. Normally, systolic blood pressure is slightly lower during inspiration than expiration due to the change in intrathoracic pressure. Pulsus paradoxus is a phenomenon in which the difference in systolic blood pressure (BP) between inspiration and expiration is more than 10 mmHg. When a patient is mechanically ventilated, the pattern of changes observed in pulsus paradoxus is reversed; that is, the systolic BP is higher during inspiration than expiration. In this article, the airway pressure and respiratory impedance tracings are used to demonstrate the inspiratory and expiratory phase of the respiratory cycle. Then BP can be determined with each respiratory phase. The difference in presentation of pulsus paradoxus in patients who are breathing spontaneously and with mechanical ventilation is described. A case study is also included to illustrate the presentation and treatment of pulsus paradoxus in a mechanically ventilated patient.
人体生理变化在疾病状态下往往会被放大，并且当患者接受机械通气时可能会发生改变。正常情况下，由于胸腔内压力的变化，吸气时收缩压略低于呼气时。奇脉是指吸气和呼气时收缩压（BP）之差超过10 mmHg的一种现象。当患者接受机械通气时，观察到的奇脉变化模式会相反；也就是说，吸气时收缩压高于呼气时。在本文中，气道压力和呼吸阻抗描记图用于展示呼吸周期的吸气和呼气阶段。然后可以在每个呼吸阶段确定血压。描述了自主呼吸患者和机械通气患者奇脉表现的差异。还包括一个病例研究，以说明机械通气患者奇脉的表现和治疗。
