- 1、本文档共47页,可阅读全部内容。
- 2、有哪些信誉好的足球投注网站(book118)网站文档一经付费(服务费),不意味着购买了该文档的版权,仅供个人/单位学习、研究之用,不得用于商业用途,未经授权,严禁复制、发行、汇编、翻译或者网络传播等,侵权必究。
- 3、本站所有内容均由合作方或网友上传,本站不对文档的完整性、权威性及其观点立场正确性做任何保证或承诺!文档内容仅供研究参考,付费前请自行鉴别。如您付费,意味着您自己接受本站规则且自行承担风险,本站不退款、不进行额外附加服务;查看《如何避免下载的几个坑》。如果您已付费下载过本站文档,您可以点击 这里二次下载。
- 4、如文档侵犯商业秘密、侵犯著作权、侵犯人身权等,请点击“版权申诉”(推荐),也可以打举报电话:400-050-0827(电话支持时间:9:00-18:30)。
查看更多
* The global end-diastolic volume consists of the end-diastolic volumes of all four cardiac chambers. Even if this volume does not exist physiologically (diastole of all four cardiac chambers is not simultaneous), it does reflect the filling status of the heart and is a valid parameter of cardiac preload compared to the filling pressures. * The correlation of the global end-diastolic volume with the cardiac stroke volume is considerably better than with CVP or PCWP. GEDV is thus much better suited for measuring the cardiac preload. * The intrathoracic blood volume corresponds to the global end-diastolic blood volume plus the blood in the pulmonary circulation. * The intrathoracic blood volume is usually 25% higher than the global end-diastolic blood volume. A linear association has been demonstrated for the two parameters. The ITBV can therefore be calculated from the GEDV. * The German Sepsis Society confirms in its official guidelines that volumetric parameters are superior to the classical filling pressures for assessing cardiac preload. GEDV and ITBV are not falsified by extravascular pressure influences, in contrast to CVP and PCWP. * The parameters stroke volume variation (SVV) and pulse pressure variation (PPV) are not preload parameters in the narrower sense but parameters of the heart‘s preload responsiveness. They thus provide information on whether the heart will respond to volume administration with an increase in cardiac stroke volume. They can help to determine whether volume administration is useful to increase cardiac output. * Everyone knows the “fluctuation“ of the arterial pressure curve in hypovolaemic patients, that is, the fluctuation in pulse pressure amplitude with the respiratory cycle. This is due to ventilation-induced preload changes, which are more marked, the more hypovolaemic the patient is. * The SVV and PPV can be measured correctly only if the induced preload changes are always the same and no other fluctuations in the stroke vo
文档评论(0)