What role does the right side of the heart play in circulation?
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Right ventricular failure (RVF) is an underestimated problem in intensive care. This review explores the physiology and pathophysiology of right ventricular function and the pulmonary circulation. When RVF is secondary to an acute increase in afterload, the picture is one of acute cor pulmonale, as occurs in the context of acute respiratory distress syndrome, pulmonary embolism and sepsis. RVF can also be caused by right myocardial dysfunction. Pulmonary arterial catheterization and echocardiography are discussed in terms of their roles in diagnosis and treatment. Treatments include options to reduce right ventricular afterload, specific pulmonary vasodilators and inotropes. (+info)
Which cardiac surgical patients can benefit from placement of a pulmonary artery catheter?
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The use of pulmonary artery catheters (PACs) during cardiac surgery varies considerably depending on local policy, ranging from use in 5-10% of the patient population to routine application. However, as in other clinical fields, recent years have witnessed a progressive decline in PAC use. One of the reasons for this is probably the increasing use of transoesophageal echocardiograpy, even though careful analysis of the information provided by PAC and transoesophageal echocardiograpy indicates that the two tools should be considered subsidiary rather than alternatives. The principal categories of cardiac patients who can benefit from PAC monitoring are those with present and those with possible haemodynamic instability. On this basis we can identify five groups: patients with impaired left ventricular systolic function; those with impaired right ventricular systolic function; those with left ventricular diastolic dysfunction; those with an acute ventricular septal defect; and those with a left ventricular assist device. This review highlights the specific role of PAC-derived haemodynamic data for each category. (+info)
Which general intensive care unit patients can benefit from placement of the pulmonary artery catheter?
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From the report by Connors and coworkers in 1996 until now, much effort has been directed at demonstrating the safety and/or effectiveness of strategies based on pulmonary artery catheter (PAC) data. Although studies have failed to demonstrate a clear benefit of PAC use, neither have any corroborated the initial report of PAC-induced mortality. With this in mind, it is important to clarify the indications for PAC, taking into account the development of new technologies to measure cardiac output and stroke volume. The present review focuses on safety and effectiveness data, with a special focus on reasonable indications for PAC use in the intensive care unit. The PAC has evolved since its initial presentation, and it now offers numerous parameters in addition to cardiac output and pressure measurement, such as mixed oxygen saturation and right ventricular ejection fraction. Because many techniques may be used to measure cardiac output, the indications for PAC use have become founded on other parameters that are useful in more specific situations, essentially involving the right circulation. (+info)
Evidence-based review of the use of the pulmonary artery catheter: impact data and complications.
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The pulmonary artery catheter (PAC) was introduced in 1971 for the assessment of heart function at the bedside. Since then it has generated much enthusiasm and controversy regarding the benefits and potential harms caused by this invasive form of hemodynamic monitoring. This review discusses all clinical studies conducted during the past 30 years, in intensive care unit settings or post mortem, on the impact of the PAC on outcomes and complications resulting from the procedure. Although most of the historical observational studies and randomized clinical trials also looked at PAC-related complications among their end-points, we opted to review the data under two main topics: the impact of PAC on clinical outcomes and cost-effectiveness, and the major complications related to the use of the PAC. (+info)
Neurosurgical application of a flow-directed oximetry thermodilution catheter for evaluation of cerebral blood flow--technical note.
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The neurosurgical application was evaluated of a flow-directed oximetry thermodilution catheter for measurement of oxygen saturation in the jugular vein, which reflects cerebral blood flow (CBF). The catheter allows estimation of changes in CBF during carotid endarterectomy and therapeutically induced hypertension in the management of delayed vasospasm after subarachnoid hemorrhage. (+info)
Direct calorimetry using Swan-Ganz catheter for evaluation of general metabolic expenditure in acute cerebrovascular disease--comparison between direct Fick method and indirect calorimetry technique.
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Oxygen consumption calculated by the direct Fick method using a Swan-Ganz catheter (D-VO2) and indirect calorimetry using a metabolic computer (ID-VO2), carbon dioxide production calculated by the latter method, and respiratory quotient were determined pre- and postoperatively in 12 patients with acute hypertensive intracerebral hemorrhage and eight patients with acute ruptured intracranial aneurysm. The mean D-VO2 value was slightly lower than the mean ID-VO2 value, but had a significantly positive correlation. The regression curve was very close to the line of identity. The total metabolic expenditure can be calculated from D-VO2 and daily urinary nitrogen excretion. Direct calorimetry using a Swan-Ganz catheter is a simple method to evaluate metabolic expenditure in acute hemorrhagic cardiovascular disease. (+info)
Haemodynamic parameters obtained by transthoracic echocardiography and Swan-Ganz catheter: a comparative study in liver transplant patients.
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OBJECTIVE: To compare the haemodynamic measurements of cardiac output (CO), central venous pressure (CVP), pulmonary capillary wedge pressure (Pw) and pulmonary artery systolic pressure (PASP), obtained by Swan-Ganz catheter and transthoracic echocardiography. MATERIAL AND METHODS: Prospective study in a Medical/Surgical Intensive Care Unit (ICU). A total of 41 post liver transplant patients were enrolled. CO, CVP, Pw and PASP, were simultaneously determined by two independent observers, utilizing a Swan-Ganz catheter and transthoracic echocardiography, using equations described in the literature. A linear correlation and a Bland-Altman analysis were performed. RESULTS: A good correlation between invasive and non- invasive measurements for CO (r=0.97) and CVP (r=0.88) was found, but determinations of Pw (r=0.41) and PASP (r=0.18) did not correlate well. Bias and 95% confidence interval for CO were negligible namely when a CO<6 l/min was considered. Pulsed-wave Doppler-echocardiography underestimates the CO when compared with thermodilution, but the 2 techniques agree on average and can be used interchangeably. CONCLUSIONS: The non-invasive determination of CO in critical care post liver transplant patients correlates well with the invasive determinations. Transthoracic echocardiography was not appropriate for calculating filling parameters studied. Although the data was obtained in post liver transplant patients, they could be useful in defining the role of echocardiography in the ICU. (+info)
The pulmonary artery catheter (PAC) guides diagnosis and treatment in the intensive care unit (ICU), but studies have shown that physicians and nurses collectively have inadequate skill in interpreting PAC waveforms. We have developed a Web-based application that provides physicians and nurses with rapid access to relevant PAC-related content for use in patient care situations in real time. The application begins with a visual index that assists in the recognition of both normal and abnormal waveforms and provides waveform-specific links to concise advice on making accurate pressure measurements, troubleshooting system problems, and avoiding complications of catheter use. Evaluation of the application's efficacy will consist of a before-and-after trial to determine whether the application improves test performance in the areas of waveform recognition, accuracy of measurement, and appropriateness of action. We have completed the pre-intervention testing of nurses in the medical intensive care unit and found performance ranging from a mean of 68% for those with less than two years of experience to a mean of 76% for those with more than 6 years of experience. (+info)