Current opinion in critical care
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Curr Opin Crit Care · Jun 2005
ReviewHemodynamic assessment of critically ill patients using echocardiography Doppler.
The evaluation of hemodynamic status in critically ill patients is a leading recommended indication of transesophageal echocardiography in the intensive care unit. Advantages and diagnostic yield of transesophageal echocardiography in this setting are particularly relevant when considering limitations and questioned prognostic impact of pulmonary artery catheterization. ⋯ Transesophageal echocardiography appears well suited for the determination of cardiac index and to track its variations after therapeutic interventions. Although repeated measurements of left ventricular end-diastolic dimension allows to accurately track preload variations, a single determination is not reliable to predict fluid responsiveness in intensive care unit patients. Identification of preload dependence in hemodynamically unstable patients currently tends to rely mainly on dynamic parameters that use cardiopulmonary interactions under mechanical ventilation. Transesophageal echocardiography also allows to adequately assess right ventricular function and left ventricular filling pressure using combined Doppler modalities. Adequate education and training of intensivists and anesthesiologists is crucial to further develop the use of transesophageal echocardiography in the intensive care unit setting. Despite the absence of randomized controlled studies documenting transesophageal echocardiography benefits on patient outcome, present evidence and experience strongly recommend a larger use of echocardiography Doppler for a comprehensive functional hemodynamic assessment of critically ill patients with circulatory failure.
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Curr Opin Crit Care · Jun 2005
ReviewHow monitoring of the microcirculation may help us at the bedside.
Recent technologic developments have allowed the direct visualization of the microcirculation at the bedside. The present review explores how the monitoring of microcirculation can help in clinical practice. ⋯ Microcirculation plays an important role in the pathogenesis of shock and organ dysfunction, especially in sepsis. Monitoring microcirculation at the bedside may be used to assess severity of the disease and to predict outcome, but in the absence of sufficient data regarding the effects of therapeutic interventions it cannot yet be used to guide therapy, even though this approach is promising.
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Curr Opin Crit Care · Jun 2005
ReviewMonitoring of pulmonary mechanics in acute respiratory distress syndrome to titrate therapy.
This paper reviews recent findings regarding the respiratory mechanics during acute respiratory distress syndrome as a tool for tailoring its ventilatory management. ⋯ The Venegas approach should be the standard analysis of pressure-volume curves. In any patient, the potential for recruitment should be assessed, as a basis for tailoring the most effective mechanical ventilation. Further studies are needed to clarify the potential use of the pressure-volume curve to guide a lung-protective ventilatory strategy.
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Curr Opin Crit Care · Jun 2005
Randomized Controlled Trial Comparative Study Clinical TrialMechanical devices for cardiopulmonary resuscitation.
For over 40 years, manual chest compressions have been the foundation of cardiopulmonary resuscitation and recent studies have clearly reconfirmed the hemodynamic significance of delivering consistent, high-quality, infrequently-interrupted chest compressions. However, there remain multiple inadequacies in the actual delivery of manual chest compressions during cardiopulmonary resuscitation. One potential solution is use of adjunct mechanical devices. ⋯ High quality chest compressions during cardiopulmonary resuscitation are critical elements in effecting successful resuscitation following a cardiac arrest. Recent studies utilizing adjunct mechanical devices have not only revealed significant increases in the effectiveness of chest compressions, including improved hemodynamics in both animal models and human studies, but also improvements in short-term human survival in the clinical setting. It is hoped that these promising findings will eventually be corroborated in terms of improved neurologically intact, long-term patient survival. Clinical trials are currently underway to validate such efficacy.
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Because the right side of the heart supplies blood to the pulmonary circulation, its integrity is required for both adequate respiratory and circulatory function. By reducing pulmonary perfusion, right-sided heart failure may compromise arterial oxygenation and left ventricular filling, and monitoring of right-sided heart function at the bedside in critically ill patients is fundamental. Two recent clinical commentaries have focused on the invaluable help provided by echocardiography for this purpose. ⋯ Monitoring of right-sided heart function is essential in a clinical setting associated with hemodynamic instability, such as severe sepsis or acute coronary artery obstruction, and also in that it is associated with increased pulmonary vascular resistance, as in massive pulmonary embolism or acute respiratory failure. Moreover, use of mechanical ventilation requires regular evaluation of its effects on the right side of the heart.