Advanced hemodynamic monitoring in the critically ill patient: Nice to have or need to treat?

Excerpt

The outcome of critically ill patients is still unacceptable high. Recently, an epidemiological investigation demonstrated that the incidence of severe sepsis and septic shock in Germany remains 11 % and that the mortality of septic shock is currently more than 40 %. Thus, every effort to improve diagnosis or treatment for critically ill patients is urgently needed. The value of hemodynamic monitoring has been under intensified discussion since the study of Connors et al. on the value of pulmonary artery catheter published exactly 20 years ago [1]. Since this time, we have learnt many lessons. Firstly, using a diagnostic tool per se cannot improve the outcome of critically ill patients. This is true for pulse oximetry, direct measurement of the arterial pressure as well as advanced hemodynamic monitoring variables. Monitoring of static variables such as central venous pressure (CVP) cannot be used for the assessment of volume status [2, 3]. Instead flow based hemodynamic variables seem to be more useful. There is evidence that the use of e.g. stroke volume or cardiac output measurement in combination with a passive leg raising test as an internal fluid challenge is a valuable tool to diagnose hypovolemia as well as to assess the volume responsiveness of a critically ill patient [4]. In this issue of the JCMC Perel and colleagues report on the value of advanced hemodynamic monitoring (transpulmonary thermodilution) for the therapeutic management of critically ill patients [5]. They performed a pre and post questionnaire study on the ability of intensivists to estimate the hemodynamic condition of critically ill patients and the impact on the decision making process. The authors revealed that unfortunately we are not as good as we think we are. The percentage error of the difference between estimated and measured thermodilution-derived variables ranged between 66 and 95 %. Only in 36 % of the cases the estimated cardiac output was within a range of ±20 % of the measured value, and in more than half of the cases intensivists underestimated the actual cardiac output by more than 20 %. Of note, these results were independent of the physician’s experience. Remarkably, in around 20 % therapeutic decisions on hemodynamic management including fluids, catecholamine or diuretics were changed according to the measured values of the advanced hemodynamic monitoring. Obviously, our patients deserve correct and rapid measurement using all possible resources and data to find out the correct diagnosis and best treatment. Furthermore, our patients cannot afford being exposed to erroneous decisions of their attending physicians, as these are frequently associated with detrimental consequences. …