Updates in Hemodynamic Monitoring(Theory to New Concept)
Gee Young Suh1
1Critical Care Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Republic of Korea
Proper monitoring of hemodynamic status of patients is essential in properly treating patients with unstable hemodynamics. Traditionally, static pressures such as central venous pressure (CVP) and pulmonary artery occlusion pressure (PAOP) were used to assess patient’s preload but it is now well established that these pressures cannot reliably predict change in cardiac output after volume infusion. Thus dynamic indices such as pulse pressure variation (PPV) or stroke volume variation (SVV) is much more reliable predictor but for these parameters to be accurate patients have to meet certain conditions thus limiting their bedside use.
For monitoring cardiac output, although thermodilution method is still considered the golden standard, non-invasive or less invasive methods are gaining popularity. Some devices that use pulse contour analysis with or without transpulmonary thermodilution methods are currently used in many ICU’s. Other methods that use Doppler flow or change in impedence could also be used.
The importance of point-of-care sonography or echocardiography cannot be over stated. Every clinician looking after acutely ill patients should be able to use this device. As the technology advances, these devices are getting smaller with better image quality. This can be used to assess preload and contractility, as well as RV pressure overload or presence of pericardial effusion.