Assessment of loading conditions with cardiac ultrasound. A comprehensive review

Abstract

Optimization of the preloading conditions and concomitant determination of endpoints of fluid administration are the most frequent therapeutic actions in critically ill patients. Besides a clinical appraisal, reproducible data should be acquired at the bedside to estimate the adequacy of fluid resuscitation. The dynamic assessment and determination of fluid responsiveness plays a major role in this respect. Right-sided cardiac variables, such as inferior and superior caval vein diameter variation during mechanical ventilation, are easily obtained with cardiac ultrasound. Moreover, left sided variables, including aortic flow variation, with intermittent swings of intrathoracic pressure during mechanical ventilation, may be achieved non-invasively with Doppler-echocardiography. Both in terms of resuscitation, as well as correct interpretation of various two-dimensional and Doppler variables, it is essential to acquire a clear understanding of the filling status of a patient. Doppler-echocardiography plays herein a pivotal role.

Lung ultrasound in the critically ill (LUCI): A translational discipline

“…Imagine the potential of a discipline which can associate, or dissociate, cardiologic from lung findings (the presence or absence of the B-profile in patients with or without visible left dysfunction, or just in the grey zone, or just without cardiac window). Fortunately, the cardiologic community is beginning to take interest in LUCI [13,14].…”

Contemporary perioperative haemodynamic monitoring

“…Thus, optimization of cardiac compliance and loading conditions can improve blood flow. To accomplish this, haemodynamic monitoring is essential to achieve optimal perfusion and balance loading conditions and cardiac systolic function in such a manner that tissue perfusion is optimized [4,5].…”

“…ΔSVC determined by means of TOE seems to be more accurate, but ΔIVC is more accessible with the transthoracic approach [33,34,59]. VTI variation > 20% predicts fluid responsiveness in mechanical ventilated patients, but cannot be used in patients with aortic valve disease [4,60]. ΔV peak > 12% predicts fluid responsiveness with a sensitivity of 100% and a specificity of 89% in mechanically ventilated patients in septic shock with preserved LV systolic function [61].…”

Assessment of hypovolaemia in the critically ill

“…Alternatively, the attending ICU doctor can estimate ("eyeball") the left ventricle on TTE and look at the left-ventricle diastolic area index (LVDAI] . This avoids the need for an invasive blood pressure monitoring system [67]. This technique has limitations.…”