Assessment of volume status
Divining hydration status with the power of ultrasound
Assessment of volume status is a question that plagues those professionals who care for acutely unwell patients. While for some the answer may be obvious, there are a broad cross section of patients who need supplementary data to answer this question; this is precisely where ultrasound fits in.
The following section will breakdown key concepts in ultrasound guided volume status assessment and will conclude with a video tutorial.
The concept of volume status is broken down into 2 key concepts. First, will this patient respond to fluids? This may manifest in an increase in blood pressure or reduction in heart rate, at least in the short term. For many patients, however, the impact can be short-lived or the effect nuanced, such as an improvement in kidney function 24 hours later. This, however, does not take into account whether fluids themselves may actually harm the patient.
Second, how much fluid to give? While we may recognize the patient who slips into frank pulmonary edema, this is clearly not an acceptable end-point. While the real answer may be “just enough and not a drop more”, knowing the limit is where the rubber hits the road. Volume tolerance has emerged as a key concept in defining this literature.