Maintaining Optimal Blood Volume in COVID-19 Patients

Daxor recently announced the first use of its blood volume analyzer, BVA-100, at a hospital to guide volume treatment in a COVID-19 patient. The test has also been shown in a prospective randomized control trial to reduce ICU mortality by up to 66%.

Technology Networks spoke to Michael Feldschuh, CEO, Daxor, to learn more about the importance of maintaining optimal blood volume, how the BVA-100 test can help to measure this, and how clinicians can use the information it provides to guide treatment of COVID-19 patients.

Anna MacDonald (AM): Why is it so important to maintain optimal blood volume?

Michael Feldschuh (MF): Optimal volume is key to tissue perfusion and survival.  If we do not oxygenate our tissues they die.  To survive COVID we give ventilator support to get oxygen to the lungs, maintain the heart to pump the blood, but we also need sufficient blood volume (but not too much) to circulate the red cells which carry the oxygen to the tissues.  If we do not have the blood volume to carry oxygen, the heart and the ventilator are useless. 

If we give too many fluids the patient can go into heart failure and die, even without death, organ damage and lengthening stay are significant negative implications of hypervolemia (too much blood volume).  The key is that current standards of estimating volume via proxy markers in ICUs not using BVA (blood volume analysis) is highly inaccurate and suboptimal  -- that is why BVA which is 98% accurate direct measure of volume has been shown to improve ICU outcomes when used to guide volume management. Clinicians need a better tool to manage this aspect of patient care.

AM: What is capillary permeability and what does capillary leakage signify?

MF: The leak rate is a marker of the rate at which fluids may be escaping the intravascular space -- high rates of capillary permeability have been shown to be a significant prognostic marker of ICU mortality.  The virus damages the capillary system, high leak rate detection is key to understanding the disease process, giving physicians a true understanding of the status of the patient.  For example, a declining leak rate would indicate that the patient is improving versus a patient with a sustained or worsening leak rate.

AM: What blood volume changes are seen in hospitalized COVID-19 patients?

MF: Patients with ARDS/respiratory distress typically need fluid adjustments, which can mean more or less supportive fluids such as saline or even blood transfusions.  There is no one adjustment they all need -- circulatory support needs to be individualized, that is the benefit of the test.

AM: Can you tell us more about Daxor’s BVA and how it works?

MF: BVA is a rapid (under 1 hour) blood test which uses a radiolabeled tracer that is injected into the patient at the bedside, blood is drawn from the patient, and a precise calculation of the patient's volume derangement and leak rate is determined by the dilution of the tracer.  The "indicator dilution" method is considered the gold standard for this measurement, this is why the BVA has generated over 45,000 test results, and used in over 100 studies, drug trials, and case studies since its launch.

AM: How can clinicians use the information it provides to guide treatment of COVID-19 patients?

MF: The test will allow care teams to immediately adjust patients to the optimal blood volume by allowing them to see if a patient is too under or over resuscitated. Correct fluid adjustments ensure circulatory integrity and optimal tissue perfusion.  In addition, the test will give the leak rate of the patient conveying key insights into the disease state of the patient as well and help triage patients.

AM: Can you tell us more about the randomized control trial and the significance of the findings?

MF: A randomized control study (RCT) published in peer-reviewed journals is considered the highest form of evidence that a finding is statistically significant.  BVA has been shown in an RCT conducted at a Level-1 (the highest) trauma center, to be of significant benefit to lower mortality by 66% in patients who predominantly suffered from respiratory distress, sepsis, and ARDS.  No one has conducted an RCT on COVID-19 patients specifically yet, so as more data comes in, more findings specific to COVID-19 will become available.

Michael Feldschuh was speaking to Anna MacDonald, Science Writer, Technology Networks.