Relative Blood Volume Monitoring during Renal Replacement Therapy in Critically Ill Patients with Septic Shock: A Preliminary Report

Abstract

Background: Volume management during renal replacement therapy (RRT) in septic shock is always in the conflict between aggravating hypovolemia by undue ultrafiltration (UF) and insufficient reduction of fluid overload which is associated with adverse outcome. Relative blood volume (RBV) monitoring could be helpful for timely transition from fluid resuscitation to fluid removal. Methods: Data of RBV were continuously monitored and used for guidance of UF and fluid resuscitation in 21 consecutive patients with severe septic multiple organ failure. RRT was applied with extended daily hemodiafiltration for median 11 h (range 6-23). Changes in RBV were analyzed during the first 4 treatment sessions. Results: During 26 treatments, RBV monitoring revealed an internal volume loss substituted by a median infusion volume of 2.38 l (maximum 8.07 l) per treatment to keep the RBV constant. In the remaining 40 sessions, a median net-UF of 1.00 l (range 0.40-4.40) was achieved. In the first 2 days predominantly substitution was necessary whereas from the third day UF became increasingly possible. The 28-day survival rate was 81%. Conclusion: Blood volume monitoring proved to be an easy and feasible tool for safe guidance of fluid management maintaining the balance between UF and vascular refilling. Video Journal Club ‘Cappuccino with Claudio Ronco' at http://www.karger.com/?doi=433415.

Net ultrafiltration prescription survey in Europe

“…A combination of dynamic hemodynamic parameters and intravascular fluid assessment is recommended for evaluation of fluid responsiveness [22]. Nevertheless, few studies have incorporated these methods into guiding ultrafiltration and monitoring, for example, passive leg raising, trans-pulmonary blood dilution, or blood volume monitoring during RRT [23][24][25].…”

Effects of Volume Overload and Current Techniques for the Assessment of Fluid Status in Patients with Renal Disease

“…As the fluid is removed, Ht or concentration of total blood proteins will rise mimicking the percent reductions in blood volume [97]. Today, RBV monitoring is a standard feature of most of modern dialysis devices [98].…”

“…There are quite a few studies, including very recent ones, showing the value of BVM in assessment of dry weight [94,[98][99][100][101][102][103]. A recent study by Kron et al [98] investigated the use of RBV monitoring in renal replacement therapy patients with septic shock and they indicated RBV monitoring as an easy, safe, and feasible tool in fluid management.…”

“…A recent study by Kron et al [98] investigated the use of RBV monitoring in renal replacement therapy patients with septic shock and they indicated RBV monitoring as an easy, safe, and feasible tool in fluid management. Another recent study by Balter et al [101] used Crit-Lane method for 12 months to regulate fluid management and they found significant increases in average hemodialysis time, on-line clearance, and Kt/V; and decreases in post-dialysis systolic BP; and decreases in pre-dialysis SBP and anti-hypertensive medications in patients with hypertension at their first evaluation.…”

“…To conclude, while there are ongoing discussions questioning the validity of RBV monitoring, with the recent favorable outcomes [98][99][100][101], it is still one of the most commonly used methods in HD settings to assess volume status today. However, there is definitely need for randomized controlled studies with large sample sizes to solve the conflict about the validity of RBV monitoring.…”