You have decided to initiate CVVHDF in a septic patient with acute renal failure. The CVVHDF circuit is set up as shown below. What are the advantages of the replacement fluid administered as shown in the diagram?
Advs:
- Flush for filter and prolong filter life by reducing clotting in filter
- May increase urea clearance by elution from red cells
This question asks the candidate to identify a pre-dilution fluid replacement strategy from a MS Word clip-art diagram, and then to list its advantages. The two replacement fluid techniques are compared in a summary chapter from the Required Reading section. There is also a whole big thing on this topic in the Renal section from the Primary Exam revision section.
In brief, the "advs" of the pre-dilution fluid replacement strategy are as follows:
Mariano, Filippo. "Continuous Renal Replacement Therapy (CRRT) in Intensive Care." Practical Issues in Anesthesia and Intensive Care 2013. Springer Milan, 2014. 131-144.
Zhongping Huang, Jeffrey J. Letteri, Claudio Ronco, Dayong Gao, and William R. Clark "Predilution and Postdilution Reinfusion Techniques"; in: Critical Care Nephrology by Ronco, Bellomo and Kellum (2009) pp. 1370
Ronco, C., et al. "The haemodialysis system: basic mechanisms of water and solute transport in extracorporeal renal replacement therapies." Nephrology Dialysis Transplantation 13.suppl 6 (1998): 3-9.
Uchino, Shigehiko, et al. "Pre-dilution vs. post-dilution during continuous veno-venous hemofiltration: impact on filter life and azotemic control." Nephron Clinical Practice 94.4 (2004): c94-c98.
Nurmohamed, Shaikh A., et al. "Predilution versus postdilution continuous venovenous hemofiltration: no effect on filter life and azotemic control in critically ill patients on heparin." ASAIO Journal 57.1 (2011): 48-52.