Solute removal during continuous renal replacement therapy in critically ill patients: convection versus diffusion

نویسندگان

  • Zaccaria Ricci
  • Claudio Ronco
  • Alessandra Bachetoni
  • Giuseppe D'amico
  • Stefano Rossi
  • Elisa Alessandri
  • Monica Rocco
  • Paolo Pietropaoli
چکیده

INTRODUCTION The best modality, for continuous renal replacement therapy (CRRT) is currently uncertain and it is poorly understood how transport of different solutes, whether convective or diffusive, changes over time. METHODS We conducted a prospective cross over study in a cohort of critically ill patients, comparing small (urea and creatinine) and middle (beta2 microglobulin) molecular weight solute clearance, filter lifespan and membrane performance over a period of 72 hours, during 15 continuous veno-venous dialysis (CVVHD) and 15 continuous veno-venous hemofiltration (CVVH)sessions. Both modalities were administered based on a prescription of 35 ml/kg/h and using polyacrylonitrile filters. RESULTS Median filter lifespan was significantly longer during CVVHD (37 hours, interquartile range (IQR) 19.5 to 72.5) than CVVH (19 hours, IQR 12.5 to 28) (p = 0.03). Median urea time weighted average (TWA) clearances were not significantly different during CVVH (31.6 ml/minute, IQR 23.2 to 38.9) and CVVHD (35.7 ml/minute, IQR 30.1 to 41.5) (p = 0.213). Similar results were found for creatinine: 38.1 ml/minute, IQR 28.5 to 39, and 35.6 ml/minute, IQR 26 to 43 (p = 0.917), respectively. Median beta2m TWA clearance was higher during convective (16.3 ml/minute, IQR 10.9 to 23) than diffusive (6.27 ml/minute, IQR 1.6 to 14.9) therapy; nonetheless this difference did not reach statistical significance (p = 0.055). Median TWA adsorptive clearance of beta2m appeared to have scarce impact on overall solute removal (0.012 ml/minute, IQR -0.09 to 0.1, during hemofiltration versus -0.016 ml/minute, IQR -0.08 to 0.1 during dialysis; p = 0.79). Analysis of clearance modification over time did not show significant modifications of urea, creatinine and beta2m clearance in the first 48 hours during both treatments. In the CVVHD group, the only significant difference was found for beta2m between 72 hours and baseline clearance. CONCLUSION Polyacrylonitrile filters during continuous hemofiltration and continuous hemodialysis delivered at 35 ml/kg/h are comparable in little and middle size solute removal. CVVHD appears to warrant longer CRRT sessions. The capacity of both modalities for removing such molecules is maintained up to 48 hours.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Effects of dialysate flow configurations in continuous renal replacement therapy on solute removal: computational modeling.

BACKGROUND/AIMS Continuous renal replacement therapy (CRRT) is commonly used for critically ill patients with acute kidney injury. During treatment, a slow dialysate flow rate can be applied to enhance diffusive solute removal. However, due to the lack of the rationale of the dialysate flow configuration (countercurrent or concurrent to blood flow), in clinical practice, the connection settings...

متن کامل

Modalities of continuous renal replacement therapy: technical and clinical considerations.

Continuous renal replacement therapies (CRRT) are continuous forms of renal functional replacement used to manage acute kidney injury (AKI) in the critically ill patient. Depurative mechanisms include convection, diffusion, and membrane adsorption utilizing high-flux highly permeable biocompatible dialysis membranes. The simultaneous infusion of replacement fluid permits fluid removal without i...

متن کامل

A practical citrate anticoagulation continuous venovenous hemodiafiltration protocol for metabolic control and high solute clearance.

Obstacles to the widespread use of continuous renal replacement therapy (CRRT) include the need for anticoagulation, customized solutions, and complex protocols that carry an attendant risk for error, raise cost, and increase pharmacy and nursing workload. However, high solute clearance using CRRT with an effluent rate of 35 ml/kg per h has also recently been associated with improved survival i...

متن کامل

Neutrophil gelatinase-associated lipocalin elimination by renal replacement therapy: minding the membrane!

The recently published data of Donadio in Critical Care provide convincing evidence that neutrophil gelatinaseassociated lipocalin (NGAL), an established key biomarker of acute kidney injury (AKI) in the critically ill, can be effectively removed by renal replacement therapy (RRT) [1]. His findings challenge recent work by Schilder et al. [2] and corroborate our concern regarding the potential ...

متن کامل

Citrate anticoagulation for continuous renal replacement therapy (CRRT) in patients with acute kidney injury admitted to the intensive care unit

Continuous forms of renal replacement therapy (CRRT) have become established as the treatment of choice for supporting critically ill patients with acute kidney injury. Typically, these patients have activation of the coagulation cascades, peripheral mononuclear cells and platelets, but also a reduction in natural anticoagulants, and are therefore prothrombotic. For continuous modes of renal re...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Critical Care

دوره 10  شماره 

صفحات  -

تاریخ انتشار 2006