Continuous Veno-Venous High Cut-Off Hemodialysis Compared to Continuous Veno-Venous Hemodiafiltration in Intensive Care Unit Acute Kidney Injury Patients

AIMS

High cut-off (HCO) continuous veno-venous hemodialysis (CVVHD) was compared to high-flux membrane (HFM) continuous veno-venous hemodiafiltration (CVVHDF) in intensive care unit (ICU) acute kidney injury (AKI) in terms of efficiency, hemodynamic tolerance, medium-sized molecules removal, albumin loss, and inflammatory system activation.

METHODS

In a prospective cross-over randomized study, 10 AKI patients underwent successively HCO (Ultraflux EmiC2: β2-microglobulin [β2M] sieving coefficient [SC]: 0.9) CVVHD and HFM (Ultraflux AV1000S: β2M SC: 0.65) -CVVHDF.

RESULTS

Over the 20 sessions, hypotensive and febrile episodes, reduction rates of urea, creatinine, and β2M were similar in both modalities. Though dialysis dose was higher with CVVHDF (36 ± 4 vs. 21 ± 6 mL/Kg/h), urea, creatinine, and β2M instantaneous and plasmatic clearances did not differ except for urea at 12 h. Protein loss, superoxide anion production, cytokines, and growth factors variations were also comparable.

CONCLUSION

HCO CVVHD is well tolerated and is as effective as HFM CVVHDF in clearance of solutes and removal of β2M. It induces neither protein loss nor overproduction of superoxide anion. Video Journal Club "Cappuccino with Claudio Ronco" at http://www.karger.com/?doi=489082.

Albumin Loss and Citrate Load in Pre-Dilution High Cut-Off-CVVHDF with Regional Citrate (18 mmol/L) and High Cut-Off CVVHD with Systemic Heparin: An in vitro Study

BACKGROUND

Convective therapies with high cut-off membranes (HCO) are usually not recommended because of theoretical excessive albumin loss. The aim of this in vitro study is to demonstrate the noninferior safety of pre-dilution hemodiafiltration with HCO (HCO-CVVHDF) with isotonic citrate anticoagulation (18 mmol/L) with respect to heparin anticoagulated hemodialysis with HCO (HCO-CVVHD) in terms of albumin removal and citrate load.

METHOD

-Albumin removal was compared in vitro between 3 pre--dilution-HCO-CVVHDF with citrate anticoagulation and 3 -HCO-CVVHD with heparin anticoagulation during 30-min single-pass and 180-min recirculation phases.

RESULTS

Considering concentrations and flows in the extracorporeal circuit, the transmembrane albumin removal was 2.06 (1.51; 2.09) g and 2.09 (1.9; 2.8) g respectively for HCO-CVVHDF and HCO-CVVHD, during the single-pass phase; 2.8 (2.67; 4.59) g and 2.54 (2.35; 4.67) g, respectively, for HCO-CVVHDF and HCO-CVVHD during the recirculation phase. Based on the citrate saturation coefficients, a citrate metabolic load of 8.86 mmol/h has been calculated for HCO-CVVHDF.

CONCLUSION

HCO-CVVHDF performed with regional anticoagulation with 18 mmol/L citrate solution does not induce higher -albumin transmembrane removal compared to HCO-CVVHD.

Pharmacokinetics of lenalidomide during high cut-off dialysis in a patient with multiple myeloma and renal failure

INTRODUCTION

High cut-off dialysis, increasingly used in multiple myeloma patients, is susceptible to influence anticancer drug elimination. We report about lenalidomide disposition in a patient on high cut-off dialysis for renal failure secondary to myeloma cast nephropathy.

METHODS

The patient received a higher dosage of lenalidomide (5 mg b.i.d.), owing to concerns about a potential decrease in lenalidomide exposure during dialysis sessions. A set of blood samples was taken in order to develop a pharmacokinetic model accounting for lenalidomide concentrations in this setting.

RESULTS

According to our model, the area under the curve was 3273 µg h/L, i.e., 60% higher than expected under usual dosage (25 mg q.d.) with normal renal function. Despite this, the patient did not develop major hematological toxicity.

CONCLUSIONS

Lenalidomide doses of 5 mg b.i.d. led to high exposure in a patient with renal failure undergoing high cut-off dialysis. Yet, the dosage of 5 mg q.d. recommended in conventional dialysis would probably be adequate in such patients.

High cut-off dialysis in chronic haemodialysis patients

BACKGROUND

Haemodialysis patients suffer from chronic systemic inflammation and high incidence of cardiovascular disease. One cause for this may be the failure of diseased kidneys to eliminate immune mediators. Current haemodialysis treatment achieves insufficient elimination of proteins in the molecular weight range 15-45 kD. Thus, high cut-off dialysis might improve the inflammatory state.

DESIGN

In this randomized crossover trial, 43 haemodialysis patients were treated for 3 weeks with high cut-off or high-flux dialysis. Inflammatory plasma mediators, monocyte subpopulation distribution and leucocyte gene expression were quantified.

RESULTS

High cut-off dialysis supplemented by a low-flux filter did not influence the primary end-point, expression density of CD162 on monocytes. Nevertheless, treatment reduced multiple immune mediators in plasma. Such reduction proved - at least for some markers - to be a sustained effect over the interdialytic interval. Thus, for example, soluble TNF-receptor 1 concentration predialysis was reduced from median 13·3 (IQR 8·9-17·2) to 9·7 (IQR 7·5-13·2) ng/mL with high cut-off while remaining constant with high-flux treatment. The expression profile of multiple proinflammatory genes in leucocytes was significantly dampened. Treatment was well tolerated although albumin losses in high cut-off dialysis would be prohibitive against long-term use.

CONCLUSIONS

The study shows for the first time that a dampening effect of high cut-off dialysis on systemic inflammation is achievable. Earlier studies had failed due to short study duration or insufficient dialysis efficacy. Removal of soluble mediators from the circulation influences cellular activation levels in leucocytes. Continued development of less albumin leaky membranes with similar cytokine elimination is justified.

Linezolid extracorporeal removal during haemodialysis with high cut-off membrane in critically ill patients

Continuous venovenous haemodialysis with high cut-off membrane (HCO-CVVHD) is often used in critically ill septic patients with acute kidney injury (AKI) to sustain renal function and to remove circulating inflammatory mediators. The aim of this study was to analyse the extracorporeal removal of linezolid and related alterations in pharmacokinetic/pharmacodynamic (PK/PD) parameters during HCO-CVVHD. Three critically ill septic patients with AKI, treated with linezolid and HCO-CVVHD, were prospectively observed. To calculate the extracorporeal clearance of linezolid and the PK parameters, effluent, pre-filter and post-filter samples were contemporaneously collected before linezolid infusion, just after 1-h infusion (maximum serum concentration; C(max)), at 3 h and 6 h after dosing, and before the next dose (trough serum concentration; C(min)). Linezolid C(max) and C(min) (pre-filter) ranged from 10.4-23.5 mg/L and from 2.9-10.3 mg/L. The dialysate saturation coefficient was 0.66-0.85 and the extracorporeal clearance with a diffusive dose of 35 m L/kg/h ranged from 2.1-2.5 L/h. Total linezolid clearance was between 1.7 L/h and 6.3 L/h. The total area under the plasma concentration-time curve (AUC0-∞) ranged from 95.1 mgh/L to 352.9 mgh/L, in accordance with the different clinical conditions. AUCfree/MIC ratios were always <85 for an MIC of 4.0 mg/L, and two of three patients did not reach the optimal PK/PD target of ≥85 even when using an MIC of 2.0 mg/L. Although extracorporeal clearance may affect linezolid total clearance, the clinical features of critically ill septic patients appear to be mainly responsible for the high variability of linezolid serum concentrations.