L. Meschini

Dialysis outcome quality initiative (DOQI) guideline for hemodialysis adequacy.

The article about Dialysis Outcome Quality Initiative (DOQI), recently published by the National Kidney Foundation in The American Journal of Kidney Disease provides clear guidelines for adequacy of hemodialysis, peritoneal dialysis, vascular access and treatment of anemia in End-Stage Renal Disease (ESRD). If the dissemination of these guidelines actually increases Kt/V, an early improvement of the outcome of dialysis patients will be expected because there is a close correlation between dialysis dose and mortality. Mortality, unless high, is the main indicator of the efficacy of guidelines in ESRD. Other indicators are needed to assess the effects of the modification in clinical practice induced by DOQI at lower mortality, as in other western European countries. Quality of life adjusted for life expectancy defined Kt/V of 1.3 as the optimal cost-effective dialysis dose; large evidence is missing to support the use of higher doses or of high technology in hemodialysis treatment. Adequacy and uniformity of isolated hemodialysis procedures are accurately defined by DOQI. Quality assessment of integrated actions in overall commitment of ESRD patients (prevention and treatment of co-morbidity of uremia, renal transplantation programs, improvement of the communication with caregivers and family, enhanced fitness and ability to work) has still to be implemented with recommendations and indicators of the outcome. NKF-DOQI defined only dialysis adequacy; further work is necessary to assess the “optimal clinical practice” for ESRD patients.

Cardiac Function and Oxygen Balance in Septic Patients during Continuous Hemofiltration

The aim of this work was to study hemodynamic, oximetric and metabolic parameters in septic patients during continuous hemofiltration, in order to determine whether the changes in hemodynamic parameters can influence the oxygen utilization in peripheral tissues. 29 multiple organ failure patients with septic shock were studied during the first 48 h of continuous hemofiltration: 18 were submitted to CAVH and 11 patients were treated with CAVHD to correct ARF and fluid overload. Our data show that RVEF improves and REDVI reduces progressively during treatment, together with a significant reduction of the cardiac index after 48 h of CAVH(D). There were no significant variations in oxygen tissue parameters, while plasma lactate was reduced significantly. In conclusion, our data confirm that continuous hemofiltration may be useful in septic patients to correct fluid overload and ARF, without affecting hemodynamic stability and oxygen balance. Moreover, in septic patients, this technique improves hemodynamics, reduces the filling pressure in the right heart and reduces hyperdynamic response as CI and SVRI, without any negative effects on O2 balance.

Disappearance of oxidative damage to red blood cell membranes in uremic patients following renal transplant.

Hemodialysis patients display increased oxidative damage to red blood cell (RBC) membranes, characterized by elevated levels of malonyldialdehyde (MDA), a short chain aldehyde produced by the oxidation of the polyunsaturated fatty acids (PUFA) in the RBC membranes. This is the result of a metabolic blockage of the pentose-phosphate shunt in uremic patients, which causes reduced detoxification of highly oxidative free radicals. The oxidative damage induces increased RBC rigidity and decreased RBC deformability, therefore favoring hemolysis. The aim of this work was to determine if a functioning renal graft would restore normal erythrocyte metabolism, reducing the oxidative damage. To this end, we have determined RBC MDA concentrations in 20 hemodialysis (HD) patients (RBC MDA 18.22 +/- 4.36 micrograms/ml packed RBC), 20 renal transplant (T) patients with well functioning grafts (serum creatinine less than 2 mg%) (RBC MDA 1.2 +/- 0.4 micrograms/ml packed RBC) (T vs. HD P less than 0.005) and 20 healthy controls (HC) (RBC MDA 1.44 +/- 0.6 micrograms/ml packed RBC) (HC vs. HD P less than 0.005; HC vs. T NS). Our findings show that a well-functioning renal graft restores normal RBC metabolism and eliminates the oxidative damage induced by uremia.

Administration of GSH has no influence on the RBC membrane: oxidative damage to patients on hemodialysis.

In patients on hemodialysis, a metabolic block of the pentose phosphate shunt has been described that impairs the reduction of oxidized glutathione. The block results in lack of detoxication of the free hydroxyl radicals produced inside the red blood cell (RBC) and causes oxidative damage to the polyunsaturated fatty acids of the RBC membrane that results in formation of aldehydes. Malonyldialdehyde has been used as an index of the oxidative damage. In a study group of 13 patients on hemodialysis, the authors have tested whether administering reduced glutathione (GSH) at 1200 mg/day for 1 month could minimize oxidative damage to the RBC membranes and improve the hematologic parameters. Treatment with GSH was followed by significant improvement of hematocrit (P = 0.008), hemoglobin (P = 0.03), and RBC count (P = 0.0037); however, oxidative damage to the membranes was increased (P = 0.0004), which suggests that improvement of the hematologic parameters is not related to reduction of the oxidative damage. This is because oxidized glutathione, formed in the oxidative process, cannot be reduced back to GSH because of alteration of the pentose phosphate shunt.

Renal Functional Reserve (RFR) in Patients with Short Term Type 1 Diabetes Mellitus (DM1) without Nephropathy

Unlike type 2, type 1 diabetes mellitus is associated with a higher risk of increased Glomerular Filtration rate (GFR) and glomerulopathy. Clinical studies have indicated that GFR increases after a protein load in healthy volunteers (RFR). The aim of the present study was to verify the existence of the RFR in DM1 pts. Our results suggest that well controlled short term DM1 pts show a normal response to protein loading as healthy subjects.