Efficacy of dialysis in peritoneal dialysis: utility of bioimpedance to calculate Kt/V and the search for a target Kt.

BACKGROUND: To calculate Kt/V, volume (V) is usually obtained by Watson formula, but bioimpedance spectroscopy (BIS) is a simple and applicable technique to determinate V, along with other hydration and nutrition parameters, in peritoneal dialysis (PD) patients. Dialysis efficacy can also be measured with Kt, but no experience exists in PD, so there is no reference/target value for Kt that must be achieved in these patients to be considered adequately dialyzed. We evaluated the efficacy of PD with Kt/V using Watson formula and BIS for V calculation, assessed hydration status in a PD unit by data obtained by BIS, and attempted to find a reference Kt from the Kt/V previously obtained by BIS. METHODS: In this observational prospective study of 78 PD patients, we measured V using BIS (V bis) and Watson formula (V w) and calculated weekly Kt/V using both volumes (Kt/V bis/V bis and Kt/V w). With the BIS technique, we obtained and subsequently analyzed other hydration status parameters. We achieved a reference Kt, extrapolating the value desired (weekly Kt/V 1.7) to the target Kt using the simple linear regression statistical technique, basing it on the results of the previously calculated Pearson's linear correlation coefficient. RESULTS: Volume was 1.8 l higher by Watson formula than with BIS (p < 0.001). Weekly Kt/V bis was 2.33 ± 0.68, and mean weekly Kt/V w was 2.20 ± 0.63 (p < 0.0001); 60.25 % of patients presented overhydration according to the BIS study (OH >1.1 l). The target value of Kt for the reference weekly Kt/V bis (1.7) was 64.87 l. CONCLUSIONS: BIS is a simple, applicable technique for calculating V in dialysis that can be especially useful in PD patients compared with the anthropometric formulas, by the abnormally distributed body water in these patients. Other parameters obtained by BIS will serve to assess both the distribution of body volume and nutritional status in the clinical setting. The target Kt value obtained from Kt/V bis allowed us to measure the efficacy of PD in a practical way, omitting V measurement.

Concordance between glomerular filtration rate estimation equations and 4-hour urinary creatinine clearance in critically ill patients with severe trauma.

BACKGROUND AND OBJECTIVE: There is a growing body of evidence that the equations used to estimate the glomerular filtration rate (GFR) are not suitable in critically ill patients, a population whose GFR fluctuates continuously. Glomerular filtration is usually estimated by measuring urine creatinine clearance (CrCl) at various time points. The aim of our study was to evaluate the performance of the most widely used GFR calculators in the subpopulation of critically ill patients admitted for severe trauma, and to compare the results against determinations of CrCl in urine collected over a 4-h period (4h-CrCl). MATERIAL AND METHODS: Observational study in patients hospitalized for severe trauma. We measured the 4h-CrCl and estimated GFR using the Cockcroft-Gault, modified Jelliffe, MDRD, t-MDRD, and CKD-EPI equations, adjusting the results for body surface area (BSA) (ml/min/1.73m2). Data were analysed using R version 4.0.4. RESULTS: A total of 85 patients were included. Median age was 51 years, and 68 were men (78.82%). The mean BSA-adjusted 4h-CrCl (4h-ClCr/1.73m2) was 84.5 ml/min/1.73m2. We found that GFR estimated using the t-MDRD equation correlated significantly with 4h-CrCl/1.73m2. The Cockcroft-Gault equation correlated significantly with 4h-CrCl/1.73m2 when GFR was greater than 130ml/min/m2. CONCLUSIONS: In ICU patients, glomerular filtration can be reliably estimated by determining urine CrCl, but GFR calculators are not accurate in this population.

[Short cold ischaemia time optimises transplant results for kidneys from expanded criteria donors]. / El tiempo de isquemia fría corto optimiza los resultados de los trasplantes renales efectuados con donantes con criterios expandidos.

INTRODUCTION: Outcome of renal transplant from expanded criteria donors (ECD) is usually inferior than those from standard criteria donors (SCD) and may be improved decreasing cold ischemia time (CIT) and minimizing preservation injury. We compare the results obtained with CIT <15 hours in kidney transplants from ECD vs SCD. SUBJECTS AND METHODS: Prospective, single center study of kidney transplants performed since June 2003 to December 2007. Minimum follow-up period was 12 months. Data of donors, receptors and transplant outcome from ECD and SCD are compared. RESULTS: CIT (mean +/- SD) was 9.3+/-2.5 hours in transplants from ECD (n=24) and 8.3+/-3.3 hours in those from SCD (N=50), p=0.18. We did not find significant differences among recipients of grafts from ECD and those from SCD regarding: primary non-function (4.2% vs 2%, respectively), delayed graft function (16.7% vs 10%), surgical complications (25% vs 16%) or acute rejection episodes (8.3% vs 2%). Glomerular filtration rate at one year follow-up was 65.8+/-14.9 ml/min in ECD recipients and 49.4+/-12.5 ml/min (p<0.0001). One year graft survival was 95.8% in ECD recipients and 94% in SCD recipients (p=0.75). CONCLUSIONS: Short CIT in kidney transplant from ECD leads to similar outcome than that obtained from SCD, although renal function is inferior in ECD grafts.

Analysis of Kidney Donation and Its Relationship With Graft Failure of the Recipient at 1 Year.

INTRODUCTION: Currently, the shortage of organs available for kidney transplantation and a change in donors' and recipients' profiles (elderly, with cardiovascular risk, donors after cardiac death), it is becoming necessary to assess grafts from expanded-criteria donors (ECD) in order to have methods that allow us to predict viability and graft survival. OBJECTIVE: The aim of this study was to analyze the different methods of renal donor assessment (estimated glomerular filtration rate [eGFR], preimplantation biopsy, and Kidney Donor Profile Index [KDPI] score) as predictors of graft survival and renal function of our recipient at 1 year. METHODS: We performed a descriptive and retrospective study of 183 deceased donor kidney transplantations performed at our center between 2011 and 2015. We calculated the KDPI scores, donor eGFR was estimated using the Chronic Kidney Disease Epidemiology Collaboration Formula equation, and biopsies were evaluated using Banff classification. RESULTS: ECDs comprised 59.60%, 93% of donors had an eGFR ≥ 60 mL/min/1.73 m2, and 41% presented with a KDPI score ≥ 90%. The most frequent range in the biopsy score was 0-3. The 1-year graft survival rate was 86.90%. Factors that negatively influenced graft survival were donor/recipient age, ECD, KDPI, and cold ischemia time (CIT). CONCLUSION: Prolonged CIT and KDPI ≥ 90% were donor variables that were related to graft failure at 1 year in our center.

Conversion to tacrolimus extended-release formulation: short-term clinical results.

OBJECTIVE: To determine the short-term clinical results of conversion of treatment from tacrolimus twice daily (BID TAC) to the extended-release formulation (OD TAC), milligram for milligram, and whether such conversion is safe in stable kidney transplant recipients. PATIENTS AND METHODS: The study included 38 kidney transplant recipients (median [SD] age, 54.3 [14.4] years) with stable renal function (mean [SD] serum creatinine concentration 1.29 [0.38] mg/dL). Posttransplantation follow-up was 3.4 (3.1) years (range, 4-168 months). All patients had been receiving BID TAC (2.45 [1.52] mg/d) when treatment was converted to OD TAC, milligram for milligram. Follow-up including clinical evaluation and laboratory tests was at 7, 21, and 90 days postconversion. RESULTS: No significant differences were observed during follow-up in serum creatinine concentration, blood glucose level, hemoglobin level, or proteinuria. There were no episodes of acute rejection. No de novo posttransplantation diabetes mellitus was diagnosed; patients with diabetes required similar dosage of hypoglycemia treatment. Arterial pressure remained stable without changes in antihypertension treatment. Tacrolimus doses were not modified (2.45 [1.52] mg/d at baseline vs 2.45 [1.67] mg/d at 3 months postconversion; however, tacrolimus concentration decreased significantly (7.6 [1.8] ng/mL at baseline vs 6.42 [1.13] ng/mL at 3 months postconversion. Reduction in tacrolimus concentration was more remarkable in patients receiving a dose of less than 0.025 mg/kg/d. CONCLUSIONS: Conversion from BID TAC to OD TAC, milligram for milligram, is clinically safe; however, monitoring of tacrolimus concentration in patients receiving low dosage is mandatory to prevent subtherapeutic levels.