Plasma NGAL levels in stable kidney transplant recipients and the risk of allograft loss.

BACKGROUND: The objective of this study was to investigate the utility of neutrophil gelatinase-associated lipocalin (NGAL) and calprotectin (CPT) to predict long-term graft survival in stable kidney transplant recipients (KTR). METHODS: A total of 709 stable outpatient KTR were enrolled >2 months post-transplant. The utility of plasma and urinary NGAL (pNGAL, uNGAL) and plasma and urinary CPT at enrollment to predict death-censored graft loss was evaluated during a 58-month follow-up. RESULTS: Among biomarkers, pNGAL showed the best predictive ability for graft loss and was the only biomarker with an area under the curve (AUC) > 0.7 for graft loss within 5 years. Patients with graft loss within 5 years (n = 49) had a median pNGAL of 304 [interquartile range (IQR) 235-358] versus 182 (IQR 128-246) ng/mL with surviving grafts (P < .001). Time-dependent receiver operating characteristic analyses at 58 months indicated an AUC for pNGAL of 0.795, serum creatinine-based Chronic Kidney Disease Epidemiology Collaboration estimated glomerular filtration rate (eGFR) had an AUC of 0.866. pNGAL added to a model based on conventional risk factors for graft loss with death as competing risk (age, transplant age, presence of donor-specific antibodies, presence of proteinuria, history of delayed graft function) had a strong independent association with graft loss {subdistribution hazard ratio (sHR) for binary log-transformed pNGAL [log2(pNGAL)] 3.4, 95% confidence interval (CI) 2.24-5.15, P < .0001}. This association was substantially attenuated when eGFR was added to the model [sHR for log2(pNGAL) 1.63, 95% CI 0.92-2.88, P = .095]. Category-free net reclassification improvement of a risk model including log2(pNGAL) in addition to conventional risk factors and eGFR was 54.3% (95% CI 9.2%-99.3%) but C-statistic did not improve significantly. CONCLUSIONS: pNGAL was an independent predictor of renal allograft loss in stable KTR from one transplant center but did not show consistent added value when compared with baseline predictors including the conventional marker eGFR. Future studies in larger cohorts are warranted.

CytoSorb Rescue for COVID-19 Patients With Vasoplegic Shock and Multiple Organ Failure: A Prospective, Open-Label, Randomized Controlled Pilot Study.

OBJECTIVES: To investigate the effect of extracorporeal cytokine reduction by CytoSorb (CytoSorbents, Monmouth Junction, NJ) on COVID-19-associated vasoplegic shock. DESIGN: Prospective, randomized controlled pilot study. SETTING: Eight ICUs at three sites of the tertiary-care university hospital Charité-Universitätsmedizin Berlin. PATIENTS: COVID-19 patients with vasoplegic shock requiring norepinephrine greater than 0.2 µg/kg/min, C-reactive protein greater than 100 mg/L, and indication for hemodialysis. INTERVENTIONS: Randomization of 1:1 to receive CytoSorb for 3-7 days or standard therapy. To account for inadvertent removal of antibiotics, patients in the treatment group received an additional dose at each adsorber change. MEASUREMENTS AND MAIN RESULTS: The primary endpoint was time until resolution of vasoplegic shock, estimated by Cox-regression. Secondary endpoints included mortality, interleukin-6 concentrations, and catecholamine requirements. The study was registered in the German Registry of Clinical Trials (DRKS00021447). From November 2020 to March 2021, 50 patients were enrolled. Twenty-three patients were randomized to receive CytoSorb and 26 patients to receive standard of care. One patient randomized to cytokine adsorption was excluded due to withdrawal of informed consent. Resolution of vasoplegic shock was observed in 13 of 23 patients (56.5%) in the CytoSorb and 12 of 26 patients (46.2%) in the control group after a median of 5 days (interquartile range [IQR], 4-5 d) and 4 days (IQR, 3-5 d). The hazard ratio (HR) for the primary endpoint, adjusted for the predefined variables age, gender, extracorporeal membrane oxygenation-therapy, or time from shock onset to study inclusion was HR, 1.23 (95% CI, 0.54-2.79); p = 0.63. The mortality rate was 78% in the CytoSorb and 73% in the control group (unadjusted HR, 1.17 [95% CI, 0.61-2.23]; p = 0.64). The effects on inflammatory markers, catecholamine requirements, and the type and rates of adverse events were similar between the groups. CONCLUSIONS: In severely ill COVID-19 patients, CytoSorb did not improve resolution of vasoplegic shock or predefined secondary endpoints.

Early Postoperative Basal Insulin Therapy versus Standard of Care for the Prevention of Diabetes Mellitus after Kidney Transplantation: A Multicenter Randomized Trial.

BACKGROUND: Post-transplantation diabetes mellitus (PTDM) might be preventable. METHODS: This open-label, multicenter randomized trial compared 133 kidney transplant recipients given intermediate-acting insulin isophane for postoperative afternoon glucose ≥140 mg/dl with 130 patients given short-acting insulin for fasting glucose ≥200 mg/dl (control). The primary end point was PTDM (antidiabetic treatment or oral glucose tolerance test-derived 2 hour glucose ≥200 mg/dl) at month 12 post-transplant. RESULTS: In the intention-to-treat population, PTDM rates at 12 months were 12.2% and 14.7% in treatment versus control groups, respectively (odds ratio [OR], 0.82; 95% confidence interval [95% CI], 0.39 to 1.76) and 13.4% versus 17.4%, respectively, at 24 months (OR, 0.71; 95% CI, 0.34 to 1.49). In the per-protocol population, treatment resulted in reduced odds for PTDM at 12 months (OR, 0.40; 95% CI, 0.16 to 1.01) and 24 months (OR, 0.54; 95% CI, 0.24 to 1.20). After adjustment for polycystic kidney disease, per-protocol ORs for PTDM (treatment versus controls) were 0.21 (95% CI, 0.07 to 0.62) at 12 months and 0.35 (95% CI, 0.14 to 0.87) at 24 months. Significantly more hypoglycemic events (mostly asymptomatic or mildly symptomatic) occurred in the treatment group versus the control group. Within the treatment group, nonadherence to the insulin initiation protocol was associated with significantly higher odds for PTDM at months 12 and 24. CONCLUSIONS: At low overt PTDM incidence, the primary end point in the intention-to-treat population did not differ significantly between treatment and control groups. In the per-protocol analysis, early basal insulin therapy resulted in significantly higher hypoglycemia rates but reduced odds for overt PTDM-a significant reduction after adjustment for baseline differences-suggesting the intervention merits further study.Clinical Trial registration number: NCT03507829.

An improved method to estimate absolute blood volume based on dialysate dilution.

Online hemodiafiltration machines equipped with a blood volume monitor and the possibility to rapidly infuse exact amounts of ultrapure dialysate into the extracorporeal circulation can be used to determine absolute blood volume in clinical practice. The aim of the present study was to evaluate the reproducibility of such measurements. Intra-individual reproducibility was evaluated in four measurements taken in hourly intervals within the same dialysis treatment. Ten patients were studied. Absolute blood volumes measured at the beginning and after 1 hour of dialysis were significantly different (80.6 ± 14.5 and 63.9 ± 14.3 mL/kg, P < .001) and highly reproducible between the last three measurements (63.9 ± 14.3, 61.4 ± 13.8, and 60.9 ± 13.9 mL/kg, P = n.s.). Measurement of absolute blood volume after 1 hour of treatment is more precise than earlier measurements and might be better suited for guidance of ultrafiltration.

Vascular Refilling Is Not Reduced in Dialysis Sessions with Morbid Events.

BACKGROUND: It is commonly believed that insufficient vascular refilling leads to hypovolemia during hemodialysis and contributes to intradialytic morbid events (IME). But data of refilling volumes at the time of IME are lacking. METHODS: We compared the vascular refilling in 10 patients with IME with 14 stable patients with normal blood volume at the dialysis end (66-80 mL/kg). RESULTS: The refilling characteristics in patients with IME did not differ from those in stable patients. The refilling fraction (refilling/ultrafiltration [UF] ratio) was 73.8 ± 9.4% in patients with IME, and 70.2 ± 6.4% in patients with normal blood volume at the end of the treatment. Refilling volume strongly correlated with UF volume in both patient groups (r2 = 0.93 and r2 = 0.81, respectively). CONCLUSION: IME are associated with a specific blood volume below 65 mL/kg. Vascular refilling is a constant fraction of UF in stable as well as in symptomatic dialysis sessions.

Comorbidities, Hospitalization, and Living Status of Dialysis Patients Over 80 Years.

BACKGROUND: An increasing number of patients start dialysis when they are over 80 years or reaches their eighties on dialysis. The burden of dialysis can affect their quality of life. METHODS: Clinical and social data of all patients aged 80 years or older who underwent chronic dialysis treatment in a single center were analyzed. RESULTS: Fifty-nine patients aged between 80 and 92 years were in chronic dialysis treatment on December 31, 2015. Median time on dialysis was 57 months (3-330 months). Hospitalization rate and days in hospital were lower in this group than in younger patients (1.05 vs. 1.34 hospitalizations; 8.3 vs. 9.0 hospital days per patient and year) despite the presence of many comorbidities. The median patency of the currently used arteriovenous shunt was 70 months (6-194 months). Social status was comparable with the population of the rest of the same average age range. CONCLUSION: Dialysis patients aged ≥80 years have a satisfactory quality of life with no more complications than younger patients.

Relative Blood Volume Monitoring during Renal Replacement Therapy in Critically Ill Patients with Septic Shock: A Preliminary Report.

BACKGROUND: Volume management during renal replacement therapy (RRT) in septic shock is always in the conflict between aggravating hypovolemia by undue ultrafiltration (UF) and insufficient reduction of fluid overload which is associated with adverse outcome. Relative blood volume (RBV) monitoring could be helpful for timely transition from fluid resuscitation to fluid removal. METHODS: Data of RBV were continuously monitored and used for guidance of UF and fluid resuscitation in 21 consecutive patients with severe septic multiple organ failure. RRT was applied with extended daily hemodiafiltration for median 11 h (range 6-23). Changes in RBV were analyzed during the first 4 treatment sessions. RESULTS: During 26 treatments, RBV monitoring revealed an internal volume loss substituted by a median infusion volume of 2.38 l (maximum 8.07 l) per treatment to keep the RBV constant. In the remaining 40 sessions, a median net-UF of 1.00 l (range 0.40-4.40) was achieved. In the first 2 days predominantly substitution was necessary whereas from the third day UF became increasingly possible. The 28-day survival rate was 81%. CONCLUSION: Blood volume monitoring proved to be an easy and feasible tool for safe guidance of fluid management maintaining the balance between UF and vascular refilling. Video Journal Club 'Cappuccino with Claudio Ronco' at http://www.karger.com/?doi=433415

A simple and feasible method to determine absolute blood volume in hemodialysis patients in clinical practice.

BACKGROUND: We developed a simple method to determine the absolute blood volume (V) during hemodialysis in everyday clinical practice and examined its relationship with volume overload, clinical relevance, and accuracy. METHODS: The increase in relative blood volume (RBVpost - RBVpre) measured before and after infusion of 240 ml of ultra-pure dialysate using the bolus function of a commercial online hemodiafiltration machine incorporating a relative blood volume monitor was applied to determine absolute blood volume. The specific blood volume (Vs, blood volume per kg body mass at dry weight, in ml/kg) was compared to volume status as assessed by bioimpedance analysis and clinical criteria. RESULTS: The blood volume measured in 30 stable hemodialysis patients was 6.51 ± 1.70 l at the beginning, corresponding to a specific blood volume of 80.1 ± 12.8 ml/kg, and dropped to 5.84 ± 1.61 l or 72.0 ± 12.1 ml/kg at the end of the dialysis session, respectively. Specific blood volume correlated with volume status assessed both clinically and by bioimpedance analysis. Intradialytic morbid events occurred only in treatments where specific blood volume fell below 65 ml/kg. The reproducibility of the technique was better than 4% and the in vitro accuracy corresponds to a resolution in Vs of better than 1 ml/kg. CONCLUSION: Absolute blood volume can be easily measured at the beginning of the dialysis session using the current dialysis technology. Information about V and Vs could be a promising tool to avoid intradialytic morbid events. This technique could be completely automated without altering the hardware of currently available online dialysis devices. Therefore, it is recommended that this technique be integrated into all hemodiafiltration machines.

Vascular refilling depends on the ratio of blood volume to extracellular volume in hemodialysis patients.

The ratio of blood volume to extracellular volume is approximately one to three under physiological conditions and also in stable chronic hemodialysis patients. Recently, it was found that this ratio remains unchanged during hemodialysis despite ultrafiltration. This would signify that the higher the ratio, the lower the refilling and vice versa. To test this hypothesis, treatment data of a previous study were re-analyzed. In 79 stable chronic hemodialysis patients, the refilling fraction was 0.749 ± 0.094. There was a significant negative correlation (r = -0.412; p < 0.001) between the blood volume to extracellular volume ratio and the refilling fraction. The blood volume to extracellular volume relationship seems to be a significant determinant of vascular refilling: the higher the ratio, the lower the refilling, and vice versa.

Extended daily on-line high-volume haemodiafiltration in septic multiple organ failure: a well-tolerated and feasible procedure.

BACKGROUND: The outcome of patients with septic multiple organ failure (MOF) remains poor. There are experimental and clinical data indicating a beneficial effect of high-volume haemofiltration. Delivering high-volume therapy is only cost effective using on-line devices because of high costs for additional solution bags in conventional continuous renal replacement therapy (CRRT). We investigated feasibility and effectiveness of extended daily on-line high-volume haemodiafiltration (HDF) with technically maximum convective volume in patients with septic MOF in a pilot study. METHODS: We included 21 consecutive critically ill patients with septic MOF having a mortality risk >50% (SAPS II >50, APACHE II >25). Renal replacement therapy (RRT) was applied with extended daily HDF for 6-23 h using the AK 200 Ultra S dialysis machine in the ultracontrol pre-dilution mode. Dialysate and substitution fluid were prepared on-line. Patients underwent 289 treatments. RESULTS: The mean convective volume was 17.8 ± 3.7 L/h and 208 ± 66 mL/kg/h, respectively, median treatment time was 10:15 h/day. Seventeen of 21 patients survived 28 days (81%). The 90-day survival rate was 52% (11/21) versus 19% compared to the survival rate predicted by APACHE II (33.6 mean) and SAPS II (68.6 mean) scores. Haemodynamics improved significantly during the treatment procedures. Material costs per treatment amounted to 35 €. CONCLUSIONS: Extended daily on-line HDF using maximum convective volume seems to improve the outcome of septic MOF, especially in the early phase. The investigated mode of treatment proved to be feasible, well tolerated and highly cost effective compared to conventional CRRT. At present, this procedure would be applicable at every ICU facility with nephrological support.

Dynamics of vascular refilling in extended nocturnal hemodialysis.

INTRODUCTION: Long dialysis treatments are generally assumed to mitigate the ultrafiltration (UF) induced volume perturbation and to improve vascular refilling because of reduced UF rates and sufficient time for volume re-equilibration. The time course of vascular refilling was therefore examined during extended nocturnal dialysis. METHODS: For each hour of dialysis, vascular refilling volume was calculated from the absolute blood volume changes and UF volume removed. Absolute blood volume was estimated by indicator dilution at the beginning of dialysis and then tracked with a relative blood volume monitor. The refilling fraction was defined as the ratio of refilling volume to UF volume. FINDINGS: Ten stable chronic hemodialysis (HD) patients were studied during extended (7 h) nocturnal treatment sessions. Specific UF rate was 4.8 ± 1.8 ml/kg/h. In the 1 h, refilling volume amounted to only 23% of UF volume. Thereafter, refilling fraction steeply increased and reached maximum values in the 2, 3 and 4 h at about mean 90% (91.5%, 88.7%, and 91.1% respectively). From the 5 h on, refilling volume decreased (5 h 81.3%, 6 h 72.5%, 7 h 70.0% of UF volume). Cumulative refilling reached 73.6% of UF volume after 4 h of treatment time. This did not change during the further course of HD. Cumulative refilling volume showed a strong correlation (r = 0.94; p < 0.001) with UF volume. The ratio of blood volume to extracellular volume (Rbex ) was 0.306 ± 0.029 before and slightly but significantly increased to 0.326 ± 0.030 after UF. DISCUSSION: In spite of low-UF rates and extended treatment times, overall refilling fraction reached only 74% and was not different from the refilling fraction observed in regular HD. This value seems to represent a point where UF-induced volume perturbation is adequately compensated by physiologic control mechanisms.

Inosine 5'-Monophosphate Dehydrogenase Activity for the Longitudinal Monitoring of Mycophenolic Acid Treatment in Kidney Allograft Recipients.

BACKGROUND: Mycophenolic acid (MPA) is a standard immunosuppressant in organ transplantation. A simple monitoring biomarker for MPA treatment has not been established so far. Here, we describe inosine 5'-monophosphate dehydrogenase (IMPDH) monitoring in erythrocytes and its application to kidney allograft recipients. METHODS: IMPDH activity measurements were performed using a high-performance liquid chromatography assay. Based on 4203 IMPDH measurements from 1021 patients, we retrospectively explored the dynamics early after treatment start. In addition, we analyzed the influence of clinically relevant variables on IMPDH activity in a multivariate model using data from 711 stable patients. Associations between IMPDH activity and clinical events were evaluated in hospitalized patients. RESULTS: We found that IMPDH activity reflects MPA exposure after 8 weeks of constant dosing. In addition to dosage, body mass index, renal function, and coimmunosuppression affected IMPDH activity. Significantly lower IMPDH activities were found in patients with biopsy-proven acute rejection as compared to patients without rejection (median [interquartile range]: 696 [358-1484] versus 1265 [867-1618] pmol xanthosine-5'-monophosphate/h/mg hemoglobin, P < 0.001). The highest IMPDH activities were observed in hospitalized patients with clinically evident MPA toxicity as compared to patients with hospitalization not related to MPA treatment (1548 [1021-2270] versus 1072 [707-1439] pmol xanthosine-5'-monophosphate/h/mg hemoglobin; P < 0.001). Receiver operating characteristic curve analyses underlined the usefulness of IMPDH to predict rejection episodes (area, 0.662; confidence interval, 0.584-0.740; P < 0.001) and MPA-associated adverse events (area, 0.632; confidence interval, 0.581-0.683; P < 0.001), respectively. CONCLUSIONS: IMPDH measurement in erythrocytes is a novel and useful strategy for the longitudinal monitoring of MPA treatment.

Feedback control of absolute blood volume: A new technical approach in hemodialysis.

INTRODUCTION: The success of automatic feedback control systems to improve hemodynamic stability by preventing relative blood volume from dropping beyond a critical value during dialysis is limited. The aim of this study was to use one of these systems for control of absolute rather than relative blood volume to prevent volume-dependent morbid events. METHODS: Dialysis was delivered by a machine providing feedback control of ultrafiltration rates, relative blood volume monitoring, and accurate bolus infusion of 240 mL of dialysate to measure absolute blood volume at the beginning of dialysis. Critical relative blood volume required by the control algorithm was calculated from absolute blood volume at the beginning and a critical absolute blood volume of 67 mL/kg. FINDINGS: In 40 stable patients, ultrafiltration was guided by blood volume using the feedback algorithm of the integrated program. Blood volume was maintained in a narrow range above the prespecified minimal value of 67 mL/kg. At the end of dialysis, absolute blood volume ranged from 67.5 to 72.5 mL/kg (69.4 ± 1.3 mL/kg). No volume-dependent intradialytic morbid event occurred. DISCUSSION: A feedback control system for relative blood volume-controlled ultrafiltration can be used for control of absolute blood volume. A prescribed target of absolute blood volume can be converted into relative blood volume, and this can subsequently be reached automatically with the integrated feedback system of the dialysis machine. Intradialytic morbid events could be considerably reduced. The whole procedure could be completely automated without altering the hardware of the dialysis device.

Adjustment of target weight based on absolute blood volume reduces the frequency of intradialytic morbid events.

INTRODUCTION: Adequate volume management removing excess volume and at the same time avoiding intradialytic morbid events (IME) remains a core problem in current hemodialysis (HD) therapy. Recently, we developed a feasible method to determine absolute blood volume (Vs, in mL/kg) in patients on HD. The aim of this study was to investigate the suitability of Vs measurements for volume management. METHODS: Following a 4 week baseline phase to quantify the frequency of IME, volume status was determined in a single specified HD session during which Vs was measured using dialysate dilution, volume overload (Vo, L) was measured using bioimpedance spectroscopy, and the occurrence of IME was recorded. Target weight was then adjusted and the frequency of IME was recorded during 4 weeks of follow-up. FINDINGS: Forty-five patients participated in this study. Twenty-two (49%) patients experienced 66 IME in 12% of HD treatments during baseline. In 15 (33%) patients who experienced IME during volume assessment both Vs (60.7 ± 4.0 vs. 73.7 ± 11.3 mL/kg, P < 0.001) and Vo (1.1 ± 0.9 vs. 2.5 ± 1.8 L, P < 0.01) were significantly lower than in stable patients, respectively. The sensitivity, specificity, and accuracy of the ≤65 mL/kg Vs threshold to predict IME was 87%, 100%, and 91%, respectively. Target weight was increased (+1.5 kg) or decreased (-5 kg) in 32 patients. The frequency of IME fell to 0.9% of all HD sessions in the following 4 weeks (P < 0.001). DISCUSSION: Adjustment of target weight based on information of Vs, Vo, and IME appears as a feasible approach to reduce the frequency of IME.

Vascular refilling is independent of volume overload in hemodialysis with moderate ultrafiltration requirements.

Introduction Blood volume changes and vascular refilling during hemodialysis (HD) and ultrafiltration (UF) have been assumed to depend on volume overload (Vo ). It was the aim to study the magnitude of vascular refilling in stable HD patients with moderate volume expansion in everyday dialysis using novel technical approaches. Methods Patients were studied during routine dialysis and UF based on clinical dry weight assessment. Pre-dialysis Vo was independently measured by bioimpedance spectroscopy. Vascular refilling volume (Vref ) was calculated as: Vref = Vuf - ΔV, where ΔV is the absolute blood volume change determined by on-line dialysate dilution using a commercial on-line hemodiafiltration machine incorporating a relative blood volume monitor, and where Vuf is the prescribed UF volume. Findings Thirty patients (dry weight: 81.0 ± 17.8 kg) were studied. Pre-dialysis Vo was 2.46 ± 1.45 L. Vuf was 2.27 ± 0.71 L, specific UF rate was 6.45 ± 2.43 mL/kg/h, and since ΔV was 0.66 ± 0.31 L, Vref was determined as 1.61 ± 0.58 L, corresponding to a constant refilling fraction (Fref ) of 70.6 ± 10.6%. Vref strongly correlated with Vuf (r(2) = 0.82) but was independent of Vo and other volumes. Fref was also independent of Vo and other volumes normalized for various measures of body size. Discussion While vascular refilling and Fref is independent of Vo in treatments with moderate UF requirements, intravascular volume depletion increases with increasing UF requirements. The relationship between blood volume and Vo needs to be more closely examined in further studies to optimize volume control in everyday dialysis.

Determination of the critical absolute blood volume for intradialytic morbid events.

The reduction of blood volume below a critical threshold is assumed to trigger intradialytic morbid events (IME). Recently, we presented a simple method to determine the absolute blood volume during routine hemodialysis (HD) carried out without blood sampling and without injection of dyes or radiolabeled markers. Such information could be used to detect excessive volume reduction during HD and to prevent IME. Therefore, we performed a pilot study in IME-prone patients to identify the absolute blood volume at which they developed clinical symptoms. A volume of 240 mL of ultrapure dialysate was automatically infused into the extracorporeal circulation using the bolus function of a commercial online hemodiafiltration machine incorporating a blood volume monitor (BVM). The increase in relative blood volume (RBV) caused by the infusion was measured and used to determine the absolute blood volume at that time. The blood volume per kilogram body mass at the time of symptomatic IME was also determined. All IME-prone patients of a single-dialysis center were included in the study. Ten out of 12 patients became symptomatic at a specific blood volume between 65 and 56 mL/kg (mean 62 mL/kg) whereas RBV showed a wide scatter (82-97%). A specific blood volume of 65 mL/kg seems to represent the threshold for IME by this method. The technique could be completely automated without altering the hardware of the dialysis device. Present feedback systems for automated blood volume-controlled ultrafiltration could be adapted to maintain absolute blood volume above this critical volume to safely prevent volume-dependent IME.

Effects of Osmotic Changes on Measuring Relative Blood Volume: Comparison of Three Hemodialysis Devices.

Recording the relative blood volume is a standard feature of modern dialysis devices. Three different measurement systems are incorporated in currently available dialysis machines. The Gambro-Hospal group and Nikkiso feature blood volume monitors based on different optical methods. The Fresenius Medical Care machines perform blood volume monitoring with an ultrasonic method. On grounds of clinical evidence suggesting a malfunction of the optical methods in the presence of sodium changes, we compared these three systems. Under the tested conditions, both optical systems show opposite and nonplausible courses of blood volume changes. The ultrasonic system seems to be less susceptible to osmotic changes.

Hemodialysis in patients over 80 years.

BACKGROUND: In Germany, every fifth patient starting dialysis is now 80 years of age or older. The question that is currently relevant is not whether we have to treat patients who are older than 80. Rather the question now is how to treat this elderly group of patients. METHODS: Single centre data of all dialysis patients aged over 80 were analyzed with regard to survival, social circumstances, vascular access, and pre-dialysis nephrology care. RESULTS: Between 2001 and 2012, 76 patients over 80 years started chronic ambulatory hemodialysis treatment. One-year survival was 87%, 3-year survival 52%, 5-year survival 27% and 10-year survival 9%. Patients (n = 55) with more than 3 months of nephrological care prior to dialysis (3-161 months, median 31 months) survived significantly longer then patients (n = 21) having had less than 3 months contact with nephrologists. On 31st December 2012 there were 38 patients aged ≥80 (median age 84, 80-95 years) in the chronic hemodialysis program accounting for 19% of all dialysis patients of this center. Thirty patients (79%) had been in long-term nephrological care prior to dialysis initiation (3-161 months, median 45 months). Thirty one patients (82%) started the first dialysis treatment with a functioning shunt access. CONCLUSION: Long-term pre-dialysis nephrology care is of most importance for successful dialysis treatment in the elderly, especially in octogenarians and nonagenarians. It enables the early establishment of functioning vascular access and careful scheduling of first dialysis treatment and increases survival. The long-term use of catheters can be avoided in almost all patients above the age of 80. © 2015 S. Karger AG, Basel.

Effects of sodium on measuring relative blood volume during hemodialysis differ by techniques.

Recording the relative blood volume is a standard feature of modern dialysis devices, enabling feedback guidance of ultrafiltration and dialysate conductivity. Technically, the process is based on optical or ultrasonic methods. On the grounds of clinical evidence suggesting a malfunction of the optical hemoglobin (Hb)-dependent absorbance method in the presence of sodium changes, we compared the system with the ultrasonic method. Six patients underwent hemodialysis with a step sodium profile (140, 150, 130, and 140 mmol/L, hourly switch), with two dialysis devices featuring the optical and the ultrasonic blood volume detector, respectively. The ultrasonic system recorded a decreasing blood volume throughout the treatment. With the optical method, changes in dialysate sodium led to inverse deviations of the blood volume curve. In another treatment without profile administering, a bolus of hypertonic sodium led to the detection of a rapid 8.7% reduction in blood volume with the optical method, which was not observed with the ultrasonic device. Blood volume monitors using the optical absorbance device are influenced by osmotic changes. An increase in osmolality produces a paradox drop in the measured blood volume and vice versa rendering the monitor inappropriate for use in sodium profiling.