Electrochemical skin conductance by Sudoscan®: a new tool to predict intradialytic hypotension.

BACKGROUND: Intradialytic hypotension (IDH), a common complication in haemodialysis (HD) patients, is associated with multiple risk factors including cardiac dysfunction and alterations of the peripheral autonomic nervous system. To what extent dysautonomia may contribute to the occurrence of IDH remains elusive. We sought to investigate the clinical utility of Sudocan®, a device that quantifies dysautonomia, in the prediction of IDH. METHODS: We conducted a prospective monocentric study in adult HD patients from July 2019 to February 2020. Dysautonomia was assessed by the measurements of hand and foot electrochemical skin conductance (ESC) using Sudocan®, before HD. The primary endpoint was the incidence of IDH (The National Kidney Foundation/Kidney-Dialysis Outcome Quality Initiative definition), according to the presence of a pathological hand and/or foot ESC value, during the 3-month study period. RESULTS: A total of 176 HD patients (64 ± 14 years old) were enrolled. Mean pre-dialysis HD hand and foot ESC was 45 ± 20 and 54 ± 22 µS, respectively. About 35% and 40% of patients had a pathological ESC at the hand and foot, respectively. IDH occurred in 46 patients. Logistic regression showed that pathologic pre-dialysis HD hand ESC was associated with an increased risk of IDH [odds ratio = 2.56, 95% CI (1.04-6.67), P = 0.04]. The cumulative risk incidence of IHD during the study was 5.65 [95% CI (2.04-15.71), P = 0.001] and 3.71 [95% CI (1.41-9.76), P = 0.008], with a pathological hand and foot ESC, respectively. CONCLUSIONS: A pathological hand ESC, as assessed by a non-invasive Sudoscan® test, is associated with an increased risk of IDH.

Feasibility and outcomes of native arteriovenous fistula in octogenarians.

INTRODUCTION: While the native arteriovenous fistula (AVF) is the preferred dialysis access, it is a matter of debate for individuals older than 80 years due to reduced primary patency rates. MATERIALS AND METHODS: We initiated a single-center, observational retrospective analysis of adult dialysis patients from January 2015 to December 2018. We included all patients older than 70 years with a minimum of 12 months of follow-up, beginning from the AVF creation. Patients were separated into two groups, octogenarians (> 80 years old) and controls (70 - 79 years old). The primary end point was the primary patency (the interval from arteriovenous access creation to the first intervention). The secondary end point were the complications at 3 months (failures of puncture, canceled dialysis sessions, local hematoma, AVF bleeding). RESULTS: 29 patients (octogenarian = 17, control = 12) were included in the analysis. The AVF radio-cephalic was the most common vascular access in each group. Primary patency was comparable between groups, but octogenarians required 40% more procedures to obtain or maintain patency. Overall, a functional AVF was obtained for all patients except in cases of complications such as hematomas, which were more frequent in octogenarians compared to controls (25 vs. 82%, p < 0.01). All catheters were removed at 6 months follow-up, with a median time to removal of 27 days (range 5 - 157 days). DISCUSSION: Despite a higher rate of interventions and local complications during the first 3 months, AVF and particularly radio-cephalic AVF, is a valid procedure for octogenarians, without lengthening the exposure time to the catheter.

Mathematical model to predict B-type natriuretic peptide levels in haemodialysis patients.

AIM: Clinical interpretation of B-type natriuretic peptide (BNP) levels in haemodialysis (HD) patients for fluid management remains elusive. METHODS: We conducted a retrospective observational monocentric study. We built a mathematical model to predict BNP levels, using multiple linear regressions. Fifteen clinical/biological characteristics associated with BNP variation were selected. A first cohort of 150 prevalent HD (from September 2015 to March 2016) was used to build several models. The best model proposed was internally validated in an independent cohort of 75 incidents HD (from March 2016 to December 2017). RESULTS: In cohort 1, mean BNP level was 630 ± 717 ng/mL. Cardiac disease (CD - stable coronary artery disease and/or atrial fibrillation) was present in 45% of patients. The final model includes age, systolic blood pressure, albumin, CD, normo-hydrated weight (NHW) and the fluid overload (FO) assessed by bio-impedancemetry. The correlation between the measured and the predicted log-BNP was 0.567 and 0.543 in cohorts 1 and 2, respectively. Age (ß = 3.175e-2 , P < 0.001), CD (ß = 5.243e-1 , P < 0.001) and FO (ß = 1.227e-1 , P < 0.001) contribute most significantly to the BNP level, respectively, but within a certain range. We observed a logistic relationship between BNP and age between 30 and 60 years, after which this relationship was lost. BNP level was inversely correlated with NHW independently of CD. Finally, our model allows us to predict the BNP level according to the FO. CONCLUSION: We developed a mathematical model capable of predicting the BNP level in HD. Our results show the complex contribution of age, CD and FO on BNP level.

Functional erythropoietin-hepcidin axis in recombinant human erythropoietin independent haemodialysis patients.

AIM: Relatively few haemodialysis (HD) patients remain independent of recombinant human erythropoietin ('rHU-EPO free patients'). We investigated the role of EPO and hepcidin, two key hormones involved in anaemia. METHODS: We report a monocentric case-control series. Iron status, EPO and hepcidin levels were analysed in 15 Adult HD (Age > 18 years) with a stable haemoglobin (Hb) level that have not received rHU-EPO for at least 6 months (=rHU-EPO free patients); and in 60 controls with a stable rHU-EPO dose and Hb level. RESULTS: The rHU-EPO free patients had a higher Hb level compared to controls (12.1 ± 0.99 g/dL vs 11.1 ± 0.73, P = 0.0014), and a lower ferritin level (183 ± 102 vs 312 ± 166 ng/mL, P = 0.001). Hepcidin levels were lower in the rHU-EPO free patients (12.53 ± 10.46 ng/mL) compared to the controls (37.95 ± 34.33 ng/mL), P = 0.0033. Hepcidin levels correlated significantly with ferritin levels; but neither with transferrin saturation, C-reactive protein nor EPO levels. Unsupervised analysis revealed that rHU-EPO free patients had a specific clinical/biological profile (presence of renal cyst, longer dialysis vintage, lower ferritin, and EPO and hepcidin levels compared to the control group). Finally, we showed that a lower ferritin level might be a surrogate marker of a lower hepcidin status in this population. CONCLUSION: Recombinant human erythropoietin free patients seem to restore the EPO-hepcidin axis that is critical for erythropoiesis. A specific combination of clinical and biological parameters may help to detect future rHU-EPO free patients.

Neutrophil:lymphocyte ratio predicts short-term outcome of COVID-19 in haemodialysis patients.

BACKGROUND: Information regarding coronavirus disease 2019 (COVID-19) in haemodialysis (HD) patients is limited and early studies suggest a poor outcome. We aimed to identify clinical and biological markers associated with severe forms of COVID-19 in HD patients. METHODS: We conducted a prospective, observational and multicentric study. Sixty-two consecutive adult HD patients with confirmed COVID-19 from four dialysis facilities in Paris, France, from 19 March to 19 May 2020 were included.Blood tests were performed before diagnosis and at Days 7 and 14 after diagnosis. Severe forms of COVID-19 were defined as requiring oxygen therapy, admission in an intensive care unit or death. Cox regression models were used to compute adjusted hazard ratios (aHRs). Kaplan-Meier curves and log-rank tests were used for survival analysis. RESULTS: Twenty-eight patients (45%) displayed severe forms of COVID-19. Compared with non-severe forms, these patients had more fever (93% versus 56%, P < 0.01), cough (71% versus 38%, P = 0.02) and dyspnoea (43% versus 6%, P < 0.01) at diagnosis. At Day 7 post-diagnosis, neutrophil counts, neutrophil:lymphocyte (N:L) ratio, C-reactive protein, ferritin, fibrinogen and lactate dehydrogenase levels were significantly higher in severe COVID-19 patients. Multivariate analysis revealed an N:L ratio >3.7 was the major marker associated with severe forms, with an aHR of 4.28 (95% confidence interval 1.52-12.0; P = 0.006). After a median follow-up time of 48 days (range 27-61), six patients with severe forms died (10%). CONCLUSIONS: HD patients are at increased risk of severe forms of COVID-19. An elevated N:L ratio at Day 7 was highly associated with the severe forms. Assessing the N:L ratio could inform clinicians for early treatment decisions.

A hepcidin-based approach for iron therapy in hemodialysis patients: A pilot study.

INTRODUCTION: Hepcidin is a key factor that regulates iron homeostasis. In hemodialysis patients (HD), a high hepcidin level may decrease intestinal iron absorption and reduce the efficacy of Oral iron vs Intravenous iron therapy. Whether the hepcidin level in HD could guide oral iron therapy is unclear. METHODS: We report a monocentric study on nine "erythropoietin (EPO)-free" patients (without recombinant human EPO [rHU-EPO] for at least 6 months) and normal hepcidin level (<20 ng mL) during the study. After 15 days of washout, oral iron (ferrous sulfate 80 mg/day) was introduced. The primary end point was the hemoglobin response and iron store at 3 months. FINDINGS: Nine patients (8 men, 1 woman) with a median age of 62 years (range 42-79) were included. After 1 week of treatment, the median transferrin saturation index increased from 15% (range 6-61) to 34% (range 13-42), P = 0.62, reflecting intestinal absorption. The median ferritin level remained stable 80 µg/L (35-293) vs 82 µg/L (range 37-496) between M0 and M3, P = 0.43. During the 3-month study, median hemoglobin level increased from 11.5 d/dL (range10.4-13.7) to 12.8 g/dL (range 11.1-15.2), P = 0.01. No major side effects were observed. Quality of life assessed by the SF-36 criteria was similar during the 3-month study. DISCUSSION: Oral iron therapy is effective and safe in EPO-free patients with normal hepcidin levels. These findings suggest that serum hepcidin may be a marker for defining iron therapy strategies in HD patients. HD patients treated with rHU-EPO and with normal hepcidin levels could benefit from oral iron treatment.

Relative Change of Protidemia Level Predicts Intradialytic Hypotension.

Background Hemodialysis patients are at risk of intradialytic hypotension (IDH), which is associated with mortality and cardiovascular and neurological events. The use of biomarkers of volemia such as relative change in protidemia and BNP (B-natriuretic peptide) levels to predict IDH remains unknown. Methods and Results We conducted a prospective observational study, which enrolled 170 chronic hemodialysis patients in a single center from September 2015 to March 2016. BNP and the relative change of protidemia level (Δprotidemia=postdialysis protidemia-predialysis protidemia) were measured monthly over 6 months. A logistic mixed regression model was used to define the best biomarkers that predict the 30-day risk of IDH. Receiver operating characteristic analysis area under the curve was used to define the cutoff values of Δprotidemia that predict IDH A logistic mixed model reveals that Δprotidemia predicts the 30-day risk of IDH but not BNP or age; odds ratio=1.12, 95% CI 1.08-1.17), odds ratio=0.81, 95% CI (0.64; 1.07) and odds ratio =0.015 95% CI (0.99; 1.03), respectively. Adding the ultrafiltration rate did not improve the model. A receiver operating characteristic curve analysis showed that Δprotidemia of 10 g/L allowed for discrimination of the patients with IDH (area under the curve= 0.67; 95% CI 0.62-0.72, P<0.05). There was an increase in area under the curve to 0.71 (95% CI 0.63-0.76) in a subgroup of hemodialysis with BNP <300 ng/L, for a cutoff value of 11 g/L, especially for the nondiabetic patients. Conclusions Relative change in protidemia level (Δprotidemia) outperforms BNP and ultrafiltration rate as a predictor for 30-day risk of IDH. These results should be confirmed by a prospective study.