The aim of this study was to estimate the incidence of COVID-19 disease in the French national population of dialysis patients, their course of illness and to identify the risk factors associated with mortality. Our study included all patients on dialysis recorded in the French REIN Registry in April 2020. Clinical characteristics at last follow-up and the evolution of COVID-19 illness severity over time were recorded for diagnosed cases (either suspicious clinical symptoms, characteristic signs on the chest scan or a positive reverse transcription polymerase chain reaction) for SARS-CoV-2. A total of 1,621 infected patients were reported on the REIN registry from March 16th, 2020 to May 4th, 2020. Of these, 344 died. The prevalence of COVID-19 patients varied from less than 1% to 10% between regions. The probability of being a case was higher in males, patients with diabetes, those in need of assistance for transfer or treated at a self-care unit. Dialysis at home was associated with a lower probability of being infected as was being a smoker, a former smoker, having an active malignancy, or peripheral vascular disease. Mortality in diagnosed cases (21%) was associated with the same causes as in the general population. Higher age, hypoalbuminemia and the presence of an ischemic heart disease were statistically independently associated with a higher risk of death. Being treated at a selfcare unit was associated with a lower risk. Thus, our study showed a relatively low frequency of COVID-19 among dialysis patients contrary to what might have been assumed.

APD patients assisted at home by a private nurse have a higher risk of developing peritonitis than family-assisted patients, unless additional regular home visits are organized by the original training centre. Therefore, we recommend that home visits be regularly made for dependent PD patients to optimize the quality of care provided by the helper.

This paper summarizes our clinical studies on hydrostatic intraperitoneal pressure (IPP), showing the interest of this measurement in routine clinical practice. IPP can easily be measured routinely by a simple an d safe method: the measure of the column of dialysate in the peritoneal dialysis (PD) line before drainage, with point 0 located on the midaxillary line. The normal value is 12±2 cm of water (cm H2O) with an intraperitoneal volume (IPV) of 2 L, with linear increases of 2.2 cm H2O for each additional liter. IPP must be measured to estimate the tolerance of IPV: the maximal permissible IPV is reached for an IPP of 18 cm H2O, squaring with a decrease of 200/0 in vital capacity and sometimes arising before clinical symptomatology. However, IPP measured at rest could not predict PD mechanical complications (hernias, dialysis leakages, hemorrhoids, etc.), which are more dependent on parietal previous history or predisposition. IPP is significantly higher during the first three days after peritoneal catheter implantation (17±3 cm H2O) than during the 12 following days (10±4 cm H2O). It is recommended to postpone the start of PD until after catheter implantation, and patients should remain supine for the first three days. On the other hand, IPP strongly reduces the overall ultrafiltration (UF) volume: an increase of 1 cm H2O in IPP caused a decrease of 70 mL in global UF after two hours. Therefore, IPP should be measured in diagnosis of losses of UF. However, UF loss during peritonitis is not due to an increase of IPP.

Dialysis patients exhibit an inverse, L- or U-shaped association between blood pressure and mortality risk, in contrast to the linear association in the general population. We prospectively studied 9333 hemodialysis patients in France, aiming to analyze associations between predialysis systolic, diastolic, and pulse pressure with all-cause mortality, cardiovascular mortality, and nonfatal cardiovascular endpoints for a median follow-up of 548 days. Blood pressure components were tested against outcomes in time-varying covariate linear and fractional polynomial Cox models. Changes throughout follow-up were analyzed with a joint model including both the time-varying covariate of sequential blood pressure and its slope over time. A U-shaped association of systolic blood pressure was found with all-cause mortality and of both systolic and diastolic blood pressure with cardiovascular mortality. There was an L-shaped association of diastolic blood pressure with all-cause mortality. The lowest hazard ratio of all-cause mortality was observed for a systolic blood pressure of 165 mm Hg, and of cardiovascular mortality for systolic/diastolic pressures of 157/90 mm Hg, substantially higher than currently recommended values for the general population. The 95% lower confidence interval was approximately 135/70 mm Hg. We found no significant correlation for either systolic, diastolic, or pulse pressure with myocardial infarction or nontraumatic amputations, but there were significant positive associations between systolic and pulse pressure with stroke (per 10-mm Hg increase: hazard ratios 1.15, 95% confidence interval 1.07 and 1.23; and 1.20, 1.11 and 1.31, respectively). Thus, whereas high pre-dialysis blood pressure is associated with stroke risk, low pre-dialysis blood pressure may be both harmful and a proxy for comorbid conditions leading to premature death.

This paper summarizes the basis of prescription for automated peritoneal dialysis (APD) established during a French national conference on APD. Clinical results and literature data show that peritoneal clearances are closely determined by peritoneal permeability and hourly dialysate flow rate, independently of dwell time or number of cycles. With APD, peritoneal creatinine clearance increases according to the hourly dialysate flow rate to a maximum (plateau), then decreases because of the multiplication of the drain-fill times. The hourly dialysate flow giving the maximum peritoneal creatinine clearance is defined as the “maximal effective dialysate flow” (MEDF). MEDF is higher for high peritoneal permeabilities: MEDF is 1.8 and 4.2 L/hr with nocturnal tidal peritoneal dialysis (TPD) for a 4-hr creatinine dialysate-to-plasma ratio (DIP) of 0.50 and 0.80, respectively. With nightly intermittent peritoneal dialysis (NIPD), MEDF is 1.6 and 2.3 Llhr for a DIP of 0.50 and 0.78, respectively. Under these conditions, tidal modalities can only be considered as a way to increase the MEDF. Using the MEDF concept for an identical APD session duration, the maximal weekly normalized peritoneal creatinine clearance can vary by 340% when 4hr DIP varies from 0.41 to 0.78. APD is not recommended when 4-hr creatinine DIP is lower than 0.50. However, the limits of this technique may be reached at higher peritoneal permeabilities in anurics because of the duration of sessions andlor the additional exchanges required by these patients.