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.

Novel oral anticoagulants (NOAs) which directly inhibit thrombin (dabigatran) or factor Xa (rivaroxaban and apixaban) have recently been developed. We report the first case of perioperative management of a patient treated with dabigatran requiring haemodialysis before emergency surgery. A 62-yr-old woman visited the emergency department for a left bi-malleolar ankle fracture; she had a past medical history of severe ischaemic cardiomyopathy, alcoholic cirrhosis Child B, and moderate chronic renal insufficiency. The patient was treated with dabigatran for a left ventricular aneurysm with thrombus. Cutaneous manifestation of a voluminous haematoma required emergency surgery. Blood tests revealed dabigatran anticoagulant activity of 123 ng ml(-1) (therapeutic values: 85-200 ng ml(-1)), activated partial thromboplastin time of 63 s, and a prothrombin ratio of 68%, indicating that dabigatran disturbed coagulation. We decided to perform emergency haemodialysis before surgery. After 2 h, the anticoagulant activity of dabigatran was 11 ng ml(-1), allowing surgery. Surgery proceeded without any problems and the postoperative period was unremarkable. This case highlights the difficulties for the anaesthesiologist regarding emergency perioperative management of patients treated with NOAs and confirms the efficacy of haemodialysis in cases of dabigatran treatment. NOAs should be prescribed with caution, especially for patients with renal or hepatic disease, at least as long as no antagonist is available. In cases of deferred operative urgency in haemodynamically stable patients treated with dabigatran, haemodialysis should be considered to reverse dabigatran's anticoagulant effects.

LETTRE À LA RÉDACTION Calciphylaxie chez l'insuffisant rénal dialysé : 8 malades traités par thiosulfate de sodium Calciphylaxis in hemodialysis patients: 8 cases treated with sodium thiosulfate * Auteur correspondant.

11, * and the Club des Jeunes Néphrologues 2Oral alkalization with sodium bicarbonate (NaHCO 3 ) or citrate is prescribed for conditions ranging from metabolic acidosis to nephrolithiasis. Although most nephrologists/urologists use this method routinely, extracellular volume (ECV) increase is the main feared adverse event reported for NaHCO 3 . Thus far, no trial has specifically studied this issue in a real-world setting. AlcalUN (NCT03035812) is a multicentric, prospective, open-label cohort study with nationwide (France) enrollment in 18 (public and private) nephrology/urology units. Participants were adult outpatients requiring chronic (>1 month) oral alkalization by either NaHCO 3 -containing or no-NaHCO 3 -containing agents. The ECV increase (primary outcome) was judged based on body weight increase (ΔBW), blood pressure increase (ΔBP), and/or new-onset edema at the first follow-up visit (V1). From February 2017 to February 2020, 156 patients were enrolled. After a median 106 days of treatment, 91 (72%) patients reached the primary outcome. They had lower systolic (135 (125, 141) vs. 141 (130, 150), P = 0.02) and diastolic (77 (67, 85) vs. 85 (73, 90), P = 0.03) BP values, a higher plasma chloride (106.0 (105.0, 109.0) vs. 105.0 (102.0, 107.0), P = 0.02) at baseline, and a less frequent history of nephrolithiasis (32 vs. 56%, P = 0.02). Patients experienced mainly slight ΔBP (< 10 mmHg). The primary outcome was not associated (P = 0.79) with the study treatment (129 received NaHCO 3 and 27 received citrate). We subsequently developed three different models of propensity score matching; each confirmed our results. Chronic oral alkalization with NaHCO 3 is no longer associated with an ECV increase compared to citrate in real-life settings.

No abstract