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European SARS-CoV-2 pandemic epicenter was detected in Northern Italy, in a little Italian town of Lodi province, the Lodi Hospital was therefore rapidly saturated, and in particularly the departments of respiratory diseases and Intensive Care Unit had been largely involved. In this paper, we describe how the first Sub-intensive Respiratory Unit in Europe completely dedicated to COVID-19 patients was organized and managed in our hospital. From February 25th to April 30th 2020, 156 patients were admitted to our Respiratory Sub-intensive Unit. Among them, 100 were discharged, 28 dead and 28 transferred to ICU for intubation.

Lower limb ischemia affects the quality of life, physical activity and life expectancy of dialysis patients. The aim of this study was to investigate the risk factors associated with ischemic foot ulcers considering clinical, laboratory and therapeutic domains. This observational cohort study was based on data from the Nephrology and Dialysis Department database of Alessandro Manzoni Hospital, Lecco (Italy). All of the incident patients who started dialysis between 1 January 1999 and 29 February 2012 were enrolled, excluding temporary guests, patients with acute renal failure and patients with previous limb ischemia or amputation. Multivariate Cox regression analysis identified the predictors in each domain, which were matched in the final model. A time-dependent approach was used to take into account the evolution of some of the prognostic covariates. Of the 526 incident dialysis patients, 120 developed a lower limb ischemic lesion after a median of 13 months. The incidence of new ulcers was constant during the study period (6 per 100 person-years), but higher in the diabetics with a relative rate of 4.5. The variables significantly related to an increased risk of lower limb ulcers were age, male gender, diabetes, ischemic heart disease, treatment with proton pump inhibitors, iron, anticoagulants and calcium-based binders, and blood levels of phosphorus, triglycerides and C-reactive protein. The incidence of lower limb ulcers was highest during the early dialysis follow-up and was associated with, in addition to diabetes, modifiable laboratory and therapeutic predictors such as anticoagulants, proton pump inhibitors, calcium-containing binders, calcimimetics and iron.

Ultrafiltration (UF) failure is one of the most important causes of long-term peritoneal dialysis (PD) failure in patients. Osmotic forces acting across small and ultra-small pores generate a UF with solutes through the small pore and free water transport (FWT) through the ultra-small pore. The ability of glucose to exert an osmotic pressure sufficient to cause UF is the so-called 'osmotic conductance to glucose' (OCG) of the peritoneal membrane. Our study proposes a simple method to determine both the OCG and FWT. In 50 patients on PD, a Double Mini-Peritoneal Equilibration Test (Double Mini-PET), consisting of two Mini-PET, was performed consecutively. A solution of 1.36% glucose was used for the first test, whereas a solution of 3.86% glucose was used for the second test. The sodium removal values and the differences in UF between the two tests were used to calculate FWT and the OCG. Patients with UF failure showed significant reductions not only in the OCG and the FWT but also of UF of small pores. The Double Mini-PET is simple, fast, and could become useful to evaluate patients on PD in everyday clinical practice.

Mini-peritoneal equilibration test: A simple and fast method to assess free water and small solute transport across the peritoneal membrane. Background Loss of ultrafiltration (UF) of peritoneal membrane is one of the most important causes of peritoneal dialysis failure. UF is determined by osmotic forces acting mainly across small pores (UFSP) and ultrasmall pores or free water transport. At present, only semiquantitative estimates or complicated computer simulations are available to assess free water transport. The aim of this study was to assess free water transport during a 3.86% peritoneal equilibration test lasting 1 hour. In this condition, sodium transport is mainly due to convection, allowing the estimate of ultrafiltration of small pores and then of free water transport (total UF - UFSP). Methods In 52 peritoneal dialysis patients we performed a 3.86% peritoneal equilibration test (4 hours) and a 3.86% mini-peritoneal equilibration test (1 hour) and compared UF and small solute transports obtained with the two methods. Results During the 3.86% mini-peritoneal equilibration test, UFSP and free water transport were 279 ± 142mL and 215 ± 86mL , respectively; free water transport well correlated to total UF during the 3.86% peritoneal equilibration test ( r = 0.67). The groups of peritoneal transporters, categorized according to glucose dialysate ratio (D/D 0 ) and to creatinine/plasma ratio (D/P Creat ), were in good agreement for the two peritoneal equilibration tests (weighted κ 0.62 and 0.61, respectively). Conclusion The 3.86% mini-peritoneal equilibration test is a simple and fast method to assess free water transport. It also gives information about total UF and small solute transports and it is in good agreement with the 3.86% peritoneal equilibration test.

How to determine ionic dialysance for the online assessment of delivered dialysis dose.BackgroundIonic dialysance may be equivalent to blood-water urea clearance corrected for recirculation (effective urea clearance); however, this is controversial. The aims of our study were (1) to verify in vivo whether the value of ionic dialysance is affected by the method of determination, given the effect of cardiopulmonary recirculation on inlet plasma water conductivity when the inlet dialysate conductivity is changed; and (2) to define the operative modalities for determining ionic dialysance to obtain an adequate estimate of effective urea clearance.MethodsThirty-three hemodialysis patients were studied during 186 dialysis sessions with low-flux polysulfone dialyzers using a modified Fresenius Medical Care 4008B machine equipped with meters to measure inlet and outlet dialysate conductivities. This machine varied inlet dialysate conductivity (Cdi) according to the following pattern: starting from baseline (step 0), Cdi was increased by 8% (step 1). After Cdi had reached the target value, which took 8 to 10 minutes, it was lowered to 8% below the baseline value (step 2). After 8 to 10 minutes, when Cdi had reached the new target, it was returned to its starting value (step 3). Four values of Conventional ionic dialysance (using the standard formula) and actual ionic dialysance (taking into account cardiopulmonary recirculation) were obtained for each cycle and were compared among them and with effective urea clearance (Kde).ResultsMean Conventional dialysance values at steps 0 to 2 and 2 to 3 (190 and 189mL/min) were similar and higher than those at steps 0 to 1 and 1 to 2 (171 and 181mL/min). Mean Conventional ionic dialysance values underestimated Kde, particularly at steps 0 to 1 (-22.2mL/min, P < 0.001) and 1 to 2 (-12.6mL/min, P < 0.001). The actual dialysance values underestimated Kde by no more than 4.3mL/min (P < 0.001). In steps 0 to 1 and 1 to 2, the underestimate of Kde by Conventional dialysance increased at higher values of Kde, but this relationship did not exist when considering actual dialysance.ConclusionsThe value of ionic dialysance is affected by the method of determination, given the effect of cardiopulmonary recirculation on inlet plasma water conductivity when inlet dialysate conductivity is changed. As a consequence, to provide a correct and direct estimate of effective urea clearance, ionic dialysance must be determined by changing inlet dialysate conductivity in such a way as to keep inlet plasma water conductivity constant by means of two symmetrical high and low dialysate conductivity steps.

Spurious estimations of sodium removal during CAPD when [Na]+ is measured by Na electrode methodology.BackgroundThe aim of this study was to investigate the effect of pH and glucose concentration on sodium removal and the dialysate and plasma sodium ratio (D/PNa) as measured by means of a flame photometer (NaF) or direct ion-selective electrode (NaE) in continuous ambulatory peritoneal dialysis (CAPD).MethodsIn vitro, glucose concentration, pH, NaF, and NaE were measured in fresh peritoneal dialysis solutions (PDSs) before and after the addition of glucose or KOH. In vivo, 66 four-hour peritoneal equilibration tests were performed in 35 patients on CAPD using a low pH PDS with a glucose concentration of 3.86%.ResultsIn vitro, NaF and NaE were significantly influenced by the glucose concentration and pH of the PDS. In vivo, in fresh PDS, there was a significant difference between the NaF and NaE results; the respective median values were 132.1 (interquartile range 129.3 to 137.5) versus 138.0 (134.4 to 141.5) mmol/L (P < 0.0001). The D/PNa ratio calculated by NaE was significantly lower than that calculated by NaF (0.88 ± 0.03 vs. 0.91 ± 0.04 and 0.90 ± 0.03 vs. 0.94 ± 0.04 at 60 and 240 min, respectively, P < 0.0001), whereas there was no significant difference between the NaE and NaF values after correction for plasma water and a Donnan factor of 0.96 (0.88 ± 0.03 vs. 0.88 ± 0.04 and 0.90 ± 0.03 vs. 0.91 ± 0.04, P < 0.3473). Sodium removal was significantly lower when calculated as NaE than when calculated as NaF (43.9 ± 32.7 vs. 61.0 ± 32.2 mmol, P < 0.0001).ConclusionsThe fresh PDS sodium concentration can be corrected using a glucose concentration-related factor. The D/PNa ratio calculated as NaE or NaF is not different after correction for plasma water and a Donnan factor of 0.96. Sodium removal must be measured by means of NaF rather than NaE. This could have an important clinical impact.

The prevalence of hepatitis B virus (HBV) infection in our unit was 45% (86/190): there were 77 (40.5%) and 9 (4.7%) patients with previous and persistent HBV infection, respectively. Recombinant hepa

Background Patients on peritoneal dialysis (PD) with high small solute peritoneal membrane transport have an increased risk of morbidity and mortality. The membrane transport is currently assessed by peritoneal equilibration test (PET), usually performed after the first month of PD because of the early increase of membrane transport after the start of PD. The aim of this study was the assessment of small solute peritoneal membrane transport before and after the start of PD. Methods The small solute peritoneal membrane transport was evaluated in 34 patients before the start of PD. Twenty-two patients were treated with continuous ambulatory peritoneal dialysis (CAPD) and 12 with automated peritoneal dialysis (APD). Results Four months after the start of PD, the small solute peritoneal membrane transport increased only in CAPD patients (D/P(Creat), the ratio between dialysate solute concentration at the end of the PET and creatinine plasma concentration, changed from 0.66 +/- 0.12 to 0.73 +/- 0.07 in CAPD patients and from 0.64 +/- 0.12 to 0.61 +/- 0.07 in APD patients), and after about 16 months of PD, the peritoneal membrane transport was higher in CAPD patients (D/P(Creat) = 0.74 +/- 0.06) than in APD patients (D/P(Creat) = 0.63 +/- 0.10). Conclusions Performing the PET before and after the start of PD could provide relevant information about the characteristics of small solute peritoneal membrane transport and could be useful to evaluate the influence of PD modality on the changes in peritoneal membrane transport.

Objective To investigate the possible effects of different concentrations of ionized sodium (NaI) on peritoneal ultrafiltration (UF) rate using lactate (Lac) and lactate/bicarbonate (Lac/Bic) dialysis solutions. Design Two random consecutive (after an interval of 48 hours) peritoneal equilibration tests (PETs) were performed in 13 patients (4 males and 9 females) on regular continuous ambulatory peritoneal dialysis (PD) treatment for at least 3 months. Two different PD solutions containing anhydrous glucose 3.86% were used: a 40 mmol/L Lac solution and a 15/25 mmol/L mixed Lac/Bic solution. Concentrations of total sodium (NaT) and NaI were measured by flame photometer and direct ion-selective electrode respectively. Results Dialysate concentrations of NaT were not different during PETs using Lac and Lac/Bic. Dialysate concentrations of NaI in fresh PD solutions were different (133.3 ± 1.7 vs 128.2 ± 3.9 mmol, p < 0.0001); however, these differences disappeared just after the end of the infusion of the fresh solutions. Peritoneal UF rate was not significantly different during PETs using Lac versus Lac/Bic (609 ± 301 mL vs 542 ± 362 mL). The dialysate-to-plasma ratios of sodium concentrations at 60 minutes of the PETs (which are expressions of free water transport) were not different using Lac versus Lac/Bic (0.89 ± 0.04 vs 0.89 ± 0.04 respectively, p = 0.96). All the other classical parameters of the PET were not different between Lac and Lac/Bic. Conclusions The higher dialysate concentrations of NaI due to lower dialysate pH and consequently the higher effective osmolality of the fresh Lac PD solutions did not influence peritoneal UF rate, probably because of the fast reduction of NaI concentrations due to rapid correction of dialysate pH at the end of the infusion of Lac solutions into the peritoneal cavity.

Background. Sodium removal (NaR) may have a major impact on the survival of peritoneal dialysis patients. The dialysate/plasma sodium concentration ratio (D/PNa) is an indirect index of transcellular water transport by aquaporin channels, and thus of ultrafiltration. Sodium concentration can be assessed by means of flame photometry (F), and direct (D-ISE) or indirect ion-selective electrodes (I-ISE), but these methods have different properties. I-ISE is being used increasingly in clinical laboratories. The aim of this study was to evaluate NaR and D/PNa using the three different measurement methods. Methods. We performed peritoneal equilibration tests (PETs) in 44 peritoneal dialysis patients and calculated the NaR. We also calculated D/PNa during the test; plasma and dialysate sodium concentrations were measured by F, D-ISE and I-ISE. Results. NaR was lower (P

The aim of this multicenter prospective study was to investigate the role of relative blood volume (RBV) reduction on intradialytic hypotension.One hundred twenty-three patients on chronic hemodialysis therapy were considered a priori normotensive (reference group A), intradialytic hypotension prone (group B), and hypertensive (group C). RBV was continuously monitored, and diastolic and systolic blood pressure (SBP) and heart rate (HR) were measured at 20-minute intervals during three dialysis sessions.Intradialytic RBV reduction was -13.8% +/- 7.0% and similar in the three groups (P = 0.841). SBP and RBV decreased during dialysis, with a sharp initial decrease (in the first 20 minutes for SBP and the first 40 minutes for RBV), followed by a slower decrease. The lying bradycardic response before dialysis was less in group B than group A (a decrease of 3 +/- 7 versus 9 +/- 9 beats/min; P0.001). When symptomatic hypotension occurred, RBV reduction was not significantly different from that recorded at the same time during hypotension-free sessions (-13.9% +/- 6.4% versus -12.7% +/- 5.2%; P = 0.149). Group, baseline plasma-dialysate sodium gradient, RBV line irregularity, and early RBV and HR reduction during dialysis influenced the relative risk for symptomatic hypotension with a sensitivity of 80% versus 30% for RBV alone.We found no difference in reduction in RBV in the three groups and no critical RBV level for the appearance of symptomatic hypotension. With variables easily available within 40 minutes of dialysis, RBV monitoring increases the prediction of symptomatic hypotension.

We conducted a prospective study in HD patients of our unit to evaluate the incidence of seroconversion for HCV in this high-risk group. Two hundred and thirty-five patients were observed during the average follow-up of 29.4 months: 183 were seronegative and 52 seropositive for anti-HCV antibodies at the start of the study. During the observation period two of 183 patients developed anti-HCV antibodies late in the study, while the other 181 patients remained seronegative throughout the observation period; anti-HCV antibodies persisted through the follow-up in the 52 HCV-positive patients at the beginning of the study. Our results showed a very low incidence of HCV seropositivity (0.44% per year) after implementation of our operative protocol including 'universal precautions' and other infection control procedures. Once infected, there is no disappearance rate of anti-HCV. The 4-RIBA results did not change during the follow-up period. Prevalence of HCV RNA by PCR technique was 41% (22 of 54) among anti-HCV-positive patients. Future investigations are warranted to clarify the exact route of transmission of HCV among HD patients and to reduce the rate of HCV transmission in this clinical setting.

The peritoneal equilibration test (PET) with 3.86% glucose concentration (3.86%-PET) has been suggested to be more useful than the standard 2.27%-PET in peritoneal dialysis (PD), but no longitudinal data for 3.86%-PET are currently available. A total of 242 3.86%-PETs were performed in 95 incident PD patients, who underwent the first test during the first year of treatment and then once a year. The classical parameters of peritoneal transport, such as peritoneal ultrafiltration (UF), D / D 0 , and D / P Creat , were analyzed. In addition, the absolute dip of dialysate sodium concentration (Δ D Na ), as an expression of sodium sieving, was studied. D / D 0 was stable, and a progressive decrease in UF was observed after the second PET, whereas D / P Creat firstly increased and then stabilized. Δ D Na was the only parameter showing a progressive decrease over time. On univariate analysis, D / D 0 and Δ D Na were found to be significantly associated with the risk of developing UF failure (risk ratio (RR) 0.987 (0.973–0.999), P =0.04, and RR 0.768 (0.624–0.933), P =0.007, respectively), but on multivariate analysis only Δ D Na showed an independent association with the risk of developing UF failure (RR 0.797 (0.649–0.965), P =0.020). UF, D / D 0 , and D / P Creat changed only in those patients developing UF failure, reflecting increased membrane permeability, whereas Δ D Na significantly decreased in all patients. The 3.86%-PET allows a more complete study of peritoneal membrane transport than the standard 2.27%-PET. Δ D Na shows a constant and significant reduction over time and is the only factor independently predicting the risk of developing UF failure in PD patients.

Ionic dialysance allows an adequate estimate of urea distribution volume in hemodialysis patients. Background An adequate estimation of urea distribution volume (V) in hemodialysis patients is useful to monitor protein nutrition. Direct dialysis quantification (DDQ) is the gold standard for determining V, but it is impractical for routine use because it requires equilibrated postdialysis plasma water urea concentration. The single pool variable volume urea kinetic model (SPVV-UKM), recommended as a standard by Kidney Disease Outcomes Quality Initiative (K/DOQI), does not need a delayed postdialysis blood sample but it requires a correct estimate of dialyser urea clearance. Methods Ionic dialysance (ID) may accurately estimate dialyzer urea clearance corrected for total recirculation. Using ID as input to SPVV-UKM, correct V values are expected when end-dialysis plasma water urea concentrations are determined in the end-of-session blood sample taken with the blood pump speed reduced to 50 mL/min for two minutes (U pwt2′ ). The aim of this study was to determine whether the V values determined by means of SPVV-UKM, ID, and U pwt2′ (V ID ) are similar to those determined by the "gold standard" DDQ method (V DDQ ). Eighty-two anuric hemodialysis patients were studied. Results V DDQ was 26.3 ± 5.2 L; V ID was 26.5 ± 4.8 L. The (V ID –V DDQ ) difference was 0.2 ± 1.6 L, which is not statistically significant ( P = 0.242). Anthropometric volume (V A ) calculated using Watson equations was 33.6 ± 6.0 L. The (V A –V DDQ ) difference was 7.3 ± 3.3 L, which is statistically significant ( P Conclusion Anthropometric-based V values overestimate urea distribution volume calculated by DDQ and SPVV-UKM. ID allows adequate V values to be determined, and circumvents the problem of delayed postdialysis blood samples.

In 11 chronic haemodialysis patients we investigated whether the increase in haematocrit during recombinant human erythropoietin (rHuEPO) treatment might alter the long-term efficiency of haemodialysis. After correction of anaemia with rHuEPO (mean Ht 35 +/- 2% vs 19 +/- 2% at baseline) (p 0.001), mean predialysis creatinine and urea did not change, while predialysis phosphate (1.77 +/- 0.38 vs 1.51 +/- 0.29 mmol/l) were significantly increased (p 0.01). In six of the 11 rHuEPO treated patients a post- versus pre-dialysis haemoconcentration (haematocrit 44% vs 35%) not attributable to different ultrafiltration regimes, was observed. In these 6 patients mean predialysis phosphate, creatinine and urea tended to be higher, but not significantly, in comparison to he remaining 5 patients who did not haemoconcentrate. Dialyser clearances and total extractions for urea, creatinine, phosphate and inulin were compared to those of 11 matched haemodialysis patients with anaemia. No differences were observed either for small and middle molecule clearances or their extractions between rHuEPO and anaemic patients. In conclusion, dialysis efficiency is not affected if haematocrit values are kept about 35%.