Better correction of metabolic acidosis, blood pressure control, and phagocytosis with bicarbonate compared to lactate solution in acute peritoneal dialysis. Oral sodium bicarbonate for the treatment of metabolic acidosis in peritoneal dialysis patients: a randomized placebo-control trial. Acetate-free biofiltration versus bicarbonate haemodialysis in the treatment of patients with diabetic nephropathy: a cross-over multicentric study. Effect of acetate, bicarbonate dialysis, and acetate-free biofiltration on nitric oxide synthesis: implications for dialysis hypotension. Is peritoneal dialysis adequate for hypercatabolic acute renal failure in developing countries? Online hemodiafiltration versus acetate-free biofiltration: a prospective crossover study. Pilot study of urgent endoscopic intervention without fluoroscopy on patients with severe acute biliary pancreatitis in the intensive care unit. Comparison of cellulose diacetate and polysulfone membranes in the outcome of acute renal failure. A prospective randomized study. A prospective comparison of bicarbonate dialysis, hemodiafiltration, and acetate-free biofiltration in the elderly.
Lactate solution has been the standard dialysate fluid for a long time. However, it tends to convert back into lactic acid in poor tissue-perfusion states. The aim of this study was to evaluate the efficacy of magnesium (Mg)- and calcium (Ca)-free bicarbonate solution compared with lactate solution in acute peritoneal dialysis (PD). Renal failure patients who were indicated for dialysis and needed acute PD were classified as shock and nonshock groups, and then were randomized to receive either bicarbonate or lactate solution. Twenty patients were enrolled in this study (5 in each subgroup). In the shock group, there were more rapid improvements and significantly higher levels of blood pH (7.40 +/- 0.04 versus 7.28 +/- 0.05, p < 0.05), serum bicarbonate (23.30 +/- 1.46 versus 18.37 +/- 1.25 mmol/L, p < 0.05), systolic pressure (106.80 +/- 3.68 versus 97.44 +/- 3.94 mm Hg, p < 0.05), mean arterial pressure (80.72 +/- 2.01 versus 73.28 +/- 2.41 mm Hg, p < 0.05), percentages of phagocytosis of circulating leukocytes (65.85% +/- 2.22 versus 52.12% +/- 2.71, p < 0.05), and percentages of positive nitroblue tetrazolium (NBT) reduction test without and with stimulation (14.43 +/- 1.93 versus 9.43 +/- 2.12, p < 0.05 and 65.08 +/- 6.80 versus 50.23 +/- 4.21, p < 0.05, respectively) in the bicarbonate subgroup compared with the lactate subgroup. In the nonshock group, blood pH, serum bicarbonate, and phagocytosis assays in both subgroups were comparable. Lactic acidosis was more rapidly recovered and was significantly lower with bicarbonate solution for both shock and nonshock groups (3.63 +/- 0.37 versus 5.21 +/- 0.30 mmol/L, p < 0.05 and 2.92 +/- 0.40 versus 3.44 +/- 0.34 mmol/L, p < 0.05, respectively). Peritoneal urea and creatinine clearances in both subgroups were comparable for both shock and nonshock groups. There was no peritonitis observed during the study. Serum Mg and Ca levels in the bicarbonate subgroup were significantly lower, but no clinical and electrocardiographic abnormality were observed. We concluded that Mg- and Ca-free bicarbonate solution could be safely used and had better outcomes in correction of metabolic acidosis, blood pressure control, and nonspecific systemic host defense with comparable efficacy when compared to lactate solution. It should be the dialysate of choice for acute PD especially in the poor tissue-perfusion states such as shock, lactic acidosis, and multiple organ failure. Acidosis causes malnutrition in peritoneal dialysis (PD) patients. The effect of oral bicarbonate in PD patients with Kt/V <2.1 has not been studied. We randomly assigned 60 PD patients with acidosis and Kt/V <2.1 to oral sodium bicarbonate (0.9 g thrice daily) or placebo. Patients were followed for 12 mo. We compared their nutritional status, including subjective global assessment (SGA) score and normalized protein nitrogen appearance (NPNA), hospitalization and all-cause mortality. Treatment with oral bicarbonate resulted in a higher plasma bicarbonate level at 4 wk (27.8 +/- 2.6 versus 24.7 +/- 3.9 mmol/L, P = 0.002), and the difference persisted until 52 wk. Bicarbonate treatment had a significant effect on the change in overall SGA score (repeated measures ANOVA, P = 0.0003). The overall SGA score of the treatment group was higher than the placebo group at 24 wk (5.07 +/- 0.94 versus 4.40 +/- 1.00, P = 0.015), and the difference persisted thereafter. NPNA rose in the treatment group (1.17 +/- 0.32 to 1.28 +/- 0.26 g/kg per d, P = 0.034), but declined in placebo group (1.13 +/- 0.25 to 1.03 +/- 0.28 g/kg per d, P = 0.054). The treatment group had a shorter hospitalization than the placebo group (8.4 +/- 17.7 versus 16.8 +/- 21.7 d/yr; P = 0.02). Mortality was not significantly different. Although our trial has limited statistical power, we find that in PD patients with mild acidosis and Kt/V <2.1, oral sodium bicarbonate probably improve nutritional status and reduce the duration of hospitalization. Morbidity and mortality rates in diabetic patients on regular dialysis treatment (RDT) are higher than in non-diabetic-subjects on RDT. Moreover, diabetic patients experience an intradialitic morbidity unacceptably higher than in patients with other causes of terminal renal failure. The aim of the present investigation was to compare standard bicarbonate haemodialysis (BHD) with acetate-free biofiltration (AFB) in a group of 41 diabetic patients stable on dialysis treatment for 25 +/- 22 months.
                Twenty-four type II and 17 type I diabetic patients, all requiring insulin therapy, were included and were followed for 1 year in a 6-month cross-over randomized study for both methods. The analysis was carried out on dialysis symptoms, interdialysis symptoms, and nutritional status, and the multivariate analysis of variance for repeated measures on the same subjects in the two techniques was used.
                AFB significantly reduced dialytic and extradialytic symptoms (P=0.003 and 0.001 respectively). Cardiovascular collapses decreased by 43%, and other dialysis symptoms showed a similar trend (-35%). The interdialysis symptoms decreased by 28% and were accompanied by an increase in subjective wellbeing (39%) when patients were switched from traditional haemodialysis to AFB. Acid base control was better with AFB (P=0.01), both at the beginning and during the session. Slightly significant differences were also obtained for Kt/V (AFB 1.48 +/- 0.29 vs BHD 1.38 +/- 0.30), while no significant difference was noted with respect to sodium mass balance, nutritional status, calorie-protein intake, nPCR, blood glucose profile, and insulin requirements. The number of hospital admissions and the mortality rate, which were much lower during the AFB than the BHD period, were not analysed statistically.
                AFB allows better control of some metabolic aspects, reduces intra- and extradialysis symptoms, and improves patient quality of life. Whether the long-term prognosis can be improved by AFB remains to be established with further studies. The effect of acetate dialysis (AD), bicarbonate dialysis (BD), and acetate-free biofiltration (AFB) on nitric oxide (NO) synthesis and the implications for dialysis hypotension was studied. The finding that uremic plasma is a potent inducer of NO synthesis by endothelial cells in vitro suggested that the cardiovascular instability of dialysis patients might result from excessive NO formation. Cardiovascular instability is more frequent in patients undergoing AD than BD. To see whether these differences were attributable to NO, we studied the NO synthetic pathway ex vivo in patients undergoing different dialysis procedures. Five patients were treated, in a random order, with AD, BD, and AFB, a technique using a buffer-free dialysate and postdilution of a sterile bicarbonate solution. Each type of dialysis was used for 1 week, comprising three dialysis sessions. A polyacrylonitrile dialyzer was used for all three methods. Before and after the third dialysis, plasma was collected, added to [3H]L-arginine, and incubated with human umbilical vein endothelial cells (HUVECs) for 24 hours. NO synthesis was evaluated as [3H]L-citrulline formation. Plasma concentrations of interleukin-1beta (IL-1beta), a potent inducer of inducible NO synthase (iNOS) in endothelial cells, were also measured. Plasma collected from patients after AD stimulated endothelial NO synthesis more than plasma from the same patients before the dialysis session (pre-AD, 0.173+/-0.028 nmol/10(5) cells v post-AD, 0.280+/-0.093 nmol/10(5) cells; P < 0.05). A slight, although not significant, increase was also observed when HUVECs were incubated with plasma drawn after BD (pre-BD, 0.151+/-0.014 nmol/10(5) cells; post-BD, 0.230+/-0.055 nmol/10(5) cells). AFB did not aggravate the stimulatory effect of uremic plasma on endothelial NO synthesis (pre-AFB, 0.184+/-0.038 nmol/10(5) cells; post-AFB, 0.189+/-0.040 nmol/10(5) cells). Plasma IL-1beta was greater (P < 0.01) after AD than after BD and AFB (post-AD, 0.234+/-0.028 pg/mL; post-BD, 0.124+/-0.019 pg/mL; post-AFB, 0.120+/-0.013 pg/mL). With AD, there was a greater intradialytic decrease in systolic blood pressure than with BD or AFB. Weight and blood volume loss and sodium balance were similar in AD, BD, and AFB. These data were consistent with the possibility that NO and cytokines, released in excessive amounts during AD, may contribute to hemodynamic instability. Peritoneal dialysis (PD) is a therapeutic option for acute renal failure (ARF) in developing countries, despite concerns about inadequacy. Shorter and more efficient tidal peritoneal dialysis (TPD) was compared with continuous equilibrating peritoneal dialysis (CEPD) therapy in ARF by using their adequacies as accepted standards and analyzing the solute reduction indices (SRI).
                A prospective, randomized crossover trial was performed in patients with mild to moderate hypercatabolic ARF who were assigned to CEPD and TPD therapy after an adequate washout period. Solute clearances (Kt/V, normalized creatinine clearances) were compared to NKF guidelines. Potassium and phosphate clearances, dextrose absorption, protein losses and costs were compared. Kt/V was compared to SRIdialysate, SRIKt/V.
                Eighty-seven patients with ARF received 236 sessions of dialysis (118 in each treatment). TPD resulted in higher clearances of solutes than CEPD (creatinine and urea clearances in mL/min of 9.94 +/- 2.93, 6.74 +/- 1.63 and 19.85 +/- 1.95, 10.63+/- 2.62, respectively, P=0.001). TPD and CEPD normalized creatinine clearances (L/week/1.73 m2 BSA) and Kt/V values were 68.5 +/- 4.43, 58.85 +/- 2.57 and 2.43 +/- 0.87, 1.80 +/- 0.32, respectively. CEPD did not meet standards of adequacy. TPD resulted in greater potassium and phosphate clearances, less dextrose absorption and was less expensive. CEPD resulted in less protein loss. Kt/V corresponded to SRIdialysate 0.88 +/- 0.12 (P=0.076).
                TPD produced higher solute clearances in less time with greater protein loss. CEPD just fell short to meet the dialysis adequacy standard. However, both TPD and CEPD are reasonable options for mild-moderate hypercatabolic ARF. Kt/V appropriately estimates solute removal in PD. Online hemodiafiltration (online HDF) and acetate-free biofiltration (AFB) are 2 innovative renal replacement therapies. Convincing evidence has shown that both techniques are superior to conventional hemodialysis in many aspects. The aim of the present investigation was to compare online HDF and AFB in 12 stable maintenance hemodialysis patients in a prospective, randomized crossover trial. Twelve stable dialysis patients, age 49.7 +/- 11.3 years and on dialysis for 83.5 +/- 76.7 months, were treated prospectively and randomly by either AFB, predilution HDF (pre-HDF), or postdilution HDF (post-HDF) for a total of 36 weeks using exclusively F60S high-flux dialyzers. Routine blood biochemical tests, bone metabolism parameters, and clearance for both small and larger molecular weight substances were measured at defined intervals. During the trial period inter- and intradialysis symptoms, e.g., hypotensive episodes and intradialysis arterial blood gas analyses, were recorded. Both online HDF and AFB were well accepted by the overwhelming majority of patients and also by the dialysis staff. Pretreatment sodium, total and ionized calcium, chloride, bicarbonate, and urea did not differ within or between the 3 treatment groups. Potassium increased slightly in HDF patients while phosphate and beta2-microglobulin (beta2-M) decreased in all groups. After dialysis, AFB patients exhibited a significantly higher bicarbonate concentration and lower potassium level when identical potassium concentrations in dialysate were used. Patients receiving AFB manifested less intradialysis partial pressure of oxygen drop and partial pressure of carbon dioxide rise than those on HDF treatments. HDF treatments could afford higher single-pool and double-pool Kt/V, higher effective urea and beta2M clearance, and lower total interdialysis symptom scores than the AFB treatment method. While bone metabolism parameters did not differ between the 3 dialysis modalities, some parameters such as deoxypyridinoline in HDF and osteocalcin, pyridinoline, and deoxypyridinoline in AFB deteriorated at the end of the crossover study. Aluminum concentration decreased progressively to about one-third of prestudy values at the end of the study with all 3 treatments. AFB was associated with a lower predialysis mean arterial pressure (MAP), a smaller drop in MAP during treatment, and similar hypotension episodes compared with the 2 HDF treatments. Albumin concentration showed a trend to decrease during the first 2 months of the trial period followed by a slight increase thereafter but still significantly lower than initial value at the end of crossover. Both online HDF and AFB share most of the features of optimal renal replacement therapy. Online HDF is superior to AFB in such aspects as increased delivered dialysis dose both for small and larger molecular weight toxins and less interdialysis symptoms. On the other hand, AFB is associated with a smaller effect on arterial blood gas values and improved intradialysis hemodynamic tolerance. Some dialysis-related symptoms and complications in the case of our AFB practice could be attributable, at least in part, to low dialysate calcium level. The effect of early endoscopic intervention (EI; within 72 hours) remains a controversial subject. This prospective study was aimed to evaluate the efficacy of early EI without fluoroscopy on severe acute biliary pancreatitis (SABP) in the intensive care unit (ICU).
                Fifty-three patients with SABP + ampullary obstruction in the ICU were divided randomly into 2 groups: conservative treatment in the ICU (CTI arm) and CTI + EI without the aid of fluoroscopy (CTI + EI arm). Decreased Acute Physiology and Chronic Health Evaluation II score was the major parameter to assess treatment efficacy.
                Endoscopic treatments including sphincterotomy + stone removal (17 cases) and nasobiliary drainage (4 cases) were successfully performed in all 21 enrolled patients without the aid of fluoroscopy in the ICU. Compared with CTI, CTI + EI significantly resulted in decreased (3.86 +/- 2.08 vs 6.57 +/- 1.54) Acute Physiology and Chronic Health Evaluation II score at day 10, P < 0.05. No deaths were observed in the CTI + EI, whereas the CTI arm had 2 mortalities.
                Urgent EI without fluoroscopy is possible to be performed by endoscopists with the experience from high volume of procedures and is beneficial for the patients with SABP in the ICU or community hospital. Whether the nature of haemodialysis (HD) membranes can influence the outcome of acute renal failure (ARF) remains debatable. Recent studies have suggested that dialysis with bioincompatible unsubstituted cellulosic membranes is associated with a less favourable patient outcome than dialysis with biocompatible synthetic membranes. Since we generally use a modified cellulosic membrane with substantially lower complement- and leukocyte-activating potential than cuprophane, for dialysis of patients with ARF, and because there are no data in the literature regarding the influence of modified cellulosic membranes on the outcome of patients with ARF, we compared the outcome of ARF patients dialysed either with cellulose diacetate or with a synthetic polysulfone membrane. We also investigated the potential role of permeability by comparing membranes with high-flux versus low-flux characteristics.
                This prospective, randomized, single centre study included 159 patients with ARF requiring HD. Patients were stratified according to age, gender, and APACHE II score and then randomized in chronological order to one of three dialysis membranes: low-flux polysulfone, high-flux polysulfone and meltspun cellulose diacetate.
                Aetiologies of ARF and the prevalence of oliguria were similarly distributed among the three groups. There was no significant difference between the three groups for survival (multivariate Cox's proportional hazards model, P=0.57), time necessary to recover renal function (P=0.82), and number of dialysis sessions required before recovery (P=0.86). Multivariate analysis showed that survival was significantly influenced only by the severity of the disease state (APACHE III score, P<0.0001), but not by the nature of the dialysis membrane (P=0.57) or the presence of oliguria (P=0.24).
                Among patients with ARF requiring HD survival and recovery time are not significantly influenced by the use of either meltspun cellulose diacetate or the more biocompatible high-flux or low-flux polysulfone. Dialysis using modified cellulose membranes is just as effective as dialysis using synthetic polysulfone membranes, but at a lower cost. In addition, the flux of the membrane did not influence patient outcome. Hemodiafiltration (HDF) and more recently acetate-free biofiltration (AFB) have shown good blood purification and cardiovascular stability in young and middle-aged hemodialysis patients. It is not clear if this is also valid for elderly patients. Twelve patients aged more than 70 years (mean age +/- SD, 76 +/- 4 years) on regular dialysis for at least 5 months were treated with bicarbonate dialysis (BD), HDF, or AFB in a randomized sequence and prospectively followed for 6 months (72 dialysis sessions/patient) for each procedure. The dialysis solution (containing bicarbonate), blood flow rate, and dialysate flow rate were the same with all the methods. During HDF and AFB solutions containing bicarbonate at a concentration of 27 to 30 mEq/L and 145 mEq/L, respectively, were infused postdilution at a rate of 66 +/- 7 mL/min and 2.81 +/- 0.12 L/hr, respectively. During the period of observation we evaluated the number of intradialytic hypotensions, the episodes of nausea, vomiting, headache (dialysis intolerance), body weight, the interdialysis weight gain, the duration of the dialysis session, the number of hospitalizations/patient, and the length of hospitalization/patient. At the end of each observation period we determined: Kt/V, protein catabolic rate, acid base balance, serum creatinine, serum calcium, serum phosphorus, alkaline phosphatases, and serum intact parathyroid hormone. After the switch from BD to either HDF or AFB, the results have shown a significant reduction of dialysis hypotension episodes (18 percent on BD, 14 percent on HDF, and 13 percent on AFB; BD v HDF, P = 0.001; BD v AFB, P = 0.0001; and HDF v AFB, P = NS) and of dialysis intolerance (3.3 percent on BD, 1.3 percent on HDF, and 1.1 percent on AFB; BD v HDF, P = 0.021; BD v AFB, P = 0.019; and HDF v AFB, P = NS). Kt/V improved significantly after the switch from BD to either HDF or AFB (1.17 +/- 0.06 on BD, 1.32 +/- 0.12 on HDF, and 1.32 +/- 0.13 on AFB; BD v HDF, P = 0.021; BD v AFB, P = 0.003; HDF v AFB, P = NS). Protein catabolic rate also improved in HDF and AFB compared with BD (0.90 +/- 0.12 on BD, 1.03 +/- 0.15 on HDF, and 1.04 +/- 0.14 on AFB; BD v HDF, P = 0.001; BD v AFB, P = 0.009; and HDF v AFB, P = NS). AFB showed a better correction of acidosis compared either with BD or HDF (serum bicarbonate, 20.3 +/- 1.1 mEq/L on BD, 20.8 +/- 2.2 mEqL on HDF, and 22.2 +/- 2.4 mEq/L on AFB; BD v HDF, P = NS; BD v AFB, P = 0.01; and HDF v AFB, P = 0.030). The other parameters observed did not differ. In conclusion HDF and AFB show a better dialysis efficiency and a better hemodynamic tolerance compared with BD. This fact is associated with an improvement in protein intake as assessed by kinetic criteria. Acetate-free biofiltration has the further advantage of a better control of the acid-base balance compared with BD and HDF. HDF and AFB are useful dialytic options to traditional BD hemodialysis even in patients older than 70 years.
There is no strong evidence that any clinical advantage for patients requiring acute PD for AKI when comparing conventional (lactate) with low GDP dialysis solutions (bicarbonate).