Quantification of free water transport in peritoneal dialysis

Quantification of free water transport in peritoneal dialysis.BackgroundIn peritoneal dialysis (PD) total net ultrafiltration (NUF) is dependent on transport through small pores and through water channels in the peritoneum. These channels are impermeable to solutes, and therefore, crystalloid osmotic-induced free water transport occurs through them. Several indirect methods to assess free water transport have been suggested. The difference in NUF between a 3.86% and a 1.36% solution gives a rough indication, but is very time consuming. The magnitude of the dip in dialysate/plasma (D/P) sodium in the initial phase of a 3.86% exchange is another way to estimate free water transport. In the present study, a method was applied to calculate free water transport by calculating sodium-associated water transport in one single 3.86% glucose dwell.MethodsForty PD patients underwent one standard peritoneal permeability analysis (SPA) with a 1.36% glucose solution, and another with a 3.86% glucose solution. At different time points intraperitoneal volume and sodium concentration were assessed. This made it possible to calculate total sodium transport. By subtracting this transport (which must have occurred through the small pores) from the total fluid transport, free water transport remained. These results were compared with the other methods to estimate free water transport.ResultsFor the 1.36% glucose dwell, total transcapillary ultrafiltration in the first hour (TCUF0-60) was 164 mL, transport through the small pores was 129 mL, and free water transport was 35 mL (21%). For the 3.86% glucose solution, total TCUF0-60 was 404 mL, transport through the small pores was 269 mL, and free water transport was 135 mL (34%). The contribution of free water transport in the first minute (TCUF0-1) was 39% of the total fluid transport. From the 40 patients, 11 patients had ultrafiltration failure (NUF <400 mL after 4 hours). For these patients the contribution of free water to TCUF0-1 was significantly lower than for those with normal ultrafiltration (20% vs. 48%, P < 0.05). A strong correlation was present between free water transport as a percentage of total fluid transport and the maximum dip in D/P sodium (r = 0.84). The correlation was not significant with the difference in net ultrafiltration of 3.86% and 1.36% solutions (r = 0.24, P = 0.3).ConclusionThe method applied here is the first direct quantification of free water transport, calculated from a single standard peritoneal function test. It offers a quick possibility to evaluate patients suffering from ultrafiltration failure. In these patients free water transport was impaired, but the origin of this impairment is still to be determined

Augmenting solute clearance in peritoneal dialysis

Augmenting solute clearance in peritoneal dialysis.BackgroundThe removal of low molecular weight solutes by peritoneal dialysis is less than by hemodialysis. The targets for Kt/Vurea and creatinine clearance formulated in the Dialysis Outcome Quality Initiative are unlikely to be achieved in a substantial portion of peritoneal dialysis patients. Possibilities to increase small solute clearances have therefore been subject to many investigations.MethodsA review of the literature and of recent new data on determinants of solute removal, such as residual renal function, the role of drained dialysate volume and manipulation of the diffusive capacity of the peritoneum are presented.ResultsThe contribution of residual GFR is more important for the clearance of creatinine than for Kt/Vurea. It is even more important for the removal of organic acids that are removed from the body by tubular secretion. High dosages of furosemide increase the urinary volume and the fractional Na+ excretion, but have no effect on the magnitude of residual GFR, renal creatinine clearance, renal urea clearance, and peritoneal transport characteristics. The drained dialysate volume per day is the main determinant of the peritoneal removal of urea. Its effect decreases the higher the molecular weight of a solute. It can be augmented by using large instillation volumes, by the application of more exchanges, and by increasing peritoneal ultrafiltration. A large exchange volume is especially effective in patients with an average transport state, but in those with high solute transport rates, Kt/Vurea is especially influenced by the number of exchanges. Possibilities to increase ultrafiltration are discussed. The diffusive capacity of the peritoneum can be augmented by using low dosages of intraperitoneally administered nitroprusside. This increases solute transport most markedly when it is applied in combination with icodextrin as osmotic agent.ConclusionsSmall solutes clearances cannot be increased by furosemide. Increasing the instilled volume of dialysis fluid and the number of exchanges both affect solute clearance. Studies are necessary on long-term effects of manipulation of the peritoneal membrane with nitroprusside

Selection of modalities, prescription, and technical issues in children on peritoneal dialysis

Peritoneal dialysis (PD) is widely employed as a dialytic therapy for uraemic children, especially in its automated form (APD), that is associated with less burden of care on patient and family than continuous ambulatory PD. Since APD offers a wide range of treatment options, based on intermittent and continuous regimens, prescription can be individualized according to patient’s age, body size, residual renal function, nutritional intake, and growth-related metabolic needs. Transport capacity of the peritoneal membrane of each individual patient should be assessed, and regularly monitored, by means of standardized peritoneal function tests validated in pediatric patients. To ensure maximum recruitment of peritoneal exchange area, fill volume should be scaled to body surface area and adapted to each patient, according to clinical tolerance and intraperitoneal pressure. PD solutions should be employed according to their biocompatibility and potential ultrafiltration capacity; new pH-neutral, glucose-free solutions can be used in an integrated way in separate dwells, or by appropriately mixing during the same dialytic session. Kinetic modelling software programs may help in the tailoring of PD prescription to individual patients’ characteristics and needs. Owing to advances in the technology of new APD machines, greater programming flexibility, memorized delivery control, and tele-dialysis are currently possible

JPN Guidelines for the management of acute pancreatitis: epidemiology, etiology, natural history, and outcome predictors in acute pancreatitis

Acute pancreatitis is a common disease with an annual incidence of between 5 and 80 people per 100 000 of the population. The two major etiological factors responsible for acute pancreatitis are alcohol and cholelithiasis (gallstones). The proportion of patients with pancreatitis caused by alcohol or gallstones varies markedly in different countries and regions. The incidence of acute alcoholic pancreatitis is considered to be associated with high alcohol consumption. Although the incidence of alcoholic pancreatitis is much higher in men than in women, there is no difference in sexes in the risk involved after adjusting for alcohol intake. Other risk factors include endoscopic retrograde cholangiopancreatography, surgery, therapeutic drugs, HIV infection, hyperlipidemia, and biliary tract anomalies. Idiopathic acute pancreatitis is defined as acute pancreatitis in which the etiological factor cannot be specified. However, several studies have suggested that this entity includes cases caused by other specific disorders such as microlithiasis. Acute pancreatitis is a potentially fatal disease with an overall mortality of 2.1%–7.8%. The outcome of acute pancreatitis is determined by two factors that reflect the severity of the illness: organ failure and pancreatic necrosis. About half of the deaths in patients with acute pancreatitis occur within the first 1–2 weeks and are mainly attributable to multiple organ dysfunction syndrome (MODS). Depending on patient selection, necrotizing pancreatitis develops in approximately 10%–20% of patients and the mortality is high, ranging from 14% to 25% of these patients. Infected pancreatic necrosis develops in 30%–40% of patients with necrotizing pancreatitis and the incidence of MODS in such patients is high. The recurrence rate of acute pancreatitis is relatively high: almost half the patients with acute alcoholic pancreatitis experience a recurrence. When the gallstones are not treated, the risk of recurrence in gallstone pancreatitis ranges from 32% to 61%. After recovering from acute pancreatitis, about one-third to one-half of acute pancreatitis patients develop functional disorders, such as diabetes mellitus and fatty stool; the incidence of chronic pancreatitis after acute pancreatitis ranges from 3% to 13%. Nevertheless, many reports have shown that most patients who recover from acute pancreatitis regain good general health and return to their usual daily routine. Some authors have emphasized that endocrine function disorders are a common complication after severe acute pancreatitis has been treated by pancreatic resection

Aftrek buitengewone uitgaven 2005 door chronisch zieken en gehandicapten (Nationaal Panel Chronisch Zieken en Gehandicapten).

Het gebruik van de belastingaftrekregeling voor buitengewone uitgaven door mensen met een chronische ziekte of handicap is vorig jaar met tien procent gestegen. Maar nog altijd maakt de helft van de chronisch zieken en gehandicapten die in aanmerking komen voor aftrek van hun ziektekosten, geen gebruik van deze regeling. Minder ziektekosten Veertig procent van de mensen met een chronische ziekte of handicap die in 2005 wel in aanmerking kwamen voor aftrek van hun ziektekosten maar er geen gebruik van maakten, heeft geen belastingaangifte gedaan en loopt daardoor de compensatie mis. Daarnaast deed 53 procent wel belastingaangifte, maar gebruikte de aftrekregeling voor buitengewone uitgaven niet omdat zij dacht daarvoor niet in aanmerking te komen. Gemiddeld hadden deze niet-gebruikers lagere ziektekosten dan de mensen die wel van de regeling gebruik maakten. “Toch komen de ziektekosten sneller boven de drempel uit dan men denkt”, verklaart NIVEL-onderzoeker Marianne Pannekeet. “Het zou voor veel chronisch zieken en gehandicapten zeker de moeite lonen hun kosten toch nog eens goed op een rijtje te zetten.” Verbetering Op verzoek van de betrokken ministeries onderzochten het NIVEL en SEO Economisch Onderzoek het gebruik van de aftrekregeling voor bijzondere uitgaven. Nadat in 2005 bleek dat de aftrekregeling in 2004 weinig door chronisch zieken en gehandicapten was benut, is door de overheid en andere partijen veel gedaan om de regeling bekender te maken. Een jaar later blijkt het gebruik van de aftrekregeling onder mensen met een chronische ziekte of handicap met 10% te zijn toegenomen. Niettemin maakt nog altijd 50% van de ‘rechthebbende’ chronisch zieken en gehandicapten geen gebruik van de regeling. Compensatie Behalve de aftrekregeling voor buitengewone uitgaven, kunnen extra ziektekosten van chronisch zieken en gehandicapten worden gecompenseerd via de regeling bijzondere bijstand, die de gemeenten uitvoeren. De bijzondere bijstand is vooral bedoeld voor lage inkomens, terwijl de aftrekregeling voor buitengewone uitgaven door alle inkomensgroepen kan worden gebruikt. Voor mensen met een laag inkomen – die dus weinig inkomstenbelasting betalen – bestaat nog de regeling tegemoetkoming buitengewone uitgaven als aanvulling op de aftrekregeling

Acute pancreatitis during CAPD in The Netherlands

Acute pancreatitis in patients on CAPD treatment is an infrequent, but serious complication. We studied the records of all CAPD patients with acute pancreatitis in the Netherlands from 1979 until May 1992. The incidence of acute pancreatitis during CAPD treatment was 0.46 per 100 treatment-years. In all patients at least one risk factor was present. Hypercalcaemia was the most frequently observed risk factor in our patients. The clinical picture consisted of abdominal pain and vomiting, with normal temperature and normal peristalsis. Plasma amylase was elevated in 18 episodes. Dialysate amylase concentrations exceeded 100 U/l in seven of ten episodes. The dialysate could either be clear, haemorrhagic, or cloudy. Positive dialysate cultures were found in five patients, in most cases with skin flora. No direct correlation with the pancreatitis could be established. Mortality was 58%. Continuation of CAPD or transfer to haemodialysis had no apparent effect on the outcome, but the best prognosis was found in patients with a persistently clear dialysat