UF failure may be defined as a net UF < 400 mL at 4 hours of dwell (i.e., drain volume < 2400 mL\/4 hrs) using a hypertonic glucose solution such as a 4.25% PD solution, or when patients are unable to achieve a daily UF volume > 750 mL once anuric, in the absence of catheter malfunction, fluid leaks or extensive intraperitoneal adhesions(1\u20135). It is based on the net UF obtained after a standard dialysis dwell and the glucose concentration of the PD solution used. UFF results in the inability to achieve adequate fluid balance and subsequent fluid overload.\u00a0 In most patients on continuous ambulatory PD (CAPD), UF capacity and membrane characteristics appear stable for up to 3 years. However, the risk of UF failure tends to increase with time on treatment and is not just as a result of the loss of residual kidney function (RKF) but progressive membrane injury. Progressive membrane injury leads to inadequate solute transfer, high solute transfer, decreased UF and decreased convective clearance. Cumulative risk of permanent UF loss has been shown to be 9% at 4 years and 35 \u2013 50% over 5 years(6). UF failure has also been shown to cause technique failure in 1.7 \u2013 13.7% of PD patients(7). Diagnostic tests usually involve assessing peritoneal membrane function (with the PET for example), measuring drain volume and determining the type of UF failure(8).<\/p>\n
UFF characterized by high small solute transport, also known as type I UFF, is characterized by high solute transport. This type of failure is thought to be due to an increase in effective peritoneal surface area and\/or permeability, resulting from the presence of vasculopathy and endothelial dysfunction, increased glucose absorption from dialysate, increased protein loss into dialysate and decreased UF. Type I UFF is the most common cause of permanent UF capacity loss and is associated with increased mortality and morbidity, and patients have a poor prognosis(9,10). Type I UFF is also associated with increased inflammation, as can occur during peritonitis(11,12).<\/p>\n
Aquaporins are essential for water transport and UF(13,14).\u00a0 UF failure due to aquaporin deficiency in PD may be yet another type of UFF, albeit rare. Although the etiology is still unclear, it may involve reduction of aquaporins in the peritoneal membrane or may be the result of increased reactive carbonyl compounds (RCOs) and glycation end products related to the use of conventional PD solutions(13\u201316). Its diagnosis is usually based on the presence of altered sodium sieving.<\/p>\n
UF failure characterized by low solute transport, or type II membrane failure,<\/em><\/strong> is relatively rare and mostly seen in patients with peritoneal sclerosis(8). It is characterized by decreased solute and water transport with decreased UF capacity and reflects major disruption of peritoneal membrane and\/or intraperitoneal fluid distribution. It is usually due to adhesions, trapped fluid or sclerosing peritonitis.<\/p>\n UFF due to high lymphatic absorption or type III membrane failure is characterized by increased resorption of dialysate from the peritoneal cavity due to increased lymphatic flow(8). The etiology is not known and exclusion of mechanical problems (leaks and catheter dysfunction) and other types of membrane failure can lead to its differential diagnosis of low UF despite normal membrane function.<\/p>\n Treatment of UFF mostly depends on the type of membrane failure.\u00a0 In the case of UFF with increased solute transport (Type I) the mainstay of therapy is shortening the dwell time, providing more frequent exchanges and preventing peritonitis(8,17,18).\u00a0 Eliminating long dwell exchanges is highly recommended.\u00a0 Temporary discontinuation of PD to allow a rest period for about 4 \u2013 12 weeks has been reported to restore membrane function(8,17\u201320). In cases of UFF due to or aquaporin failure, shorter dwells with higher glucose solutions or the use of polyglucose for long dwells are recommended. For cases of UFF with low solute transfer (Type II), transfer to HD may be required for adequate patient management. However, if some degree of RRF is present, maintenance on this dialytic modality may be feasible. If UFF due with high lymphatic absorption (Type III) is suspected, all interventions that maximize UF (short dwell time, high tonicity of dialysate) need to be combined. This would serve to maintain the balance between continuous tissue reabsorption and declining UF. Pharmacologic interventions not recommended at this time due to the lack of supporting evidence.<\/p>\n The information and reference materials contained in this document are intended solely for the general education of the reader. It is intended to provide pertinent data to assist you in forming your own conclusions and making decisions. This document should not be considered an endorsement of the information provided nor is it intended for treatment purposes and is not a substitute for professional evaluation and diagnosis. Additionally, this information is not intended to advocate any indication, dosage or other claim that is not covered, if applicable, in the FDA-approved label.<\/em><\/p>\n P\/N 102496-01 Rev. A 06\/2016<\/span><\/p>\nTreatment<\/h4>\n
References<\/h4>\n
\n