Glucose is the most commonly used osmotic agent in

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1 Peritonel Dilysis Interntionl, Vol. 32, pp doi: /pdi /12 $ Copyright 2012 Interntionl Society for Peritonel Dilysis ULTRAFILTRATION AND DIALYSIS ADEQUACY WITH VARIOUS DAILY SCHEDULES OF DIALYSIS FLUIDS Rmón Pnigu, 1 Mlgorzt Debowsk, 2 Mrí-de-Jesús Ventur, 1 Mrcel Ávil Díz, 1 Crmen Prdo Uribe, 1 Crmen Mor, 1 Elvi Grcí López, 3 Bengt Lindholm, 3 nd Jcek Wniewski 2 Unidd de Investigcion Medic en Enfermeddes Nefrologics, 1 Hospitl de Especiliddes, Centro Medico Ncionl Siglo XXI, Mexico City, Mexico; Nlecz Institute of Biocybernetics nd Biomedicl Engineering, 2 Polish Acdemy of Sciences, Wrsw, Polnd; nd Krolinsk Institutet, 3 Divisions of Bxter Novum nd Renl Medicine, Deprtment of Clinicl Science, Intervention nd Technology, Stockholm, Sweden Dilysis regimens for continuous mbultory peritonel dilysis (CAPD) ptients vry with the need for fluid removl, but lso becuse of concerns bout the locl nd systemic consequences of high glucose exposure. The implictions of vrious regimens for dilysis dequcy tht is, fluid nd smll-solute removl re not lwys cler. We therefore nlyzed ultrfiltrtion (UF) nd dequcy indices for 4 different combintions of dilysis fluid. Collections of 24-hour dilyste nd urine were crried out in 99 ptients on CAPD. On 4 seprte occsions, ech ptient performed 4 exchnges in 24 hours, including 3 dily exchnges with 1.36% glucose nd 1 night exchnge with either 1.36% glucose (G1 schedule), 2.27% glucose (G2 schedule), 3.86% glucose (G3 schedule), or icodextrin (Ico schedule). Weekly, totl, nd dilysis Kt/V nd KT were clculted for both ure nd cretinine. The men vlues of ure Kt/V nd KT were significntly lower for the G1 schedule thn for the G3 nd Ico schedules. The dequcy indices for overnight ppliction of 3.86% glucose nd icodextrin were similr. Using dilysis fluids with 1.36% nd 2.27% glucose overnight reduces glucose exposure, but those schedules my provide indequte UF nd smll-solute removl in some ptients (UF < 1 L dily, Kt/V < 1.7). Perit Dil Int 2012; 32(5): epub hed of print: 01 Feb 2012 doi: /pdi KEY WORDS: Continuous mbultory peritonel dilysis; ultrfiltrtion; dilysis dequcy; Kt/V; KT; clernce; ure; cretinine. Correspondence to: M. Debowsk, Nlecz Institute of Biocybernetics nd Biomedicl Engineering, Polish Acdemy of Sciences, Trojden 4, Wrsw PL Polnd. mdebowsk@ibib.ww.pl Received 4 Mrch 2011; ccepted 31 October 2011 Glucose is the most commonly used osmotic gent in peritonel dilysis (PD) fluids, nd bgs contining solutions with 1.36%, 2.27%, nd 3.86% glucose re vilble in most countries. Among the importnt problems in PD therpy re the potentil side effects of high glucose lod, including metbolic problems nd dmge to the peritonel membrne. Icodextrin, glucose polymer, hs been introduced s n lterntive to the glucose in PD solutions becuse it provides better ultrfiltrtion (UF) during long dwells nd reduces the metbolic effects (1,2). The ppliction of vrious dilysis fluids influences fluid nd solute removl. The Europen Best Prctice Guidelines nd the Kidney Disese Outcomes Qulity Inititive guidelines indicte tht dequcy trgets for dilysis should include both ure removl nd fluid removl (3,4). Trgets should be bsed only on the removls chieved by PD. According to the guidelines, the minimum peritonel trget for ure Kt/V should be 1.7 weekly, nd the minimum peritonel trget for net UF (in nuric ptients) should be 1.0 L in 24 hours (3,4). Previously, minimum weekly cretinine clernce trget of 60 L/1.73 m 2 ws commonly pplied (5); however, this trget clernce is not included in the current guidelines (4). In the present study, we used uniform schedule of dily exchnges to investigte both fluid removl (peritonel net UF, urine volume, nd totl fluid removl) nd bttery of dilysis dequcy indices (DAIs) bsed on smll solutes (both ure nd cretinine) in nuric nd non-nuric continuous mbultory PD (CAPD) ptients. METHODS The study ws performed in 99 ptients on CAPD (men ge: 54 ± 13 yers; 56 men). Four ptients were copies for distribution, contct Multimed Inc. t mrketing@multi-med.com. 545

2 PANIAGUA et l. september Vol. 32, No. 5 PDI low trnsporters, 38 were low-verge, 48 were highverge, nd 8 ptients were high trnsporters ccording to Twrdowski s peritonel equilibrtion test clssifiction (9); 1 ptient ws not clssified becuse of lck of dt. Of the 99 ptients, 46 were nuric (dily urine output <100 ml), 52 were non-nuric, nd 1 ptient ws not clssified. The 4 study schedules ech consisted of 4 exchnges in 24 hours (Tble 1): 3 dytime exchnges using one type of glucose-bsed dilysis fluid (lwys 1.36% glucose) nd 1 overnight exchnge using 4 different types of dilysis fluid in ech ptient: 1.36% (G1 schedule), 2.27% (G2 schedule), or 3.86% glucose (G3 schedule), or 7.5% icodextrin (Ico schedule). Typiclly, the infused volume ws 8.3 L dily, but in 13 of 396 collections, it ws less tht is, 6 L 7.6 L including the overfill volume t 75 ml per bg [see, for exmple, Dvies (10) nd L Mili et l. (11)]. Ech schedule ws performed in ech ptient, nd 24-hour drined dilyste nd urine were collected. The fluids were mixed (seprtely by ptient), nd urine nd dilyste smples were tken for concentrtion mesurements. The DAIs used in the study included the frctionl volume clered from ure or cretinine; Kt/V, which is type of frctionl solute removl index; nd KT (weekly clernce) of ure or cretinine, which is type of equivlent continuous clernce (6 8). Volumes of urine nd dilyste (by 24-hour collection) nd of totl body wter (by bioimpednce), nd serum concentrtions of ure nd cretinine were mesured. The mesured solute concentrtions nd volumes were used to estimte DAIs bsed on clcultion of the totl solute mss in the ptient s body nd the solute mss removed from the body. Weekly dilysis (subscript d ) nd weekly totl Kt/V nd KT (in liters) were clculted s follows (6,7): Kt/V d = 7 d /M b, KT d = 7 d /, Kt/V = 7 (d + ΔM r ) / M b, nd KT = 7 (d + ΔM r ) /, where d nd ΔM r re, respectively, the solute msses in 24-hour dilyste nd urine collections; M b is the solute mss in the body; nd is the solute concentrtion in serum. Dilytic Kt/V nd totl Kt/V re the sme s the index Kt/V ure regulrly used in clinicl prctice for the ssessment of PD efficiency. For cretinine, the weekly clernce, Cl Cr, scled to body surfce re (BSA), is often clculted s follows: Cl Cr = (7,Cr /,Cr ) / (1.73 / BSA), where,cr is the sum of the cretinine mss in 24-hour dilyste nd urine collections, nd,cr is the serum cretinine concentrtion. Thus, Cl Cr is equl to cretinine KT scled by the fctor 1.73 / BSA. Ultrfiltrtion ws clculted s the difference between the volume of collected dilyste nd the volume of fluid infused per bg of dilyste. STATISTICAL ANALYSIS For multiple comprisons of the results obtined by pplying the 4 different fluid schedules, one-wy nlysis of vrince nd the Tukey Krmer honestly significnt difference criterion were pplied. Comprisons between nuric nd non-nuric ptients were performed using the t-test or two-sided rnk sum test, s pplicble. For ech vrible, the hypothesis bout norml distribution ws checked by chi-squre goodness-of-fit test. Spermn correltion nlysis ws used to investigte possible reltions between the studied prmeters. A p vlue less thn 0.05 ws considered sttisticlly significnt. RESULTS TABLE 1 The Investigted Dilysis Fluid Schedules Fluid Type of fluid schedule For dytime For overnight G % G % G G % G % G G % G % G Ico % G 1 7.5% Ico G = glucose; Ico = icodextrin. Tested in 99 ptients on continuous mbultory peritonel dilysis. Ure nd cretinine concentrtions in serum (mesured once for 4 dily collections) were, respectively, ± 36.1 mg/dl nd 10.7 ± 3.6 mg/dl. UF AND TOTAL FLUID REMOVAL The 24-hour net peritonel UF ws different for most of the dilysis schedules, except for G3 nd Ico, which hd similr dily UF vlues. The 24-hour urine volumes collected concomitntly with the dilyste collections were ll similr (Tble 2). In the G1 nd G2 schedules, the dily men UF ws less thn 1 L, vlue tht my not be cceptble for nuric ptients. In fct, 24-hour UF nd totl fluid removl were much lower thn 1 L for the G1 nd G2 schedules in nuric ptients (Tble 3). There ws 546 copies for distribution, contct Multimed Inc. t mrketing@multi-med.com.

3 PDI september Vol. 32, No. 5 CAPD EFFICIENCY tendency for UF to be higher in nuric thn in non-nuric ptients, but the difference ws sttisticlly significnt only for the G3 schedule (Tble 3). The totl fluid removl ws lower in nuric thn in non-nuric ptients, but for schedule G3, the difference ws not sttisticlly significnt (Tble 3). ADEQUACY OF VARIOUS DIALYSIS SCHEDULES Tble 2 shows the Kt/V nd KT for ure nd cretinine nd the Cl Cr for the 4 dilysis fluid schedules. The men vlue of ure Kt/V in schedule G1 (nd mrginlly in schedule G2) ws below 1.7 tht is, the minimum TABLE 2 Adequcy Prmeters (Men ± Stndrd Devition) for the Investigted Fluid Schedules Vlue by fluid schedule Prmeter G1 G2 G3 Ico Ure Weekly Kt/V Totl 1.52± ± ± ±0.51 Dilytic 1.49± ± ± ±0.50 Weekly KT (L) Totl 53.0± ± ± ±14.4 Dilytic 51.6± ± ± ±13.9 Weekly M R (g) 60.4± ± ± ±24.3 Cretinine Weekly Kt/V Totl 1.27± ± ± ±0.42 Dilytic 1.19± ± ± ±0.4 Weekly KT (L) Totl 44.0± ± ± ±12.2 Dilytic 41.3± ± ± ±11.0 Weekly clernce (L) 46.7± ± ± ±14.3 Weekly M R (g) 4.5± ± ± ±1.8 Dily fluid removl (L) Ultrfiltrtion b 0.39± ± ± ±0.42 Urine volume 0.26± ± ± ±0.31 Totl volume b 0.65± ± ± ±0.48 G1, G2, G3 = ll-glucose schedules (see Tble 1); Ico = schedule with icodextrin for the overnight dwell (see Tble 1); M R = totl removed mss. Significnt difference, t the 0.05 level, compred with G1. b Significnt differences t the 0.05 level were found between ll schedule pirs except for G3 compred with Ico. TABLE 3 24-Hour Fluid Removl in Anuric (n=46) nd Non-Anuric (n=52) Continuous Ambultory Peritonel Dilysis Ptients Using the Investigted Fluid Schedules Fluid Ultrfiltrtion (L) Urine volume (L) Totl fluid removl (L) schedule Anuric Non-nuric Anuric Non-nuric Anuric Non-nuric G1 0.46± ± ± ± ± ±0.63 G2 0.81± ± ± ± ± ±0.59 G3 1.35± ± ± ± ± ±0.63 Ico 1.12± ± ± ± ± ±0.49 G1, G2, G3 = ll-glucose schedules (see Tble 1); Ico = schedule with icodextrin for the overnight dwell (see Tble 1). Significnt difference, t the 0.05 level, for nuric compred with non-nuric ptients. copies for distribution, contct Multimed Inc. t mrketing@multi-med.com. 547

4 PANIAGUA et l. september Vol. 32, No. 5 PDI suggested by interntionl guidelines (3,4). The men vlue of ure Kt/V ws significntly lower for the G1 schedule thn for the G3 nd Ico schedules. The men vlues of cretinine Kt/V nd Cl Cr were similr in ll investigted schedules. The Kt/V nd KT for ure were bout 26% higher thn those for cretinine. Weekly Cl Cr tht is, KT scled using 1.73 m 2 /BSA m 2 ws bout 6% higher thn KT without scling. The KT d ws similr in nuric nd non-nuric ptients for both ure nd cretinine; however, the Kt/V d ws higher for nuric thn for non-nuric ptients (Tble 4) becuse of lower V for nuric ptients (totl body wter ws 33.9 ± 7.5 L for nuric ptients nd 39.0 ± 9.3 L for non-nuric ptients, p < 0.01). Totl KT tht is, dilytic plus residul renl KT ws, s expected, lower for nuric ptients (lthough the difference ws sttisticlly significnt only for cretinine). No significnt difference ws found for totl Kt/V (Tble 4). CORRELATIONS BETWEEN Kt/V, KT, UF, AND SERUM CONCENTRATIONS AND REMOVED MASSES OF UREA AND CREATININE In the nlyzed dilysis schedules, ure Kt/V nd ure KT both correlted with UF (0.23 < r < 0.53, p < 0.05). However, no correltion ws observed between the dilysis dequcy indices (Kt/V nd KT) for cretinine nd UF, except in the Ico schedule (0.35 < r < 0.42, p < 0.01). The correltions between the vrious DAIs nd other prmeters, nd their sttisticl significnce, were similr when nlyzed seprtely for ech schedule. We therefore present only the pooled dt for ll schedules (Tbles 5, 6, nd 7). Ure Kt/V ws positively correlted with cretinine Kt/V, nd ure KT with cretinine KT, but the ltter correltion ws weker (Tble 5). There ws strong reltion between the ure nd cretinine msses removed by the kidneys (r = 0.95, p < 0.01), but the correltion between the ure nd cretinine msses removed by dilysis ws weker (r = 0.57, p < 0.01). Serum ure nd cretinine concentrtions were lso correlted (Tble 5). The msses removed by dilysis correlted positively with serum concentrtions for ure nd cretinine (r = 0.76 nd r = 0.79 respectively), but similr correltions for the msses removed in urine were much weker nd negtive for cretinine (r = 0.15 for ure nd r = 0.24 for cretinine, Tbles 6 nd 7). When considered seprtely for ure nd cretinine, totl nd dily KT correlted with the respective Kt/V (Tbles 6 nd 7). For cretinine nd ure, we observed negtive ssocitions between the serum concentrtion nd the Kt/V nd KT ( 0.5 r 0.17, Tbles 6 nd 7). No or only wek reltion ws observed between the totl removed mss of ure nd cretinine nd totl Kt/V, but correltions were found between totl KT nd totl removed mss for ure nd cretinine (r = 0.43 nd r = 0.27 respectively, Tbles 6 nd 7). Similr correltions, or lck of correltion, were found between the msses removed by dilysis nd the estimted DAIs (Tbles 6 nd 7). DISCUSSION Assessments of dequcy for 4 different CAPD schedules were performed using two different DAIs (Kt/V TABLE 4 Ure nd Cretinine Removl in Anuric (n=46) nd Non-Anuric (n=52) Continuous Ambultory Peritonel Dilysis Ptients Using the Investigted Fluid Schedules Prmeter Weekly Kt/V Weekly KT (L) nd fluid Totl Dilytic Totl Dilytic schedule Anuric Non-nuric Anuric Non-nuric Anuric Non-nuric Anuric Non-nuric Ure G1 1.58± ± ± ± ± ± ± ±12.5 G2 1.76± ± ± ± ± ± ± ±12.4 G3 1.82± ± ± ± ± ± ± ±15.7 Ico 1.81± ± ± ± ± ± ± ±13.0 Cretinine G1 1.28± ± ± ± ± ± ± ±10.8 G2 1.35± ± ± ± ± ± ± ±9.8 G3 1.39± ± ± ± ± ± ± ±8.0 Ico 1.38± ± ± ± ± ± ± ±11.6 G1, G2, G3 = ll-glucose schedules (see Tble 1); Ico = schedule with icodextrin for the overnight dwell (see Tble 1). Significnt difference, t the 0.05 level, for nuric compred with non-nuric ptients. 548 copies for distribution, contct Multimed Inc. t mrketing@multi-med.com.

5 PDI september Vol. 32, No. 5 CAPD EFFICIENCY TABLE 5 Correltions (r Vlues) Between Cretinine- nd Ure-Bsed Adequcy Prmeters in All Ptients Ure Kt/V KT Totl Dilytic Totl Dilytic Totl Dilytic Urinry Cretinine Kt/V KT Totl Dilytic Totl Dilytic Totl Dilytic Urinry = serum concentrtion; = removed mss. Boldfce type indictes vlues with n ssocited p < Ure Kt/V KT TABLE 6 Correltions (r Vlues) Between Ure-Bsed Adequcy Prmeters in All Ptients Ure Kt/V KT Totl Dilytic Totl Dilytic Totl Dilytic Urinry Totl Dilytic Totl Dilytic Totl Dilytic Urinry 1.00 = serum concentrtion; = removed mss. Boldfce type indictes vlues with n ssocited p < nd KT, estimted for both ure nd cretinine) in 99 ptients from 24-hour collections of dilyste nd urine. Peritonel net UF, urine volume, nd totl fluid removl were investigted seprtely in nuric nd non-nuric ptients. To the best of our knowledge, neither the KT for ure, nor the Kt/V nd KT for cretinine, hve previously been reported for CAPD ptients, lthough some studies hve ddressed those indices for other tretment modlities (12 14). Our work showed tht, in some ptients, the use of 3 dily 1.36% glucose exchnges nd 1 overnight exchnge with either 1.36% glucose (G1) or 2.27% glucose (G2) my not provide cceptble dilysis dequcy ( indequcy here defined s weekly Kt/V ure below 1.7). The G1 nd G2 schedules both resulted in 24-hour net peritonel UF below 1.0 L in severl ptients, which cn be considered too low ccording to current guidelines (3). The UF volumes nd DAIs for ptients using 3.86% glucose (G3) or icodextrin (Ico) overnight were similr nd generlly ccorded with estblished trgets. The nlysis of vrious dilysis schedules showed tht UF correlted better with ure dequcy indices thn with cretinine indices, becuse ure concentrtions in dilyste nd in blood equilibrte during dilysis. By contrst, the cretinine concentrtion in dilyste is considerbly lower thn tht in serum t the end of dwell (15). The removl of ure in PD therefore strongly depends on fluid removl, but the dilytic removl of cretinine depends on both the UF nd the rte of cretinine diffusive trnsport. copies for distribution, contct Multimed Inc. t mrketing@multi-med.com. 549

6 PANIAGUA et l. september Vol. 32, No. 5 PDI TABLE 7 Correltions (r Vlues) Between Cretinine-Bsed Adequcy Prmeters in All Ptients Cretinine Kt/V KT Totl Dilytic Totl Dilytic Totl Dilytic Urinry Cretinine Kt/V KT Totl Dilytic Totl Dilytic Totl Dilytic Urinry 1.00 = serum concentrtion; = removed mss. Boldfce type indictes vlues with n ssocited p < The ure nd cretinine msses removed by dilysis correlted positively with serum concentrtions, but similr correltions for the mss removed with urine were much weker nd even negtive for cretinine (Tbles 6 nd 7). Tht observtion grees with the previling understnding of diffusive trnsport for those two solutes during dilysis. However, the solute DAIs correlted negtively with their respective serum concentrtions (Tble 6 nd 7), mening tht ptients with higher DAIs hve lower serum levels of the removed solutes, despite the solute mss removed by dilysis being generlly lower in ptients with low serum concentrtion of tht solute. It is importnt to note tht the 24-hour studies reported here used fluid schedules tht were not the schedules prescribed for the study ptients (nevertheless, 95 of the 99 ptients routinely used one of the 4 fluid schedules in the clinicl protocol), nd therefore the removed mss ws not, in generl, equl to the generted mss (except for the routine schedule of the ptient). However, the DAIs cn lso be ssessed for non-stedy metbolic conditions (8,12). It is interesting to observe tht, lthough the Kt/V nd KT indices correlted (Tbles 6 nd 7), the correltions were not very strong (r 2 < 0.36). It might then be inferred tht those two types of indices re sensitive to fctors (such s differences in the genertion rtes for ure nd cretinine) other thn the removed msses nd serum concentrtions lone. Furthermore, the correltions between the Kt/V indices for ure nd cretinine were much stronger (r 2 > 0.58) thn the correltions between the KT indices for those two solutes (r 2 < 0.28, Tble 5). In the evlution of dilysis dequcy for ptients on PD, the focus hs long been on the ure Kt/V, nd ttention to ure KT, cretinine Kt/V, nd (t lest recently) cretinine 550 KT (tht is, in the form of Cl Cr ) hs been lcking. The focus on ure Kt/V in the clinicl nd reserch settings is, to some extent, justified by our finding tht ure Kt/V correltes with ll other DAIs. On the other hnd, our dt nd some previous studies lso show tht, when only ure Kt/V is used, some informtion bout the removl of smll solutes is lost becuse the correltions between ure Kt/V nd other prmeters re generlly wek [see Tbles 5 nd 6, nd reports by other uthors (16 18)]. Therefore, lthough the stndrd clinicl evlution of dequcy my be for prcticl resons reduced to one dequcy index (ure Kt/V), it would be resonble tht future clinicl studies on the reltionship between dilysis dequcy nd ptient survivl lso tke into ccount other indices in the extended DAI system, nd tht ssessments be bsed t lest on two smll solutes, ure nd cretinine. DISCLOSURES BL is employed by Bxter Helthcre Corportion. The remining uthors hve no finncil conflicts of interest to disclose. REFERENCES 1. Freid P, Issd B, Drtw M, Lobbedez T, Wu L, Leypoldt JK, et l. A combined crystlloid nd colloid PD solution s glucose-spring strtegy for volume control in hightrnsport APD ptients: prospective multicenter study. Perit Dil Int 2009; 29: Pnigu R, Ventur MD, Avil Díz M, Cisneros A, Vicenté Mrtínez M, Furlong MD, et l. Icodextrin improves metbolic nd fluid mngement in high nd high-verge trnsport dibetic ptients. Perit Dil Int 2009; 29: copies for distribution, contct Multimed Inc. t mrketing@multi-med.com.

7 PDI september Vol. 32, No. 5 CAPD EFFICIENCY 3. Dombros N, Drtw M, Ferini M, Gokl R, Heimbürger O, Krediet R, et l. Europen best prctice guidelines for peritonel dilysis. 7. Adequcy of peritonel dilysis. Nephrol Dil Trnsplnt 2005; 20(Suppl 9): Peritonel Dilysis Adequcy 2006 Work Group. Clinicl prctice guidelines for peritonel dequcy, updte Am J Kidney Dis 2006; 48(Suppl 1):S II. NKF-K/DOQI clinicl prctice guidelines for peritonel dilysis dequcy: updte Am J Kidney Dis 2001; 37(Suppl 1):S Wniewski J, Debowsk M, Lindholm B. Theoreticl nd numericl nlysis of different dequcy indices for hemodilysis nd peritonel dilysis. Blood Purif 2006; 24: Wniewski J, Lindholm B. Frctionl solute removl nd Kt/V in different modlities of renl replcement therpy. Blood Purif 2004; 22: Wniewski J, Debowsk M, Lindholm B. Cn the diverse fmily of dilysis dequcy indices be understood s one integrted system? Blood Purif 2010; 30: Twrdowski ZJ. PET simpler pproch for determining prescriptions for dequte dilysis therpy. Adv Perit Dil 1990; 6: Dvies SJ. Overfill or ultrfiltrtion? We need to be cler. Perit Dil Int 2006; 26: L Mili V, Pozzoni P, Crepldi M, Loctelli F. Overfill of peritonel dilysis bgs s cuse of underestimtion of ultrfiltrtion filure. Perit Dil Int 2006; 26: Debowsk M, Lindholm B, Wniewski J. Adequcy indices for dilysis in cute renl filure: kinetic modeling. Artif Orgns 2010; 34: Leypoldt JK, Burkrt JM. Smll-solute nd middlemolecule clernces during continuous flow peritonel dilysis. Adv Perit Dil 2002; 18: Leypoldt JK, Jber BL, Lysght MJ, McCrthy JT, Morn J. Kinetics nd dosing predictions for dily hemofiltrtion. Nephrol Dil Trnsplnt 2003; 18: Wniewski J, Heimbürger O, Werynski A, Prk MS, Lindholm B. Diffusive nd convective solute trnsport in peritonel dilysis with glucose s n osmotic gent. Artif Orgns 1995; 19: Blke P, Burkrt JM, Churchill DN, Dugirds J, Depner T, Hmburger RJ, et l. Recommended clinicl prctices for mximizing peritonel dilysis clernces. Perit Dil Int 1996; 16: Blke PG. Cretinine is the best molecule to trget dequcy of peritonel dilysis. Perit Dil Int 2000; 20(Suppl 2):S Vonesh EF, Morn J. Discrepncies between ure Kt/V versus normlized cretinine clernce. Perit Dil Int 1997; 17: copies for distribution, contct Multimed Inc. t mrketing@multi-med.com. 551