Recent work has shown that the dialyzer mass transfer area coefficient (KoA) for urea increases when the dialysate flow rate is increased from 500 to 800 mL/min. In this study we determined urea and creatinine clearances for two commercial dialyzers containing polysulfone hollow fibers in vitro at 37°C, a nominal blood flow rate of 300 mL/ min, and dialysate flow rates (Qd) ranging from 100 to 800 mL/min. A standard bicarbonate dialysis solution was used in both the blood and dialysate flow pathways, and clearances were calculated from solute concentrations in the input and output flows on both the blood and dialysate sides. Urea and creatinine KoA values, calculated from the mean of the blood and dialysate side clearances, increased (p < 0.01) with increasing Qd over the entire range studied. The increase in both urea and creatinine KoA with increasing Qd was proportional to the KoA value. These data show that changes in Qd alter small solute clearances greater than predicted assuming a constant KoA.
In spite of the growing evidence that daily hemodialysis (DHD) improves clinical outcomes and quality of life, the additional dialysis costs are not currently reimbursed in the United States. Nor have there been reports of the effects of DHD on end-stage renal disease (ESRD) global costs, which would help predict the financial impact of DHD on the ESRD program. Since 1996, 22 patients (20 in-center, 2 home) have switched from conventional thrice-weekly dialysis to short, daily dialysis with six treatments per week. Eighteen patients started for medical indications, and four started for nonmedical reasons. Causes of ESRD were the following: diabetes mellitus (6), hypertension (4), glomerulonephritis (6), hereditary (2), and other (4). Mean age was 56 ± 16 years. Patients had an average of 3.3 major comorbidities. Weekly conventional HD dialysis times were divided into six DHD treatments, each 2.0 ± 0.3 hours. Weekly Kt/V remained unchanged. Twenty-two patients were followed on DHD for 220 patient-months: 7 patients died after 1.8 ± 1.3 months, 2 were transplanted at 4.3 ± 3.2 months, and 2 discontinued DHD at 3.6 ± 4.8 months. Eleven patients remain on DHD at 17.4 ± 8.3 months. Actual costs per extra dialysis session are as follows: $14.30 for supplies and $3.20 for labor for setup/cleanup time (15 minutes at $12.80/hour). Annualized DHD savings are based on comparison of doses of epoetin alpha (Epogen) and blood pressure medication at the start and after 12 months of DHD. Hospitalization rates include all enrolled patients, comparing rates for the 12 months prior to DHD with the first year on DHD, or annualized rates for those on DHD less than one year. Cost assumptions are $9/ 1000 U Epogen, $1/blood pressure pill, and $1200/per day of hospitalization. Extra transportation costs were covered by the patients. No increased access problems were observed. For patients on short DHD longer than 12 months, supply and labor costs increased to $2733/patient/year; however, Epogen use was reduced 55%, and blood pressure medications were reduced 40%. For all patients who switched to DHD, hospitalization rates were reduced 24%. This resulted in a net savings of about $4241/patient/ year after 12 months on DHD. Overall ESRD costs were substantially decreased on DHD. These cost savings must be passed on to providers before DHD becomes more widely available.
Home hemodialysis (HD) for the treatment of end-stage renal disease was first implemented about 30 years ago. In this paper the application of telematics monitoring services for supporting patients who need home HD or satellite HD is described. Two modified HD machines were located in two renal units, and a central control station (CCS, UNIX workstation with multimedia PC terminal) was located in another room of the hospital. Bidirectional communication between the modified HD machines and the CCS was managed using ISDN (Integrated Services Digital Network) links. Nine patients had 150 HD sessions performed using these HD machines over a period of 5 months. This system, called the HOMER-D system, provided on-line, remote supervision of the HD machine-related functions and the clinical condition of the patients through measurement of blood pressure, pulse rate, PO2 (pulse oxymetry), and ECG from the CCS. Any disturbances in the functioning of the HD machines were both visible and audible in the CCS, and the observer could give teleconsultation to the renal unit staff. No major dialysis-associated complications were observed; all data and alarms were transmitted correctly; and patients received adequate HD treatment.
Defining adequacy of dialysis remains an elusive goal. The application of the Kt/Vurea concept to clinical dialysis was a major improvement in trying to define a dialysis dose. Intuitively, the Kt/V concept makes a great deal of sense: the urea clearance of the dialyzer during dialysis (K), multiplied by the time (t) of dialysis, divided by the patient's urea distribution volume (V) ought to give the best number to compare the efficiency of dialyses that patients receive. There are, however, many pitfalls associated with the whole Kt/Vurea concept.
Urea kinetic modeling measures the delivered dose of hemodialysis and is used to monitor dialysis adequacy. Obtaining samples for adequacy calculations is a challenge for home hemodialysis (HHD) patients. Ideally, the urea reduction ratio (URR) should be measured at a typical dialysis session; therefore, for HHD patients test specimens should be drawn at home and transferred to a clinical laboratory. Would blood urea nitrogen (BUN) remain stable if samples were mailed to the laboratory? To answer this question, BUN was measured in pre- and postdialysis samples from 20 patients over 8 days of laboratory storage. While BUN values varied among the patient population, neither pre- nor postdialysis values showed any significant variation during the 8-day storage time. These results suggest that BUN values are sufficiently stable for specimens to be drawn at home and mailed to a testing laboratory.
Home Hemodialysis InternationalVolume 3, Issue 1 p. 9-12 Article Dialysis Therapy in the United States: A Historical Perspective Belding H. Scribner, Corresponding Author Belding H. Scribner scrib@u.washington.edu University of Washington, Seattle, Washington, U.S.A.Correspondence to: Belding H. Scribner, MD, 3110-H Portage Bay, Place East, Seattle, Washington 98102 U.S.A.Search for more papers by this author Belding H. Scribner, Corresponding Author Belding H. Scribner scrib@u.washington.edu University of Washington, Seattle, Washington, U.S.A.Correspondence to: Belding H. Scribner, MD, 3110-H Portage Bay, Place East, Seattle, Washington 98102 U.S.A.Search for more papers by this author First published: 08 September 2016 https://doi.org/10.1111/hdi.1999.3.1.9Citations: 7Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Citing Literature Volume3, Issue1January 1999Pages 9-12 RelatedInformation
The growing interest in daily dialysis and combined continuous and intermittent dialysis treatments has created the need for a dialysis dosing model that is valid over a wide range of dosing frequency and intensity. Three models have been described for this purpose and are reviewed here. They have in common the concept of a continuous clearance value which is equivalent to the summed intermittent dialysis prescribed. The continuous clearance models all define a point on the saw-toothed blood urea nitrogen (BUN) concentration profile and calculate the continuous clearance required to achieve this at the same urea generation rate. The points modeled are the peak predialysis concentration (pkKt/V), the average Co (standard Kt/V, stdKt/V), and time-averaged urea concentration (TAC), which is termed equivalent renal clearance (EKRt/V). At the present time the only data for evaluation of clinical relevance of the three models is continuous ambulatory peritoneal dialysis (CAPD) outcome. The stdKt/V predicts that optimal CAPD outcome requires weekly stdKt/V 2.0, while the pkKt/V and EKRt/V models predict optimal doses of 1.8 and 3.0. These results suggest that the stdKt/V is the most realistic model, but data over much higher levels of therapy are not yet available to judge generalizability. The stdKt/V model was used to assess dose in two hemodialysis studies with 5 to 6 dialyses per week and showed that in one study the stdKt/V was only 2.0, while in the second study it was 5.6. These results show that dose can vary widely with a similar number of dialyses per week and point to the need for a generalized dosing model to guide and compare studies of daily home dialysis.
Home Hemodialysis InternationalVolume 3, Issue 1 p. 72-74 Article Reflections on 24 Years of Renal Care Judy Weintraub, Corresponding Author Judy Weintraub judyweb9@earthlink.net Los Angeles, California, U.S.A.Correspondence to: Judy Weintraub, MS ED, P.O. Box 67E87, Los Angeles, California, 90067 U.S.A.Search for more papers by this author Judy Weintraub, Corresponding Author Judy Weintraub judyweb9@earthlink.net Los Angeles, California, U.S.A.Correspondence to: Judy Weintraub, MS ED, P.O. Box 67E87, Los Angeles, California, 90067 U.S.A.Search for more papers by this author First published: 08 September 2016 https://doi.org/10.1111/hdi.1999.3.1.72Citations: 1Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume3, Issue1January 1999Pages 72-74 RelatedInformation
Seven patients, mean age 42.57 ± 15.69 years (range 21 - 67 years), on standard hemodialysis (SHD), 4 - 5 hours, three times per week for 11.0 ± 6.63 years (range 1 - 18 years), were switched to daily hemodialysis (DHD), 2 - 2.5 hours, six times per week. For each type of treatment similar parameters were applied, and the total weekly time was the same. Mean duration of DHD was 15.4 ± 4.98 months (range 7 - 20 months). We report here our results of quantification in each method, including time-averaged concentration (TAC), normalized protein catabolic rate (PCRn), equilibrated Kt/V (eKt/V), equivalent normalized continuous standard clearance [std(Kt/V)], equivalent renal urea clearance (eKRn), and time-averaged deviation (TAD). With DHD, urea TAC was reduced from 19.09 ± 3.47 to 15.16 ± 3.21 mmol/L (p = 0.026), urea TAD diminished from 4.76 ± 1.04 to 2.52 ± 0.57 mmol/L (p = 0.000 53), PCRn increased from 1.11 ± 0.23 to 1.42 ± 0.24 g/kg/day (p = 0.001), weekly eKt/V increased from 4.11 ± 0.31 to 4.74 ± 0.43 (p = 0.000 25), std(Kt/V) rose from 2.17 ± 0.06 to 4.02 ± 0.25 (p = 0.0001), and eKRn increased from 12.96 ± 0.60 to 21.7 ± 3.09 mL/min (p = 0.000 45). On DHD the most important quantitative variation is the decrease of urea TAD (closer to that of a healthy kidney), due to the increased frequency of dialysis; std(Kt/V) practically doubled and represents 30% of that of normal renal function. These changes are probably the main explanation for the clinical improvements, but it is difficult to dissociate the effects of increased dialysis dose from the effects of decreased TAD.
What constitutes adequate dialysis has been debated in the nephrology literature over the past eight years. The mortality rate of patients on dialysis in the United States is about 20% per year. We believed that short and infrequent dialysis sessions contributed to poor outcomes. To improve the results, Lynchburg Nephrology started the nightly home hemodialysis (NHHD) program in September 1997. Ten patients were trained in the first 15 months of the program. Patients dialyzed 7 - 9 hours, 6 nights/week, using the Fresenius 2008H machine. A standard dialysis solution with 2.0 mEq/L potassium, calcium concentration of 3.0 - 3.5 mEq/L was used. Dialysis solution flow rates were 200 - 300 mL/min. Serum phosphate levels were maintained above 2.5 mg/dL by adding 0 - 45 mL Fleet's Phosphosoda to the bicarbonate bath. Patients had marked improvement in quality of life as measured with the SF-36. Blood pressure was better controlled with fewer medications. All phosphate binders were eliminated. Caloric intake and protein intake increased to normal levels as measured by three-day dietary histories pre-NHHD, and at 3, 6, and 12 months on NHHD. Epoetin alfa dosages were reduced by about 50%. Nightly home hemodialysis should be considered as a valuable modality option for end-stage renal disease patients; it is potentially superior to conventional thrice-weekly hemodialysis.
Blood flow, measured by an ultrasound flowmeter, and the extent of hemolysis were assessed during a single, routine dialysis in 100 patients. Before and after the hemodialysis session, blood was drawn for measurements of haptoglobin (HPT), hemoglobin (HGB), albumin (ALB), and lactate dehydrogenase (LDH). The average values were as follows: pump speed 510 mL/ min, real blood flow 422 mL/min, arterial chamber pressure -350 mm Hg, and venous chamber pressure 279 mm Hg. Haptoglobin concentrations were higher in patients with central vein catheters compared to patients with arteriovenous access. The meaning of this finding is unclear. Mean HPT concentrations increased significantly less during hemodialysis (2.37%) than concentrations of ALB (11.3%), HGB (9.17%), and LDH (18.2%), indicating that some hemolysis is present in all dialyses. In dialyses with arterial chamber pressures more negative than -350 the median concentration of ALB (8.70%) increased significantly more than the median concentration of HGB (7.99%). This indicates significantly more hemolysis in dialyses with more negative pressures compared to those with less negative arterial chamber pressures. Median LDH increased more in dialyses with more negative prepump chamber pressures (16.19% vs 13.78%), but not significantly; however, LDH increases were significantly higher than either HGB or ALB, thus indicating significantly more hemolysis in dialyses with more negative pressures compared to those with less negative arterial chamber pressures. Erythropoietin dose was not significantly different in patients dialyzed with more or less negative arterial chamber pressures (17 645 ± 1226 U/week vs 16 308 ± 1506 U/week). We conclude that dialyses with negative arterial chamber pressures greater than -350 mm Hg cause slightly higher hemolysis than dialyses with less negative arterial chamber pressures, but this increased hemolysis is not associated with an increased requirement of erythropoietin dose. Whether this increased hemolysis is of clinical significance is uncertain.
Home Hemodialysis InternationalVolume 3, Issue 1 p. 75-79 Article Nocturnal Home Hemodialysis: Patients' Personal Experiences Joyce Cagle, Joyce CagleSearch for more papers by this authorMargaret Horsley, Margaret HorsleySearch for more papers by this authorHoward Scott, Howard ScottSearch for more papers by this authorChristine Scott, Christine ScottSearch for more papers by this authorCarolyn Lattimer, Carolyn LattimerSearch for more papers by this authorSamuel W. Smith, Samuel W. SmithSearch for more papers by this authorMaxine Diggs, Maxine DiggsSearch for more papers by this authorCecil Fulton, Cecil FultonSearch for more papers by this authorSheila Walthalle, Sheila WalthalleSearch for more papers by this author Joyce Cagle, Joyce CagleSearch for more papers by this authorMargaret Horsley, Margaret HorsleySearch for more papers by this authorHoward Scott, Howard ScottSearch for more papers by this authorChristine Scott, Christine ScottSearch for more papers by this authorCarolyn Lattimer, Carolyn LattimerSearch for more papers by this authorSamuel W. Smith, Samuel W. SmithSearch for more papers by this authorMaxine Diggs, Maxine DiggsSearch for more papers by this authorCecil Fulton, Cecil FultonSearch for more papers by this authorSheila Walthalle, Sheila WalthalleSearch for more papers by this author First published: 08 September 2016 https://doi.org/10.1111/hdi.1999.3.1.75Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Volume3, Issue1January 1999Pages 75-79 RelatedInformation
Home Hemodialysis InternationalVolume 3, Issue 1 p. 1-4 Article Laudatio: Professor Paul E. Teschan Zbylut J. Twardowski, Zbylut J. TwardowskiSearch for more papers by this author Zbylut J. Twardowski, Zbylut J. TwardowskiSearch for more papers by this author First published: 08 September 2016 https://doi.org/10.1111/hdi.1999.3.1.1Citations: 2Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume3, Issue1January 1999Pages 1-4 RelatedInformation
Over half a century of hemodialysis therapy has brought significant progress in technology and in our approach to its use. This brief review has three objectives: (1) to describe what dialysis was like in the beginning, 50 years ago; (2) to review the origins and interval evolution of the paradigm of daily hemodialysis; and (3) to introduce some vistas for the future.
Ideally, an artificial kidney should simulate the normal kidney in providing continuous metabolic control, removal of toxins, and unrestricted patient freedom. Of the dialysis procedures available, continuous ambulatory peritoneal dialysis (CAPD) comes the closest to this ideal but provides inadequate dialysis and fails to remove protein-bound toxins. A continuous, wearable, peritoneal-based artificial kidney is proposed in which the spent peritoneal dialysate is regenerated using a REDY sorbent cartridge one-tenth the size of the present cartridge, with the urease chemically bound to an inert support to eliminate the possibility of its displacement by protein in the spent dialysate. To simplify the flow path and to increase clearance, the dialysate flow will be through the peritoneal cavity using a dual lumen catheter instead of the traditional in/outflow through a single catheter. At a flow rate of 4 L/hour through the peritoneal cavity, of which 2 L/hour will pass through the sorbent cartridge, it is estimated that the weekly Kt/V will be 6.5 and the creatinine clearance will be 250 L. In addition, any protein in the spent peritoneal dialysate will be stripped of toxins by the sorbents and returned to the patient, thereby minimizing protein loss. The only disposables will be the sorbent cartridge and infusate, which will be changed every 8 hours.
Long, slow hemodialysis (3 × 8 hours/week) has been used without significant modification in Tassin, France, for 30 years with excellent morbidity and mortality rates. A long dialysis session easily provides high Kt/Vurea and allows for good control of nutrition and correction of anemia with a limited need for erythropoietin (EPO). Control of serum phosphate and potassium is usually achieved with low-dose medication. The good survival achieved by long hemodialysis sessions is essentially due to lower cardiovascular morbidity and mortality than in short dialysis sessions. This, in turn, is mainly explained by good blood pressure (BP) control without the need for antihypertensive medication. Normotension in this setting is due to the gentle but powerful ultrafiltration provided by the long sessions, associated with a low salt diet and moderate interdialytic weight gains. These allow for adequate control of extracellular volume (dry weight) in most patients without important intradialytic morbidity. Therefore, increasing the length of the dialysis session seems to be the best way of achieving satisfactory long-term clinical results.
Cuffed catheters, although not ideal for long-term use, are now used more frequently due to an increase in the aging population, in whom the vessels are not suitable for either arteriovenous fistulas or polytetrafluoroethylene (PTFE) grafts. Infections and thrombosis remain the major causes for removal or change of catheters. We recently identified eight catheter defects that required replacement of catheters. Of these, two were due to patient negligence: one catheter was accidentally severed while the patient was shaving; the other was snipped during a haircut. One was believed to have a manufacturing defect. One catheter sustained needle-prick damage near the hub while irrigating the catheter. Two catheters were lost due to needle pricks during skin closure, and one catheter sustained similar damage while fixing the suture wing to the skin. The other two were damaged by suture material slicing through the lumen of the catheter as it expanded due to increased blood flow during repeated dialyses. Importantly, several of these injuries to the catheters were not immediately obvious and were detected only after repeated use of the catheters. Delayed bleeding of cuffed catheters necessitating change or removal has not been reported. Such bleeding may be due to manufacturing defects, patient carelessness, or iatrogenic causes. Avoiding the use of sutures can minimize the latter. Skin closure strips and a double transparent dressing may serve the same purposes, such as securing the catheter and aiding wound healing. In addition, these dressings have the added advantage of being waterproof, bacteria-proof, and cost effective.
Daily hemodialysis therapy (DHD), 2 hours, 6 times per week, is able to cure complications that persist on standard hemodialysis (SHD), 4 hours, 3 times per week. Cardiovascular manifestations (high blood pressure, left ventricular hypertrophy), nutritional deficient states, and postdialysis asthenia are improved during the first month of DHD therapy and are usually cured at 3 months. Daily hemodialysis may be considered as a rescue therapy. The next step will be to select which patients can return to the classical SHD therapy without recurrence of their complications.
