Cycler adequacy and prescription data in a national cohort sample: the 1997 core indicators report. Health Care Financing Administration Peritoneal Dialysis Core Indicators Study Group.
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BACKGROUND: The Health Care Financing Administration Peritoneal Dialysis Core Indicator Project obtains data yearly in four areas of patient care: dialysis adequacy, anemia, blood pressure, and nutrition. METHODS: Adequacy and dialysis prescription data were obtained using a standardized data abstraction form from a random sample of adult U.S. peritoneal dialysis patients who were alive on December 31, 1996. RESULTS: For the cohort receiving cycler dialysis, 22% were unable to meet the National Kidney Foundation Dialysis Outcome Quality Initiatives (NKF-DOQI) dialysis adequacy guidelines because they did not have at least one adequacy measure during the six-month period of observation. Thirty-six percent of patients met NKF-DOQI guidelines for weekly Kt/V urea, 33% met guidelines for weekly creatinine clearance (CCr), and 24% met guidelines for both urea and creatinine clearances. The mean weekly adequacy values were 2.24 +/- 0.56 for Kt/V urea and 67.5 +/- 24.4 liter/1.73 m2 for CCr, and the median values were 2.20 and 62.25 liter/1.73 m2, respectively. The mean prescribed 24-hour volume was 12,040 +/- 3255 ml, and the median prescribed volume was 11,783 ml. Only 60% of patients were prescribed at least one daytime dwell. By logistic regression analysis, risk factors for an inadequate dose of dialysis included being in the highest quartile of body surface area (odds ratio = 3.3 for CCr and 3.4 for Kt/V urea) and a duration of dialysis greater than two years (odds ratio = 4.2 for CCr and 2.1 for Kt/V urea). CONCLUSION: There is much room for improvement in providing an adequate dose of dialysis to cycler patients. Practitioners should be more aggressive in increasing dwell volumes, adding daytime dwells, and adjusting nighttime dwell times in order to compensate for the loss of residual renal function over time. These changes can only be accomplished if practitioners measure periodically the dose of dialysis as outlined in the NKF-DOQI guidelines. (+info)
High peritoneal residual volume decreases the efficiency of peritoneal dialysis.
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BACKGROUND: Wide variation in peritoneal residual volume (PRV) is a common clinical observation. High PRV has been used in both continuous ambulatory peritoneal dialysis (CAPD) and automated peritoneal dialysis to minimize the time of a dry peritoneal cavity and to achieve better dialysis. However, the impact of PRV on peritoneal transport is not well established. In this study, we investigated the effect of PRV on peritoneal transport characteristics. METHODS: Peritoneal effluents were collected in 32 male Sprague-Dawley rats after a five-hour dwell with 1.36% glucose solution. Forty-eight hours later, a four hour dwell using 25 ml of 3.86% glucose solution and frequent dialysate and blood sampling was done in each rat with 125I-albumin as a volume marker. Before the infusion of the 3.86% glucose solution, 0 (control), 3, 6, or 12 ml (8 rats in each group) of autologous effluent (serving as PRV) was infused to the peritoneal cavity. RESULTS: After subtracting the PRV, the net ultrafiltration was significantly lower in the PRV groups as compared with the control group: 13.4 +/- 0.5, 12.0 +/- 1.0, 11.7 +/- 1.7, and 8.9 +/- 0.4 ml for 0, 3, 6, and 12 ml PRV groups, respectively (P < 0.001). The lower net ultrafiltration associated with higher PRV was due to (a) a significantly lower transcapillary ultrafiltration rate (Qu) caused by a lower osmotic gradient, and (b) a significantly higher peritoneal fluid absorption rate (KE) caused by an increased intraperitoneal hydrostatic pressure. No significant differences were found in the diffusive mass transport coefficient for small solutes (glucose, urea, sodium, and potassium) and total protein, although the dialysate over plasma concentration ratios values were higher in the high-PRV groups. The sodium removal was significantly lower in the PRV groups as compared with the control group (P < 0.01). CONCLUSION: Our results suggest that a high PRV may decrease net ultrafiltration through decreasing the Qu, which is caused by a decreased dialysate osmolality, and increasing the KE caused by an increased intraperitoneal hydrostatic pressure. The high volume of PRV also decreased the solute diffusion gradient and decreased peritoneal small solute clearances, particularly for sodium. Therefore, a high PRV may compromise the efficiency of dialysis with a glucose solution. (+info)
Effects of arteriovenous fistulas on cardiac oxygen supply and demand.
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BACKGROUND: Arteriovenous (AV) fistulas used for hemodialysis access may affect cardiac load by increasing the preload while decreasing the afterload. In dogs, AV fistulas have also been shown to affect coronary perfusion negatively. We investigated the net effect of AV fistulas on cardiac oxygen supply and demand. METHODS: Aortic pressure waves were reconstructed from finger pressure recordings obtained on the nonfistula arm using a wave-form filter. Changes in systolic, mean, and diastolic aortic pressure were calculated, together with changes in heart rate (HR), stroke volume (SV), cardiac output (CO), and systemic vascular resistance (SVR) during a 60-second compression of AV fistulas in 10 patients. Changes in cardiac supply and demand were estimated by calculating the area under the aortic pressure curve during diastole [diastolic pressure time index (DPTI)] and systole [systolic pressure time index (SPTI)], respectively. RESULTS: During fistula compression, systolic, mean and diastolic pressure increased by 4.2 +/- 4.3, 2.6 +/- 3.0, and 2.8 +/- 2.9 mm Hg (mean +/- SD, all P < 0.05). The HR decreased by 3.8 +/- 2.5 beats per minute (P < 0.01), and SV decreased 3.7 +/- 6.1% (NS). CO decreased 9.4 +/- 8.6%, and SVR increased 14.3 +/- 11.7% (both P < 0.05). The SPTI increased by 1.5 +/- 1.5 mm Hg.sec (P < 0.01), and the DPTI increased by 7.6 +/- 8.1 mm Hg.sec (14.8% increase, P < 0.05) during compression. The ratio of supply and demand (DPTI/SPTI) improved by 13.5 +/- 13.0% (P < 0.01) when the fistula was compressed. CONCLUSION: AV fistulas have a small effect on left ventricular oxygen demand, but decrease cardiac oxygen supply considerably. (+info)
Peritoneal elimination of homocysteine moieties in continuous ambulatory peritoneal dialysis patients.
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BACKGROUND: The amount of total homocysteine eliminated by peritoneal dialysis and its relationship to peritoneal transport characteristics in continuous ambulatory peritoneal dialysis (CAPD) patients are unknown. METHODS: The influence of total homocysteine, folate, and vitamin B12 plasma concentrations, serum albumin levels, age, sex, dialysate to plasma ratio (D/P) creatinine, D/D0 glucose, D/P albumin, dialysate effluent volume, and effluent albumin on the daily peritoneal excretion of total homocysteine was investigated in 39 CAPD patients. The relationship of D/P creatinine to D/P total homocysteine, D/P free homocysteine, and D/P protein-bound homocysteine was analyzed additionally in a subgroup of 25 patients. RESULTS: We observed a significant influence of plasma total homocysteine concentrations (P = 0.0001) of the daily dialysate effluent volume (P = 0.0221) and of the D/P creatinine (P = 0.0132) on peritoneal elimination of total homocysteine. The daily peritoneal excretion of total homocysteine was 38.94 +/- 20.82 mumol (5.27 +/- 2.81 mg). There was a positive linear association of the daily total homocysteine elimination with plasma total homocysteine concentrations (P = 0.0001). A significant linear correlation was observed between D/P creatinine and D/P total homocysteine (P = 0.0001), D/P free homocysteine (P = 0.0001), as well as D/P protein-bound homocysteine (P = 0.0001). CONCLUSIONS: The peritoneal elimination of total homocysteine primarily depends on the plasma total homocysteine concentration. Elevated total homocysteine plasma levels cannot be reduced efficiently by peritoneal dialysis. (+info)
Growth plate cartilage formation and resorption are differentially depressed in growth retarded uremic rats.
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To characterize the modifications of growth plate in individuals with growth impairment secondary to chronic renal failure, young rats were made uremic by subtotal nephrectomy (NX) and, after 14 d, their tibial growth plates were studied and compared with those of sham-operated rats fed ad libitum (SAL) or pair-fed with NX (SPF). NX rats were growth retarded and severely uremic. Growth plate height (mean +/- SD) was much greater (P<0.05) in NX (868.4+/-85.4 microm) than SAL (570.1+/-93.5 microm) and SPF (551.9+/-99.7 microm) rats as a result of a higher (P<0.05) hypertrophic zone (661.0+/-89.7 versus 362.8+/-71.6 and 353.0+/-93.9 microm, respectively). The increased size of the growth plate was associated with a greater number of chondrocytes and modifications in their structure, particularly in the hypertrophic zone adjacent to bone. In this zone, chondrocytes of NX animals were significantly (P<0.05) smaller (12080.4+/-1158.3 microm3) and shorter (34.1+/-2.5 microm) than those of SAL (16302.8+/-1483.4 microm3 and 37.8+/-2.0 microm) and SPF (14465.8+/-1521.0 microm3 and 36.3+/-1.8 microm). The interface between the growth plate cartilage and the metaphyseal bone appeared markedly irregular in NX rats. Kinetics of chondrocytes was also modified (P<0.05) in the NX rats, which had lower cell turnover per column per day (5.4+/-0.9), longer duration of hypertrophic phase (89.0+/-15.2 h), and reduced cellular advance velocity (7.4+/-2.2 microm/h) compared with SAL (8.0+/-1.6, 32.1+/-6.7 h, and 11.3+/-2.7 microm/h) and SPF (7.2+/-1.1, 34.8+/-5.1 h, and 10.1+/-2.5 microm/h). Cell proliferation was no different among the three groups. Because the growth plates of SPF and SAL rats were substantially not different, modifications observed in the NX rats cannot be attributed to the nutritional deficit associated with renal failure. These findings indicate that chronic renal failure depresses both the activity of the growth plate cartilage by altering chondrocyte hypertrophy and the replacement of cartilage by bone at the metaphyseal end. The two processes are differentially depressed since cartilage resorption is more severely lowered than cartilage enlargement and this leads to an accumulation of cartilage at the hypertrophic zone. (+info)
Effects of insulin and amino acids on glucose and leucine metabolism in CAPD patients.
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This study investigates the basal and insulin-stimulated glucose metabolism, substrate utilization, and protein turnover in eight patients maintained on continuous ambulatory peritoneal dialysis (CAPD) (mean age 39+/-5 yr, body mass index [BMI] 108+/-6) and 14 control subjects (mean age 33+/-4 yr, BMI 103+/-3). Euglycemic insulin clamp studies (180 min) were performed in combination with continuous indirect calorimetry and 1-14C leucine infusion (study I). Postabsorptive glucose oxidation was higher (1.75+/-0.18 versus 1.42+/-0.14 mg/kg per min) and lipid oxidation was lower (0.43+/-0.09 versus 0.61+/-0.12 mg/kg per min) in CAPD patients than in control subjects (P<0.05 versus control subjects). During the last 60 min of euglycemic hyperinsulinemia, the total rate of glucose metabolism was similar in CAPD and control subjects (6.33+/-0.51 versus 6.54+/-0.62 mg/kg per min). Both insulin-stimulated glucose oxidation (2.53+/-0.27 versus 2.64+/-0.37 mg/kg per min) and glucose storage (3.70+/-0.48 versus 3.90+/-0.58 mg/kg per min) were similar in CAPD and control subjects. Basal leucine flux (an index of endogenous proteolysis) was significantly lower in CAPD patients than in control subjects (1.21+/-0.15 versus 1.65+/-0.07 micromol/kg per min). Leucine oxidation (0.13+/-0.02 versus 0.26+/-0.02 micromol/kg per min) and nonoxidative leucine disposal (an index of protein synthesis) (1.09+/-0.16 versus 1.35+/-0.05 micromol/kg per min) were also reduced in CAPD compared with control subjects (P<0.01 versus control subjects). In response to insulin (study I), endogenous leucine flux decreased to 0.83+/-0.08 and 1.05+/-0.05 micromol/kg per min in CAPD and control subjects, respectively (all P<0.01 versus basal). Leucine oxidation declined to 0.06+/-0.01 and to 0.19+/-0.02 micromol/kg per min in CAPD and control subjects, respectively (P<0.01 versus basal). A second insulin clamp was performed in combination with an intravenous amino acid infusion (study II). During insulin plus amino acid administration, nonoxidative leucine disposal rose to 1.23+/-0.17 and 1.42+/-0.09 micromol/kg per min in CAPD and control subjects, respectively (both P<0.05 versus basal, P = NS versus control subjects), and leucine balance, an index of the net amino acid flux into protein, become positive in both groups (0.30+/-0.05 versus 0.40+/-0.07 micromol/kg per min in CAPD and control subjects, respectively) (both P<0.01 versus basal, P = NS versus control subjects). In summary, in CAPD patients: (1) basal glucose oxidation is increased; (2) basal lipid oxidation is decreased; (3) insulin-mediated glucose oxidation and storage are normal; (4) basal leucine flux is reduced; (5) the antiproteolitic action of insulin is normal; and (6) the anabolic response to insulin plus amino acid administration is normal. Uremic patients maintained on CAPD treatment show a preferential utilization of glucose as postabsorptive energy substrate; however, their anabolic response to substrate administration and the sensitivity to insulin are normal. (+info)
Impact of aortic stiffness on survival in end-stage renal disease.
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BACKGROUND: Damage to large arteries is a major factor in the high cardiovascular morbidity and mortality of patients with end-stage renal disease (ESRD). Increased arterial stiffness and intima-media thickness, together with increased pulse pressure, are the principal arterial alterations. Whether increased aortic pulse-wave velocity (PWV), a classic marker of increased arterial stiffness, may predict all-cause and/or cardiovascular mortality has never been investigated. METHODS AND RESULTS: A cohort of 241 patients with ESRD undergoing hemodialysis was studied between April 1987 and April 1998. The mean duration of follow-up was 72+/-41 months (mean+/-SD). Mean age at entry was 51.5+/-16.3 years. Seventy-three deaths occurred, including 48 cardiovascular and 25 noncardiovascular fatal events. At entry, together with standard clinical and biochemical analyses, patients underwent echocardiography and aortic PWV measured by Doppler ultrasonography. On the basis of Cox analyses, 2 factors emerged as predictors of all-cause and cardiovascular mortality: age and aortic PWV. Hemoglobin and low diastolic pressure interfered to a smaller extent. After adjustment for all the confounding factors, an OR for PWV >12. 0 versus <9.4 m/s was 5.4 (95% CI, 2.4 to 11.9) for all-cause mortality and 5.9 (95% CI, 2.3 to 15.5) for cardiovascular mortality. For each PWV increase of 1 m/s in our study population, all-cause mortality-adjusted OR was 1.39 (95% CI, 1.19 to 1.62). CONCLUSIONS: These results provide the first direct evidence that in patients with ESRD, increased aortic stiffness determined by measurement of aortic PWV is a strong independent predictor of all-cause and mainly cardiovascular mortality. (+info)
Localization of a bone imaging agent in a calcified hematoma.
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A patient with chronic renal failure and secondary hyperparathyroidism had iliac bone biopsy. The procedure was complicated by a soft-tissue hematoma, which had calcified. A 3-4-cm palpable mass was visible in the lower left abdominal wall. Intense uptake of 99mTc-HMDP corresponded with the location of the calcified hematoma in this patient. (+info)