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Biomedical subjects

N V Dombros

Publications and source records attributed to N V Dombros.

At least 19 recordsLinked to original sources

Serum albumin in continuous peritoneal dialysis: absence of universal predictors.

Factors shown to affect serum albumin concentration in continuous peritoneal dialysis (CPD) were compared between two CPD populations residing in Greece (patient n = 108) and the United States (patient n = 194). Compared to the U.S. group, the Greek CPD population had higher serum albumin levels (35.1 +/- 4.6 vs 33.9 +/- 5.0 g/L, p = 0.031), was older (61.2 +/- 12.0 vs 52.7 +/- 16.5 years, p < 0.001), and had a greater number of high or high-average peritoneal solute transport types (69.4% vs 52.1%, p = 0.003). The American CPD population had a higher number of diabetics (53.1% vs 27.8%, p < 0.001), higher total Kt/Vurea (2.06 +/- 0.57 vs 1.93 +/- 0.46 weekly, p = 0.046), and higher total creatinine clearance (76.3 +/- 38.7 vs 63.4 +/- 23.5 L/1.73 m2 weekly, p < 0.001), while normalized protein nitrogen appearance values were comparable (0.95 +/- 0.21 in the Greeks vs 0.94 +/- 0.22 g/(kg x 24 hr) in the Americans, NS). A logistic regression model developed in the United States identified advanced age, diabetes, and high/high-average peritoneal solute transport as the predictors of hypoalbuminemia (serum albumin < 35 g/L). This model generated the following areas with 95% confidence intervals (CI) under the receiver operating characteristic (ROC) curve: in the Greek CPD population, ROC area 0.594 (95% CI 0.486-0.702); in the American CPD population, ROC area 0.850 (95% CI 0.810-0.890). In Greek CPD patients serum albumin appears to be affected by factors other than those identified in North America. This complicates comparisons of serum albumin, and probably morbidity and mortality, between CPD populations residing in different parts of the world.

Creatinine↗

Fractional urea clearance in continuous ambulatory peritoneal dialysis: effects of volume disturbances.

The effects of volume disturbances on the KT/V were investigated prospectively in 133 consecutive urea clearance studies on patients on continuous ambulatory peritoneal dialysis (CAPD). Four subjects (group A) had fluid loss (actual weight < dry weight), 57 (group B) were studied on the basis of their dry weight, 58 (group C) had moderate fluid excess (0.5% of dry weight), and 14 patients (group D) had severe fluid excess (> 5% of dry weight). The KT/V was calculated on the basis of dry weight and actual weight with V obtained from the Watson anthropometric formulae which were applied either uncorrected or with a correction for changes in body water from dry weight conditions. The groups compared by variance analysis. The following weekly KT/V estimates were obtained: (1) using dry weight V: group A 1.81 +/- 0.17, group B 2.0 +/- 0.59, group C 1.79 +/- 0.46, group D 1.85 +/- 0.37 (no difference between groups); (2) using uncorrected actual weight V: group A 1.85 +/- 0.15, group B 2.05 +/- 0.59, group C 1.77 +/- 0.45, group D 1.78 +/- 0.37 (group B had a higher KT/V than group C, p < 0.05), and (3) using corrected actual weight V: group A 1.93 +/- 0.14, group B 2.05 +/- 0.59, group C 1.70 +/- 0.43, group D 1.63 +/- 0.36, (group B had a higher KT/V than either group C or group D, both at p < 0.01). In CAPD, fluid deficit is rare and causes a small increase in KT/V, whereas fluid retention is frequent and causes a decrease in KT/V. This decrease is pronounced in patients with severe fluid excess. The uncorrected Watson formulae underestimate V and, consequently, overestimate KT/V in CAPD patients with fluid excess.

Aged↗

Anabolic steroids in the treatment of malnourished CAPD patients: a retrospective study.

OBJECTIVE: To assess the effect of anabolic steroids on malnutrition of continuous ambulatory peritoneal dialysis (CAPD) patients. DESIGN: Retrospective analysis of medical records, charts, and computer-generated laboratory and medication data. SETTING: Peritoneal Dialysis Unit of The Toronto Hospital. PATIENTS: Thirteen patients with moderate to severe malnutrition who had received nandrolone decanoate (ND) intramuscularly (IM) for at least three months. Nine of these patients (group A), with a mean age of 59.4 years, received only ND (100-200 mg IM monthly). Group B consisted of 4 patients (mean age 74.0 years) who, in addition to ND, received intraperitoneal (IP) amino acids. RESULTS: In group A, serum albumin, while declining before ND treatment (34.4 +/- 3.2 to 31.5 +/- 3.35, x +/- SEM, g/L at -2 and 0 months), showed a progressive and significant (p < 0.001) increase during treatment, sustained up to the third month (36.57 +/- 1.51). In group B, serum albumin did not increase significantly (30.25 +/- 2.62, 30.75 +/- 1.9, and 31.5 +/- 4.8, mean +/- SEM, g/L at -2, 0, and +3 months, respectively. In group A, serum creatinine was increased significantly (p < 0.01) from 0 to +3 months (731 +/- 185 to 938 +/- 92.5 mmol/L). Blood urea, bicarbonate, and total protein levels did not change significantly. In group B, serum creatinine fluctuated considerably with an insignificant trend to rise. Blood urea showed a steady trend to increase without reaching statistical significance. In relation to time 0, bicarbonate levels (28.7 +/- 3.3) were decreased significantly (p < 0.05) (27 +/- 0.8, 24.6 +/- 1.5, and 25 +/- 1 mEq/L, at +1, +2, and +3 months, respectively). CONCLUSIONS: Nandrolone decanoate alone, in relatively low doses, exerted a definite anabolic effect in 9 malnourished CAPD patients. The lack of a similar effect in 4 patients, who in addition to ND received amino acids IP, could be explained by the low dose of ND, the concurrent acidosis, the severity of malnutrition, and the older age of this group.

Adult↗

Destructive spondyloarthropathy in a patient on continuous ambulatory peritoneal dialysis for 13 years.

Since 1984 there have been reports of a destructive spondyloarthropathy occurring in patients on long-term hemodialysis. The primary abnormality appears to be an accumulation of beta 2-microglobulin, which is not adequately removed by dialysis, and forms amyloid deposits in articular and periarticular tissues. We report a case of this disease in a patient treated only by peritoneal dialysis. While this form of treatment may delay the development of arthropathy, as compared to hemodialysis, it does not prevent it. An increasing incidence of this disorder may be expected, since increasing numbers of patients have been on long-term peritoneal dialysis.

Aged↗

Procollagen type-I in the serum and dialysate of continuous ambulatory peritoneal dialysis patients.

Procollagen-I carboxylterminal extension peptide (PICP) was determined in the serum and dialysate of 26 continuous ambulatory peritoneal dialysis (CAPD) patients and in the serum of 11 healthy controls. PICP serum levels were significantly higher in CAPD patients than in healthy controls (p < 0.001). There was no correlation between serum PICP levels and those of calcium, phosphorus, magnesium, alkaline phosphatase, osteocalcin, and intact parathyroid hormone (iPTH). Serum and dialysate levels of osteocalcin and iPTH showed a significant correlation (p < 0.001). The dialysate-to-serum PICP ratio in 21 patients was lower than 1.0. In the remaining 5 patients, however, the above ratio was higher than 1.0. We conclude that in CAPD patients serum PICP levels do not correlate with biochemical parameters of renal osteodystrophy. A dialysate-to-serum PICP ratio above 1.0 could implicate an increased local peritoneal fibroblastic activity and could be a useful marker of peritoneal fibrosis in CAPD.

Aged↗

Long-term continuous ambulatory peritoneal dialysis.

Of 174 patients who entered our CAPD program, 58 received transplants, 7 were transferred to another center, one recovered satisfactory kidney function, 22 were transferred to hemodialysis, 24 to IPD, 52 died and 10 remained on CAPD for at least seven years, when this study was completed. These 10 patients (8 women and 2 men) who are described here in detail had a median age of 46 (range of 24 to 63) years at entry. Their primary renal disease was glomerulonephritis (6), polycystic kidney disease (2), nephrosclerosis (1) and Alport's disease (1). They spent 91 to 134 (average 113) months on CAPD. They had a significant (p = 0.025) increase in body weight from 54.5 +/- 2.8 kg to 59.6 +/- 3.0 kg during the first 3 years, and a decrease in ultrafiltration capacity; BUN and serum creatinine remained relatively stable. Mean total protein and serum albumin remained unchanged at 65 and 35 g/l respectively, throughout the study. There were no significant changes in the hemoglobin and lipid values. Renal osteodystrophy progressed slowly. Peritonitis rate in this group was one episode every 18.9 patient months. These 10 patients had a total of 25 catheters implanted during the study period. The average hospitalization rate was 8.76 days per patient year, 5.34 of which were for peritonitis. Of these 10 patients, one was transferred to hemodialysis, 5 died (4 of or during peritonitis, one of myocardial infarction) and 4 remained on CAPD. Our experience with these 10 patients indicates that CAPD can be carried out over long periods.(ABSTRACT TRUNCATED AT 250 WORDS)

Body Weight↗

Recent developments in peritoneal dialysis.

Significant developments over the past 10 years have established continuous ambulatory peritoneal dialysis as a successful kidney-replacement treatment. Peritonitis rates have fallen, and investigators are attempting to establish objective criteria for adequacy of dialysis. Malnutrition is a serious concern, but short-term experience with intraperitoneal amino acids promises success in the management of this complication. A significant improvement in the well-being of patients with end-stage renal disease was produced by recombinant human erythropoietin, and use of recombinant human growth hormone promises catch-up growth for children receiving long-term peritoneal dialysis treatment. As increasing numbers of patients are maintained on continuous ambulatory peritoneal dialysis over longer periods, we will begin to encounter beta 2-microglobulin-related amyloidosis possibly at the same rate in these patients as in those receiving long-term hemodialysis treatment.

Humans↗

Six-month overnight intraperitoneal amino-acid infusion in continuous ambulatory peritoneal dialysis (CAPD) patients--no effect on nutritional status.

The long-term effect of an AA solution based on Travasol, a solution for total parenteral nutrition, given intraperitoneally over a 6-month period was studied in 5 patients 22 to 75 years old, having been on continuous ambulatory peritoneal dialysis (CAPD) for 3 to 57 months. A low oral protein intake (less than 0.8 g/kg bw/day) and/or a low serum albumin (less than 35 g/L) were used as inclusion criteria. Two liters of 1% AA solution were infused overnight, while a glucose Dianeal was used for the other exchanges. During the study, BUN increased from 22.04 mM/L to 28.06 mM/L the first month and remained at these levels, indicating the increased protein intake. However, average oral total energy and protein intake, body weight (bw), serum creatinine, cholesterol, triglycerides, total proteins, albumin, transferrin, skinfold thickness, total body potassium, and plasma AA levels remained basically unchanged. The average total body nitrogen decreased from 1.746 to 1.554 Kg, but this decrease did not reach statistical significance (p greater than 0.05). We conclude that intraperitoneal overnight administration of 2 L of 1% AA based on Travasol over 6 months did not improve the nutritional status of CAPD patients. This ineffectiveness might be due to the AA composition of the solution, the timing of administration, or to a low caloric intake and/or that our patients were not severely malnourished.

Amino Acids↗

On the usefulness of glycylglycine in hemodialysis and peritoneal dialysis solutions.

This article reviews current knowledge on the usefulness of glycylglycine in preparing single stable hemodialysis (HD) and peritoneal dialysis (PD) solutions containing bicarbonate. The coexistence of bicarbonate and glycylglycine in a dialysis solution renders it a potent, stable buffer in which the well known reactions between bicarbonate and calcium and magnesium, and the subsequent formation of insoluble neutral calcium and magnesium carbonate salts, are avoided. Single stable bicarbonate-glycylglycine (BiGG) solutions for HD and PD have been successfully prepared and studied, both experimentally and clinically. These studies have demonstrated the advantages of BiGG solutions in terms of simplicity, stability, convenience, tolerance, biocompatibility, protection of the peritoneum, and higher ultrafiltration, compared to standard acetate or lactate solutions, and on-line prepared bicarbonate solutions. Progressive accumulation of glycylglycine or glycine, even after prolonged use, side effects, or signs of toxicity were not observed. In conclusion, BiGG solutions ensure a physiologic dialysis both from the theoretic and practical points of view.

Acetates↗

The relationship between urine volume and drain volume as determinants of fractional urea clearance in continuous peritoneal dialysis.

A logistic regression model developed and validated in Albuquerque identified 24 hr urine volume (UV) and 24 hr drain volume/(body water) (DV/V) as predictors of fractional urea clearance (KT/V) in continuous peritoneal dialysis (CPD). Solution of this model provided DV/V values consistent with KT/V at least equal to a target KT/V for a given UV. The predictive accuracy of these unique DV/V values was tested in urea kinetic studies performed in 108 CPD patients in Thessaloniki and Athens with UV varying between 0 and 2 L/24 h. Two target weekly KT/V values, 1.70 and 1.90, were investigated. The equation DV/V = (5.2811-3.6996 UV)/ 17.554, derived by solving the logistic regression model, detected weekly KT/V > 1.70 (69/108, or 63.9% of the studies) with a sensitivity of 87.3% and a specificity of 60.4%. According to the same equation, the maximal UV consistent with weekly KT/V < or = 1.70 is 1.427 L/24 hr. The equation DV/V = (5.4994-2.6007 UV)/17.007 detected weekly KT/V > 1.90 (44/108, or 40.7% of the studies) with a sensitivity of 90.3% and a specificity of 79.2%. According to this equation, the maximal UV consistent with weekly KT/V < or = 1.90 is 2.115 L/24 hr. Determination of the lowest daily DV consistent with a target KT/V at any daily UV (within a wide range) is feasible in CPD.

Feasibility Studies↗

Continuous peritoneal dialysis in heavyweight individuals: urea and creatinine clearances.

OBJECTIVE: To study whether or not continuous peritoneal dialysis (CPD) can provide acceptable levels of normalized urea and creatinine clearance in heavyweight individuals. DESIGN: Retrospective analysis of urea and creatinine clearance studies. SETTING: CPD patients followed in four dialysis units in Albuquerque, two dialysis units in Thessaloniki, and two dialysis units in Athens. PARTICIPANTS: One hundred and ninety-nine patients on CPD with 266 clearance determinations between 1991 and 1995. INTERVENTIONS: The heavyweight group consisted of 22 patients (24 clearance studies) weighing 100 kg or more (109 +/- 8.7 kg) at the time of the clearance study. All subjects were obese. The reference group consisted of 177 CPD subjects (242 clearance studies) of normal weight (68.7 +/- 12.2 kg). Urea fractional clearance (KT/V) and normalized creatinine clearance (Ccr) were compared between the heavyweight and the reference groups. MAIN OUTCOME MEASURES: The lowest acceptable weekly levels were set at 1.70 for KT/V and 54.4 L/1.73 m2 for Ccr. RESULTS: Weekly KT/V was 1.75 +/- 0.41 in the heavyweight group and 1.94 +/- 0.52 in the reference group (p = 0.047). Corresponding weekly Ccr levels were 64.0 +/- 24.3 and 77.6 +/- 40.3 L/1.73 m2, respectively (p = 0.021). In the heavyweight group, 13 studies (54.2%) had acceptable KT/V values compared to 160 studies (66.1%) in the reference group (NS). Corresponding values for acceptable Ccr were 17 (70.8%) and 165 (68.2%), respectively (NS). Drain volume was 12.96 +/- 4.40 L/24 hours in the heavyweight group and 9.63 +/- 2.58 L/24 hours in the reference group (p = 0.001). High daily exchange volume was delivered by a combination of daily continuous ambulatory peritoneal dialysis (CAPD) and nocturnal automated peritoneal dialysis (APD) in 13/16 heavyweight studies. This combination was tolerated better than any other method of delivering a large daily exchange volume. CONCLUSION: Although normalized urea and creatinine clearances are lower in obese, heavyweight individuals than in lean CPD subjects with lower weight, approximately equal percentages of these two groups achieve acceptable clearance levels. However, heavyweight individuals require larger-than-usual daily exchange volumes. The preferred way to deliver these large dialysate volumes is a combination of daily CAPD and nocturnal APD.

Body Weight↗