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Biomedical subjects

R M Raja

Publications and source records attributed to R M Raja.

At least 55 records · Page 3Linked to original sources
PubMed1976

Recirculation peritoneal dialysis with sorbent Redy cartridge.

Sorbent regeneration of peritoneal dialysate and use of small volume of dialysate for intermittent peritoneal dialysis (IPD) has been shown to be feasible. The present study compares the solute clearance (C) for urea (U) and creatinine (Cr) at varying flow rates in IPD and in recirculation peritoneal dialysis (RPD) utilizing Redy cartridge in ten dogs. Two silastic peritoneal catheters and one Sarns roller pump were used for RPD. CU was 12 +/- 2 ml/min (mean +/- 1SD),18 +/- 2 with IPD and 15 +/- 2,21 +/- 4 with RPD at flow rate of 66 and 100 ml/min, respectively, while CCr was 9 +/- 2,12 +/- 2 with IPD and 10 +/- 2, 13 +/- 3 with RPD. At increasing flow rates of 150,200 and 250 ml/min, CU was 27 +/- 3,31 +/- 4 and 32 +/- 6, and CCr was 17 +/- 2,20 +/- 3 and 22 +/- 3 with RPD. U and Cr were completely removed by the Redy. Glucose was not removed by the cartridge after initial saturation. Serum sodium concentration increased 2-3 mEq/l after 6 h of RPD. The data suggest that at comparable flow rates, RPD is relatively more efficient than IPD (p greater than 0.01). This may be due to continuous exchange across the peritoneal membrane in RPD. At high flow rate in RPD, solute removal is 2-3 times higher than the currently used IPD. RPD with Redy cartridge is mechanically simple, efficient, and may help reduce total peritoneal dialysis time.

Animals↗
PubMed1976

Solute transport in comparable surface area dialyzers.

The present study compared clearance (K) for urea (U), uric acid (Ua), and BSP in relatively equal surface area dialyzers, EX-29 to dual EX-21 in parallel (DEX-21) at QB and QD 300 ml/min, and hollow fiber kidney model 5 (HFK-5) to dual HFK model 4 in series (DHFK-4) at QB 200, QD 500 ml/min. KU was 158 +/- 20 ml/min, 129 +/- 22; KUa was 106 +/- 10, 96 +/- 5, and KBSP was 80 +/- 11 and 67 +/- 12 (p less than 0.01) for EX-29 and DEX-21, respectively. KU was 173 +/- 8 ml/min, 159 +/- 6; KUa was 131 +/- 6, 117 +/- 8, and KBSP was 65 +/- 9 and 56 +/- 7 (p less than 0.01) for HFK-5 and DHFK-4, respectively. Comparable changes in outlet pressure had a varied effect on ultrafiltration and solute transport. 3-hour hemodialysis in the same patients showed that EX-29 was better tolerated than DEX-21. The data suggest that dialyzer designs with the same membrane of equal surface area may significant affect K for both small and middle molecular weight solutes. Comparable changes in outlet pressure may have a varied effect on K in different designs. Due to these variations, comparison of dialysis schedules with different dialyzers on the basis of the square meter hour dialysis to prove validity of middle molecule hypothesis should be interpreted cautiously.

Kidneys, Artificial↗
PubMedDate not supplied

Effect of varying dialysate bicarbonate concentration on serum phosphate.

Hyperphosphatemia is practically a universal problem in patients with chronic renal failure. Conventional treatment of hyperphosphatemia in this situation is either only partially effective or may be associated with potentially serious adverse effects. The authors examined the effect of inducing a metabolic alkalosis on serum phosphate in chronic hemodialysis patients by increasing the concentration of bicarbonate in dialysate. Seven patients participated in the study. Each patient was on dialysis for 2 weeks with each of 2 dialysate regimens. Regimen A contained a bicarbonate concentration of 25 mEq/L and Regimen B a bicarbonate concentration of 40 mEq/L. Despite Regimen B resulting in a significant increase in predialysis and postdialysis serum bicarbonate concentration and arterial pH, no significant difference in serum phosphate was demonstrated after 2 weeks of therapy.

Bicarbonates↗
PubMedDate not supplied

Retroperitoneal feeding tube for peritoneal dialysis patients.

Treatment of the cachetic, hypoalbuminemic, peritoneal dialysis patient represents a vexing patient management problem. In the past, when the cause of inanition was intractable vomiting secondary to gastroparesis, the solution was to create a transperitoneal percutaneous enterogastrostomy. This endoscopic procedure bypassed the nonfunctioning stomach and allowed for adequate nutrition. When hypoalbuminemia is present, the patient is predisposed to the possible complications of peritoneal sepsis, dialysis fluid leak, and wound dehiscence. The authors report a unique, enteric feeding tube that is a solution to the problem of continuing adequate, complication-free dialysis in a cachetic, hypoalbuminemic peritoneal dialysis patient with no available site for either temporary or permanent hemodialysis vascular access. The procedure does not violate the peritoneal cavity and has proven to be effective, acceptable to the patient, apparently safe, and easy for both staff and patient use.

Cachexia↗
PubMedDate not supplied

Influence of Kt/V and protein catabolic rate on hemodialysis morbidity. A long-term study.

Urea clearance over time, divided by volume of total body water (Kt/V) and protein catabolic rate (PCR), were calculated monthly in 88 long-term hemodialysis patients. Patients were divided into four groups: Group A (n = 40), Kt/V > 1.0 and PCR > 1.0 g/kg/day; Group B (n = 7), Kt/V > 1.0 and PCR < 1.0; Group C (n = 24), Kt/V < 1.0 and PCR > 1.0; and Group D (n = 17), Kt/V < 1.0 and PCR < 1.0. Various clinical, biochemical, and morbidity factors were compared. Group A had significantly less morbidity than did the other groups (p < 0.05). Blood urea nitrogen, serum creatinine, serum albumin, and phosphorus were lower in Group B than in the other groups (p < 0.05). These data suggest that determination of Kt/V and PCR is important for predicting dialysis morbidity and that they should be monitored together for adequacy of therapy and dialysis quality assurance.

Aged↗
PubMedDate not supplied

Plasma refilling during hemodialysis with decreasing ultrafiltration. Influence of dialysate sodium.

Inadequate plasma refilling is an important determinant of vascular instability during hemodialysis. Hypotension is more frequent toward the end of dialysis, as the patient reaches dry weight. This study compared plasma volume changes in 12 patients dialyzed with constant ultrafiltration and a constant dialysate Na of 140 mEq/L (Group A), sequentially decreasing ultrafiltration (50% in first hour, 30% in the second hour, and 20% in the third hour) using constant dialysate Na (Group B), and sequentially decreasing ultrafiltration with sequentially decreasing dialysate Na from 150 to 140 mEq/L (Group C). All of the patients had midweek dialysis with each protocol. Blood pressure, hematocrit, blood urea nitrogen, serum osmolality, and albumin were determined before and hourly thereafter. Ultrafiltration was constant at 12.2 ml/min in Group A but 18.4 ml/min in the first hour, 11.0 in the second hour, and 7.3 in the third hour in Groups B and C. In Group A, plasma volume did not change during the first hour but decreased in the second and third hours (4.9%). In Group B, plasma volume decreased during the first and second hours 5.6% but slightly increased during the third hour 5.3%, whereas in Group C, plasma volume increased during the first hour (2.1%), was unchanged during the second hour, and decreased 1.2% during the third hour. These data suggest that plasma refilling is enhanced during hemodialysis using sequentially decreasing ultrafiltration and high-to-low dialysate Na (Group C); this strategy may be preferred to hemodialysis with constant dialysate Na and ultrafiltration (Group A) or sequentially decreasing ultrafiltration with constant dialysate Na (Group B) when improvement in vascular stability is needed.

Aged↗
PubMedDate not supplied

Erythropoietin (EPO) requirements remain high in EPO resistant patients after iron repletion.

Iron deficiency is an important factor for high erythropoietin (EPO) requirements. Some studies have shown a decrease in recombinant human erythropoietin (rHuEPO) dosage with correction of iron deficiency. This is a 2 year prospective study of 58 chronic hemodialysis (HD) patients in whom iron deficiency was corrected with intravenous iron therapy. Patients were stratified into two groups: Group 1 with 25 patients (EPO < 70 U/kg per HD), and Group 2 with 33 patients (EPO > 70 U/kg per HD). For Groups 1 and 2, respectively, differences in mean age (56.5 vs 64.1 years), rHuEPO dose (30.1 vs 148.7 U/kg per HD), and hematocrit concentration (36.5% vs 32.7%) were statistically significant (p < 0.05). Although iron saturation was 45% compared with 41.3% for Groups 1 and 2, respectively, serum parathyroid hormone, aluminum, and urea reduction ratio were similar for both. These data suggest that some patients continue to require a high rHuEPO dose in spite of adequate iron repletion. Further investigation into factors causing EPO resistance is important to decrease rHuEPO requirements and improve cost effectiveness.

Dextrans↗