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Biomedical subjects

F Dumler

Publications and source records attributed to F Dumler.

80 records · Page 5Linked to original sources
PubMedDate not supplied

Nutritional status assessment and body composition analysis in pre-end stage renal disease patients.

Malnutrition is a known risk factor for survival in renal failure patients. Of concern, a significant degree of malnutrition may develop in the predialysis period due to dietary restrictions and uremia. To further define this issue, we evaluated 25 predialysis patients using serum chemistries, body mass index (BMI), fat free mass (FFM), body cell mass (BCM), and protein appearance rate (PAR) as surrogates of nutritional status and compared their results to those obtained in established hemodialysis patients and recipients of living donor renal allografts during a nine-month observation period. Pre- dialysis patients had significantly (p<0.0001) higher body weight (28%), body mass index (26%), body cell mass (17%) and fat free mass (15%) than hemodialysis and transplant patients. Intracellular water content was similar in all groups. As many patients do not start dialysis until clearance values fall below 10 ml/min, it is possible that greater tissue mass losses occur in the weeks preceding initiation of dialytic therapy. Why renal transplant recipients fail to increase tissue mass may relate to the catabolic effects of immunosuppression. We conclude that the early stages of pre-end stage renal disease are associated with relatively good preservation of body cell mass.

Body Composition↗
PubMedDate not supplied

Use of urea kinetics in the nutritional care of the acutely ill patient.

In acutely ill patients nitrogen balance is often assessed clinically from measurements of protein intake and urinary urea nitrogen. We have utilized urea kinetic modeling to measure urea generation rates, protein catabolic rates and nitrogen balance in 19 acutely ill patients with varying degrees of renal dysfunction and have studied the effect of varying caloric intake on protein balance during a period of fixed protein intake. In patients with measured creatinine clearances equal to or greater than 50 ml/min there was a highly significant correlation between nitrogen balance estimates derived from urea kinetic modeling and those obtained from urinary urea nitrogen (R = 0.939; p less than 0.001). When creatinine clearance measurements were between 20 to 50 ml/min the correlation between the two estimates was poorer (R = 0.337; p less than 0.001). In patients whose creatinine clearance was below 20 ml/min the correlation between measurements was worse still (R = 0.229; p less than 0.002). To determine the effects of increasing caloric intake on protein catabolic rate seven acutely ill patients were studied. When caloric intake was increased from 27.8 to 34.2 kcal/kg/day while on a fixed protein intake of 1.27 g/kg/day there was a significant fall in protein catabolic rate from 1.39 to 0.99 g/kg/day (p less than 0.002). As urea kinetic modeling takes into account changes in blood urea nitrogen, extrarenal losses of urea and the urinary urea pool, it is the preferred method for measuring protein balance in acutely ill patients particularly those with poor renal function. Serial monitoring of protein catabolic rates permits easy continuous assessment of the effect of increasing caloric intake on protein sparing during parenteral hyperalimentation.

Acute Disease↗
PubMedDate not supplied

Skeletal surveys in renal osteodystrophy.

The authors reviewed the clinical usefulness of routine comprehensive skeletal surveys in monitoring renal osteodystrophy in 66 patients on chronic maintenance hemodialysis. Only fourteen (22%) of the 66 patients had roentgenographic evidence of hyperparathyroid bone disease. There were no significant differences in serum calcium, phosphate, or aluminum levels between patients with and without evidence of phalangeal subperiosteal bone resorption in the hands. However, serum levels of parathyroid hormone (PTH) (both intact and mid-molecule) and alkaline phosphatase values were significantly higher in the group with subperiosteal bone resorption (p less than 0.01 and p less than 0.02, respectively). Serum intact PTH correlated with alkaline phosphatase better than the mid-molecule assay. Neither intact nor mid-molecule PTH values correlated with serum calcium, phosphate, or aluminum. Hand roentgenograms were most sensitive in detecting early changes of hyperparathyroidism; symphysis pubis was the next best. Other skeletal roentgenographic findings were less revealing, and in a subset of 20 patients, roentgenograms correlated poorly with bone histology. During this study the authors found an 8% prevalence of vertebral compression fractures; all in postmenopausal white women.

Alkaline Phosphatase↗
PubMedDate not supplied

The effect of cooled dialysate on thermal energy balance in hemodialysis patients.

The authors have monitored extracorporeal thermal energy balance using continuous in-line arterial and venous temperature and blood flow measurements. Use of dialysate at 37 degrees C resulted in a mean heat energy gain of 83 +/- 61 cal/min, whereas dialysate at 34 degrees C produced a loss of 463 +/- 121 cal/min. Monitoring extracorporeal thermal energy balance during cooled-dialysate hemodialysis will facilitate the use of feedback loops for dialysate temperature control in order to maximize hemodynamic stability while reducing discomfort. This methodology also may be helpful in assessing the metabolic effects of protein intake, high flux dialysis, membrane biocompatibility, and adequacy of dialysis in relation to thermal energy balance.

Adult↗
PubMedDate not supplied

Use of bioelectric impedance analysis and dual-energy X-ray absorptiometry for monitoring the nutritional status of dialysis patients.

Despite recent technological advances, inadequate nutrition has been clearly identified as a significant risk factor to survival of patients undergoing chronic maintenance dialysis therapy. Although body density by underwater weight and residual lung volume, total body water by isotope dilution, bone mineral content, and total body potassium measurements will provide a very accurate multicompartmental analysis of body composition, they are not applicable to routine clinical or field work. Because of availability and simplicity, in addition to anthropometry, bioelectrical impedance and dual energy X-ray absorptiometry have received the most attention from the renal community. Several studies have validated the use of total body water by BEI as a surrogate for isotope dilution methods in dialysis patients, whereas others have established an excellent correlation with the volume of distribution of urea as measured by urea kinetic volume. Bioimpedance analysis has been extensively validated in stable healthy populations for measurement of lean body mass. Results are similar to those obtained with hydrodensitometry and total body potassium. Several studies in dialysis patients have compared lean body mass measurements by BEI and DEXA. Although the number of patients studied is relatively small, there is a high degree of correlation and concordance between the two methods. Nevertheless, selective equations for specific patient populations may be required with both methodologies for individual clinical applications. Longitudinal follow-up of body composition using BEI and DEXA in dialysis patients is contingent on a stable hydration status and/or accurate estimation of extracellular volume status for appropriate corrections. Consistency of technique and standardization of BEI and DEXA equipment is essential for reproducibility of results. Equations used in calculations must be age, sex, race, body habitus, and population specific whenever possible. Multiple compartment models including BEI, DEXA and isotopic dilution provide the best current "gold standard" for body composition analysis. BEI methodology is a practical bedside tool for assessment of total body water, and provides more consistent and reproducible results than anthropometry.

Absorptiometry, Photon↗