Correction of metabolic acidosis increases serum albumin concentrations and decreases kinetically evaluated protein intake in haemodialysis patients: a prospective study.

BACKGROUND: Metabolic acidosis in haemodialysis (HD) patients increases whole body protein degradation while the correction of acidosis reduces it. However, the effects of the correction of acidosis on nutrition have not been clearly demonstrated. STUDY DESIGN: In this study we have evaluated the effects of 3 months of correction of metabolic acidosis by oral sodium bicarbonate supplementation on protein catabolic rate (PCRn) and serum albumin concentrations in 12 uraemic patients on maintenance HD for at least 6 months (median 49 months; range 6-243 months). Pre-dialysis serum bicarbonate, arterial pH, serum albumin, total serum proteins, serum creatinine, plasma sodium, haemoglobin, PCRn, Kt/V, and TACurea, were evaluated before and after correction. RESULTS: Serum bicarbonate levels and arterial pH increased respectively from 19.3 +/- 0.6 mmol/l to 24.4 +/- 1.2 mmol/l (P < 0.0001) and 7.34 +/- 0.03 to 7.40 +/- 0.02 (P < 0.0001). Serum albumin increased from 34.9 +/- 2.1 g/l to 37.9 +/- 2.9 g/l (P < 0.01), while PCRn decreased from 1.11 +/- 0.17 g/kg/day to 1.03 +/- 0.17 g/kg/day (P < 0.001). No changes in Kt/V, total serum proteins, serum creatinine, plasma sodium, haemoglobin, body weight, pre dialysis systolic and diastolic blood pressure, and intradialytic weight loss were observed. CONCLUSIONS: Our data demonstrate that correction of metabolic acidosis improves serum albumin concentrations in HD patients. The correction of acidosis induces a decrease in PCRn values, as evaluated by kinetic criteria, suggesting that in the presence of moderate to severe acidosis this parameter does not reflect the real dietary protein intake of the patients probably as a result of increased catabolism of endogenous proteins. The correction of metabolic acidosis should be considered of paramount importance in HD patients.

Evidence for an independent role of metabolic acidosis on nutritional status in haemodialysis patients.

BACKGROUND: Malnutrition in haemodialysis (HD) patients has been referred to underdialysis with low protein intake, and to acidosis. However, the separate effects of underdialysis and acidosis on nutrition have not been clearly demonstrated. To evaluate the role of the dialysis dose and of metabolic acidosis on nutrition, we measured the predialysis serum HCO3, pH, serum albumin, PCRn, Kt/V, and BMI in 81 uraemic patients on maintenance bicarbonate HD for 93+/-80 months. Patients with chronic liver diseases, malignancies, and cachexia were excluded. RESULTS: Mean age was 59+/-17 years, Kt/V was 1.29+/-0.21, PCRn 1.06+/-0.22 g/kg/day, serum albumin 4.07+/-0.28 g/dl, BMI 23+/-4 kg/m2, HCO3 21.1+/-1.9 mmol/l, pH 7.36+/-0.04. Serum albumin showed a significant direct correlation with: PCRn (P=0.001), HCO3 (P=0.001), pH (P=0.002), but no correlation with Kt/V and BMI. Serum HCO3 correlated inversely with PCRn (P=0.027). Multiple regression analysis confirmed the significant role of serum bicarbonate and age, but not of Kt/V, on serum albumin concentrations. The role of PCRn appeared to be marginal compared to serum bicarbonate in determining serum albumin levels. Dividing patients into two groups, serum albumin was 3.96+/-0.22 g/dl with HCO3 < or = 20 mmol/l and 4.18+/-0.31 g/dl in those with serum HCO3 > or = 23 mmol/l (P=0.002). PCRn in the same groups was respectively 1.14+/-0.24 g/kg/day and 1.01+/-0.23 g/kg/day (P=0.03). Most importantly, serum albumin levels did not appear to be affected by the dialysis dose, with Kt/V ranging from 0.90 to 1.88. CONCLUSIONS: In HD patients with adequate Kt/V, metabolic acidosis exerts a detrimental effect on serum albumin concentrations partially independently of the protein intake, as evaluated by PCRn. In the presence of moderate to severe metabolic acidosis, PCRn does not reflect the real dietary protein intake of the patients, probably as a result of increased catabolism of endogenous proteins. For this reason PCRn should be considered with caution as an estimate of the dietary protein intake in HD patients in the presence of metabolic acidosis.

Acute visual disorders in patients on regular dialysis given desferrioxamine as a test.

Aluminium (Al) overload has been recognised as a frequent complication in uraemic patients on regular dialysis treatment. We report how acute visual disorders occurred after performing a desferrioxamine (DFO) test in patients on regular dialysis treatment suspected of having aluminium overload. Fifteen patients on regular dialysis treatment for 132 +/- 73 (range 17-250) months, aged 61 +/- 10 (range 47-79) years were given DFO as a test at standard dosage. In the 13 patients who complained of visual disorders, we performed ophthalmologic examinations soon after DFO administration, and again 5 months later in 11 of them. A decrease in visual acuity and/or dyschromatopsia, transient or permanent, were present in ten patients. Four had permanent maculopathy and three also had a permanent alteration of VEP (visual evoked potential). Visual fields were normal in all patients except one who presented a permanent central scotoma. The EOG (electro-oculogram) was permanently impaired in five patients and some of them had fluoroangiographic alterations due to damage of the pigmented epithelium. Six to eight months after the DFO test four patients still complained of visual acuity reduction. We conclude that there is a high rate of visual disorders after giving DFO at the standard doses; therefore we stress the need to modify the doses commonly used and/or the mode of infusion.

The role of hematocrit in efficiency of dialysis.

To test the role of hematocrit (Hct), particularly when in the nearly normal range, on efficiency of dialysis, we analyzed the urea kinetics for 36 metabolically and hematologically stable patients on regular dialysis treatment and for 7 patients from this group before and after 3 months of treatment with human recombinant erythropoietin (rHuEPO). The volume of distribution of urea (V), the dialyzer clearance (Kd) and Kt/V were plotted against Hct. Hct showed a significant inverse correlation with Kd (r = 0.479, p = 0.003) and Kt/V (r = 0.572, p = 0.0002). Further division of the patients into groups with respect to Hct showed that the lowest Kt/V values were in the group with Hct greater than or equal to 37%. In the patients treated with rHuEPO, Hct rose from 18 +/- 1 to 35 +/- 5% (p less than 0.0001), and Kt/V decreased from 1.22 +/- 0.21 to 1.09 +/- 0.18 (p = 0.037). We conclude that Hct exerts a negative influence on efficiency of dialysis as evaluated by Kt/V. This is important for patients with normal or nearly normal Hct levels as well as for patients treated with rHuEPO, for whom normalization of Hct is pursued.

Is CAPD competitive with haemodialysis for long-term treatment of uraemic patients?

Although there are only 10 years of clinical experience with CAPD, compared to about 30 years of clinical practice with haemodialysis, it is time to compare the results obtained from the two methods. In this review, after briefly summarising the state of the art for some worrisome aspects of CAPD (peritonitis, loss of ultrafiltration and peritoneal clearance, malnutritional status), the ability of CAPD and haemodialysis to control the uraemic abnormalities are compared. Anaemia, blood pressure, cardiac function, renal bone disease, beta 2-microglobulin, and uraemic neuropathy are examined in the light of our personal experience and the literature; data so far published seem to indicate that the two methods are roughly similar for controlling these conditions. A survey of the studies comparing patient and method survival is also included. Patient survival on CAPD or on haemodialysis does not differ by more than 6 years. Method survival is better for haemodialysis; this is primarily due to the high drop-out rate from CAPD because of peritonitis, and the difference is very much reduced in CAPD centres with a low incidence of peritonitis. On the whole, CAPD seems to be able to compete, sometimes favourably, with haemodialysis. However, in our opinion the two methods are not in competition; each has its preferential indications, limits and complications, and both should be offered to uraemic patients in accordance with their medical or social needs. One should be ready to shift the patient from one method to the other when necessary, either for short periods of time or indefinitely.

A six-year comparison of patient and technique survivals in CAPD and HD.

Comparisons of patient and technique survival were made for 120 CAPD and 139 HD patients undergoing dialysis between January 1981 and December 1986. Cox's proportional hazard regression model was used to compare patient and technique survival, with an adjustment for pre-treatment prognostic differences. Only the patients' first treatments were considered. The CAPD patients were 10 years older, on the average, than the HD patients and had more complicated conditions (58% with 3 or more co-existing risk factors vs. 35%). Overall patient survival between CAPD and HD did not differ (P = 0.2694). However, when adjusted for patient age, sex and other comorbid complicating conditions, CAPD patients over the age of 66 had a significantly lower risk of death than their HD counterparts (P less than 0.05). There were no differences in the adjusted patient survival for patients aged 30 to 66. Four pre-treatment prognostic factors had statistically significant adverse effects on patient survival: age, diabetes, malignancy and peripheral vascular disease. Survival of the HD technique, when unadjusted, was better than survival of CAPD (P = 0.0457). Even after adjustment for sex and age, this difference was still very nearly significant (P = 0.0656). No risk factors were found to be significantly associated with technique survival. Based on patient and technique survival, CAPD would appear to be an excellent alternative to HD and may be the preferred treatment for high risk patients over the age of 66.

CAPD is a first class treatment: results of an eight-year experience with a comparison of patient and method survival in CAPD and hemodialysis.

An 8-year experience on CAPD, in a single center with all treatments of ESRF (end-stage renal failure) available, is presented. Method choice was left to the patient, after extensive counselling. However, CAPD selection was very negative, and CAPD patients were older, with a much larger percentage of diabetics and loaded by more risk factors, suggesting an influence of the staff preferences on patient choice. After a first period with unsatisfactory results, we obtained an important improvement of patient and method survival coinciding with the introduction of a new connector with disinfectant (Y-system) which allowed a reduction of peritonitis rate to 1 episode for 36 patient/months. For the period 1.1.81 to 31.12.86 a comparison was made (life table analysis) between new ESRF patients placed initially on CAPD or on HD. The 5-year survival was not statistically different in spite of the very negative CAPD selection of patients, who were 10 years older, on the average. Excluding diabetics, survival curves were identical in the two methods. Age at death and causes of death were not different. Method survival was better on HD (98% vs. 71% on CAPD, at 5 years, p less than 0.01): significance and limits of this evaluation are discussed. Drop-out figures were definitely lower than in the literature and this was attributed to the sharp reduction in peritonitis rate. Only 1.7% of CAPD patients discontinued the method due to inadequate ultrafiltration. In 29 CAPD and 28 HD patients with more than 4 years treatment some biochemical and clinical data were compared. Serum cholesterol was significantly higher and serum proteins lower in CAPD.(ABSTRACT TRUNCATED AT 250 WORDS)

Micro-chromatographic measurement of hemoglobin A1 in uremia.

In an investigation of the reliability of the measurement of HbA1 by microcolumn chromatography for monitoring glucose metabolism in chronic renal failure, measurements were made in 96 uremic patients. Thirty-one patients were undialyzed, 42 patients including 10 with primary diabetes mellitus were on hemodialysis, and 23 patients were on continuous ambulatory peritoneal dialysis (6 with primary diabetes mellitus). Significantly raised HbA1 values were observed in all groups, whether their glucose tolerance was normal or decreased. Azotemia was not statistically correlated either with HbA1 values, or with glucose tolerance. Dialyzed primary diabetic patients showed HbA1 levels which were significantly higher than those in non-diabetics, but some overlap was evident. The results suggest that the increased values of HbA1 in uremic patients depend on the plasma concentration of either glucose which leads to the formation of glycosylated Hb or of urea which leads to the formation of carbamylated Hb. These are indistinguishable by microcolumn chromatography. Therefore this method cannot be recommended for evaluation of glucose metabolism in uremic patients.

Measurements of the distribution of technetium-99m sulfur colloid and technetium-99m HEDP in normal humans.

Technetium-99m sulfur colloid and technetium-99m hydroxyethylidene diphosphonate (HEDP) are two radiopharmaceuticals that have been widely used in nuclear medicine. Radiation dose estimates for both materials have been published in the literature and are found in the package inserts of the commercial kits. However, these estimates were made without the benefit of quantitative human organ uptake data. Estimates of absorbed radiation dose to the kidneys differ by nearly a factor of 6 between the two calculations for HEDP. The results of this study are in agreement with the lower previous estimate. Other than that one exception, agreement of the previous estimates with the measurements reported here is surprisingly good.

Survey of 99mTc contamination of laboratory personnel: hand decontamination.

Decontamination after exposure to various 99mTc radiopharmaceuticals was tested with serial hand washings both with and without soap. All radiopharmaceuticals were removed more effectively with soap and the degree of decontamination related closely to the number of washings. The affinity of the radiopharmaceuticals for the skin varied, depending upon the labeled material, and only macroaggregated albumin was effectively removed to less than 1% of its original activity with soap. Activity transfer to the opposite hand could be substantial with macroaggregated albumin and sulfur colloid if soap is not used.

Survey of 99mTc contamination of laboratory personnel: its degree and routes.

Internal contamination of personnel preparing 99mTc labeled radiopharmaceuticals was confirmed by detection of radioactivity in urine. Observation of work habits, whole-body scanner studies, nose swabs, and wipe tests in the hot laboratory demonstrated that: (a) contamination of the laboratory coat occurred during radiopharmaceutical preparation; (b) the degree of personnel contamination appeared to be higher among the short in stature; and (c) no gross evidence was found to indicate that internal contamination took place through an air-borne route. While the calculated internal radiation dose is minimal, even this could be avoided if particular precautionary practices are observed.

Absorbed dose comparison: positron emitters 11C, 13N, and 15O versus gamma-ray emitters.

Absorbed doses were calculated or taken from the literature for various compounds of 11C, 13N, and 15O, and compared to those of presently gamma-ray-emitting nuclear medicine radiopharmaceuticals. As a rule of thumb, the doses per millicurie of the injectable positron-emitting compounds are of the same order of magnitude as the dose per millicurie of 99mTc compounds. The absorbed doses from the injectable positron emitters are nearly one or more orders of magnitude lower on a per millicurie basis than those from the other injectable gamma emitters that were investigated.

[Distribution of obstetrical and postnatal risk-factors in 400 randomly selected newborns. A study using Prechtl's concept of optimal conditions (author's transl)]. / Die Verteilung obstetrischer und postnataler Risikofaktoren bei 400 zufällig ausgewählten Neugeborenen. Anwendung des Optimalitätskonzeptes nach Prechtl.

The distribution of obstetrical and postnatal risk-factors in a population of 400 newborns was investigated. For documentation, an extended list of Prechtl's list of optimal obstetric conditions was used. The newborns had been selected randomly from two populations, born 1972 in two different hospitals (County hospital, University hospital). The reduction of optimal conditions was calculated by percentiles. It was found that the number -3 (of 52 items, representing full optimal conditions) defined the 10th percentile of the population; number -5 the median, and number -10 the 90th percentile. In addition, percentiles were calculated regarding the history of the mother and the history of the infant respectively. Using the distribution of reduced obstetrical and postnatal optimal conditions allows to compare the history of a single newborn or the histories of a population of newborns with defined problems. Newborns with rather low negative numbers of reduced optimal conditions are at lower risk regarding their psychomotor development wheras newborns with high negative numbers carry a much higher irsk in this respect.

[Results and consequences using Prechtl's concept of optimal conditions. Obstetrical and Postnatal complications (author's transl)]. / Die Erfassung obstetrischer und postnataler Risikofaktoren durch eine Liste optimaler Bedingungen. Anwendung des Optimalitätskonzepts nach Prechtl.

An extended list of Prechtl's list of optimal obstetric conditions was used to describe the history of 200 newborns, randomly chosen from a defined population born in 1972. Differences between the population from Groningen (Prechtl's) and Tübingen, and different definitions of the items used in the list are discussed. Reduced optimal conditions in the history of the mother effectively reduced the optimal conditions in the newborn aswell. This was particularly so in case of: Preterm deliveries and miscarriages, bleedings in the first trimester, preterm onset of labour, operative deliveries, less than 38 weeks of gestational age, and an Apgar score below 7.

Dose to the metaphyseal growth complexes in children undergoing 99mTc-EHDP bone scans.

The spatial temporal distribution of radionuclides in children may differ greatly from that accepted for adults. Following injection of a bone-seeking agent (99mTc-EHDP), radioactivity in the metaphyseal growth complexes of the distal femur and proximal tibia was quantitated in a series of children 4 to 16 years of age, using a gamma camera/computer system. The dose to the growth plate was fount to range from 0.8 to 4.7 rads when adjusted to an administered activity of 200 muCi/kg, compared to approximately 0.6 rad to the adult skeleton for a corresponding study.

Nuclide parameters and S factors for 201Tl dosimetry estimates.

The mean numbers per disintegration, n, and equilibrium-dose constants delta for the various emissions of 201Tl were computed. The sums of the penetrating and nonpenetrating equilibrium-dose constants are 0.1931 and 0.0874 g rad/muCi h, respectively. The S factor, the value of that portion of the MIRD dose equation which is independent of biological distribution, was calculated for various combinations of target and source organs.