A previous short-term study of 10 weeks in 8 patients had shown us that with half the dose of elemental calcium, calcium acetate (CaAc) could control predialysis plasma phosphate (PPO4) as well as calcium carbonate (CaCO3) but that the incidence of hypercalcemia was not decreased. To better appreciate the value of CaAc in comparison to CaCO3, CaAc was given to 28 patients on chronic hemodialysis (6 men, 22 women, age 61 ± 14 years; dialyzate Ca: 1.5 mmol/l) for 6 months to replace CaCO3 at half the dose of elemental calcium (1,235 ± 521 versus 2,375 ± 1,470 mg/day). Because of gastrointestinal intolerance, CaAc had to be discontinued in 5 patients after 1-5 months. Magnesium hydroxide [Mg(OH)2] given in 18 of them in association with CaCO3 was discontinued and reintroduced in 6 patients in order to keep PPO4 < 2 mmol/l. Mean dosage of Mg(OH)2 was 2.09 ± 1.4 g/day with CaCO3 and 0.9 ± 0.5 with CaAc. Predialysis plasma concentrations of calcium and phosphate were monitored weekly during the 3 months of the control period under CaCO3 and during the 6-month administration of CaAc. Plasma calcium (PCa) was comparable with the 2 treatments (2.47 ± 0.11 vs. 2.5 ± 0.10 mmol/l), but PPO4 was significantly lower with CaAc (1.82 ± 0.26 vs. 1.73 ± 0.23 mmol/l). Plasma alkaline phosphatase remained constant (122 ± 66 vs. 122 ± 70; normal < 170 UI/l) as well as plasma intact PTH (121 ± 153 vs. 121 ± 146; normal < 54 pg/ml) and plasma aluminum (0.34 ± 0.23 vs. 0.32 ± 0.20 μmol/l). Hypercalcemia (PCa > 2.7 mmol/l) was present in 11 patients with CaCO3 and in 16 patients with CaAc, and its incidence did not decrease with CaAc (8.2 vs. 8%). In conclusion, this long-term study confirms that CaAc is a more efficient PO4 binder than CaCO3. However, its gastrointestinal tolerance seems poorer and the incidence of hypercalcemia is not decreased. The paradox of the unchanged incidence of hypercalcemia with acetate in spite of a reduction by half of the amount of calcium ingested may have two explanations: the very presence of a lower plasma PO4 concentration (by a physicochemical mechanism) and the possible greater bioavailability of the calcium for absorption when it is given as CaAc.
Objetivo: Analisar as evidências científicas disponíveis na literatura sobre as medidas de prevenção e controle da COVID-19. Métodos: Trata-se de uma revisão integrativa de artigos publicados em português, inglês ou espanhol, do ano de 2020, nas bibliotecas/bases Biblioteca Virtual em Saúde (BVS) e Medical Literature Analysis and Retrieval System Online (MEDLINE/Pubmed), sendo a amostra final composta por 08 artigos. A pergunta norteadora foi: Quais as medidas de prevenção e controle da COVID-19? Resultados: A partir da busca de estudos por meio de cruzamentos duplos e triplos, foram encontrados 2.246 artigos, dentre estes, 08 artigos foram selecionados que correspondiam ao tema do estudo, estes foram divididos em duas classes: 1 - A influência ou a percepção dos usuários em relação às medidas de prevenção da COVID-19 a partir das mídias digitais e 2 - As medidas de prevenção e controle da COVID-19 aplicadas pela gestão sanitária. Considerações Finais: Infere-se que, sendo a pandemia desencadeada por uma patologia emergente, ainda com estudos incipientes, concorreu para a disseminação de informações por vezes conflitantes pelos próprios representantes legais, gerando incredulidade e insegurança da população para adesão às medidas sanitárias.
Since Mai et al. found, with the intestinal lavage technique, that the same dose of elemental calcium given as acetate (Ca Ac) complexed in the gut of uremic patients twice as much phosphate as calcium carbonate (CaCO3) while inducing a rather low calcium absorption, we wanted to see if half the dose of elemental calcium given as Ca Ac could control, on medium term, the predialysis plasma phosphate as well as CaCO3 while inducing less frequent hypercalcemia. This was evaluated in a cross-over study of 3 periods of 10 weeks according to the sequence Ca Ac, CaCO3 and Ca Ac, in 12 compliant patients on chronic dialysis previously treated by CaCO3. Because of poor tolerance of Ca Ac during the first period, 4 patients were excluded and the results were assessed only on the 8 patients who completed the study. For half the doses of elemental calcium (620 ± 250 mg versus 1,310 ± 560 mg versus 710 ± 200 mg/day), Ca Ac allowed the same control of predialytic hyperphosphatemia (1.67 ± 0.34; 1.74 ± 0.32; 1.75 ± 0.38) with paradoxically comparable normal mean plasma calcium concentration (2.61 ± 0.14; 2.56 ± 0.13; 2.55 ± 0.14 mmol/l). Plasma alkaline phosphatases and intact PTH concentrations remained also stable during the 3 periods. The frequency of hypercalcemia greater than 2.75 mmol/l (12; 9; 20%) and of hyperphosphatemia greater than 2 mmol/l (17; 22; 27%) were comparable with the 2 treatments. In conclusion, Ca Ac controls predialytic hyperphosphatemia as efficiently as CaCO3 for half the dose of elemental calcium without, however, decreasing the frequency of hypercalcemia. These results challenge the validity of extrapolating the results of the intestinal lavage technique for assessing the medium-term absoφtion of calcium. The real advantage of Ca Ac over CaCO3 as phosphate binder remains to be established.
The purpose of this study is to evaluate the place of intravenous 1α-hydroxyvitamin D3 (1α-OH-D3) in the prevention of radiologically obvious hyperparathyroidism (HPT) in patients on maintenance dialysis while excluding aluminium phosphate binder and using a dialysate calcium concentration of 1.62 mmol which keeps the intradialytic calcium balance neutral. Therefore, 47 patients without subperiosteal resorption and previously treated by oral CaCO3 and if necessary Mg(OH)2 as phosphate binder while their dialysate calcium had a Ca level of 1.62 and a Mg level of 0.2 mmol/l were randomized into a control group of 24 who were maintained on the same treatment and an experimental group of 23. This group discontinued CaCO3 and received intravenous 1α-OH-D3 after each dialysis at increasing doses up to 4 μg and increased Mg(OH)2 as their sole phosphate binder. When plasma Ca increased above 2.7 mmol/l, the dose of 1α-OH-D3 was decreased. When plasma P04 increased above 2 mmol/l, the dose of Mg(OH)2 was increased to the highest dose not inducing diarrhea, hypermagnesemia ( < 2 mmol/l) or hyperkalemia ( < 6 mmol/l). In case of persistent hyperphosphatemia, the dose of 1α-OH-D3 was decreased. Since mean plasma alcaline phosphatase was normal, HPT was monitored on the plasma concentration of 1-84 PTH for which a previous histological study showed that frank osteitis fíbrosa was present only when they were above 70 pg/ml, i.e. (about twice the upper limit of the normal value). Before the study, plasma PTH was below this limit in 16 patients of the CaCO3 group and in 14 patients of the 1α-OH-D3 group. After 6 months, they remained below this limit in all patients except 2 of each group. Plasma PTH was initially above 70 pg/ml in 8 of the CaCO3 and did not change significantly throughout the study, 2 patients having at 6 months a PTH level below 70 pg/ml. In contrast with intravenous 1α-OH-D3, all the 9 patients with initial frank HPT decreased their PTH levels after 2 months, the levels being below 70 pg/ml in 6 cases. However, because of hypercalcemia and/or of hyperphosphatemia in spite of a highest tolerable dose of Mg(OH)2, 1α-OH-D3 doses had to be decreased down to 0.4 μg per dialysis at the 6th month so that at 6 months 6 of 9 patients had their PTH levels above 70 pg/ml, a number comparable to that of patients treated with CaCO3 (6 of 8). Conclusion: (l) CaCO3 and intravenous 1α-OH-D3 are comparably capable of preventing HPT in two thirds of the dialyzed patients; (2) only intravenous 1α-OH-D3 is able to correct an established frank HPT but this correction is only transient when Mg(OH)2 is the sole phosphate binder. As a matter of fact, the highest tolerable doses of Mg(OH)2 cannot prevent the hyperphosphatemia worsening induced by intravenous 1α-OH-D3, which ...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.