Diss. Linköping : Univ., 2002.

Diss. (sammanfattning) Stockholm : Karolinska institutet, 2007. / Härtill 6 uppsatser.

Diss. (sammanfattning) Linköping : Linköpings universitet, 2006. / Härtill 5 uppsatser.

A high-performance liquid chromatography was developed to assay levofloxacin and vancomycin. Fluorescence polarization immunoassay was to assay amikacin. The oseltamivir carboxylate and telavancin concentrations were assayed by high-performance liquid chromatography coupled with tandem mass spectrometry. / An in vitro model was utilized to examine adsorption of antibiotics onto haemofilters. In order to test antibiotics from a range of classes, levofloxacin, amikacin, vancomycin, telavancin, and oseltamivir carboxylate were studied. / In summary, the antibiotic adsorption by haemofilters is a complex process. Both characteristics of antibiotics and haemofilters may determine adsorption. Among the studied antibiotics, in vitro adsorption of amikacin by PAN filters may have clinical significance, thus the routine monitoring of amikacin peak concentration in vivo during CRRT is recommended. / In the in vitro model, blood was pumped from an agitated, glass mixing chamber (heated using an automatic water bath), around a circuit and returned to the mixing chamber using a haemofiltration machine. Ultrafiltrate was also returned to the mixing chamber to constitute a closed circuit. As a result any decrease in drug concentration could only be due to adsorption to the filter and extracorporeal circuit, spontaneous degradation or metabolism by red cells. / The main findings were: (1) low adsorption of levofloxacin and vancomycin by haemofilters at clinically relevant concentrations; (2) significant absolute adsorption of amikacin by polyacrylonitrile haemofilters; (3) the adsorption of antibiotics was membrane-material dependent with greater adsorption by polyacrylonitrile filters; (4) lack of relationship between membrane surface area and amikacin adsorption; (5) the adsorption of levofloxacin is reversible, contrary to irreversibility of vancomycin and amikacin; (6) sieving coefficient of oseltamivir is very near to 1.0. / This thesis investigated: (1) the extent of antibiotic adsorption (levofloxacin, vancomycin, amikacin, telavancin and oseltamivir carboxylate) by haemofilters; (2) the time course of antibiotic adsorption by haemofilters; (3) the effects of plasma albumin concentration, initial dosage, pH, filter membrane material, filter membrane surface area and repeated dosing on adsorption; (4) the reversibility or irreversibility of adsorption; (5) clearance of oseltamivir carboxylate and telavancin by ultrafiltration. / Up to 25% of critically ill patients develop acute renal failure with sepsis being the most common cause. Outside of North and South America, these patients usually receive continuous renal replacement therapy (CRRT) which utilizes high flux haemofilter membranes. Thus it is common for these patients to be concurrently receiving antibiotics and CRRT. However, information about the adsorptive capacity of various haemofilters for most drugs is lacking. / "September 2007." / Advisers: Charles Gomersall; Tony Gin. / Source: Dissertation Abstracts International, Volume: 69-08, Section: B, page: 4659. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2007. / Includes bibliographical references (p. 147-164). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract in English and Chinese. / School code: 1307.

Introdução: Não há estudos que avaliem o impacto da reutilização do dialisador na remoção de solutos em sessões de hemodiafiltração online curta diária (HDF-OL-D). Objetivo: Avaliar o impacto do reuso do dialisador na dose do tratamento, na cinética de beta2-microglobulina e na extração de solutos em sessões de HDF-OL-D e comparar com sessões de hemodiálise curta diária de alto fluxo (HD-D). Métodos: Foram incluídos 14 pacientes do programa de HD-D. Foram coletadas amostras de sangue pré, no meio e pós-diálise e amostras do dialisato no 1º, 7º e 13º usos do dialisador em sessões de HD-D e de HDF-OL-D. Resultados: A massa total extraída (MTDQ) e a depuração (KDQ) diretamente quantificada dos solutos pequenos (ureia, fósforo, creatinina e ácido úrico), bem como a dose de diálise ofertada, foram semelhantes quando o 1º, 7º e 13º usos do dialisador em sessões de HD-D foram comparados, respectivamente, ao 1º, 7º e 13º usos em sessões de HDF-OL-D. A MTDQ e a KDQ dos solutos pequenos e a dose de diálise foram semelhantes entre os usos do dialisador tanto em sessões de HD-D e quanto em sessões de HDF-OL-D. A MTDQ, a KDQ e o Kt/V diretamente quantificado (Kt/VDQ) de beta2-microglobulina foram maiores em sessões de HDF-OL-D do que nos respectivos usos do dialisador em sessões de HD-D. Não houve diferença quanto à cinética de beta2-microglobulina, avaliada pela MTDQ, KDQ ou Kt/VDQ, entre o 1º, 7º e 13º usos do dialisador em sessões de HD-D nem em sessões de HDF-OL-D. Na HDF-OL-D, a perda intradialítica de albumina foi significativamente diferente entre os usos do dialisador (p < 0,001), estando reduzida no 7º e 13º usos, quando comparados ao 1º uso do dialisador. Não houve correlação entre o volume de enchimento do dialisador e a MTDQ e a KDQ de moléculas pequenas em nenhum dos métodos dialíticos estudados. Em sessões de HDF-OL-D, foi observada uma correlação fraca entre o volume de enchimento do dialisador e a KDQ de beta2-microglobulina, não percebida com a MTDQ ou o Kt/VDQ de beta2-microglobulina. Conclusão: O reprocessamento de dialisadores de alto fluxo e alta eficiência não resulta em comprometimento da dose do tratamento, da cinética de beta2-microglobulina nem da extração de solutos em sessões de HDF-OL-D. A extração de beta2-microglobulina foi maior em sessões de HDF-OL-D do que em sessões de HD-D, sem diferenças significativas na remoção dos demais solutos. O reprocessamento do filtro, em sessões de HDF-OL-D, resultou numa redução significativa da perda intradialítica de albumina. Não parece haver influência do volume de enchimento do filtro na extração de solutos em nenhum dos métodos de diálise estudados / Introduction: There no studies evaluating the impact of dialyzer reutilization on solute removal in daily online hemodiafiltration (D-OL-HDF) sessions. Objectives: Our aim was to evaluate the impact of dialyzer reuse on solute extraction, beta2-microglobulin kinetics and dialysis dose in D-OL-HDF and compare to those in high-flux short daily hemodialysis (D-HD). Methods: 14 patients undergoing a D-HD program were included. Pre, middle and post-dialysis blood samples and effluent dialysate were collected in the 1st, 7th and 13th dialyzer uses in D-HD sessions and in D-OL-HDF sessions. Results: Directly quantified small solute (urea, phosphorus, creatinine and uric acid) total mass removal (TMDQ) and clearance (KDQ), as well as dialysis dosis, were similar when the 1st, 7th and 13th dialyzer D-HD uses were compared to the 1st, 7th and 13th D-OL-HDF uses. TMDQ and KDQ of small solutes and dialysis dose were similar among dialyzer uses in D-HD sessions and also in D-OL-HDF sessions. beta2-microglobulin TMDQ, KDQ and directly quantified Kt/V (Kt/VDQ) were statistically higher in D-OL-HDF dialyzer uses than in the respective D-HD uses. There was no difference in beta2-microglobulin kinetics, evaluated by TMDQ, KDQ or Kt/VDQ, among 1st, 7th and 13th uses in D-OL-HDF sessions or in D-HD sessions. In D-OL-HDF, albumin loss was significantly different among studied dialyzer uses (p < 0.001), being reduced in the 7th and 13th dialyzer uses, when compared to the first use. There was no correlation between dialyzer priming volume and small molecules TMDQ, KDQ in neither analyzed dialytic method. In D-OL-HDF sessions, it was observed a week correlation between dialyzer priming volume and beta2-microglobulin KDQ, not observed with beta2-microglobulin MTDQ or Kt/VDQ. Conclusion: High flux, high efficiency dialyzer reprocessing did not did result in a reduction of the offered dialysis dose, beta2-microglobulin kinetics or solute extraction in D-OL-HDF. beta2-microglobulin removal was greater in D-OL-HDF than in D-HD sessions, without difference in other solutes extraction. There was a significant reduction in intradialytic albumin loss with dialyzer reprocessing in D-OL-HDF sessions. Dialyzer priming volume does not appear to influence solute removal in neither analyzed dialytic method

Introdução: Não há estudos que avaliem o impacto da reutilização do dialisador na remoção de solutos em sessões de hemodiafiltração online curta diária (HDF-OL-D). Objetivo: Avaliar o impacto do reuso do dialisador na dose do tratamento, na cinética de beta2-microglobulina e na extração de solutos em sessões de HDF-OL-D e comparar com sessões de hemodiálise curta diária de alto fluxo (HD-D). Métodos: Foram incluídos 14 pacientes do programa de HD-D. Foram coletadas amostras de sangue pré, no meio e pós-diálise e amostras do dialisato no 1º, 7º e 13º usos do dialisador em sessões de HD-D e de HDF-OL-D. Resultados: A massa total extraída (MTDQ) e a depuração (KDQ) diretamente quantificada dos solutos pequenos (ureia, fósforo, creatinina e ácido úrico), bem como a dose de diálise ofertada, foram semelhantes quando o 1º, 7º e 13º usos do dialisador em sessões de HD-D foram comparados, respectivamente, ao 1º, 7º e 13º usos em sessões de HDF-OL-D. A MTDQ e a KDQ dos solutos pequenos e a dose de diálise foram semelhantes entre os usos do dialisador tanto em sessões de HD-D e quanto em sessões de HDF-OL-D. A MTDQ, a KDQ e o Kt/V diretamente quantificado (Kt/VDQ) de beta2-microglobulina foram maiores em sessões de HDF-OL-D do que nos respectivos usos do dialisador em sessões de HD-D. Não houve diferença quanto à cinética de beta2-microglobulina, avaliada pela MTDQ, KDQ ou Kt/VDQ, entre o 1º, 7º e 13º usos do dialisador em sessões de HD-D nem em sessões de HDF-OL-D. Na HDF-OL-D, a perda intradialítica de albumina foi significativamente diferente entre os usos do dialisador (p < 0,001), estando reduzida no 7º e 13º usos, quando comparados ao 1º uso do dialisador. Não houve correlação entre o volume de enchimento do dialisador e a MTDQ e a KDQ de moléculas pequenas em nenhum dos métodos dialíticos estudados. Em sessões de HDF-OL-D, foi observada uma correlação fraca entre o volume de enchimento do dialisador e a KDQ de beta2-microglobulina, não percebida com a MTDQ ou o Kt/VDQ de beta2-microglobulina. Conclusão: O reprocessamento de dialisadores de alto fluxo e alta eficiência não resulta em comprometimento da dose do tratamento, da cinética de beta2-microglobulina nem da extração de solutos em sessões de HDF-OL-D. A extração de beta2-microglobulina foi maior em sessões de HDF-OL-D do que em sessões de HD-D, sem diferenças significativas na remoção dos demais solutos. O reprocessamento do filtro, em sessões de HDF-OL-D, resultou numa redução significativa da perda intradialítica de albumina. Não parece haver influência do volume de enchimento do filtro na extração de solutos em nenhum dos métodos de diálise estudados / Introduction: There no studies evaluating the impact of dialyzer reutilization on solute removal in daily online hemodiafiltration (D-OL-HDF) sessions. Objectives: Our aim was to evaluate the impact of dialyzer reuse on solute extraction, beta2-microglobulin kinetics and dialysis dose in D-OL-HDF and compare to those in high-flux short daily hemodialysis (D-HD). Methods: 14 patients undergoing a D-HD program were included. Pre, middle and post-dialysis blood samples and effluent dialysate were collected in the 1st, 7th and 13th dialyzer uses in D-HD sessions and in D-OL-HDF sessions. Results: Directly quantified small solute (urea, phosphorus, creatinine and uric acid) total mass removal (TMDQ) and clearance (KDQ), as well as dialysis dosis, were similar when the 1st, 7th and 13th dialyzer D-HD uses were compared to the 1st, 7th and 13th D-OL-HDF uses. TMDQ and KDQ of small solutes and dialysis dose were similar among dialyzer uses in D-HD sessions and also in D-OL-HDF sessions. beta2-microglobulin TMDQ, KDQ and directly quantified Kt/V (Kt/VDQ) were statistically higher in D-OL-HDF dialyzer uses than in the respective D-HD uses. There was no difference in beta2-microglobulin kinetics, evaluated by TMDQ, KDQ or Kt/VDQ, among 1st, 7th and 13th uses in D-OL-HDF sessions or in D-HD sessions. In D-OL-HDF, albumin loss was significantly different among studied dialyzer uses (p < 0.001), being reduced in the 7th and 13th dialyzer uses, when compared to the first use. There was no correlation between dialyzer priming volume and small molecules TMDQ, KDQ in neither analyzed dialytic method. In D-OL-HDF sessions, it was observed a week correlation between dialyzer priming volume and beta2-microglobulin KDQ, not observed with beta2-microglobulin MTDQ or Kt/VDQ. Conclusion: High flux, high efficiency dialyzer reprocessing did not did result in a reduction of the offered dialysis dose, beta2-microglobulin kinetics or solute extraction in D-OL-HDF. beta2-microglobulin removal was greater in D-OL-HDF than in D-HD sessions, without difference in other solutes extraction. There was a significant reduction in intradialytic albumin loss with dialyzer reprocessing in D-OL-HDF sessions. Dialyzer priming volume does not appear to influence solute removal in neither analyzed dialytic method