Sonication did not provide reliability to Maki technique for catheter related bloodstream infection diagnosis / La sonicación no proporciona rentabilidad a la técnica de Maki para el diagnóstico de bacteriemia relacionada con catéter

Objective. The aim of our study was to analyze sonicationand Maki techniques for diagnosis of catheter tip colonizationand catheter-related bloodstream infection (CRBSI) on patientsadmitted to ICU.Material and methods. Observational and prospectivestudy in one Intensive Care Unit. Patients with some centralvenous catheter (CVC) at least for 7 days and catheter-relatedinfection (CRI) suspicion (new episode of fever or sepsis) wereincluded. We performed Maki technique followed by sonication of catheter tip. We compared area under the curve (AUC)of Maki, sonication, and techniques combination to diagnosiscatheter tip colonization and CRBSI.Results. We included 94 CVC from 87 CRI suspicion episodes. We found 14 cases of catheter tip colonization and 10cases of CRBSI. Of the 14 catheter tip colonization cases, 7(50.0%) were detected by Maki and sonication techniques, 6(42.9%) were detected only by Maki technique, and 1 (7.1%)was detected only by sonication technique. Of the 10 CRBSI,6 (60.0%) were detected by Maki and sonication techniques,4 (40.0%) were detected only by Maki technique, and anyonly by sonication technique. We found higher AUC in Makitechnique than in sonication technique to diagnosis of CRBSI(p=0.02) and to diagnosis of catheter tip colonization (p=0.03).No significant differences were found in AUC between Makitechnique and combination techniques for diagnosis of catheter tip colonization (p=0.32) and of CRBSI (p=0.32).Conclusion.: Sonication did not provide reliability to Makitechnique for diagnosis of catheter tip colonization and CRBSI. (AU)

Objetivo. El objetivo de nuestro estudio fue analizar lastécnicas de sonicación y Maki para el diagnóstico de la colonización de la punta del catéter y la bacteriemia relacionada conel catéter (CRBSI) en pacientes ingresados en UCI.Material y método. Estudio observacional y prospectivoen una Unidad de Cuidados Intensivos. Se incluyeron pacientescon algún catéter venoso central (CVC) insertado al menos durante 7 días y sospecha de sospecha de infección relacionadacon el catéter (IRC) (nuevo episodio de fiebre o sepsis). Se realizó técnica de Maki y posteriormente sonicación de la puntadel catéter. Comparamos áreas bajo la curva (AUC) de Maki,sonicación y combinación de técnicas para el diagnóstico decolonización de la punta del catéter y de CRBSI.Resultados. Se incluyeron 94 CVC de 87 episodios de sospecha de IRC. Encontramos 14 casos de colonización de la puntadel catéter y 10 casos de CRBSI. De los 14 casos de colonizaciónde la punta del catéter, 7 (50,0%) fueron detectados por Maki ytécnicas de sonicación, 6 (42,9%) fueron detectados solo por latécnica de Maki y 1 (7,1%) fue detectado solo por la técnica desonicación. De los 10 CRBSI, 6 (60,0%) fueron detectados portécnicas de Maki y sonicación, 4 (40,0%) fueron detectados solopor la técnica de Maki, y ninguno solo por la técnica de sonicación. Encontramos mayor AUC con Maki que en la sonicaciónpara el diagnóstico de CRBSI (p=0.02) y para el diagnóstico decolonización de la punta del catéter (p=0.03). No encontramosdiferencias significativas en AUC entre Maki technique y combinación de técnicas para el diagnóstico de CRBSI (p=0.32) y parael diagnóstico de colonización de la punta del catéter (p=0.32).Conclusiones. La sonicación no proporcionó rentabilidada la técnica de Maki para el diagnóstico de colonización de lapunta del catéter y CRBSI. (AU)

Skin insertion site culture for the prediction of primary bloodstream infection.

PURPOSE: Previous studies have analyzed the capability of skin insertion site culture to predict catheter-related bloodstream infection (CRBSI). However, there has been not analyzed its capability to predict primary bloodstream infection (PBSI), that include CRBSI and bloodstream infection of unknown origin (BSIUO). The novel objective of our study was to determine the capability of insertion skin site culture to predict CRBSI and primary bloodstream infection (PBSI), that include CRBSI and bloodstream infection of unknown origin (BSIUO). MATERIAL AND METHODS: Observational and prospective study in one Intensive Care Unit. Patients with some central venous catheter (CVC) at least during 7 days and suspected catheter-related infection (CRI) (new episode of fever or sepsis) were included. Cultures of insertion skin site, paired blood samples, catheter-tip, and other clinical samples were taken. Capability of insertion skin site culture to predict CRBSI and PBSI was determined. RESULTS: We included 108 CVC from 96 CRI suspicion episodes. The causes that motivated CRI suspicion were 20 (18.5%) PBSI, 44 (40.7%) other infections, and 44 (40.7%) unknown. Among the 20 PBSI, 11 (55%) were CRBSI and 9 (45%) were BSIUO. Negative predictive value of insertion skin site culture to predict CRBSI was 95% (87-98%) and to predict PBSI was 85% (76-91%). CONCLUSIONS: The new finding of our study was that skin insertion site culture had a good negative predicted valued for the prediction of CRBSI and PBSI.

Liquid chromatographic method for the simultaneous determination of imipenem and sulbactam in mouse plasma.

The first analytical method is developed and validated for the simultaneous determination of imipenem and sulbactam in mouse plasma. Sample treatment is based on plasma stabilization with 4-(2-hydroxyethyl)piperazine-ethanesulfonic acid (HEPES) (0.5 mol/L; pH 7.0)-water-ethylene glycol (2:1:1, v/v/v), precipitation of plasma proteins with acetonitrile, centrifugation, evaporation, and reconstitution with borate buffer. Analytical determination is carried out by high-performance liquid chromatography with diode-array detection. Chromatographic separation is achieved within 11 min on a C(18) column by gradient elution with borate buffer (0.1 mol/L, pH 7.2) and methanol. Imipenem and sulbactam are monitored at 295 and 230 nm, respectively. The overall interday accuracy is in the range of 95% to 100% and from 98% and 101% for imipenem and sulbactam, respectively. Interday precision is below 8% and 4% for imipenem and sulbactam, respectively. Limits of quantitation of imipenem and sulbactam are 0.05 and 1.0 microg/mL, respectively. The mean extraction recoveries are 94.5% and 94.2% for imipenem and sulbactam, respectively. The described method allows an accurate, simple, and rapid identification and quantitation of imipenem and sulbactam in mouse plasma. This method is applied to the analysis of imipenem and sulbactam in mouse plasma after drug administration.

Simultaneous determination of rifampicin and sulbactam in mouse plasma by high-performance liquid chromatography.

A simple and rapid high-performance liquid chromatographic (HPLC) method with ultraviolet detection has been developed and validated for the simultaneous determination of rifampicin and sulbactam in mouse plasma. Plasma samples were deproteinized with acetonitrile and separated by HPLC on a RP-18 (125 x 4 mm, 5 microm) column and gradient elution with potassium dihydrogen phosphate solution (pH 4.5; 50 mm) and acetonitrile at a flow-rate of 1.0 mL/min. Rifampicin and sulbactam were monitored at 230 nm and confirmed by means of their UV spectra using a diode-array detector. The method was linear at plasma levels from 1 to 100 microg/mL for rifampicin and from 5 to 200 microg/mL for sulbactam. The limits of quantification were 0.6 microg/mL for rifampicin and 4.2 microg/mL for sulbactam. The intra- and inter-day precisions of the method (RSD) were lower than 5% for both compounds. Average recoveries of rifampicin and sulbactam from mice plasma were 98.2 and 89.3%, respectively. The developed method was successfully applied to the determination of the pharmacokinetic profile of both compounds in mice.

Electrochemical study of imipenem's primary metabolite at the mercury electrode. Voltammetric determination in urine.

Imipenem shows a fast chemical conversion to the more stable imin form (identical to that from biochemical dehydropeptidase degradation) in aqueous solutions that shows a wave at lower cathodic potential than the imipenem one. The aim of this work is the study of the electrochemical behaviour of the primary metabolite of imipenem (M1) and the proposal of electrochemical methods for the determination of M1 in human urine samples. Electrochemical studies were realized in phosphate buffer solutions over pH range 2.0-8.0 using differential pulse polarography, dc-tast polarography, cyclic voltammetry and linear sweep voltammetry (staircase). In acidic media, a non-reversible diffusion-controlled reduction involving two electrons and two protons occurs and the mechanism for the reduction was suggested. A differential pulse polarographic method for the determination of M1 in the concentration range 10(-6) to 10(-4)M with a detection limit of 4.5 x 10(-7)M was proposed. Also, a method based on controlled adsorptive pre-concentration of M1 on the hanging mercury drop electrode (HMDE) followed by linear sweep voltammetry allows its determination in the concentration range 2 x 10(-9) to 4 x 10(-8)M with a detection limit of 1.05 x 10(-9)M. The proposed methods have been used for the direct determination of M1 in spiked human urine and real human-derived urine with good results and should be appropriate for monitoring purposes.

Spectrofluorimetric and micelle-enhanced spectrofluorimetric determination of gatifloxacin in human urine and serum.

A spectrofluorimetric method to determine gatifloxacin has been developed and applied to the quantification of this fluoroquinolone in spiked human urine and serum. The native fluorescence of gatifloxacin allow the determination of 0.040-0.700 micro gmL(-1) of this molecule in aqueous solution containing acetic acid-sodium acetate buffer (pH 3.5), with lambda(exc)=292 nm and lambda(em)=484 nm. Micelle-enhanced fluorescence led to 75% higher analytical signals in presence of 12 mM sodium dodecyl sulphate, which allow the determination of 0.020-0.450 microg mL(-1) fluoroquinolone with lambda(exc)=292 nm and lambda(em)=470 nm. Both methods were successfully applied to gatifloxacin determination in spiked human urine and serum.

Electrochemical reduction of cefminox at the mercury electrode and its voltammetric determination in urine.

The electrochemical behaviour of cefminox in phosphate buffers solutions over pH range 2.0-9.0 using differential-pulse polarography, DC-tast polarography, cyclic voltammetry and linear sweep voltammetry (staircase) has been studied. In acidic media, a non reversible diffusion-controlled reduction involving two electrons occurs and the mechanism for the reduction was suggested. A differential-pulse polarographic method for the determination of cefminox in the concentration range 5.8x10(-6)-6.0x10(-5) M with a detection limit of 1.76x10(-6) M was proposed. Also, a method based on controlled adsorptive pre-concentration of cefminox on the hanging mercury drop electrode followed by linear sweep voltammetry, allows its determination in the concentration range 8.3x10(-8)-1.5x10(-6) M with a detection limit of 2.47x10(-8) M. These methods have been used for the direct determination of cefminox in human urine with recoveries between 98 and 103%, and precision around +/-2%.

Spectrofluorimetric determination of acrivastine in spiked human urine and pharmaceuticals.

A spectrofluorimetric method to determine acrivastine is proposed and applied to its determination in human urine and pharmaceuticals. The fluorimetric method allows the determination of 58-2000 ng ml(-1) of acrivastine in aqueous solutions containing acetic acid-sodium acetate buffer (pH 6.5) with lambda(exc)=230 nm and lambda(em)=380 nm.