Development and validation of an assay for the measurement of gentamicin concentrations in dried blood spots using UHPLC-MS/MS.

Gentamicin sulfate (GEN) is an aminoglycoside antibiotic with a narrow therapeutic range of plasma concentrations. The collection of venous blood represents a significant burden for patients, especially in neonatology. Dried blood spots (DBS) obtained from capillary blood can be an alternative for drug measurements in this particular population. This study aimed to develop and validate an assay for the quantification of GEN in DBS using UHPLC-MS/MS. Total GEN concentrations were obtained by adding the individual concentrations of the GEN forms C1, C1a, and C2. The assay used a DBS disk containing approximately 17 µL of blood for GEN quantitation in the range of 0.1-40 mg L-1. Measurement accuracy for total GEN was in the range of 102.6-108.6%, inter-assay precision was 11.3-13.1% and intra-assay precision was 9.1-12.8.% GEN was stable for 21 days at - 20 and 8 °C, but only for 24 h at room temperature. Blood Hct affected the accuracy within acceptable limits (93.8-95% at Hct% of 30, 104.3-113% at Hct% of 50). Blood spotted volume did not affect GEN measurement accuracy. Concentrations of GEN in DBS obtained after heel pricks were correlated to plasma levels in a small cohort of neonatal patients. However, percentual differences between estimated plasma concentrations and actual plasma levels presented values between - 64-35.3% (average difference of - 1.9%). The use of DBS for the measurement of GEN concentrations can increase access to TDM of this antibiotic due to the ease of sample collection and the facilitated specimen transportation logistics when testing is not available onsite.

Sensitive determination of gentamicin in plasma using ion-exchange solid-phase extraction followed by UHPLC-MS/MS analysis.

BACKGROUND: Therapeutic drug monitoring (TDM) of gentamicin sulfate (GEN) is usually recommended, particularly in critical patients. Only a few reports had described the determination of GEN in plasma or plasma using LC-MS/MS. OBJECTIVE: This study aimed to develop and validate a sensitive ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) assay for the quantification of GEN in small volumes of human plasma. RESULTS: The use of a very low concentration of the ion-pairing agent HFBA allowed significant retention of the very polar GEN forms in a reversed phase UHPLC column. The solid-phase extraction (SPE) procedure allowed clean extracts, with no interferences detected in blank samples, and high sensitivity. The assay was linear on the range of 0.2-40 mg L-1 of GEN complex. The combined GEN complex had inter-assay CV of 8.8-10.0%, intra-assay CV of 10.2-11.0%, and accuracy of 96.8-104.0%. The assay was applied to 17 clinical samples obtained from neonate patients. Measured concentrations were in the range of 0.15-3.57 mg L-1 for GEN C1, 0.12-3.55 mg L-1 for GEN C1a, 0.20-5.77 mg L-1 for GEN C2, and 0.47-12.88 mg L-1 for the GEN complex, all within the linear range of the assay. CONCLUSION: A sensitive assay for the quantification of gentamicin in plasma using anion-exchange SPE and UHPLC-MS/MS was validated. The assay can be used for TDM of gentamicin, particularly in centers with access to proper instrumentation and with a low demand for gentamicin measurements, where immunoassays are not cost-effective.

Artroplastia de quadril em idosos hospitalizados e o uso de antibioticoprofilaxia / Hungal arthroplasty in hospitalized elderly people and the use of antibioticoprofilaxia / Artroplastia cadera en ancianosy hospitalizados y el uso de antibioticoprofilaxia

Justificativa e Objetivos: O envelhecimento populacional aumenta os riscos de fraturas de quadril e de complicações pós-operatórias advindas de cirurgias, podendo causar morbidade e a reinternação desses pacientes. Recomendações visam orientar os profissionais em relação aos cuidados necessários para que as infecções de sítios cirúrgicos (ISC) possam ser evitadas ou minimizadas. Desse modo o estudo teve por objetivo descrever o perfil epidemiológico e clínico de idosos hospitalizados para artroplastia de quadril e verificar a adesão aos protocolos de antibioticoprofilaxia em cirurgias de quadril. Métodos: Estudo transversal retrospectivo, realizado em um hospital de ensino. Foram coletados dados secundários dos prontuários de idosos submetidos a cirurgia de quadril durante o ano de 2016. Resultados: Foram verificadas 203 artroplastias de quadril em idosos, 57,6% eram mulheres, média de idade de 73,2±8,1 anos. Artroplastia total coxo-femoral foi realizada em 32% dos pacientes, a média de intenação foi de 8±8,7 dias e 94,1% tiveram alta hospitalar. A cefazolina 1g 6/6h foi o antibiótico mais utilizado em 73,4%, em média utilizou-se o ATB por 65,52 hrs. A taxa de ISC foi de 0,99% e a adesão a posologia, dose e duração dos antibióticos conforme os protocolos institucionais ocorrerram em 16,2%, 13,7% e 8,6%, respectivamente. Conclusão: A taxa de infecção pós-operatória relacionada a cirurgias de prótese de quadril foi baixa, apesar de ter ocorrido inadequada adesão aos protocolos de antibióticoprofilaxia cirúrgica. Entretanto, deve-se considerar que não foi avaliada a dose de antibiótico administrada antes do início da cirurgia, devido à ausência de informação no prontuário.(AU)

Background and Objectives: Population aging increases the risk of hip fractures and postoperative complications arising from surgeries, which may lead to morbidity and rehospitalization of these patients. Recommendations are aimed at guiding professionals in relation to the necessary care so that infections of surgical sites (ISC) can be avoided or minimized. Thus, the study aimed to describe the epidemiological and clinical profile of elderly hospitalized for hip arthroplasty and to verify the adherence to protocols of antibiotic prophylaxis in hip surgeries. Methods: A retrospective cross-sectional study, carried out in a teaching hospital. Secondary data were collected from the medical records of elderly patients submitted to hip surgery during the year 2016. Results: There were 203 hip arthroplasties in the elderly, 57.6% were women, mean age 73.2 ± 8.1 years. Lacto-femoral total arthroplasty was performed in 32% of the patients, the mean intention was 8 ± 8.7 days, and 94.1% were hospital discharge. Cefazolin 1 g 6 / 6h were the most used antibiotic 73.4% on average the ATB was used for 65.52 hrs. The SSI rate was 0.99% and adherence to the dosage, dose and antibiotic duration according to the institutional protocols occurred in 16.2%, 13.7% and 8.6% respectively. Conclusion: The postoperative infection rate related to hip prosthesis surgeries was low, despite inadequate adherence to the protocols of surgical antibiotic prophylaxis. However, it should be considered that the dose of antibiotic administered prior to the start of surgery was not evaluated, due to the lack of information in the medical record.(AU)

Justificación y objetivos: El envejecimiento poblacional aumenta los riesgos de fracturas de cadera y de complicaciones postoperatorias provenientes de cirugías, pudiendo causar morbilidad y la reinternación de esos pacientes. Las recomendaciones para orientar a los profesionales en relación con los cuidados necesarios para que las infecciones de sitios quirúrgicos (ISC) puedan ser evitadas o minimizadas. De este modo el estudio tuvo por objetivo describir el perfil epidemiológico y clínico de ancianos hospitalizados para artroplastia de cadera y verificar la adhesión a los protocolos de antibioticoprofilaxis en cirugías de cadera. Métodos: Estudio transversal retrospectivo, realizado en un hospital de enseñanza. Se recogieron datos secundarios de los prontuarios de ancianos sometidos a cirugía de cadera durante el año 2016. Resultados: Se verificaron 203 artroplastias de cadera en ancianos, el 57,6% eran mujeres, promedio de edad de 73,2 ± 8,1 años. La arritmia total coxofemoral fue realzada en el 32% de los pacientes, la media de intención fue de 8± 8,7 días, y el 94,1% tuvo alta hospitalaria. La cefazolina 1 g 6 / 6h fue el antibiótico más utilizado el 73,4%, en promedio se utilizó el ATB por 65,52 hrs.La tasa de ISC fue del 0,99% y la adhesión a la dosis, dosis y duración de los antibióticos conforme a los protocolos institucionales ocurrió en el 16,2% , el 13,7% y el 8,6% respectivamente. Conclusión: La tasa de infección postoperatoria relacionada con las cirugías de prótesis de cadera fue baja, a pesar de que se produjo inadecuada adhesión a los protocolos de antibióticooprofilaxis quirúrgica. Sin embargo, se debe considerar que no se ha evaluado la dosis de antibiótico administrada antes del inicio de la cirugía, debido a la ausencia de información en el prontuario.(AU)