Respiratory Variation in Femoral Vein Diameter Has Moderate Accuracy as a Marker of Fluid Responsivity in Mechanically Ventilated Septic Shock Patients.

Ultrasound (US) is considered the first step in evaluation of patients with shock; respiratory variation of the inferior vena cava (inferior vena cava collapsibility [IVCc]) is an important measurement in this scenario that can be impaired by patient condition or technical skills. The main objective of this study was to evaluate if respiratory variation of the femoral vein (femoral vein collapsibility [FVc]), which is easier to visualize, can adequately predict fluid responsiveness in septic shock patients. Forty-five mechanically ventilated septic shock patients in a mixed clinical-surgical, 30-bed intensive care unit were enrolled in this study. All patients underwent assessments of FVc, IVCc and cardiac output using a portable US device. The passive leg raising test was used to evaluate fluid responsiveness. FVc presented an area under the receiver operating characteristic curve of 0.678 (95% confidence interval: 0.519-0.837, p = 0.044) with a cutoff point of 17%, yielding a sensitivity of 62% and specificity of 65% in predicting fluid responsiveness. IVCc had greater diagnostic accuracy compared with FVc, with an area under the receiver operating characteristic curve of 0.733 (95% confidence interval: 0.563-0.903, p = 0.024) and a cutoff point of 29%, yielding a sensitivity of 47% and specificity of 86%. In conclusion, FVc has moderate accuracy when employed as an indicator of fluid responsiveness in spontaneously mechanically ventilated septic shock patients.

Prevalência de carbapenemases em enterobactérias resistentes a carbapenêmicos em quatro hospitais terciários de Porto Alegre / Prevalence of carbapenemases in carbapenem-resistant Enterobacteriaceae in four tertiary care hospitals in Porto Alegre

INTRODUÇÃO: A disseminação de Klebsiella pneumoniae carbapenemase (KPC) no Brasil e a recente detecção de bactérias produtoras de New Delhi metalo-β-lactamase (NDM-1) em hospital terciário do sul do Brasil indicam a necessidade da avaliação da presença destas enzimas em enterobactérias resistentes a carbapenêmicos (ERC).OBJETIVO: Avaliar prevalência de carbapenemases nas ERC em quatro hospitais terciários de Porto Alegre, por meio de PCR multiplex em tempo real. MÉTODOS: Estudo descritivo, período de abril a dezembro de 2013. Isolados bacterianos de pacientes internados foram identificados pelo sistema automatizado VITEK 2, com realização do teste de suscetibilidade aos antimicrobianos. Amostras com isolados de ERC foram encaminhadas ao laboratório de referência para análise por PCR em tempo real para identificação de carbapenemases. RESULTADOS: Total de 701 isolados. As ERC predominantes foram K. pneumoniae (47% das amostras positivas) e Enterobacter cloacae (18%). As carbapenemases mais frequentes foram KPC (48%), OXA-48-like (3%) e NDM (2%). Em 47% das amostras não foi identificado o mecanismo de resistência. Isolados originados de culturas de vigilância foram associados com maior positividade para carbapenemases do que isolados de amostras clínicas (p<0,0001). Isolados de ERC pertencentes ao grupo Proteae (Proteus spp., Morganella spp., Providencia spp.) foram associados a menor positividade para carbapenemase do que isolados de outras ERC (p<0,0001). CONCLUSÃO: KPC foi a carbapenemase mais frequentemente detectada. A circulação de uma enzima OXA-48-like foi demonstrada, um achado novo e preocupante. O achado da carbapenemase NDM também é preocupante devido ao seu potencial de disseminação. Esses dados e outros estudos poderão contribuir para um entendimento maior da epidemiologia das ERC.

BACKGROUND: The spread of Klebsiella pneumoniae carbapenemase (KPC) in Brazil and the recent detection of bacteria producing New Delhi metallo-β-lactamase (NDM-1) in a tertiary care hospital in Porto Alegre indicate the need to evaluate the presence of these enzymes in carbapenem-resistant Enterobacteriaceae (CRE). AIM: To evaluate the prevalence of carbapenemases in CRE in four tertiary care hospitals in Porto Alegre using multiplex real-time PCR.METHODS: Descriptive study from April to December 2013. Bacterial isolates from hospitalized patients were identified by VITEK 2 automated system, with antimicrobial susceptibility testing. Samples with CRE isolates were sent to the reference laboratory for analysis using real-time PCR for identification of carbapenemases. RESULTS: Total of 701 isolates. The predominant CRE were K. pneumoniae (46% of positive samples) and Enterobacter cloacae (18%). The most frequent carbapenemases were KPC (48%), OXA-48-like (3%), and NDM-1 (2%). In 47% of the samples no carbapenemase was identified. Isolates originated from surveillance cultures were associated with higher positivity for carbapenemases than isolates from clinical samples (p<0.0001). CRE isolates belonging to the Proteae group (Proteus spp., Morganella spp., Providencia spp.) were associated with less positivity for carbapanemase than isolates of other CRE (p<0.0001). CONCLUSION: KPC was the most frequently detected carbapenemase. The movement of an OXA-48-like enzyme was demonstrated, a novel and worrisome finding. The finding of carbapenemase NDM is also worrisome due to its dissemination potential. These data and further studies may contribute to a better understanding of the epidemiology of CRE.