In vitro detection of Candida and Aspergillus antigen in parenteral nutrition and fixed combinations of piperacillin-tazobactam.

BACKGROUND: Screening for Aspergillus (Asp-AG) and Candida antigen (Ca-AG) with immunoassays is established for stem cell recipients at high risk for invasive fungal infections (IFI). While parenteral nutrition (PN) will be applied in case of complications leading to insufficient alimentation, piperacillin-tazobactam (TZP) is started at the onset of febrile neutropenia. OBJECTIVES: The aim of this study was to investigate drug-laboratory interactions between PN and TZP and both immunoassays which could affect the specificity of the assays and lead to the false assumption of an IFI. METHODS: Batches of TZP and PN were tested with both assays in vitro. In total, 380 samples of 83 batches were analysed. RESULTS: None of the examined preparations were tested positive with Asp-AG assay. Measurable amounts of Ca-AG were detected in a lipid emulsion, two different trace element supplements, a fat-soluble vitamin preparation and all tested brands of TZP. CONCLUSIONS: We conclude that false positivity of Asp-AG assay due to TZP and PN does not occur. Cross reactions with Ca-AG assay have been detected in some preparations. The in vivo relevance of Ca-AG positivity has to be reviewed in further studies considering an effect of dilution. Physicians should be aware of a possible cross reaction with Ca-AG assays which could lead to false-positive results.

[Periprosthetic infection after total hip replacement : Risk factors for an early infection after primary implantation]. / Periprothetischer Infekt nach Hüftprothesenimplantation : Risikofaktoren für die Entwicklung einer Frühinfektion nach Primärimplantation.

BACKGROUND: Periprosthetic infection is one of the most serious complications in primary arthroplasty. The infection rates reported in the current literature range from 0.36 to 2.23%. OBJECTIVES: The aim of this retrospective case-control study was to determine preoperative risk factors for the occurrence of early periprosthetic infection after primary hip arthroplasty. MATERIALS AND METHODS: The influence of patient age, gender, body mass index (BMI), C­reactive protein, preoperative leukocyte count and morbidity level (American Society of Anaesthesiologists score) on the occurrence of periprosthetic early infection of the hip joint was examined, and their correlation was investigated. RESULTS: Of the 1383 patients followed up, 25 were diagnosed with early infection. With an increase in BMI of 1 kg/m2, the risk of periprosthetic early infection increased by 12.1% (p < 0.001). In addition, using the receiver operating characteristic (ROC) curve, a BMI ≥ 29 kg/m2 is identified as a significant cut-off for the increased likelihood of periprosthetic hip infection. Using the ROC curve, a preoperative CrP value > 5 mg/l can be validated as a cut-off value for an increased risk of early infection. Using binary logistic regression, no influence of CrP > 5 mg/l on the development of early infection was statistically proven (p = 0.065). CONCLUSIONS: Patients with a BMI ≥ 29 kg/m2 should be informed about the increased risk of periprosthetic early infection after hip prosthesis implantation and a risk assessment should be performed. Furthermore, the determination of the preoperative CrP value should be considered standard.