Clinical Performance Evaluation of VersaTrek 528 Blood Culture System in a Chinese Tertiary Hospital

Background: The aim of this study was to evaluate the clinical performance of VersaTrek 528 compared to BACTEC FX 400 blood culture (BC) systems.Materials and Methods: Simulated and clinically obtained BCs were used in the study. Confirmed bacterial species (n = 78), including 43 Gram-positives, 30 Gram-negatives, and 5 Candida albicans strains, were each inoculated into BC bottles. Clinically obtained BCs were subdivided into two groups, A and B. In group A were 72 BC sets (pair: aerobic and anaerobic) in which a set inoculated with 5 ml blood was processed in the VersaTrek BC system, whilst the one inoculated with 10 ml blood was processed in the FX BC system. In group B, 76 BC sets (pairs) corresponding to 152 VersaTrek bottles and 152 FX bottles were inoculated with the same volume (10 ml) of blood, and processed in each system.Results: In the simulated BC study, 90% (63/70) of the VersaTrek aerobic bottles were positive, which was higher than that of FX 400 (59/70, 84%), but was not statistically significant (P = 0.423). In contrast, FX 400 anaerobic bottles had a higher positive rate than the other BC system (84 vs. 77%), although it was statistically insignificant (P = 0.267). Time to detection of organisms in the two BCs was comparable for both aerobic (P = 0.131) and anaerobic bottles (P = 0.104). In clinical BCs of group A, FX BC system had slightly higher positive rates for both aerobic (11.1 vs. 9.7%, P = 0.312) and anaerobic (8.3 vs. 6.9%, P = 0.375) bottles. However, the difference was not statistically significant. In group B, VersaTrek aerobic bottles had a higher positive rate compared to the other BC system (10.5 vs. 5.2%, P = 0.063). In terms of positive rates of sub-studies A and B, VersaTrek and FX BC systems were comparable.Conclusion: There was no significant difference between the two BC systems in the detection of bacteria and fungi in simulated BCs. In clinical BCs, the performance of the VersaTrek BC system, with inoculation of 5 or 10 ml patient’s blood, was comparable to the FX system with inoculation of 10 ml patient’s blood

Peak Value of Central Venous Pressure and Acute Kidney Injury in Cardiac Patients After Cardiopulmonary Bypass Surgery

Objective  To explore the relationship between the post-operative peak value of central venous pressure (CVPp) and the incidence of acute kidney injury (AKI) in patients who had undergone cardiopulmonary bypass surgery (CBS).  Methods  Clinical data were retrospectively collected from 1 May 2016 to 1 May 2018 from all patients undergoing CBS in the Department of Intensive Care Medicine, Peking Union Medical College Hospital. The CVP values immediately after transfer to ICU (CVP 0h) and at 6 h(CVP 6h), and CVPp within 48 h(CVPp 48h) of transfer to ICU, the incidence of AKI after 48 h of transfer to ICU and in-hospital mortality were recorded. The receiver operating characteristic (ROC) curve was used to evaluate the clinical value of CVP-related indicators in predicting AKI after CBS and determine the optimal threshold. The risk factors for AKI and in-hospital mortality after CBS were analysed using single factor and multifactorial Logistic regression.  Results  A total of 485 patients after CBS who met the inclusion and exclusion criteria were enrolled, with an incidence of AKI after 48 h of transfer to ICU of 25.2% (122/485) and an in-hospital mortality rate of 2.5% (12/485). The ROC curve analysis showed that the area under the curve (AUC) for CVPp 48h to predict AKI after CBS was 0.634 (95% CI: 0.577-0.692, P < 0.001), with an optimal threshold value of 14 mm Hg, sensitivity of 49.6% and specificity of 63.5%. Multifactorial logistic regression analysis showed that hypertension(OR=2.505, 95% CI: 1.581-3.969, P < 0.001), pulmonary hyperten-sion(OR=2.552, 95% CI: 1.573-4.412, P < 0.001), prolonged aortic block time(OR=1.009, 95% CI: 1.004-1.014, P=0.001), and CVPp 48h≥14 mm Hg(OR=1.613, 95% CI: 1.030-2.526, P=0.037) were independent risk factors for AKI after CBS; CVPp 48h≥14 mm Hg was an independent risk factor for in-hospital death(OR=8.044, 95% CI: 1.579-40.979, P=0.012).  Conclusions  CVPp 48h is associated with AKI in patients who have undergone CBS. The monitoring and management of CVP might be a way to improve the prognosis of these patients