Shock Index for Early Detection of Low Plasma Fibrinogen in Trauma: A Prospective Observational Cohort Pilot Study.

Shock index (a ratio between heart rate and systolic blood pressure) predicts transfusion requirements and the need for haemostatic resuscitation in severe trauma patients. In the present study, we aimed to determine whether prehospital and on-admission shock index values can be used to predict low plasma fibrinogen in trauma patients. Between January 2016 and February 2017, trauma patients admitted from the helicopter emergency medical service into two large trauma centres in the Czech Republic were prospectively assessed for demographic, laboratory and trauma-associated variables and shock index at scene, during transport and at admission to the emergency department. Hypofibrinogenemia defined as fibrinogen plasma level of 1.5 g·L-l was deemed as a cut-off for further analysis. Three hundred and twenty-two patients were screened for eligibility. Of these, 264 (83%) were included for further analysis. The hypofibrinogenemia was predicted by the worst prehospital shock index with the area under the receiver operating characteristics curve (AUROC) of 0.79 (95% CI 0.64-0.91) and by the admission shock index with AUROC of 0.79 (95% CI 0.66-0.91). For predicting hypofibrinogenemia, the prehospital shock index ≥ 1 has 0.5 sensitivity (95% CI 0.19-0.81), 0.88 specificity (95% CI 0.83-0.92) and a negative predictive value of 0.98 (0.96-0.99). The shock index may help to identify trauma patients at risk of hypofibrinogenemia early in the prehospital course.

Subcostal TAPSE measured by anatomical M-mode: prospective reliability clinical study in critically ill patients.

BACKGROUND: Tricuspid annular plane systolic excursion (TAPSE), evaluated from a four-chamber apical view, is an echocardiographic parameter for the detection of right ventricular systolic dysfunction (RVD). We decided to assess the reliability of TAPSE measured from subcostal view (sTAPSE) by anatomical M-mode imaging (AMM) for evaluation of right ventricular systolic function and prediction of RVD in the critically ill patients by comparison with other echocardiographic parameters. METHODS: We conducted an observational, prospective clinical study in 100 patients hospitalized in the intensive care unit. TAPSE, doppler tissue imaging-derived tricuspid lateral annular systolic velocity (DTI-S' wave), two-dimensional fraction area change (2D FAC) and DTI-right ventricular index of myocardial performance (DTI-RIMP) were measured by transthoracic echocardiography. A subcostal four-chamber view was recorded for sTAPSE measurement. For that purpose, the cursor of AMM was aligned along the direction of the tricuspid lateral annulus movement and the amplitude of the movement was measured. RESULTS: In a group of patients aged 64±16 years with a 31% prevalence of RVD we identified strong correlation between TAPSE and sTAPSE (r=0.963, P<0.001). sTAPSE correlated well with other measures of right ventricular systolic function (DTI-S' wave: r=0.765; 2D FAC: r=0.701; DTI-RIMP: r=-0.661, P<0.001, respectively). The value of sTAPSE ≤15 mm predicted the presence of RVD defined by TAPSE with a sensitivity of 94.7% and specificity of 100.0%. CONCLUSIONS: The sTAPSE measured by AMM in a population of critically ill patients has been found to be a reliable parameter of right ventricular systolic function and predicted RVD with high reliability.

Targeting bacterial biofilms via surface engineering of gold nanoparticles.

Bacterial biofilms are associated with persistent infections that are resistant to conventional antibiotics and substantially complicate patient care. Surface engineered nanoparticles represent a novel, unconventional approach for disruption of biofilms and targeting of bacterial pathogens. Herein, we describe the role of surface charge of gold nanoparticles (AuNPs) on biofilm disruption and bactericidal activity towards Staphylococcus aureus and Pseudomonas aeruginosa which are important ventilator associated pneumonia (VAP) pathogens. In addition, we study the toxicity of charged AuNPs on human bronchial epithelial cells. While 100% positively charged AuNP surface was uniformly toxic to both bacteria and epithelial cells, reducing the extent of positive charge on the AuNP surface at moderate concentrations prevented epithelial cell toxicity. Reducing surface charge was however also less effective in killing bacteria. Conversely, increasing AuNP concentration while maintaining a low level of positivity continued to be bactericidal and disrupt the bacterial biofilm and was less cytotoxic to epithelial cells. These initial in vitro studies suggest that modulation of AuNP surface charge could be used to balance effects on bacteria vs. airway cells in the context of VAP, but the therapeutic window in terms of concentration vs. surface positive charge may be limited. Additional factors such as hydrophobicity may need to be considered in order to design AuNPs with specific, beneficial effects on bacterial pathogens and their biofilms.