Urinary biomarkers to predict acute kidney damage and mortality in COVID-19.

INTRODUCTION: Acute kidney injury (AKI) is a frequent condition in patients hospitalized for COVID-19. There are only a few reports on the use of urinary biomarkers in COVID-19 and no data so far comparing the prognostic use of individual biomarkers in the prediction of adverse outcomes. MATERIALS AND METHODS: We performed a prospective mono-centric study on the value of urinary biomarkers in predicting the composite endpoint of a transfer to the intensive care unit, the need for renal replacement therapy, mechanical ventilation, and in-hospital mortality. 41 patients hospitalized for COVID-19 were enrolled in this study. Urine samples were obtained shortly after admission to assess neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), calprotectin, and vascular non-inflammatory molecule-1 (vanin-1). RESULTS: We identified calprotectin as a predictor of a severe course of the disease requiring intensive care treatment (AUC 0.728, p = 0.016). Positive and negative predictive values were 78.6% and 76.9%, respectively, using a cut-off concentration of 127.8 ng/mL. NGAL tended to predict COVID-19-associated AKI without reaching statistical significance (AUC 0.669, p = 0.053). The best parameter in the prediction of in-hospital mortality was NGAL as well (AUC 0.674, p = 0.077). KIM-1 and vanin-1 did not reach significance for any of the investigated endpoints. CONCLUSION: While KIM-1 and vanin-1 did not provide prognostic clinical information in the context of COVID-19, the present study shows that urinary calprotectin is moderately predictive of the need for intensive care unit (ICU) admission, and NGAL may be modestly predictive of AKI in COVID-19. Calprotectin and NGAL show promise as potential helpful adjuncts in the identification of patients at increased risk of poor outcomes or complications in COVID-19.

Feasibility of non-invasive measurement of central blood pressure and arterial stiffness in shock.

BACKGROUND: Patients in haemodynamic shock are in need for an intensive care treatment. Invasive haemodynamic monitoring is state of the art for these patients. However, evolved, non-invasive blood pressure monitoring devices offer advanced functions like the assessment of central blood pressure and arterial stiffness. We analysed the feasibility of two oscillometric blood pressure devices in patients with shock. METHODS: We performed a monocentre prospective study, enrolling 57 patients admitted to the intensive care unit (ICU), due to septic and/or cardiogenic shock. We assessed invasive and non-invasive peripheral and central blood pressure <24 hours and 48 hours after admission on the ICU. Additional haemodynamic parameters such as pulse wave velocity (PWV), augmentation pressure and augmentation index were obtained through Mobil-o-Graph PWA (IEM) and SphygmoCor XCEL (AtCor Medical). RESULTS: A complete haemodynamic assessment was successful in all patients (48) with the Mobil-o-Graph 24 hours PWA and in 29 patients with the SphygmoCor XCEL (P = .001), when cases of death or device malfunction were excluded. Reasons for failure were severe peripheral artery disease, haemodynamic instability, oedema and agitation. Invasive blood pressure showed a sufficient correlation with both devices; however, large differences between invasive and non-invasive techniques were recorded in Bland-Altmann analysis (P < .05 for all parameters). PWV differed between the two devices. CONCLUSION: Non-invasive peripheral blood pressure measurement remains a rescue technique. However, non-invasive assessment of arterial stiffness and central blood pressure is possible in patients with septic or cardiogenic shock. Further studies are required to assess their clinical significance for patients in shock.

Is bone-cement augmentation of screw-anchor fixation systems superior in unstable femoral neck fractures? A biomechanical cadaveric study.

OBJECTIVES: Improved fixation techniques with optional use of bone cements for implant augmentation have been developed to enhance stability and reduce complication rates after osteosynthesis of femoral neck fractures. This biomechanical study aimed to evaluate the effect of cement augmentation on implant anchorage and overall performance of screw-anchor fixation systems in unstable femoral neck fractures. METHODS: Ten pairs of human cadaveric femora were used to create standardized femoral neck fractures (Pauwels type 3 fractures; AO/OTA 31-B2) with comminution and were fixed by means of a rotationally stable screw-anchor (RoSA) system. The specimens were assigned pairwise to two groups and either augmented with PMMA-based cement (Group 1, augmented) or left without such augmentation (Group 2, control). Biomechanical testing, simulating physiological loading at four distinct load levels, was performed over 10.000 cycles for each level with the use of a multidimensional force-transducer system. Data was analysed by means of motion tracking. RESULTS: Stiffness, femoral head rotation, implant migration, femoral neck shortening, and failure load did not differ significantly between the two groups (p ≥ .10). For both groups, the main failure type was dislocation in the frontal plane with consecutive varus collapse). In the cement-augmented specimens, implant migration and femoral neck shortening were significantly dependent on bone mineral density (BMD), with higher values in osteoporotic bones. There was a correlation between failure load and BMD in cement-augmented specimens. CONCLUSION: In screw-anchor fixation of unstable femoral neck fractures, bone-cement augmentation seems to show no additional advantages in regard to stiffness, rotational stability, implant migration, resistance to fracture displacement, femoral neck shortening or failure load.