Assessment of Platelet Thrombus Formation under Flow Conditions in Adult Patients with COVID-19: An Observational Study.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is associated with systemic inflammation, which may dysregulate platelet function. Total Thrombus-Formation Analysis System (T-TAS) is a flow-chamber device that analyses platelet-mediated thrombus formation in capillary channels through the following parameters: (1) the area under the flow-pressure curve (AUC), (2) occlusion start time (OST), time needed to reach OST, and (3) occlusion time (OT), time needed to reach the occlusion pressure. METHODS AND FINDINGS: Sixty-one COVID-19 patients admitted to intensive, subintensive, and low intensive care were prospectively enrolled according to the time of admission: group A (up to 8 days) (n = 18); group B (from 9 to 21 days) (n = 19), and group C ( > 21 days) (n = 24). T-TAS measurements were performed at enrolment and after 7 days. Median OST was similar among groups. AUC was lower in group A compared to B (p = 0.001) and C (p = 0.033). OT was longer in group A compared to B (p = 0.001) and C (p = 0.028). Platelet count (PC) was higher in group B compared to A (p = 0.024). The linear regression showed that OT and AUC were independent from PC in group A (OT: 0.149 [95% confidence interval [CI]: -0.326 to 0.624], p = 0.513 and AUC: 0.005 [95% CI: -0.008 to 0.017], p = 0,447). In contrast, in group B, PC was associated with OT (-0.019 [-0.028 to 0.008], p = 0.023) and AUC (0.749 [0.358-1.139], p = 0,015), similarly to group C. Conversely, patients with different illness severity had similar T-TAS parameters. CONCLUSION: COVID-19 patients display an impaired platelet thrombus formation in the early phase of the disease compared to later stages and controls, independently from illness severity.

Viscoelastic Coagulation Monitor as a Novel Device to Assess Coagulation at the Bedside. A Single-Center Experience During the COVID-19 Pandemic.

Viscoelastic coagulation monitor (VCM) is a portable device developed to evaluate the viscoelastic properties of whole blood activated by contact with glass. In this study, VCM was employed to analyze the viscoelastic profiles of 36 COVID-19 intensive care patients. Full anticoagulant dose heparin (unfractionated [UFH]; low molecular weight [LMWH]) was administrated to all patients. The association between VCM and laboratory parameters was retrospectively analyzed. The administration of UFH-influenced VCM parameters prolonging clotting time (CT) and clot formation time (CFT) and reducing angle (alpha) and amplitudes of the VCM tracings (A10, A20, and maximum clot firmness [MCF]) compared with LMWH therapy. A tendency toward hypercoagulation was observed by short CT and CFT in patients receiving LMWH. Clotting time was correlated with UFH dose (Spearman's rho = 0.48, p ≤ 0.001), and no correlation was found between CT and LMWH. All VCM tracings failed to show lysis at 30 and 45 minutes, indicating the absence of fibrinolysis. A10, A20, and MCF exhibited very-good to good diagnostic accuracy for detecting platelet count and fibrinogen above the upper reference limit of the laboratory. In conclusion, VCM provided reliable results in COVID-19 patients and was easy to perform with minimal training at the bedside.

Case Report: Late-Onset Congenital Adrenal Hyperplasia and Acute Covid-19 Infection in a Pregnant Woman: Multidisciplinary Management.

Background: The impact of the Covid-19 infection on patients with chronic endocrine disease is not fully known. We describe here the first case of a pregnant woman with Covid-19 acute infection and non-classical congenital adrenal hyperplasia (NCAH). Case description: A woman at 36 weeks of gestation was referred to our Maternity Hospital for premature rupture of membranes (PROM). Her medical history was positive for NCAH on chronic steroid replacement till the age of 17 years (cortisone acetate and dexamethasone, both in the morning). At admission, her naso-oro-pharyngeal swab resulted positive for SARS-CoV-2. Due to hyperpyrexia and late preterm PROM, cesarean section was planned, and she was started on a 100 mg-bolus of hydrocortisone, followed by continuous infusion of 200 mg/24 h. A female neonate in good clinical condition and with a negative nasopharyngeal Covid-19 swab was delivered. On second postpartum day, the mother was in good condition and was switched to oral steroid therapy. On third postpartum day she worsened, with radiological signs of acute pulmonary embolism. Oro-tracheal intubation and mechanical ventilation were started, and she was switched back to intravenous steroid therapy. On April 30, pulmonary embolism was resolved, and on May 13th she was discharged in good condition. Conclusions: We report the first case of Covid-19 acute infection that occurred in late-pregnancy in a woman with NCAH on chronic steroid replacement. The management of the patient in a reference center with early involvement of a multidisciplinary team granted prompt care and adequate protection for all the involved sanitary operators.

Skeletal muscle lactate overproduction during metformin intoxication: An animal study with reverse microdialysis.

Lactic acidosis during metformin intoxication is classically mainly attributed to diminished lactate clearance through liver gluconeogenesis. Here we studied 6 healthy, sedated and mechanically ventilated pigs to clarify whether high dose of metformin also increases skeletal muscle lactate production. Each animal had two microdialysis catheters inserted in gluteus muscles, one per side. One catheter was infused with saline (control) while the other one was infused with metformin diluted in saline (1M), both at a rate of 0.3µl/min. Dialysate lactate concentration and lactate-to-pyruvate ratio, a marker of the balance between anaerobic glycolysis and aerobic (mitochondrial) metabolism, were measured every 3h, for 12h. Continuous infusion of metformin caused a progressive rise in dialysate lactate level (p=0.007) and lactate-to-pyruvate ratio (p<0.001) compared to that of saline, as for mitochondrial "poisoning". These findings suggest that skeletal muscle lactate overproduction contributes to the development of metformin-induced lactic acidosis.