The use of viscoelastic haemostatic assays in non-cardiac surgical settings. a systematic review and meta-analysis

Background: Thrombelastography (TEG) and rotational thromboelastometry (ROTEM) are viscoelastic haemostatic assays (VHA) which exploit the elastic properties of clotting blood. The aim of this systematic review and meta-analysis was to evaluate the usefulness of these tests in bleeding patients outside the cardiac surgical setting. Materials and methods: We searched the Cochrane Library, MEDLINE, EMBASE and SCOPUS. We also searched clinical trial registries for ongoing and unpublished studies, and checked reference lists to identify additional studies. Results: We found 4 randomised controlled trials (RCTs) that met our inclusion criteria with a total of 229 participants. The sample size was small (from 28 to 111 patients) and the follow-up periods very heterogenous (from 4 weeks to 3 years). Pooled data from the 3 trials reporting on mortality (199 participants) do not show any effect of the use of TEG on mortality as compared to standard monitoring (based on the average treatment effect from a fixed-effects model): Risk Ratio (RR) 0.71; 95% Confidence Interval (CI): 0.43 to 1.16. Likewise, the use of VHA does not reduce the need for red blood cells (mean difference -0.64; 95% CI: -1.51 to 0.23), platelet concentrates (mean difference -1.12; 95% CI: -3.25 to 1.02), and fresh frozen plasma (mean difference -0.91; 95% CI: -2.02 to 0.19) transfusion. The evidence on mortality and other outcomes was uncertain (very low-certainty evidence, down-graded due to risk of biases, imprecision, and inconsistency). Conclusions: Overall, the certainty of the evidence provided by the trials was too low for us to be certain of the benefits and harms of viscoelastic haemostatic assay in non-cardiac surgical settings. More, larger, and better-designed RCTs should be carried out in this area

Safety and efficacy of tranexamic acid for prevention of obstetric haemorrhage. An updated systematic review and meta-analysis

Background. A number of clinical systematic review and meta-analysis have been published on the use of tranexamic in the obstetric setting. The aim of this meta-analysis was to evaluate the safety and effectiveness of tranexamic acid in reducing blood loss when given prior to caesarean delivery. Materials and methods. We searched the Cochrane Wounds Specialized Register, Cochrane Central, MEDLINE (through PUBMED), Embase, and SCOPUS electronic databases. We also searched clinical trials registries for ongoing and unpublished studies, and checked reference lists to identify additional studies. We used no restrictions with respect to language and date of publication. Two review authors independently performed study selection, "Risk of bias" assessment, and data extraction. Initial disagreements were resolved by discussion, or by including a third review author when necessary. Results. We found 18 randomised controlled trials (RCTs) that met our inclusion criteria. Overall, 1,764 women receiving intravenous tranexamic acid for prevention of bleeding following caesarean sections and 1,793 controls receiving placebo were enrolled in the 18 RCTs evaluated. The use of tranexamic acid compared to controls (placebo or no intervention) reduces post-partum haemorrhage >400 mL (risk ratio [RR] 0.40, 95% confidence interval [CI] 0.24-0.65; 5 trials with a total of 786 participants), severe post-partum haemorrhage >1,000 mL (RR 0.32, 95% CI: 0.12-0.84; 5 trials with a total of 1,850 participants), and need for red blood cell transfusion (RR 0.30, 95% CI: 0.18-0.49; 10 trials with a total of 1,873 participants). No particular safety concerns on the use of this antifibrinolytic agent emerged from the analysis of the 18 RCTs included. Discussion. Overall, the results of this meta-analysis support the evidence of a beneficial effect of tranexamic acid in reducing blood loss and need for blood transfusion in pregnant women undergoing caesarean section

Towards Safer Robot-Assisted Surgery: A Markerless Augmented Reality Framework

Robot-assisted surgery is rapidly developing in the medical field, and the integration of augmented reality shows the potential of improving the surgeons' operation performance by providing more visual information. In this paper, we proposed a markerless augmented reality framework to enhance safety by avoiding intra-operative bleeding which is a high risk caused by the collision between the surgical instruments and the blood vessel. Advanced stereo reconstruction and segmentation networks are compared to find out the best combination to reconstruct the intra-operative blood vessel in the 3D space for the registration of the pre-operative model, and the minimum distance detection between the instruments and the blood vessel is implemented. A robot-assisted lymphadenectomy is simulated on the da Vinci Research Kit in a dry lab, and ten human subjects performed this operation to explore the usability of the proposed framework. The result shows that the augmented reality framework can help the users to avoid the dangerous collision between the instruments and the blood vessel while not introducing an extra load. It provides a flexible framework that integrates augmented reality into the medical robot platform to enhance safety during the operation

COVID-19-associated coagulopathy

Coronavirus disease 2019 (COVID-19), a viral respiratory illness caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has been recently recognized as a systemic disorder inducing a prothrombotic state. The molecular mechanisms underlying the hypercoagulable state seen in patients with COVID-19 is still incompletely understood, although it presumably involves the close link between inflammatory and hemostatic systems. The laboratory coagulation monitoring of severely ill COVID-19 patients is mandatory to identify those patients at increased thrombotic risk and to modulate thromboprophylaxis accordingly. In this review, we summarize the current understanding on the pathogenesis, epidemiology, clinical and laboratory features and management of coagulopathy associated with COVID-19

A comparative study of the antimicrobial and antioxidant activities of Inonotus hispidus fruit and their mycelia extracts

Inonotus hispidus (Bull.) P. Karst. has been used as traditional medicine for the treatment of dyspepsia, cancer, and diabetes. Numerous studies have confirmed the antimicrobial, antiviral, antioxidant, anti-inflammatory, immunomodulatory, antiproliferative and cytotoxic biological activities of extracts from this species. The purpose of this study was a comparative analysis of the antioxidant and the antimicrobial activities of methanol extracts from fruit and liquid-cultured mycelia. Four compounds (N-butylbenzenesulfonamide, lauramidopropyl betaine, 3,5-di-tert-butyl-4-hydroxybenzaldehyde, and uplandicine), determined by hybrid HRMS, were found only in mycelia culture extracts. Free radical scavenging, measured by DPPH assay on methanol extracts, showed an activity of about 17.2% and 22.1% of Trolox in fruiting bodies and mycelia, respectively. The I. hispidus methanol extracts from fruit and mycelia culture were found to have varying degrees of antibacterial and antifungal effects against the pathogenic microorganisms tested (minimum inhibitory concentration from 0.17 to 2.56 μg mL−1)

Toward a framework integrating augmented reality and virtual fixtures for safer robot-assisted lymphadenectomy

Lymphadenectomy generally accompanies various oncology surgeries to remove infected cancer cells. However, there are two limitations in robot-assisted lymphadenectomy: 1) lymph nodes are not visible during operation since they are hidden by the superficial fat layer; 2) intra-operative bleeding may occur during lymph node removal caused by collisions between surgical instruments and delicate blood vessels (arteries or veins) near the lymph nodes. Therefore, we propose a framework integrating augmented reality and virtual fixtures to address these limitations. Augmented reality intraoperatively visualizes the hidden lymph nodes by projecting the corresponding 3D pre-operative model, and virtual fixtures are used to provide force feedback to surgeons to avoid possible collisions when they operate the surgical instruments to resect the lymph nodes surrounding the blood vessel. Ten human subjects were invited to perform an emulated lymphadenectomy based on the da Vinci robot in a dry lab. Experimental results demonstrated that the proposed framework can keep localizing the hidden lymph nodes, and reduce the number of collisions (21% and 48% reduction rates using two different force models compared to the standard setup, respectively) between the instruments and the delicate blood vessel during lymph node resection. It shows the potential to enhance the safety of robotassisted lymphadenectomy

Serum eye drops for the treatment of ocular surface diseases. a systematic review and meta-analysis

Background. The use of blood-derived eye drops for topical treatment of ocular surface diseases has progressively increased in recent years.Materials and methods. To evaluate the use of serum eye drops in ocular surface disorders, we performed a systematic search of the literature.Results. In this systematic review, we included 19 randomised controlled trials ( RCTs) investigating the use of serum eye drops in 729 patients compared to controls. For the quantitative synthesis, we included only 10 RCTs conducted in patients with dry eye syndrome comparing autologous serum to artificial tears. At 2-6 weeks, no clear between-group differences in Schirmer test ( MD 1.05; 95% CI: -0.17-2.26) and in fluorescein staining ( MD -0.61; 95% CI: -1.50-0.28) were found ( very lowquality evidence, down-graded for inconsistency, serious risk of biases, and serious imprecision). Slightly higher increase in tear film break-up time ( TBUT) scores in autologous serum compared to control ( MD 2.68; 95% CI: 1.33-4.03), and greater decrease in ocular surface disease index ( OSDI) in autologous serum compared to control ( MD -11.17; 95% CI: -16.58- -5.77) were found ( low quality evidence, down-graded for serious risk of bias, and for inconsistency). For the Schirmer test, fluorescein staining and TBUT, data were also available at additional follow-up timing ( 2-12 months): no clear between-group differences were found, and the quality of the evidence was graded as low/very-low.Conclusions. In patients with dry eye syndrome, it is unclear whether or not the use of autologous serum compared to artificial tears increases Schirmer test and fluorescein staining scores at short-term and medium-/long-term follow up. Some benefit at short-term follow up for the outcome of TBUT and OSDI was observed, but the quality of the evidence was low