Explicit teaching in the operating room:Adding the why to the what

CONTEXT: Residents need their supervisors in the operating room to inform them on how to use their expertise in present and future occasions. A few studies hint at such explicit teaching behaviour, however without explaining its underlying mechanisms. Understanding and improving explicit teaching becomes more salient nowadays, as access of residents to relevant procedures is decreasing, while end-terms of training programs remain unchanged: high quality patient care. OBJECTIVES: A structured analysis of 1. The practices supervisors use for explicit teaching and 2. How supervisors introduce explicit teaching in real time during surgical procedures. METHODS: An observational qualitative collection study in which all actions of nine supervisor-resident dyads during a total hip replacement procedure were videotaped. Interactions in which supervisors explicitly or implicitly inform residents how to use their expertise now and in future occasions were included for further analysis, using the iterative inductive process of conversation analysis. RESULTS: 1. Supervisors used a basic template of if/then rules for explicit teaching, which they regularly customized by adding metaphors, motivations, and information about preference, prevalence and consequence. 2. If/then rules are introduced by supervisors to solve a (potential) problem in outcome for the present patient in reaction to local circumstances, e.g. what residents said, did or were about to do. CONCLUSIONS: If/then rules add the why to the what. Supervisors upgrade residents' insights in surgical procedures (professional vision) and teach the degree of individual freedom and variation of their expert standards for future occasions. These insights can be beneficial in improving supervisors' teaching skills

Ethical aspects of hemophilia gene therapy:a qualitative interview study with stakeholders

Background: There are great expectations for the potential role of gene therapy in the treatment of hemophilia. At the same time, developments in the field of hemophilia gene therapy have always raised ethical issues. It remains unknown how these ethical issues are perceived by stakeholders, particularly regarding the most recent developments in the field. Objectives: To obtain insight into stakeholders’ morally reasoned opinions on gene therapy for hemophilia. Methods: We conducted qualitative research with Dutch people with hemophilia (n = 13), parents of children with hemophilia (n = 5), physicians (n = 4), nurses (n = 3), a regulator (n = 1), and a representative from a pharmaceutical company (n = 1). We conducted semistructured interviews based on a topic list and reported the results according to the Consolidated Criteria for Reporting Qualitative Research guidelines. Results: We identified 3 main themes. The theme freedom and independence describes the hope people with hemophilia have of increasing their freedom through gene therapy, as well as concerns that gene therapy increases their dependence on their treatment center. The theme trust and altruism describes how people with hemophilia have a high level of trust in their physician and treatment center as well as in scientific research. As a result of this trust, they are willing to participate in research to help other people with hemophilia. The theme incremental benefits describes doubts respondents have about the added value of gene therapy compared to standard treatment. Conclusion: Stakeholders embrace the theoretical potential of gene therapy, while several people with hemophilia question the added value of the current gene transfer products for themselves.</p

Self-infusion of prophylaxis: Evaluating the quality of its performance and time needed

Prophylactic replacement therapy is the cornerstone of treatment in severe haemophilia. Regular infusions with clotting factor concentrate have been proven effective to prevent bleeding, subsequent (joint) damage, and positively affect the impact of haemophilia on daily life [1]. Patients or parents of younger patients learn to infuse clotting factor concentrate in a peripheral vein (i.v.) or a central venous access device (CVAD) [2]

In silico evaluation of limited sampling strategies for individualized dosing of extended half-life factor IX concentrates in hemophilia B patients

PURPOSE: Hemophilia B is a bleeding disorder, caused by a factor IX (FIX) deficiency. Recently, FIX concentrates with extended half-life (EHL) have become available. Prophylactic dosing of EHL-FIX concentrates can be optimized by assessment of individual pharmacokinetic (PK) parameters. To determine these parameters, limited sampling strategies (LSSs) may be applied. The study aims to establish adequate LSSs for estimating individual PK parameters of EHL-FIX concentrates using in silico evaluation. METHODS: Monte Carlo simulations were performed to obtain FIX activity versus time profiles using published population PK models for N9-GP (Refixia), rFIXFc (Alprolix), and rIX-FP (Idelvion). Fourteen LSSs, containing three or four samples taken within 8 days after administration, were formulated. Bayesian analysis was applied to obtain estimates for clearance (CL), half-life (t(1/2)), time to 1% (Time(1%)), and calculated weekly dose (Dose(1%)). Bias and precision of these estimates were assessed to determine which LSS was adequate. RESULTS: For all PK parameters of N9-GP, rFIXFc and rIX-FP bias was generally acceptable (range: −5% to 5%). For N9-GP, precision of all parameters for all LSSs was acceptable (< 25%). For rFIXFc, precision was acceptable for CL and Time(1%), except for t(1/2) (range: 27.1% to 44.7%) and Dose(1%) (range: 12% to 29.4%). For rIX-FP, all LSSs showed acceptable bias and precision, except for Dose(1%) using LSS with the last sample taken on day 3 (LSS 6 and 10). CONCLUSION: Best performing LSSs were LSS with samples taken at days 1, 5, 7, and 8 (N9-GP and rFIXFc) and at days 1, 4, 6, and 8 (rIX-FP), respectively

Graphene-porphyrin single-molecule transistors

We demonstrate a robust graphene-molecule-graphene transistor architecture. We observe remarkably reproducible single electron charging, which we attribute to insensitivity of the molecular junction to the atomic configuration of the graphene electrodes. The stability of the graphene electrodes allow for high-bias transport spectroscopy and the observation of multiple redox states at room-temperature

Population pharmacokinetics of the von Willebrand factor-factor VIII interaction in patients with von Willebrand disease

Recent studies have reported that patients with von Willebrand disease treated perioperatively with a von Willebrand factor (VWF)/factor VIII (FVIII) concentrate with a ratio of 2.4:1 (Humate P/Haemate P) often present with VWF and/or FVIII levels outside of prespecified target levels necessary to prevent bleeding. Pharmacokinetic (PK)-guided dosing may resolve this problem. As clinical guidelines increasingly recommend aiming for certain target levels of both VWF and FVIII, application of an integrated population PK model describing both VWF activity (VWF:Act) and FVIII levels may improve dosing and quality of care. In total, 695 VWF:Act and 894 FVIII level measurements from 118 patients (174 surgeries) who were treated perioperatively with the VWF/FVIII concentrate were used to develop this population PK model using nonlinear mixed-effects modeling. VWF:Act and FVIII levels were analyzed simultaneously using a turnover model. The protective effect of VWF:Act on FVIII clearance was described with an inhibitory maximum effect function. An average perioperative VWF:Act level of 1.23 IU/mL decreased FVIII clearance from 460 mL/h to 264 mL/h, and increased FVIII half-life from 6.6 to 11.4 hours. Clearly, in the presence of VWF, FVIII clearance decreased with a concomitant increase of FVIII half-life, clarifying the higher FVIII levels observed after repetitive dosing with this concentrate. VWF:Act and FVIII levels during perioperative treatment were described adequately by this newly developed integrated population PK model. Clinical application of this model may facilitate more accurate targeting of VWF:Act and FVIII levels during perioperative treatment with this specific VWF/FVIII concentrate (Humate P/Haemate P).Thrombosis and Hemostasi

Treatment of patients with rare bleeding disorders in the Netherlands:Real-life data from the RBiN study

Background Patients with rare inherited bleeding disorders (RBDs) exhibit hemorrhagic symptoms, varying in type and severity, often requiring only on-demand treatment. Prolonged bleeding after invasive procedures is common. Adequate peri-procedural therapy may reduce this bleeding risk. Objective To describe general treatment plans of RBD patients and evaluate the use of peri-procedural hemostatic therapy. Methods In the Rare Bleeding Disorders in the Netherlands (RBiN) study, RBD patients from all six Dutch Hemophilia Treatment Centers were included. General treatment plans were extracted from patient files. Patients with a dental or surgical procedure in their history were interviewed about use of peri-procedural treatment and bleeding complications. Results Two-hundred sixty-three patients with a rare coagulation factor deficiency or fibrinolytic disorder were included. Eighty-four percent had a documented general treatment plan. General treatment plans of patients with the same RBD were heterogeneous, particularly in factor XI deficiency. Overall, 308 dental and 408 surgical procedures were reported. Bleeding occurred in 50% of dental and 53% of surgical procedures performed without hemostatic treatment and in 28% of dental and 19% of surgical procedures performed with hemostatic treatment. Not only patients with severe RBDs, but also patients with mild deficiencies, experienced increased bleeding without proper hemostatic treatment. Conclusion Large heterogeneity in general treatment plans of RBD patients was found. Bleeding after invasive procedures was reported frequently, both before and after RBD diagnosis, irrespective of factor activity levels and particularly when peri-procedural treatment was omitted. Improved guidelines should include uniform recommendations for most appropriate hemostatic products per RBD and emphasize the relevance of individual bleeding history