Study goal: This study was carried out to answer the following research question: which motivation do healthy volunteers have to participate in phase I clinical trials? - Methods: A literature search was done through Google Scholar and Academic Search Premier, followed by three interviews with volunteers who had recently concluded their participation in a (non-commercial) phase I trial. - Results: Our literature search revealed mainly commercial motives for volunteers to participate in phase I clinical trials. The interviews (with volunteers in a non-commercial trial) showed that other factors may also play a decisive role, such as: (1) wish to support the investigator (2) wish to contribute to science, (3) access to more/better health care (4) sociability: possibility to relax and to communicate with other participants (5) general curiosity. Precondition is that risks and burden are deemed acceptable. - Conclusions: financial remuneration appears to be the predominant motive to participate voluntarily in a clinical trial. Other reasons were also mentioned however, such as general curiosity, the drive to contribute to science and the willingness to help the investigator. In addition, social reasons were given such as possibility to relax and to meet other people. Potential subjects state that they adequately assess the (safety) risks of participating in a trial as part of their decision process.
Study objective: The three-dimensional shape of the ultrasound beam produces a thicker scan plane than most users assume. Viewed longitudinally, a needle placed lateral to a vessel just outside the central scanning plane can be displayed incorrectly in the ultrasound image as if placed intravascularly. This phenomenon is called the beam width artefact, also known as the elevation or slice thickness artefact. The goal of this study was to demonstrate the potential negative effect of the beam width artefact on the performance of in-plane ultrasound- guided vascular access procedures, and to provide a solution. Design: Randomized, double-blinded study Setting: Department of anaesthesiology and intensive care of a teaching hospital Participants: 31 experienced (anesthesiologists and intensivists) and 36 inexperienced (anesthetic nurses) ultrasound users Interventions: We developed an acoustic lens that narrows the scan plane to reduce the beam width artefact. The lens was tested in a simulated vascular access study. Measurements: The primary endpoint was first pass success. Secondary endpoints were the number of punctures and needle withdrawals, procedure time, needle visibility and operator satisfaction. Main results: First pass success was highly enhanced using the acoustic lens, with a success rate of 92.5% versus 68.7% without the lens (difference 23.8, 95% confidence interval 11.0–35.3, p <0.001). The total number of punctures needed to obtain intravenous access was also reduced using the lens (1.10 versus 1.38, difference 0.27, 95% CI 0.11–0.43, p =0.002). Procedure time, needle withdrawals, needle visibility and satisfaction were similar. Both inexperienced and experienced users benefited from the acoustic lens. Conclusions: The beam width artefact has a significant effect on the performance of ultrasound-guided needle- based procedures. The efficacy of in-plane superficial vascular access procedures can be enhanced by narrowing the imaging plane using an acoustic lens.
MULTIFILE
Skeletal muscle-related symptoms are common in both acute coronavirus disease (Covid)-19 and post-acute sequelae of Covid-19 (PASC). In this narrative review, we discuss cellular and molecular pathways that are affected and consider these in regard to skeletal muscle involvement in other conditions, such as acute respiratory distress syndrome, critical illness myopathy, and post-viral fatigue syndrome. Patients with severe Covid-19 and PASC suffer from skeletal muscle weakness and exercise intolerance. Histological sections present muscle fibre atrophy, metabolic alterations, and immune cell infiltration. Contributing factors to weakness and fatigue in patients with severe Covid-19 include systemic inflammation, disuse, hypoxaemia, and malnutrition. These factors also contribute to post-intensive care unit (ICU) syndrome and ICU-acquired weakness and likely explain a substantial part of Covid-19-acquired weakness. The skeletal muscle weakness and exercise intolerance associated with PASC are more obscure. Direct severe acute respiratory syndrome coronavirus (SARS-CoV)-2 viral infiltration into skeletal muscle or an aberrant immune system likely contribute. Similarities between skeletal muscle alterations in PASC and chronic fatigue syndrome deserve further study. Both SARS-CoV-2-specific factors and generic consequences of acute disease likely underlie the observed skeletal muscle alterations in both acute Covid-19 and PASC.
