REVIEW | doi:10.20944/preprints202012.0755.v1
Subject: Medicine & Pharmacology, Allergology Keywords: titin; muscle; diaphragm; atrophy; physical dysfunction, biomarker; urine; post-intensive care syndrome; nutrition; rehabilitation
Online: 30 December 2020 (14:15:47 CET)
Titin is a giant protein that functions as a molecular spring in sarcomeres. Titin interplays the contraction of actin-containing thin filaments and myosin-containing thick filaments. The breakdown product of titin has been measurable in urine as urinary titin N-fragments. Urinary titin N-fragment was originally reported to be a useful biomarker in the diagnosis of muscle dystrophy. Recently, the urinary titin N-fragment has been increasingly gaining attention as a novel biomarker of muscle atrophy and intensive care unit-acquired weakness in critically ill patients, in whom titin loss is a possible pathophysiology. Furthermore, several studies reported that the urinary titin N-fragment also reflected muscle atrophy and weakness in patients with chronic illnesses. It may be used to predict the risk of post-intensive care syndrome or to monitor patients’ condition after hospital discharge for better nutritional and rehabilitation management. We provide several tips on the use of this promising biomarker in post-intensive care syndrome.
ARTICLE | doi:10.20944/preprints202104.0301.v1
Subject: Medicine & Pharmacology, Allergology Keywords: Ultrasound; phantom; rectus femoris muscle; echogenicity; training
Online: 12 April 2021 (12:50:45 CEST)
Ultrasound has become widely used as a mean to measure the rectus femoris muscle in the acute and chronic phase of critical illness. Despite its noninvasiveness and accessibility, its accuracy highly depends on the skills of the technician. However, few ultrasound phantoms for the confirmation of its accuracy or to improve technical skills exist. In this study, we created a novel phantom model and used it for investigating the accuracy of measurements and for training. Study 1 investigated how various conditions affect ultrasound measurements such as thickness, cross-sectional area, and echogenicity. Study 2 investigated if the phantom can be used for training of various health care providers in vitro and vivo. Study 1 showed that thickness, cross-sectional area, and echogenicity were affected by probe compression strength, probe angle, phantom compression, and varying equipment. Study 2 in vitro showed that using the phantom for training improved the accuracy of the measurements taken within phantom, and Study 2 in vivo showed the phantom training had a short-term effect on improving the measurement accuracy in a human volunteer. The new ultrasound phantom model revealed that various conditions affected ultrasound measurements, and phantom training improved the measurement accuracy.