Bedside Ultrasound Measurement of Rectus Femoris: A Tutorial for the Nutrition Support Clinician

Abstract

Intensive care unit acquired weakness is a long-term consequence after critical illness; it has been related to muscle atrophy and can be considered as one of the main nutritional support challenges at the intensive care unit. Measuring muscle mass by image techniques has become a new area of research for the nutritional support field, extending our knowledge about muscle wasting and the impact of nutritional approaches in the critical care setting, although currently there is no universally accepted technique to perform muscle measurements by ultrasound. Because of this, we present this tutorial for nutrition support clinicians, in order to understand and perform muscle measurements by this reliable, accessible, low-cost, and easy-to-use technique. Reviewing issues such as quadriceps muscle anatomy, correct technique (do's and don'ts), identification of structures, and measurement of the rectus femoris and vastus intermedius muscles helps to acquire the basic concepts of this technique and encouraging more research in this field.

Ultrasound imaging for measuring muscle and subcutaneous fat tissue thickness of the anterior thigh: A two-year longitudinal study in middle age

“…The technique has been used to monitor lean mass loss at the bedside in critically ill patients who experience quadriceps and skeletal muscle atrophy at a very early stage especially critically ill children . Clinicians can utilize objective data from US imaging to administer an appropriate metabolic support to improve muscle morphology and subsequently function . The authors believe that monitoring both muscle and subcutaneous thickness to assess their relative contributions is important.…”

“…28 Clinicians can utilize objective data from US imaging to administer an appropriate metabolic support to improve muscle morphology and subsequently function. 14,16,29 The authors believe that monitoring both muscle and subcutaneous thickness to assess their relative contributions is important.…”

“…Quadriceps muscle atrophy is common in patients with knee osteoarthritis and other painful knee conditions . Sudden muscle atrophy is almost an unavoidable consequence in critically ill patients in intensive care units . Objective assessment of muscle thickness at the bedside could be a useful marker for clinicians to assess relative contributions of muscle and fat and balance nutritional support to attenuate such muscle mass loss.…”

Changes in Quantitative Muscle Ultrasound for Diagnosis of Intensive Care Unit-Acquired Weakness in Critically Ill Patients

“…After strength assessment, other researchers who were trained and blinded for the muscle strength results started to measure the muscle parameters immediately for the rst time by using a Philips ultrasound machine (IU22, USA) and a linear transducer or probe (frequency: 10-13MHz) which enabled acquiring images of super cial structures in high resolution [24]. Before performing, the patient must be in a supine position with extended elbows, wrists, knees and relaxed muscles, meanwhile palms and toes of patients were facing or pointing to the ceiling [25]. The muscle parameters for ultrasonography including CSA and TH of biceps brachii (BB) muscle, vastus intermedius (VI) muscle, and rectus femoris (RF) muscles.…”

“…The transducer was oriented transversally in relation to the longitudinal axis of the arm or thigh for obtaining a cross-sectional image, thus creating a right angle to the skin surface. Landmarks for ultrasound image acquisition were at standardized anatomical points, including the midpoint between supraglenoid tubercle and radial tuberosity for BB muscle [26], the second third of the distance between the anterior inferior iliac spine (AIIS) and the midpoint of the proximal border of the patella for RF muscle, and the midline of the same distance as RF muscle for VI muscle [25]. When performing ultrasonography, the pressure to the skin was kept minimal, and adequate coupling agents were used for obtaining the images [3].…”