Thigh ultrasound monitoring identifies muscle atrophy in mechanically ventilated pediatric patients

Abstract

Over the last decade, ultrasonography has taken on an increasingly important role in the daily management of critically patients and has recently been proposed as a means of measuring muscle volume and architecture. This study had two main aims: to monitor for the onset of muscle atrophy in mechanically ventilated pediatric patients during stays in a pediatric intensive care unit based on quadriceps femoris muscle thickness measurements and to study whether demographic and clinical variables have an impact on muscle loss in critically children. The study followed a prospective, observational, single-center design. The sample included all children admitted to our pediatric intensive care unit (PICU) who required mechanical ventilation for more than 48 h. Two trained clinicians measured the thickness of the quadriceps using a 12-MHz linear ultrasound transducer within 24 h of initiating invasive mechanical ventilation and again at 72 h, 1 week, and weekly thereafter until extubation. For the entire cohort, quadriceps femoris muscle thickness decreased by 4.67% on average (IQR = -13.4 to -0.59) between the first two assessments and 13% by the time of the final measurement (IQR = -24 to -0.5%) or 1.57%/day (p < 0.001). Approximately half of all the children (23/41; 56%) experienced muscle atrophy (defined a priori as a decrease in thickness of 10% or more). Bivariate analyses revealed that increasing age, being a child (vs. infant), cumulative energy and protein deficit, highest C-reactive protein value, exposure to neuromuscular blockers, and a longer stay in the PICU were all predictive of a greater decrease in thickness. In a multivariate model, exposure to neuromuscular blockers was linked with greater muscle loss. Conclusion: In mechanically ventilated children, point-of-care ultrasonography can identify skeletal muscle atrophy. Muscle atrophy of limbs is strongly associated with the use of neuromuscular blockers. Ultrasound-based monitoring of the quadriceps femoris is a clinically useful tool for assessing muscle mass that can provide information on nutritional status and guide rehabilitation. What is Known: • ICU-acquired muscle atrophy is common and has a deleterious effect on adult outcomes. The prevalence and severity of muscular atrophy in critically ill children, however, are poorly understood. • Point-of-care ultrasonography has been put forward as an accurate, reliable method for monitoring variations in muscle mass.. What is New: • The quadriceps femoris muscle tends to suffer an intense loss of thickness early on in most critically ill children. • Quadriceps femoris ultrasound monitoring is a helpful tool for measuring muscle thickness and could lead to the development of novel therapies for critically ill children.

Keywords: Critically ill children; Muscle atrophy; Point-of-care ultrasound; Quadriceps femoris; Nutrition.