Thigh ultrasound monitoring identifies muscle atrophy in mechanically ventilated pediatric patients.

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.

Ultrasound assessment of ventilator-induced diaphragmatic dysfunction in mechanically ventilated pediatric patients.

INTRODUCTION: Ultrasonography has recently emerged as a promising technique that can rapidly estimate diaphragm function, especially during the weaning period. The aims of this study were to describe the evolution of diaphragmatic morphology and functional measurements by ultrasound in ventilated children. MATERIAL AND METHODS: This was a prospective, observational, single-center study. All the children admitted to our Pediatric Intensive Care Unit requiring mechanical ventilation for more than 48 h were included. Diaphragmatic thickness and the thickening fraction were assessed by ultrasound. RESULTS: From June to December 2018, 47 patients (median age 3 months; interquartile range, 1-17) underwent 164 ultrasonographic evaluations. The median duration of mechanical ventilation was 168 h (interquartile range, 96-196). At the initial measurement, the thickness at end-inspiration was 2.2 mm (interquartile range, 1.8-2.5) and the thickness at end-expiration was 1.8 mm (interquartile range, 1.5-2.0) with a median decrease in thickness of -14% (interquartile range, -33% to -3%) and a -2% daily atrophy rate (interquartile range, -4.2% to 0%). Diaphragmatic atrophy was observed in 30/47 cases. Children who had been exposed to neuromuscular blockade infusion (n = 31) had a significantly lower mean thickness [-22% (interquartile range, -34% to -13%) vs. -6% (interquartile range, -12% to 0%); p = 0.009] and increased daily atrophy rate [-2.2% (interquartile range, -4.6 to 0%) vs. -1.4% (interquartile range, -2.6 to 0%); p = 0.049] compared to unexposed children. The decrease in thickness was significantly less in children ventilated for at least 12 hours with pressure support before extubation compared with those with shorter periods of spontaneous respiratory effort [-9.5% (interquartile range, -21 to 0%) vs. -26% (interquartile range, -37 to -12%); p = 0.011]. CONCLUSIONS: Point-of-care diaphragmatic ultrasound can detect diaphragmatic atrophy in mechanically ventilated children. Diaphragmatic atrophy was strongly associated with the use of mechanical ventilation and neuromuscular blockade. Diaphragmatic thickness also tended to decrease less in the pre-extubation stage with pressure support. We found no correlation between progressive diaphragm thinning, extubation failure, or an increased need for non-invasive ventilation post extubation.