(831) Describing Muscle Loss in Critically ill Children Using Point-of-Care Ultrasound (POCUS)

Introduction: ICU-acquired weakness in critically ill children continues to be a substantial concern, often leading to increased morbidity, and mortality rates. The current gold standard for diagnosing this condition involves nerve conduction studies and Electromyography. However, these methods are considered invasive, expensive, and require specialized expertise for accurate interpretation. This highlights the crucial necessity for a non-invasive, cost-effective alternative tool to effectively diagnose this condition.

The aim of this study is to assess feasibility of using Point of Care Ultrasound (POCUS) for muscle assessment to describe the incidence, severity, and risk factors associated with muscle loss in critically ill children.

Methods: A prospective single-center study was conducted to investigate muscle loss in critically ill children. Children aged between 18 months and 18 years, who were receiving invasive mechanical ventilation for 24-48 hours, were enrolled in the study. Baseline ultrasound assessment of the Quadriceps Femoris muscle thickness (QT) and cross-sectional area (CSA) was obtained upon enrollment, with subsequent assessments conducted every 72 hours until discharge from the ICU for comparative analysis. Data on potential risk factors for muscle loss, such as sedation and the use of steroids, were collected from the electronic medical records.

Results: The sample currently comprises of 24 patients with 69-day measurements. Muscle thickness was 3.3 (SD 0.9) cm, and cross-sectional area was 8 (SD 3.6) cm². Muscle thickness (QT) did not decrease significantly at each interval (p=0.21), while cross-sectional area (CSA) decreased significantly (p < 0.001). Fluid overload did not impact the measurements (p=0.31).

Conclusions: Muscle CSA more reliably detected muscle loss than the QT. This may be because measuring muscle thickness might underestimate muscle loss due to the scanning technique itself, on the other hand, cross sectional area is less likely to be affected with it. Our approach supports that obtaining point-of-care ultrasound in critically ill children is feasible. It can possibly serve as a dependable, non-invasive, and cost-effective bedside tool for detecting muscle loss. This method shows promise as an indicator for predicting ICU-acquired weakness and functional outcomes.