Point-of-care ultrasound of the diaphragm has been proposed as a simple, noninvasive, dynamic bedside quantitative evaluation of diaphragm function that involves no ionizing radiation, does not require patient transport, and enables the serial evaluation of diaphragmatic function over time.In addition to the adverse effects on the diaphragm attributed to mechanical ventilation and ventilator-induced diaphragm dysfunction (longer weaning times, ventilation time and weaning failure), recent investigations of POCUS evaluating the expiratory muscles of the lateral abdominal wall have found similar adverse effects of mechanical ventilation on these important respiratory muscles resulting in weaning difficulty. Children with medical complexity have significant chronic health conditions that may involve multisystem disease (congenital or acquired), high medical fragility, functional and psychosocial impairment, technology dependence (tracheostomies, MV, feeding tubes) and high resource utilization (frequent and/or prolonged hospitalizations).We present a case of weaning difficulty in a child with medical complexity and the important role of point-of-care ultrasound in the evaluation of the diaphragm and expiratory muscles during a spontaneous breathing trial.