View Abstract

A1764 - Bone Health in Children with Respiratory Technology Dependence
Author Block: A. Agarwal1, M. Hutchison2, C. Velasco3, L. Willis4, U. Chalawadi1, K. El Taoum5, J. L. Carroll6; 1Pulmonary, UAMS/Arkansas Children Hosp, Little Rock, AR, United States, 2Endocrine, UAMS/Arkansas Children Hosp, Little Rock, AR, United States, 3Biostatistcs, Arkansas Children Research Institute, Little Rock, AR, United States, 4Arkansas Children s Hospital, Little Rock, AR, United States, 5Pediatrics, UAMS/Arkansas Children's Hospital, Little Rock, AR, United States, 6Pediatrics, UAMS Arkansas Childrens Hosp, Little Rock, AR, United States.
Background: As technology improves, children with complex conditions are surviving longer. Many are reliant on respiratory technology dependence (RTD). We see a high rate of bone fractures in these children, but little is known about bone health in this population.We performed a retrospective chart review of our population of children with RTD to estimate the prevalence and potential causative factors of low bone mineral density (BMD) in these children. Study Design/Methods: This study was approved by IRB at UAMS. Patients were 0-20 years of age, and RTD was defined as use of an airway clearance device (high frequency chest wall oscillation technology (Vest®), Cough In exsufflator) or a ventilator to maintain clinical stability due to an underlying problem such as neuromuscular disease NMD), chronic lung disease, spinal cord injury, traumatic brain injury, spinal bifida, cerebral palsy were included. Patients with cystic fibrosis, osteogenesis imperfecta, known skeletal dysplasia, or hypophosphatasia were excluded. Data collected included duration of RTD, duration of immobility, number and location of fractures, medications, and laboratory data such as bone turnover markers, vitamin D levels, x-rays and DXA results. The data was recorded and analyzed in database to determine which factors predict low BMD. Results: The preliminary findings are from 192 patients. 135 (72.6%) were non-ambulatory. Most frequent primary respiratory diagnoses were (N, %): Central nervous system disorder (94, 48.7%), Neuromuscular Disease (50, 25.9%), and Parenchymal Lung Disease (17, 8.8%). Scoliosis was documented in 95 (51.91%) patients, of which 33 (34.7%) had surgical repair. 25 of these patients had at least one fracture (3 patients had two fractures, one patient had three); of these, 18 (72%) had a femur fracture. DXA was measured in 63 patients (lumbar/spine 38 patients, total body ten patients). There was a significant difference (p=0.002) in DXA z-score at lumbar spine by primary diagnosis for RTD. CNS Disorder patients had lower scores (median=-2.0, min=-4.7, max=0.2) than neuromuscular disease patients (-0.6, -3.3, 0.7). By multivariate regression analysis, DXA positively correlated with ambulation status and inversely correlated with fracture, but neither was statistically significant. Conclusions: Low BMD is common in children with RTD, predisposing them to a high risk of fractures. Contributory factors may include poor nutrition, decreased physical activity, and immobilization. As we gather more data, we hope to determine which factors are most strongly predictive of fracture risk, which will then allow us to make recommendations regarding screening these patients for Low BMD.