The Awake Resting Breathing and Thoraco-Abdominal Pattern In Children With Achondroplasia: A Pilot Cross-Sectional Study

Achondroplasia is the most common skeletal dysplasia with an estimated prevalence of 1 in 20–30 thousand live births. Acute brainstem compression, due to a small foramen magnum, is the most common cause of mortality in children younger than 4 years, while cardiovascular deaths are more prevalent in adults. Respiratory complications occur mainly during childhood. Breathing was exclusively investigated during sleep, while the awake respiratory function in children with achondroplasia was not previously evaluated. Testing the respiratory function in young children is difficult because it often requires a high degree of collaboration. The use of techniques requiring only passive collaboration, like optoelectronic plethysmography, can overcome this limitation. Opto‐electronic plethysmography is a motion analysis system that measures the movement of passive reflective markers put on the chest wall according to anatomical points. Starting from the coordinates of the markers, the thoraco‐abdominal volume variations arecomputedandthecompleteventilatory pattern is derived. Optoelectronic plethysmography was previously validated and proved to be suited also for infants and young children. We tested the feasibility of opto‐electronic plethysmography to assess the thoraco‐abdominal volumes at rest for the first time in a small sample of children with achondroplasia. We aimed to verify whether these children were characterized by particular ventilatory and/or thoraco‐abdominal patterns during awake breathing.