Fig. 1From: Using non-invasive bi-level positive airway pressure ventilator via tracheostomy in children with congenital central hypoventilation syndrome: two case reportsOvernight trend graphs of end-tidal carbon dioxide and respiratory rate. When end-tidal carbon dioxide increased to the peak level, respiratory rate did not increase indicating blunted physiologic response to hypercapnia. ETCO 2 end-tidal carbon dioxide, RR respiratory rateBack to article page