Use of continuous positive airway pressure during flexible bronchoscopy in young children.

Young children are at increased risk for hypoxaemia and hypercapnia during flexible bronchoscopy due to the small size and increased collapsibility of their airways. Various strategies are used to prevent hypoventilation and to provide oxygen during the procedure. The aim of this study was to assess the impact of continuous positive airway pressure (CPAP) on ventilation during flexible bronchoscopy in infants and young children. Tidal breathing was measured in 16 spontaneously breathing and deeply sedated children, aged 3-25 months, by ultrasound spirometry via an airway endoscopy mask. Measurements were made with the tip of the bronchoscope positioned in the pharynx with no CPAP, and in mid-trachea with 0, 5 and 10 cmH2O of CPAP. Transition of the bronchoscope through the vocal cords was associated with significant decreases of tidal volumes (5.0+/-0.5 versus 3.4+/-0.5 mL.kg(-1)), peak tidal expiratory flows (78+/-12 versus 52+/-10 mL.s(-1)) and peak tidal inspiratory flows (98+/-15 versus 66+/-12 mL.kg(-1)). CPAP (5-10 cmH2O) induced almost complete reversal of these changes. In conclusion, it is shown here that flexible bronchoscopy in spontaneously breathing young children is associated with significant decreases in tidal volume and respiratory flow. These changes are largely reversible with continuous positive airway pressure.