Pulmonary function studies in a newborn with congenital laryngeal atresia.

Congenital laryngeal atresia is a rare cause of upper airway obstruction that leads to death unless a surgical airway is immediately established. We were able to resuscitate a baby boy with laryngeal atresia by the placement of an 18-gauge plastic intravenous cannula into the trachea, connected in turn to a 3-mL syringe without the plunger, and then to the connector to a 7.0-mm endotracheal tube. This arrangement allowed hand ventilation and sufficient gas exchange until a formal tracheotomy was established minutes later. The baby boy had deficient abdominal musculature (without cryptorchidism or obstructive uropathy), bilateral inguinal hernias, and idiopathic hypercalcemia (since spontaneously resolved), but no other major anomalies. His survival allowed measurements of pulmonary function in lungs distal to an obstructed upper airway, an arrangement that mimics experiments that examine the influence of lung fluid volume and pressure on developing lungs. The baby's lungs had a forced vital capacity (FVC) in the upper limits of normal (not grossly enlarged lungs seen in newborn animals undergoing ligation of the trachea in utero). Maximal expiratory flow at 25% of FVC from residual volume (MEF25) was decreased, indicating airway obstruction involving smaller airways. Although direct laryngoscopy failed to find a opening in the larynx, some communication probably existed during development to allow some drainage of lung fluid. This opening, in the form of a persistent pharyngoglottic duct, prevented gross distention of the developing lung, but provided an insufficient airway at birth.