Stridor (from Latin 'creaking/grating noise') is an extra-thoracic high-pitched breath sound resulting from turbulent air flow in the larynx or lower in the bronchial tree.
Flexible fiberoptic bronchoscopy can also be very helpful, especially in assessing vocal cord function or in looking for signs of compression or infection.
The first issue of clinical concern in the setting of stridor is whether or not tracheal intubation or tracheostomy is immediately necessary.
A reduction in oxygen saturation is considered a late sign of airway obstruction, particularly in a child with healthy lungs and normal gas exchange.
If intubation can be delayed for a period, a number of other potential options can be considered, depending on the severity of the situation and other clinical details.