A 2-year-old with respiratory distress may have swallowed an object. What should be the next step to determine the cause?

For a 2-year-old with respiratory distress who may have swallowed an object, bronchoscopy is the most appropriate next step to determine the cause. This procedure allows for direct visualization of the airway, enabling healthcare providers to identify and potentially retrieve any foreign object that may be obstructing the airway or causing respiratory distress.

In cases of suspected foreign body aspiration, immediate assessment of the airway is crucial. Bronchoscopy not only aids in confirming the presence of an object but can also provide the necessary intervention to remove it if found. This real-time diagnostic and therapeutic capability makes bronchoscopy the go-to choice in such acute scenarios where airway compromise is a concern.

While pulse oximetry and arterial blood gas analysis can provide important information about the child's oxygenation and acid-base status, they would not identify the presence of a foreign body. Spirometry, on the other hand, is not suitable in this acute setting, especially for a toddler, because it requires patient cooperation and is typically used to assess chronic respiratory conditions rather than acute obstruction caused by foreign objects.