What is the most dangerous complication associated with an EGD?

The most dangerous complication associated with an esophagogastroduodenoscopy (EGD) is secondary respiratory arrest. During an EGD, patients are often sedated to ensure comfort. This sedation can potentially impair the patient's respiratory drive, leading to inadequate breathing and, in some cases, respiratory arrest.

Moreover, the procedure involves manipulating the endoscope through the throat and esophagus, which can induce a gag reflex or even transient airway obstruction. If not properly managed, these factors can culminate in a serious respiratory event. Additionally, patients may have underlying conditions or reactions to sedatives that further elevate the risk.

While gastric bleeding, pneumothorax, and infection are indeed complications that can occur with an EGD, they are generally less immediate or lethal compared to the possibility of respiratory arrest. Gastric bleeding might happen if there are lesions or injuries to the stomach lining, pneumothorax could occur if there is improper placement of the endoscope, and infection, while a concern, typically develops later and is usually manageable. Therefore, the immediate threat posed by the potential for respiratory complications makes secondary respiratory arrest a critical focus for health professionals during and after the procedure.