Potential indications for mechanical ventilation include hypoxemia unresponsive to oxygen administration, hypercapnia resulting in acidemia, and an unstable chest wall. For best results, carefully prepare the patient (both physically and emotionally) before instituting ventilation. Sedatives and local anesthesia can facilitate intubation; avoid paralytic agents unless you are experienced at intubation. The oral route is most commonly used. Once the patient circuit is attached to the endotracheal tube, reexamine the patient and double-check the inspiratory flow and I:E ratio; adjust the ventilator's settings as necessary. Monitor the patient frequently to ascertain the adequacy of alveolar ventilation and arterial oxygen.