What is the appropriate procedure for endotracheal tube suctioning after the appropriate catheter is selected?

After selecting the appropriate catheter for endotracheal tube suctioning, first ensure the suction device is functioning and set to the recommended pressure (typically 80-120 mmHg for adults). Don clean or sterile gloves and use a sterile technique to insert the catheter into the endotracheal tube, applying suction intermittently while withdrawing the catheter. Limit suctioning to no more than 10-15 seconds to prevent hypoxia, and provide supplemental oxygen if needed. After suctioning, assess the patient's respiratory status and clear the catheter with saline if necessary before reusing it.