A 59-year-old intubated patient in the ICU has coarse rhonchi, visible secretions in the endotracheal tube, and a transient desaturation after coughing, with a sterile suction kit and closed-system catheter available at bedside. Which suctioning technique should the therapist use to clear an artificial airway while preserving oxygenation and sterility?

Preoxygenate, insert a sterile catheter without suction, and apply brief intermittent suction only while withdrawing. Preoxygenation restores oxygen reserve after the transient desaturation; sterile insertion protects the lower airway, which bypasses upper-airway defenses; and suction on withdrawal clears visible secretions while limiting mucosal trauma, atelectasis, hypoxia, and vagal stimulation. Inserting a sterile catheter without preoxygenation and suctioning briefly on withdrawal otherwise follows the right technique, but misses the oxygenation step: with low reserve, even a brief pass can cause profound hypoxemia and dysrhythmia. Applying suction during insertion as well as withdrawal fails the atraumatic principle: negative pressure on entry can strip mucosa, provoke edema, bleeding, and bronchospasm, remove oxygen, and prolong hypoxia without improving clearance. Using a clean rather than sterile catheter, despite preoxygenation and brief suction on withdrawal, fails the sterility principle: an artificial airway lacks filtration and cough protection, so nonsterile introduction can seed the tracheobronchial tree and increase ventilator-associated pneumonia risk; clean technique may be accepted for oropharyngeal suction, not this airway. Exam caveat: connect a desaturation history to preoxygenation, and reject routine lavage, prolonged passes, and suction on insertion even when other steps are appropriate. Practical check: use the sterile closed-system catheter available, choose a catheter less than half the tube lumen, limit each pass to 10–15 seconds, monitor saturation and rhythm, and reoxygenate between passes.