Mechanical ventilation delivers positive-pressure breaths to a patient who cannot maintain adequate oxygenation, ventilation or airway protection on their own. It is supportive, not curative — it buys time while the underlying problem is treated, and it carries its own substantial risks. That trade-off shapes the whole of nursing care for a ventilated patient. Positive pressure is the reverse of normal physiology: healthy breathing draws air in by generating negative pressure inside the chest, while a ventilator pushes air in. That inversion reduces venous return, can drop blood pressure, and can injure the lung it is supporting. Every complication flows from it. The RN's role is precise and worth stating clearly at the outset. You do not prescribe ventilator settings and you do not intubate. What you do is assess the patient, recognize deterioration, respond to alarms, prevent the complications that ventilation causes, deliver prescribed sedation and analgesia thoughtfully, protect the patient's skin, mouth, mobility and dignity, and escalate. In practice the nurse is the person who notices that a patient's peak pressures have been creeping up all shift, and...