A mechanical ventilator is a machine that helps a patient breathe (ventilate) when they are having surgery or cannot breathe on their own due to a critical illness. The patient is connected to the ventilator with a hollow tube (artificial airway) that goes in their mouth and down into their main airway or trachea. They remain on the ventilator until they improve enough to breathe on their own.A mechanical ventilator is a machine that helps a patient breathe (ventilate) when he or she cannot breathe on his or her own for any reason. There are many benefits, but a major risk is infection.A mechanical ventilator is used to decrease the work of breathing until patients improve enough to no longer need it. The machine makes sure that the body receives adequate oxygen and that carbon dioxide is removed. This is necessary when certain illnesses prevent normal breathing.The main risk of mechanical ventilation is an infection, as the artificial airway (breathing tube) may allow germs to enter the lung. This risk of infection increases the longer mechanical ventilation is needed and is highest around two weeks. Another risk is lung damage caused by either over inflation or repetitive opening and collapsing of the small air sacs Ialveoli) of the lungs. Sometimes, patients are unable to be weaned off of a ventilator and may require prolonged support. When this occurs, the tube is removed from the mouth and changed to a smaller airway in the neck. This is called a tracheostomy. Using a ventilator may prolong the dying process if the patient is considered unlikely to recover.