Mechanical Ventilation

The use of mechanical ventilation is a common intervention in both the operating room and intensive care units worldwide. Often the goal is merely to facilitate a patient undergoing major surgery, other times it is to prevent life-threatening deterioration in a critically ill patient. It needs to be remembered that mechanical ventilation is a supportive therapy, and it rarely treats the underlying disease process. With this sentiment in mind, much of the focus of positive pressure ventilation is aimed at preventing its negative effects such as lung injury, infection, and hypotension. There are numerous ways that mechanical ventilation may damage the body. The various types of lung damage caused by ventilators are collectively known as ventilator-induced lung injury (VILI). Specific examples of VILI that mechanical ventilation may induce include parenchymal air leaks, also known as barotrauma, and diffuse alveolar over-distension that causes a volutrauma injury to the lung. Another mechanism of injury is due to the cyclic opening and closing of the alveoli, and this is termed atelectrauma.