lung and airway disorders
Mechanical Ventilation
Complications of Mechanical Ventilation
Pushing air into the lungs under too much pressure or with too high a volume can overstretch the lungs and cause lung damage. Sometimes the fragile alveoli (small air sacs in the lungs) rupture, allowing air to accumulate around the lung and collapse it, a condition called Pneumothorax . To avoid these problems, doctors try to limit the volume and pressure of air delivered by the ventilator. On the other hand, too little pressure and volume may not move enough air in and out, causing the level of carbon dioxide in the blood to become too high and letting the small airways and alveoli close. Doctors constantly monitor and adjust the frequency and size of breaths delivered by the ventilator and the ventilator pressure to strike a careful balance. Although most people undergoing mechanical ventilation need extra oxygen, too much oxygen actually can damage the lungs. Doctors monitor the person’s oxygen level to ensure that just the right amount is given. People undergoing mechanical ventilation, particularly with intubation of the trachea, may have agitation, which doctors can control with sedating drugs, such aspropofol,lorazepam, andmidazolam, or opioids, such asmorphineorfentanyl. These drugs can also help relieve breathlessness. When the trachea is intubated, bacteria from the nose and mouth can easily enter the lungs and cause serious infection. These infections must be diagnosed and treated as quickly as possible. Because people on mechanical ventilation cannot eat, nutritional support is usually provided by giving liquid supplements through a tube positioned in the stomach ( Tube Feeding ). 