Positive end-expiratory pressure (PEEP), which delivers air at a given pressure at the end of the expiratory cycle, can reduce edema and keep alveoli from collapsing. PEEP is considered necessary with mechanical ventilation; however, if the pressure is too great it can expand the size of the contusion and injure the lung. When the compliance of the injured lung differs significantly from that of the uninjured one, the lungs can be ventilated independently with two ventilators in order to deliver air at different pressures; this helps avoid injury from overinflation while providing adequate ventilation. Fluid therapy
The administration of fluid therapy in individuals with pulmonary contusion is controversial. Excessive fluid in the circulatory system (hypervolemia) can worsen hypoxia because it can cause fluid leakage from injured capillaries (pulmonary edema), which are more permeable than normal. However, low blood volume (hypovolemia) resulting from insufficient fluid has an even worse impact, potentially causing hypovolemic shock; for people who have lost large amounts of blood, fluid resuscitation is necessary. A lot of the evidence supporting the idea that fluids should be withheld from people with pulmonary contusion came from animal studies, not clinical trials with humans; human studies have had conflicting findings on whether fluid resuscitation worsens the condition. Current recommendations suggest giving enough fluid to ensure sufficient blood flow but not giving any more fluid than necessary. For people who do require large amounts of intravenous fluid, a catheter may be placed in the pulmonary artery to measure the pressure within it.
A pulmonary contusion, also known as lung contusion, is a bruise of the lung, caused by chest trauma. As a result of damage to capillaries, blood and other fluids accumulate in the lung tissue. The excess fluid interferes with gas exchange, potentially leading to inadequate oxygen levels (hypoxia). Unlike pulmonary laceration, another type of lung injury, pulmonary contusion does not involve a cut or tear of the lung tissue. A pulmonary contusion is usually caused directly by blunt trauma but can also result from explosion injuries or a shock wave associated with penetrating trauma. With the use of explosives during World Wars I and II, pulmonary contusion resulting from blasts gained recognition. In the 1960s its occurrence in civilians began to receive wider recognition, in which cases it is usually caused by traffic accidents. The use of seat belts and airbags reduces the risk to vehicle occupants. Diagnosis is made by studying the cause of the injury, physical examination and chest radiography. Typical signs and symptoms include direct effects of the physical trauma, such as chest pain and coughing up blood, as well as signs that the body is not receiving enough oxygen, such as cyanosis. The contusion frequently heals on its own with supportive care. Often nothing more than supplemental oxygen and close monitoring is needed; however, intensive care may be required. For example, if breathing is severely compromised, mechanical ventilation may be necessary.