–VILI refers to the following lung injuries that are caused by high peak inspiratory pressures (PIP) and/or high TVs
- Barotraumas, or injuries resulting from leakage of air outside of the lungs, occur when the alveoli rupture due to high
PIP. Types of barotraumas include pneumothorax (i.e., a collection of air in the space around the lungs, which can
cause lung collapse), subcutaneous or interstitial emphysema, and pneumomediastinum (i.e., a collection of air in the
mediastinum, which is the space between the lungs)
- Volutrauma refers to overexpansion of normal alveoli (i.e., those previously unaffected by the primary illness or injury)
in response to high TVs. This results in local lung inflammation and worsening of the initial lung injury
- Atelectrauma is injury caused by the sheer forces exerted against the alveoli as they are repeatedly opened and collapsed
during MV. Positive end-expiratory pressure (PEEP) is used to reduce risk for this type of injury by preventing complete
alveolar collapse at end expiration
- Biotrauma refers to the release of inflammatory mediators (e.g., cytokines) that occurs when the alveoli become injured.
Biotrauma can result in both localized and systemic manifestations. The adverse effects of biotrauma can extend to
distal organs, resulting in multisystem organ failure (for details, see Facts and Figures, above). Low to moderate TVs
reduce risk for biotrauma
–Cardiovascular abnormalities, including reduction in cardiac output and venous return, can occur due to the effect of
high intrathoracic pressures produced with positive pressure ventilation. Decreased cardiac output in turn reduces the
functioning of other body systems, particularly the renal, hepatic, and gastrointestinal systems. These cardiovascular
effects are more pronounced at high levels of pressure support and high TVs
–Oxygen toxicity is caused by prolonged exposure to high oxygen concentrations (FiO2), which results in accumulation
of harmful oxygen byproducts (e.g., free radicals, including hydrogen peroxide, superoxide anion, and hydroxyl). Effects