DIAGNOSIS
The diagnosis of VAP is difficult and varies across institutions. American Thoracic Society and Infectious Disease Society of America guidelines define VAP as a “new lung infiltrate plus clinical evidence that the infiltrate is of an infectious origin, which include the new onset of fever, purulent sputum, leukocytosis, and decline in oxygenation” which develops >48 hours after endotracheal intubation.8
Determination of whether a pulmonary abnormality is of infectious origin is particularly challenging, especially in trauma patients. Blast injury and penetrating chest injury patients are highly likely to have injury-related chest radiography findings that may obscure or mimic infections.
Patients on mechanical ventilation are at risk for a variety of serious complications in addition to VAP, including acute respiratory distress syndrome, pneumothorax, pulmonary embolism, lobar atelectasis, and pulmonary edema. The Centers for Disease Control have large scale, ongoing quality projects designed to validate and streamline surveillance measures, though these have yet to be validated for a priori diagnosis of various ventilator associated conditions. Despite the changing language surrounding ventilator associated conditions, the strongest and most consistent evidence continues to support daily sedation interruptions and spontaneous breathing trials for aggressive liberation from mechanical ventilation as the factors most likely to reduce all ventilator associated conditions.9