Background: Postinjury organ dysfunction is a result of unbridled systemic hyperinflammation. According to the two-event construct, patients are resuscitated into an early vulnerable window of systemic hyperinflammation (primed) in which a second otherwise innocuous event precipitates uncontrolled hyperinflammation, leading to secondary organ damage and dysfunction (activated). Recent efforts to decrease postinjury morbidity have focused on limiting the potential of second events and systemic inflammation. We hypothesized that the collective effects of recently implemented therapeutic strategies have resulted in decreased activation of the systemic inflammatory response relative to priming in recent years.
Methods: Data were collected prospectively on trauma patients at risk for postinjury multiple organ failure (MOF). Inclusion criteria were age >15 years, trauma intensive care unit admission, Injury Severity Score >15 and survival >48 hours. Isolated head injuries and head injuries with an extracranial abbreviated injury score <2 were excluded. Daily physiologic and laboratory data were collected through surgical intensive care unit day 28, and clinical events were recorded thereafter until death or hospital discharge. Organ failure was characterized with the use of the Denver MOF Scale. Acute respiratory distress syndrome (ARDS) was defined according to the consensus definition.
Results: Over a 6.5-year period 897 patients were studied; 271 (31%) developed ARDS, and 226 (25%) developed MOF. Early lung dysfunction, as a measure of systemic priming, did not change over the study period. In contrast, the incidence of ARDS and MOF decreased from 43% to 25% and 33% to 12%, respectively. The incidence of early MOF decreased from 22% to 7% over the study period.
Conclusions: Priming of the postinjury inflammatory response is an early event and is primarily influenced by the injury itself. Recent advances in postinjury care such as judicious blood transfusion, lung protective ventilation, treatment of adrenal insufficiency, and tight glucose control are known to attenuate systemic inflammation. Step-wise adoption of these therapies is coincident with a decrease in the destructive processes resulting in ARDS and MOF. The global effect is a decrease in activation of the systemic inflammatory response over recent years.