Review Question - QID 214068

Two or more SIRS criteria are required to correctly diagnose SIRS (Illustration A). A respiratory rate >20 and a heart rate of 90/min meets this definition.

Immediate and early trauma deaths are the result of massive brain injury or hemorrhage. However, those that survive the initial injury insult can go on to develop multiorgan failure and sepsis because of the body’s immune response to injury – a hyperinflammatory state followed by a hypoinflammatory state. By recognizing this, damage control orthopaedics (DCO) was established. The justification for DCO is based on the two-hit theory. The first hit (hypoxia, hypotension, soft tissue injuries, and fractures) followed by the second hit (ischemia/reperfusion injuries, compartment syndrome, infections, and operative interventions) induce a host defense response that can lead to the development of multiple organ failure and mortality. Recognition of the systemic inflammatory response syndrome (SIRS) criteria (Illustration A) is of great importance to help determine the surgical management of polytrauma patients and avoid a second hit.

Keel and Trentz published a review article on the pathophysiology of polytrauma. The authors sought to better understand the pathophysiological mechanisms of polytrauma patients to aid in decision making for ideal surgical timing and to limit the morbidity of a second hit. They placed an emphasis on recognizing the presence of the SIRS criteria and understanding how this can affect the surgical management.

Lord et al. reviewed SIRS as it relates to traumatic injuries and the advances made in understanding the biological mechanisms and novel treatments implemented since the Keel and Trentz review. The systemic response induced by the initial injury is a complex orchestration of multiple organ systems – hemostatic, inflammatory, endocrine, and neurological – as result of end organ hypoperfusion from the initial trauma and the body’s initial inflammatory response. The current objective of treatment is to blunt the body’s inflammatory response to a degree that surgeons can avoid the second hit while not losing the body’s ability to fight infection.

Singer et al. report the updated definitions for sepsis and septic shock as determined by the collaborative efforts of the Society of Critical Care Medicine and the European Society of Intensive Care Medicine from 2016. Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. Septic shock is a subset of sepsis in which underlying circulatory and cellular/metabolic abnormalities are the result of an underlying infection and are profound enough to substantially increase mortality. The authors propose a distilled bedside diagnostic criterion that, if met, portend a longer ICU stay and mortality: altered mental status, systolic blood pressure less than or equal to 100 mm Hg, or respiratory rate greater than or equal to 22/min.

Illustration A lists the individual SIRS criteria.

Incorrect Answers:
Answers 1, 2, 3, & 5: Two or more SIRS criteria are required to correctly diagnoses SIRS. Although, lactate is a useful laboratory value that can help indirectly assess adequate resuscitation, it is not one of the SIRS criteria.