Marcus K. Hoffman

BACKGROUND The evolving field of acute care surgery (ACS) traditionally includes trauma, emergency general surgery, and critical care. However, the critical role of ACS in the rescue of patients with a surgical complication has not been explored. We here describe the role of “surgical rescue” in the practice of ACS. METHODS A prospective, electronic medical record-based ACS registry spanning January 2013 to May 2014 at a large urban academic medical center was screened by ICD-9 codes for acute surgical complications of an operative or interventional procedure. Long-term outcomes were derived from the Social Security Death Index. RESULTS Of 2,410 ACS patients, 320 (13%) required “surgical rescue”: most commonly, from wound complications (32%), uncontrolled sepsis (19%), and acute obstruction (15%). The majority of complications (85%) were related to an operation; 15% were related to interventional procedures. The most common rescue interventions required were bowel resection (23%), wound debridement (18%), and source control of infection (17%); 63% of patients required operative intervention, and 22% required surgical critical care. Thirty-six percent of complications occurred in ACS primary patients (“local”), whereas 38% were referred from another surgical service (“institutional”) and 26% referred from another institution (“regional”). Hospital length of stay was longer, and in-hospital and 1-year mortalities were higher in rescue patients compared with those without a complication. Outcomes were equivalent between “local” and “institutional” patients, but hospital length of stay and discharge to home were significantly worse in “institutional” referrals. CONCLUSION We here describe the distinct role of the acute care surgeon in the surgical management of complications; this is an additional pillar of ACS. In this vital role, the acute care surgeon provides crucial support to other providers as well as direct patient care in the “surgical rescue” of surgical and procedural complications. LEVEL OF EVIDENCE Epidemiological study, level III; therapeutic/care management study, level IV.

BACKGROUND Toll-like receptors (TLRs) detect endogenous ligands released after trauma and contribute to the proinflammatory response to injury. Posttraumatic mortality correlates with the extent of the immunoinflammatory response to injury that is composed of a complex regulation of innate and adaptive immune responses. Although TLRs are known to modulate innate immune responses, their role in the suppression of lymphocyte responses following traumatic tissue injury is unclear. METHODS This study used a murine model of severe peripheral tissue injury, involving muscle crush injury and injection of fracture components, to evaluate the roles of TLR2, TLR4, and TLR9 in the early and delayed immunoinflammatory phenotype. Posttraumatic immune dysfunction was measured in our trauma model using the following parameters: ex vivo splenocyte proliferation, TH1 cytokine release, and iNOS (inducible nitric oxide synthase) induction within splenic myeloid-derived suppressor cells. Systemic inflammation and liver damage were determined by circulating interleukin 6 levels and hepatocellular injury. RESULTS Suppression of splenocyte responses after injury was dependent on TLR4 and TLR9 signaling as was posttraumatic iNOS upregulation in splenic myeloid-derived suppressor cells. TLR2 was found to have only a partial role through contribution to inhibition of splenocyte proliferation. This study also reveals the involvement of TLR2 and TLR4 in the initial systemic inflammatory response to traumatic tissue injury; however, this response was found to be TLR9 independent. CONCLUSION These findings demonstrate the previously unidentified role of TLR2, TLR4, and TLR9 in the T cell–associated immune dysfunction following traumatic tissue injury. Importantly, this study also illustrates that TLRs play differing and selective roles in both the initial proinflammatory response and adaptive immune response after trauma. Furthermore, results in TLR9-deficient mice establish that the upregulation of early proinflammatory markers do not always correlate with the extent of sustained immune dysfunction. This suggests potential for targeted therapies that could limit immune dysfunction through selective inhibition of receptor function following injury.