Early versus delayed restoration of flow with temporary vascular shunt reduces circulating markers of injury in a porcine model.

BACKGROUND: Temporary vascular shunting to restore flow after vascular injury has been advocated. The effectiveness of this adjunct in protecting against ischemic injury has not been established. This study will assess the temporal impact of shunts on ischemic injury and arterial flow. METHODS: A porcine model of hind-limb ischemia via iliac artery occlusion was used (N = 36; weight [kg] +/- SD: 89 +/- 4.4). Animals were randomized into one control (Iscctrl) and four study groups (Isc0, Isc1, Isc3, and Isc6) according to ischemic time. Shunt placement followed ischemia, and flow and circulating injury markers were collected incrementally during 18 hours of reperfusion. Flow proportions and a calculated Ischemia Injury Index were used to characterize group differences. RESULTS: There were no intergroup differences concerning initial weight, hemodynamic, or laboratory values. Shunt patency was 92% in the absence of anticoagulation. The proportion of common femoral arterial flow to baseline flow in the Isc6 group was lower than the Iscctrl group (p = 0.02). There was a similar trend with the Isc1 and Isc3 groups. The Ischemia Injury Index demonstrated that there was a difference in the Isc3 and Isc6 groups (late shunt placement) compared with the Iscctrl, Isc0, and Isc1 groups (early shunt placement) (p < 0.001). CONCLUSION: This study provides physiologic insight into the benefit of shunts in a model of extremity ischemia. Early shunting protects the extremity from further ischemic insult and reduces circulating markers of tissue injury. Additionally, the presence of a shunt does not increase the Ischemic Injury Index and patency is maintained in the absence of heparinization.

Surgical response to multiple casualty incidents following single explosive events.

BACKGROUND: Modern publications on response to single explosive events are from non-US hospitals, predate current resuscitation guidelines and lack detail on surgical and intensive care unit (ICU) requirements. The objective of this study is to provide a contemporary account of surge response to multiple casualty incidences following explosive events managed at a US trauma hospital in Iraq. METHODS: Observational study and retrospective chart review of 72-hour transfusion, operating room, and ICU resource utilization from 3 multiple casualty incidences managed at the US Air Force Theater Hospital, Balad AB, Iraq between February and April 2008. RESULTS: Fifty patients were treated with a mean injury severity score of 19. Forty-eight percent (n = 24) of casualties required blood transfusion with 4 patients receiving 43% (N = 74 units) of the packed red blood cells (pRBC). An average of 3.5 and 3.8 units of pRBC and plasma, respectively, was transfused per casualty (pRBC:plasma ratio of 1:1.1). Seventy-six percent (n = 38) of patients required immediate operation upon initial presentation. A total of 191 procedures were performed in parallel during 75 operations (3.8 procedures per casualty). Fifty percent (n = 25) of patients required ICU admission with nearly the same number (n = 24) requiring mechanical ventilator support beyond that required for operation. All cause, in-hospital mortality was 8% (n = 4). CONCLUSIONS: Results from this study provide a contemporary assessment of transfusion, surgical, and intensive care resource requirements after a single explosive event. Data from this experience may translate into useful guidelines for emergency planners worldwide.