48 ABSTRACT If blood products are not available, current military guidelines recommend a hetastarch bolus (HEX, Hex- tend ™ 6% hetastarch in lactated electrolyte buffer, www .hospira.com) for initial treatment of hypovolemic shock in the field. We previously reported that a HEX plus standard of care (SOC = crystalloid plus blood products) was safe during initial resuscitation in 1714 trauma patients. This study tests the hypothesis that HEX+SOC is more effective than SOC alone for vol- ume expansion in trauma patients requiring urgent op- eration. Methods: From July 2009 to August 2010, the records from all adults who required emergency surgery within 4 hours of admission were screened for a retro- spective cohort observational study. Burns, and those with primary neurosurgical or orthopedic indications, were excluded. The study population was comprised of 281 patients with blunt (n = 72) or penetrating (n = 209) trauma; 141 received SOC and 140 received SOC+HEX in the emergency room only (ER, n = 81) or the ER and operating room (OR, n = 59). Each case was reviewed with waiver of consent. Results: After penetrating injury, with SOC, the injury severity score was 17 and mortality was 12%; the corresponding val- ues in the HEX ER and HEX OR groups were 19–21 and 8%, but these apparent differences did not reach signifi- cance. However, in patients receiving HEX, initial heart rate was higher, base deficit was lower, and hematocrit was lower (consistent with relative hypovolemia), even though blood product requirements were reduced, and urine output was greater (all p < 0.05). These effects were absent in patients with blunt trauma. Platelet con- sumption was higher with HEX after either penetrating (p = 0.004) or blunt trauma (p = 0.045), but coagu- lation tests were unchanged. Conclusion: HEX is safe for initial resuscitation in young patients who required urgent operation after penetrating trauma, but there was no apparent effect after blunt trauma. A bolus of HEX reduced transfusion requirements without induc- ing coagulopathy or causing renal dysfunction, but a randomized controlled trial is necessary to eliminate the possibility of selection bias. KEYWORDS: hydroxyethyl starch, Hextend, trauma resus- citation, colloid, tactical combat casualty care, first re- sponder, field medic Level of Evidence: Level III, retrospective review. Introduction In 1994, Bickell et al 1 reported that aggressive prehospital crystalloid resuscitation was associated with higher mor- tality after penetrating torso trauma. In 1996, the Com- mittee on Tactical Combat Casualty Care (CoTCCC) incorporated these findings into their recommendations for limited fluid administration during prehospital care of Soldiers injured on the battlefield. 2 However, medics were advised to carry hydroxyethyl starch, instead of crystal- loid, because of its favorable weight/benefit ratio and sustained intravascular volume expansion. 3 The current CoTCCC fluid resuscitation guidelines (2009) for tactical field care to assess for hemorrhagic shock are being used throughout the Department of Defense. 4 Altered mental status (in the absence of head injury) and weak or absent peripheral pulses is regarded as best field indicators of shock. If not in shock, no intravenous (IV) fluids are nec- essary. If in shock, a 500ml IV bolus of Hextend ™ (HEX, 6% hetastarch in lactated electrolyte buffer, www.hospira .com) should be administered and repeated once after 30 min if shock persists. Anecdotal data resulting from these recommendations have been encouraging to date but the current status of prehospital trauma care documentation is not adequate to allow any definitive statement about the success of this strategy at present. The logistic advantage of not having to carry additional weight for resuscitation with crystalloid and the perceived hemostatic advantage and reduction in fluid overload syndromes from use of the hypotensive resuscitation strategy are also factors in continuing to recommend the current “hypotensive resus- citation with Hextend” fluid resuscitation technique. 4 Effect of Hetastarch Bolus in Trauma Patients Requiring Emergency Surgery Mark L Ryan, MD; Michael P Ogilvie, MD, MBA; Bruno MT Pereira, MD FCCM; Juan Carlos Gomez-Rodriguez, MD; Alan S Livingstone, MD, FACS; and Kenneth G Proctor, PhD Dewitt-Daughtry Family Department of Surgery, University of Miami Miller School of Medicine