Hypovolemic Shock Resuscitation Leslie Kobayashi, MD, Todd W. Costantini, MD, Raul Coimbra, MD, PhD* DEFINITION OF SHOCK Shock is the inability of the body to maintain adequate end-organ perfusion. Hypovo- lemic shock caused by blood loss is frequently encountered after severe injury. 1 Hemorrhagic shock should be assumed to be the cause of hypotension in all trauma patients until proven otherwise. Shock is a strong predictor of mortality, and is a major risk factor for the development of complications, particularly multiple organ dysfunc- tion. Hence, it is important to rapidly identify patients in shock so that appropriate resuscitation can begin as soon as possible. Indicators of shock include elevated heart rate, low blood pressure, narrowed pulse pressure, decreased capillary refill, cool clammy extremities, pale skin, increased skin turgor, low urine output, dry mucus membranes, and alterations in mental status. In certain patients, clinicians must keep in mind that significant blood loss can occur with little effect on vital signs. In particular, pediatric patients have excellent cardiovascular reserve, preventing a drop in blood pressure even in the presence of large volume blood loss. Conversely, elderly patients are often unable to mount a tachycardic response to hemorrhage, or may be on medi- cations that blunt or prohibit normal response to blood loss. Elderly patients often also The authors have nothing to disclose. Division of Trauma, Surgical Critical Care, and Burns, Department of Surgery, University of California San Diego School of Medicine, 200 West Arbor Drive ##8896, San Diego, CA 92103, USA * Corresponding author. E-mail address: rcoimbra@ucsd.edu KEYWORDS  Hemorrhagic shock  Septic shock  Massive transfusion  Blood loss  Crystalloid KEY POINTS  Hypovolemic shock is defined as inadequate tissue perfusion caused by decreased intra- vascular circulating volume.  Early transfusion with a 1:1:1 ratio of fresh frozen plasma to platelets to packed red blood cells has been associated with improved outcomes in patients requiring massive transfusion.  Monitoring coagulation function with thromboelastography or rotational thromboelastom- etry may be superior to conventional coagulation assays in patients with hypovolemic shock. Surg Clin N Am 92 (2012) 1403–1423 http://dx.doi.org/10.1016/j.suc.2012.08.006 surgical.theclinics.com 0039-6109/12/$ – see front matter Ó 2012 Elsevier Inc. All rights reserved.