Intraoperative life-threatening hemorrhage must be controlled with teamwork between the surgeons and anesthesiologist. With the realization that ongoing hemorrhage after injury leads to derangements in the body’s ability to maintain hemostasis and homeostasis, trauma surgeons have evolved the concept of “damage control surgery,” which proposes that definitive repair or fixation can in many cases be delayed until the patient has been resuscitated to the goals of appropriate blood composition, normalization of acid-base status, and normothermia. Among the anesthesia provider’s roles in the care of the massively bleeding patient is to implement the accompanying concept of “damage control anesthesia” and help the nontrauma surgical team recognize that the magnitude of hemorrhage may require altering the surgical goals and plan.

At its most basic, damage control anesthesia seeks to mitigate the effects of the lethal triad of acidosis, hypothermia, and coagulopathy. Hypothermia results from infusion of intravenous (IV) fluids, and convective and conductive heat losses. Coagulopathy, resulting from depletion of clotting factors by ongoing hemorrhage, is exacerbated by hypothermia and acidosis, leading to further bleeding and hypotension. Resulting poor perfusion furthers acidosis, and the classic “downward spiral” ensues.

Dutton identifies the essentials of damage control anesthesia as: (a) control of the airway and ventilation, (b) control of bleeding, (c) preservation of homeostasis, and (d) analgesia and sedation. Indeed, these are similar to routine anesthetic care, but there are a few key differences.

Fluid resuscitation needs to focus not only on replacing circulating volume, but also on maintaining the appropriate blood composition in terms of oxygen-carrying capacity, clotting potential, and chemistry. This requires large-bore IV access, usually considered to be a minimum of two 18-gauge or larger IVs, and frequent laboratory analysis of blood. The desired end points or goals of volume resuscitation are currently being re-examined in light of recent evidence suggesting that hypotensive resuscitation may be beneficial. Strategies for hypotensive resuscitation include delayed resuscitation, in
which fluid resuscitation is delayed until after control of the site of bleeding, and permissive hypotension, in which resuscitation is continuous but with a goal of a subnormal blood pressure. In a landmark study, Bickell et al. demonstrated a survival advantage to limited volume replacement until the time of operative intervention in the setting of penetrating torso trauma. A proposed mechanism for the advantage of hypotensive resuscitation is that, by limiting fluid volume, regional vasoconstriction and lower blood pressure allow the adhesion of the fragile platelet-fibrin clot. In addition, the composition of the blood, including coagulation factors, is minimally diluted. Limited infusion of fluids reduces the development of hypothermia.