Once access is secured, resuscitation should begin with immediate infusion of warmed fluids to restore circulating blood volume replacing losses from hemorrhage.Classical resuscitation strategies for hemorrhagic shock, taught by Advanced Trauma Life Support (ATLS), suggest bolus infusion of 2 L of warmed crystalloid if hypotension is present, followed by replacement of ongoing fluid or blood losses with isotonic fluids in a 3:1 ratio to accommodate losses into the interstitial space