LACTATED RINGER SOLUTION VERSUS 3-PERCENT ALBUMIN FOR RESUSCITATION OF A LETHAL INTESTINAL ISCHEMIC SHOCK IN RATS

Previously, we determined that a colloid concentration of about 3% was optimal for resuscitation of lethal ischemic intestinal shock model in rats. Maximal volumes of lactated Ringer's solutioin (RL) alone only expanded plasma volume (PV) to 80% of preshock level, while increasing volumes of 3% albumin (ALB) in RL linearly expanded PV up to twice the preshock level. This study compares the effect of RL and ALB on survival and PV in 175 rats. The solutions were given in volumes to induce suboptimal PV expansion, requiring 10 and 44 ml/100 g body weight (bwt) of ALB and RL, respectively. ALB (20 ml/100 g bwt) was then given to induce a PV above the preshock level. Shock was induced by exteriorizing the small intestine and occlusing the superior mesenteric vessels for 75 min. PV was estimated using Hct. Therefore, infusions were given continuously for 6 h in volumes that maintained a stable Hct. Untreated shocked animals developed hemoconcentration (Hct 58%) corresponding to a PV of 56% of preshock level, with 2% (1/53) of the animals surviving 24 h. The maximum effect of RL (44 ml/100 g bwt) was to expand PV to 80% of preshock level, with a 32% 24-h survival rate. Only 23% as much ALB (10 mg/100 g bwt) was needed to induce similar blood volume expansion with 24-h survival rate of 46%. When the larger volume of ALB (20 mg/100 g bwt) was used, PV expanded to 115% of preshock level, and 24-h survival to 76%, greater than that achieved with either the smaller volume of ALB or RL alone (p < .01). We conclude that intravascular volume expansion is a major factor in postshock survival. RL alone, even when given in the volume previously shown to produce maximal PV expansion, is inadequate for resuscitation in a severe shock model. ALB 3% in RL is able to expand PV above preshock levels and improve survival significantly more than RL alone.