HYPERTONIC SALINE RESUSCITATION DETRIMENTALLY AFFECTS RENAL-FUNCTION AND SURVIVAL IN DEHYDRATED RATS

The purpose of our studies was to determine whether hypertonic (7.5%) saline (HTS) resuscitation is effective in the setting of dehydration. We compared the effects of HTS (5 cc/kg) to those of Ringer's lactate (RL; 45 cc/kg) on renal function, following resuscitation from hypovo lemia in hydrated (free access to food/water) vs. dehydrated (food/wat er restricted) rats (30-350 g). Renal failure was produced by hemorrha ge (15 cc/kg) plus renal artery occlusion (25 min) followed by fluid r esuscitation. Dehydration was confirmed by hemoconcentration and weigh t loss (8-10%). Renal function was assessed at 24 hr using C-14-inulin clearance (C(in)) measurements. In hydrated animals, the C(in) of RL- treated rats (625 +/- 54 mu/min/100 g; n = 12) was no different from t he C(in) in HTS-treated rats (517 +/- 48 mul/min/100 g; n = 13). Among dehydrated rats, C(in) in HTS-treated rats (n = 6) was significantly lower (P less-than-or-equal-to 0.05) than in RL-treated rats (n = 5) ( 117 +/- 33 mul/min/100 g vs. 542 +/- 84 mul/min/100 g, respectively). C(in) in dehydrated RL-treated rats was not significantly different fr om that in hydrated RL-treated rats. Furthermore, in dehydrated animal s, nine of nine resuscitated with RL survived, compared to six of 13 r esuscitated with HTS. All hydrated animals survived. In summary, renal failure was ameliorated by RL and worsened by HTS resuscitation in de hydrated rats. Furthermore, mortality was increased in dehydrated anim als resuscitated with HTS compared to RL.