HYPERTONIC SALINE RESUSCITATION DECREASES SUSCEPTIBILITY TO SEPSIS AFTER HEMORRHAGIC-SHOCK

Background: We hypothesized that improvements in cellular immune funct ion after hypertonic saline (HTS) resuscitation mill alter the outcome of sepsis after hemorrhage. Methods: To test this hypothesis, a two-h it model was used, Hemorrhage,vas induced in BALB/c mice by catheteriz ing the femoral artery and bleeding until a mean arterial pressure = 3 5 mm Hg was reached and maintained for 1 hour, Resuscitation was perfo rmed with HTS (NaCl 7.5%, 4 mL/kg) or lactated Ringer's (LR, twice the shed blood volume), plus the shed blood, Cecal Ligation and puncture (CLP) was performed 24 hours after hemorrhage. Mortality was assessed for 72 hours, comparing HTS (n = 14) and LR (n = 13) resuscitation, An other set of animals (n = 10 in each group at each time point) were ki lled at 2 and 24 hours after blood collection, Liver and blood were cu ltured for the presence of bacteria, and lung and liver samples were s cored on a scale from 0 (normal) to 4 (most severe) in a blind fashion by a pathologist. Results: Mortality 72 hours after CLP was 14.3% in BTS and 76.9% in LR treated animals (p < 0.002), At 24 hours after CLP , 44% of HTS, but 77% of LR treated animals had > 1,000 colony forming units/mL of blood, Positive liver cultures (> 100,000 colony forming units/g) also showed the same trend (HTS = 30%, LR = 60%), Autopsies r evealed a better containment of the infection (abscess formation) in t he HTS group, At 2 hours, lung scores were 1.2 +/- 0.25 and 2.6 +/- 0. 31 for HTS and LR, respectively (p < 0.002). At 24 hours, HTS treated animals showed marked improvement of lung injury, while the scores in the LR group remained high, A significant difference was also observed regarding liver injury, At 2 hours, scores were 0.4 +/- 0.22 and 2.3 +/- 0.16 for HTS and LR, respectively (p < 0.002), At 24 hours, HTS tr eated animals showed normal hepatic architecture, although mild injury was still observed in the LR group. Conclusion: HTS resuscitation lea ds to increased survival after hemorrhage and CLP, Marked improvements were observed in lung and liver injury compared with isotonic resusci tation, The better containment of the infection observed with BTS resu scitation corresponds to a marked decreased in bacteremia. HTS resusci tation stands as an alternative resuscitation regimen with immunomodul atory potential.