Influence of hypertonic saline on bacterial translocation in controlled hemorrhagic shock.

ABSTRACT

Translocation of enteric bacteria has been described in rats following hemorrhagic shock (HS). The aim of the present study was to evaluate the effect of hypertonic saline (HTS) on bacterial translocation (BT) in the setting of controlled HS in rats. The study included 2 arms. Arm I was a qualitative assessment of translocation. Sixty-eight anesthetized animals were studied. The rats were divided into 5 groups. Group I (n = 10) was sham shock controls. In groups II-V, HS was induced by arterial bleeding to mean arterial pressure (MAP) of 35-45 mmHg, which was maintained for 30 min. The animals were then allocated into 4 groups group II (n = 19) untreated HS; group III (n = 13) normal saline (NS) treated; group IV (n = 13) HTS-treated; and group V (n = 13) HTS and blood treated. Mesenteric lymph nodes, liver, spleen, portal, and systemic blood were sent for culture after 24 h. Translocation occurred if enteric bacteria were cultured from at least one site. Arm II was a quantitative assessment of translocation. Two groups were studied untreated HS (n = 7) and HTS treated (n = 6). In the qualitative arm, the 24-h mortality in untreated rats (group II) was 31.5% compared to 5.1% in treated animals (groups II-V) (P = 0.01). No BT was detected in control animals (group I). BT after HS was not different between groups II, III, and IV (92.3%, 91.6%, and 100%, respectively). Group V showed fewer translocations than groups II-IV, a difference that was especially significant compared with group IV (P = 0.039). However, BT to distant sites (systemic blood and spleen) was significantly lower in group V than in groups II-IV (P < 0.05). In the quantitative arm, the mortality rate was 16.7% in the untreated group. Although no qualitative significant difference in the translocation rate was found between the two groups (67% in untreated animals vs. 50% in HTS treated), there was significant quantitative difference in HTS-treated group a significantly lesser bacteria translocated than in untreated animals (0.4 x 10(5) cfu/g vs. 4.2 x 10(5) cfu/g, respectively [P = 0.001]). We concluded that whereas assessed qualitatively, in this model of severe HS in rats, the hemorrhagic insult itself resulted in BT in most animals and treatment with NS, HTS, and blood resulted in reduced early mortality but did not alter significantly the translocation rate. Only the combination of HTS and blood resulted in reduced BT to distant sites. However, quantitative assessment showed that HTS significantly reduced the number of translocating bacteria.