The role of antibiotic prophylaxis with sodium ceftriaxone to prevent bacterial translocation associated with hypovolemic shock: an experimental study in rats.

One of the measures adopted to reduce or prevent intestinal bacterial translocation (BT) in patients who are in hemorrhagic shock consists of prophylactic antibiotics. This study attempted to assess the effectiveness of administering systemic antibiotic to suppress BT in rats submitted to hemorrhagic shock. Sixty-eight male Wistar rats were divided into two experiments. In experiment 1 (n = 28), the animals were randomly divided into three groups: group I (n = 7), sham operation; group II (n = 11), constituted by animals that were submitted to hemorrhagic shock by removing 40% of the volemia, and were resuscitated after 40 min of sustained shock, replacing the previously removed blood; and group III (n = 10), animals that, besides hemorrhagic shock and volemic replacement, received 50 mg/kg of sodium ceftriaxone intravenous 1 min after blood readministration. Mesenteric lymph nodes (MLN) for culture tests and segments of the small bowel were removed for histopathological studies 1 day after the operation in the three groups. In experiment 2, the same procedures were performed, except the laparotomy for removing MLN and segments of jejunal and ileal bowel, but the animals were followed during 7 days, in order to evaluate the mortality rate. In the control group (group I), the bacteriological assessment of the MLN was negative in all cases. Only 40% of the animals treated with antibiotics after hypovolemic shock (group III) presented positive bacteriological exams of the MLN, and this rate was 90% in the group of animals that did not receive this substance (group II) (p < .05). Escherichia coli was the bacteria identified most frequently in culture tests (92.8%). The villosities atrophy and inflammatory infiltrate of the lamina propria were the most common histological changes in the bowel, although the intensity was similar in groups II and III (p > .05), but more intense that in group I (p < .05). The mortality rates in groups I, II, and III 7 days after hypovolemic shock were 0%, 20%, and 20%, respectively. Prophylactic antibiotics significantly reduced the presence of bacteria in the MLN in situations of hypovolemic shock, in rats. This was probably related to a lower BT. However, this aspect did not modify the mortality rate of the animals. Also, the possibility that BT may not have a significant influence in this outcome should be considered.