CO_2气腹对急性腹膜炎大鼠细菌生长及移位的影响

Effects of CO_2 pneumoperitoneum on bacterial growth and translocation of acute peritonitis rats

目的研究不同气腹压力及作用时间对急性腹膜炎大鼠细菌生长繁殖和细菌移位的影响。方法于60只SD大鼠的腹腔内注射大肠杆菌标准混悬液,建立大鼠急性细菌性腹膜炎模型。本实验给予3类气腹压力:15 mm Hg(1 mm Hg=0.133 kPa)为高气腹压,5 mm Hg为低气腹压,空白对照大鼠未建立气腹;给予2类处理时间:1 h和3 h。将60只SD大鼠模型采用随机数字表法分为6组(每组10只),分别接受不同气腹压力和时间的组合处理。之后抽取腹水进行细菌定量培养和菌种分离鉴定,收集门静脉血进行血培养和内毒素含量测定。结果 (1)腹水细菌含量:析因设计的方差分析结果表明,不同气腹压力组的细菌含量不同(F=9.02,P=0.020),不同时间组的细菌含量也不同(F=8.47,P=0.003),且不同气腹压力组中时间的影响不同(F=8.07,P=0.020)。(2)血培养结果:6组大鼠都发生了细菌移位。3类气腹压力下1 h和3 h组之间的血培养阳性率类似(P>0.05),2个时点下高气腹组的血培养阳性率均高于未建立气腹组(P<0.05)。(3)门静脉血的内毒素含量:不同气腹压力组的内毒素含量不同(F=14.70,P<0.01),高气腹组的内毒素含量高于低气腹组(P=0.018)和未建立气腹组(P<0.01),且低气腹组的内毒素含量高于未建立气腹组(P=0.005);不同时间组的内毒素含量也不同(F=148.90,P<0.01),3 h组的门静脉血内毒素含量高于1 h组;不同气腹压力组中时间的影响的差异不大(F=0.14,P=0.874)。结论 CO_2气腹促进了急性腹膜炎大鼠的肠道内毒素和细菌移位,并且随压力和时间的增加而严重。

Objective To study the effects of different carbon dioxide pneumoperitoneum pressure and time on abdominal cavity infection bacteria of peritonitis in rats, including bacteria growth and bacterial translocation. Methods Sixty Sprague Dawley rats were injected with Eseherichia coli into the abdominal cavity to establish models of intra-abdominal infection. To give 3 types of pneumoperitoneum pressure for the experimental group： 15 mm Hg （1 mm Hg= 0.133 kPa） for high pressure group, 5 mm Hg for low pressure group, and blank control group for no-pneumoperi- toneum. To give 2 types of experimental period： 1 h and 3 h. These 60 Sprague Dawley rats were randomly divided intomoperi 6 groups by random number table. They were treated by different pneumoperitoneum pressure and time. All rats were killed at the end of the carbon-dioxide pneumo-peritoneum experiment. Peritoneal lavage fluids and portal vein blood were taken for microbiological examinations and culture. The endotoxin content in portal vein blood was detected too. Results （1） Bacteria content： bacteria counts of different pneumoperitoneum pressure groups were obviously different （F=9.02, P=-0.020）, bacteria counts of different experimental period groups were obviously different （F=8.47, P=0.003）,the effect of time was different in different pneumoperitoneum pressure groups （F=8.07, P=0.020）. （2） Bacterial translocation： Bacterial translocation occurred in all 6 groups. Blood culture positive rates were similar between 1 h group and 3 h group at 3 types of pneumoperitoneum pressure groups （P〉0.05）. The positive rate of blood culture in high pneumoperitoneum group was significantly higher compared with the no-pneumoperitoneum group （P〈0.05）. （3） The endotoxin content： the endotoxin content of different pneumoperitoneum pressure groups were obviously different （F=14.70, P〈0.01）, the endotoxin content in plasma increased obviously in high pressure group compared with low pressure group （P=0.018） and no-pneumoperitoneum group （P〈0.01）, the endotoxin content in plasma increased obviously in low pressure group compared with no-pneumoperitoneum group （P=0.005）. The endotoxin content of different experimental period groups were obviously different （F=148.90, P〈0.01）, the endotoxin content in plasma increased obviously in 3 h group compared with 1 h group. There were no significant difference in the effect of time with different pneumoperitoneum pressure groups （F=0.14, P=0.874）. Conclusion CO2pneumoperitoneum promoted intestinal bacterial endotoxin and bacterial translocation in peritonitis of rats, which increased with the pressure and time.