Guitard P-G, Abriou-Guérin C, Royon V, Frébourg N, Pons J-L, Aimé I, Guéné B, Dureuil B, Veber B
Département d'anesthésie-réanimation, CHU Charles-Nicolle, 1, rue de Germont, 76031 Rouen cedex, France.
Ann Fr Anesth Reanim. 2011 Jul-Aug;30(7-8):546-52. doi: 10.1016/j.annfar.2011.03.011. Epub 2011 May 23.
To create a reliable and reproducible model of pulmonary contusion (PC) in rats in order to evaluate the influence of PC on bacterial lung proliferation.
Experimental.
Male albino CD rats.
Animals were anesthetized and a PC was performed using a spring-loaded metal bar. The existence of an isolated right PC was confirmed by macroscopic, histological and radiological analysis. This model was used to compare four randomized groups of animals. These were either injured or only anesthetized and inoculated with a pneumococcal solution concentrated in 2 or 4 log(CFU/mL). The animals' lungs were collected for microbiological culture at 24 hours. The bacterial count evolution per gram of lung was the primary endpoint.
Twelve rats were needed to validate the model, 84 to determine the morbidity and mortality and its reproducibility and 66 to assess the intra-pulmonary bacterial proliferation. The PC obtained was unilateral and isolated in 95% of cases. Mortality rate was 43%. For a low initial inoculum concentration (2 log [CFU/mL]), there is bacterial overgrowth in the PC group versus the no-PC group (P=0.0017). This difference was not found when the inoculum was more concentrated.
This experimental model is reliable and reproducible. The initially high mortality seems to decrease with the experience of operators. The CP significantly increases intra-pulmonary bacterial proliferation when the inoculation is low. A high inoculum neutralizes the effect of CP. These results suggest that enhanced prevention of micro-inhalation could be beneficial in cases of CP.
建立一种可靠且可重复的大鼠肺挫伤（PC）模型，以评估肺挫伤对肺部细菌增殖的影响。
实验性研究。
雄性白化病CD大鼠。
将动物麻醉后，使用弹簧加载金属棒造成肺挫伤。通过宏观、组织学和放射学分析确认孤立性右肺挫伤的存在。该模型用于比较四组随机分组的动物。这些动物要么受伤，要么仅麻醉并接种浓度为2或4 log（CFU/mL）的肺炎球菌溶液。在24小时时收集动物的肺进行微生物培养。每克肺组织的细菌计数变化是主要终点。
验证该模型需要12只大鼠，确定发病率、死亡率及其可重复性需要84只大鼠，评估肺内细菌增殖需要66只大鼠。所获得的肺挫伤在95%的病例中是单侧且孤立的。死亡率为43%。对于低初始接种浓度（2 log [CFU/mL]），肺挫伤组与无肺挫伤组相比存在细菌过度生长（P = 0.0017）。当接种浓度更高时未发现这种差异。
该实验模型可靠且可重复。最初较高的死亡率似乎随着操作者经验的增加而降低。当接种量较低时，肺挫伤显著增加肺内细菌增殖。高接种量可抵消肺挫伤的影响。这些结果表明，在肺挫伤病例中加强预防微吸入可能有益。
