Ballistic bacteria changes and drug sensitivity analysis after abdominal intestinal firearm pen-etrating wound in pig models exposed in simulated cold and high altitude environments
Objective To investigate the changes in body temperature,ballistic bacteriology,and drug sen-sitivity after abdominal intestinal firearm penetrating injuries in pig models in simulated cold and high altitude envi-ronments.Methods Twenty experimental pigs of 2-3 months old were randomly(random number table)divided into high altitude cold(HC)group and lowland normal temperature(LN)group,with 10 pigs in each group.All the experimental pigs were placed in an artificial experimental chamber in northwest China.For the HC group,the environment was set at 6000 m altitude(atmospheric pressure 47.33 kPa,air oxygen partial pressure 9.87 kPa)and 10 ℃ temperature,while the LN group at 800 m altitude(atmospheric pressure 89.87 kPa,air oxygen partial pressure 18.8 kPa)and 25 ℃ temperature.Pigs in each group stayed in the simulated environment for 48 h.After anesthesia,the pigs were suspended at the shooting range in a standing position,and the right lower abdomen was shot with a semi-automatic pistol.After successful modeling,the pigs were simply bandaged and returned to the la-boratory.The 1-cm deep tissue in the trajectory was sampled at 2,4,8,12,and 24 h for bacterial culture,identifica-tion,and drug sensitivity test.Results The body temperature of the HC group was significantly higher than that of the LN group at 2,4,and 8 h after injury(P＜0.001),which turned as slightly lower at 24 h,but the difference was insignificant(P＞0.05).The bacteria at the ballistic entry and exit of both groups proliferated significantly after in-jury,revealing significant differences compared with the previous time point(P＜0.05,P＜0.01 or P＜0.001),except for the ballistic exit of HC group at 12 and 24 h(P＞0.05 compared with the previous time point).At each time point,both groups showed significantly higher bacterial content at the ballistic exit than at the ballistic entrance(P＜0.01 or P＜0.001),moreover,the LN group revealed a much higher bacterial count at the ballistic entrance and exit at all time points(P＜0.001 compared with HC group),except for the 24-h ballistic entrance(P＞0.05).In the LN group,there was a high proportion of intestinal bacteria,represented by Escherichia coli,at the ballistic entrance and exit in the early stage after injury,in which all kinds of epidermal bacteria were mixed.No epidermal bacteria were detected at the entrance from 12 h and the exit from 4 h.In the HC group,there was a high proportion of intestinal bacteria,represented by Escherichia coli,Enterococcus faecium,and Enterococcus faecalis,at the ballistic entrance and exit in the early stage after injury,in which a small number of epidermal bacteria were mixed.No epidermal bacteria were detected at the entrance from 24 h and at the exit from 8 h.Among the 14 types of bacteria detected in the HC group,there were 7,9,1,11,2,6,9,and 3 types of bacteria with a resistance rate of＞50％to ampicillin,penicillin,imipenem,tetracycline,ceftazidime,ofloxacin,azithromycin,and gentamicin,respectively.Conclusion The cold en-vironment at a high altitude(6000 m)will decrease the reproduction rate of ballistic bacteria in abdominal firearm wounds,lessen the content and species of epidermal bacteria,and change the structure of intestinal flora.Early de-bridement and combined use of antibiotics are necessary for the intestinal penetrating injury in cold environment at high altitude.
NETL
NSTL
万方数据
维普
