Investigation And Analysis Of Open Fracture Intraoperative And Postoperative Bacterial Culture

Objective: With the widespread use of highway patrol vehicle, openfractures is becoming inceasingly frequent and serious, consequently, makingthe treatment become more and more challenging. The foremost treatment ofopen fracture is to prevent the bone and soft tissue from being infected.Infection can result in nonunion and loss of limb function. Germiculture anddrug sensitivity assessment of open fracture wound surface is a necessary wayto determine the type of bacteria and guide antibiotic selection. If the doctorcan predict the kind of pathogens before the infection occurs, sensitiveantibiotics will be selected and administered in advance to reduce or avoid theoccurrence of infections. Could Bacterial culture in the debridement of openfracture helps to identify species of bacteria in the subsequent infection anddirect clinical medication？For this reason, we made a comparative analysisof61cases who received emergency treatment in debridement of openfracture and the outcomes of their bacterial culture and drug susceptibilityafter infection, and it may provide some implications for clinical work.Methods:1Case collection61cases who received emergency treatment indebridement of open fracture and infected after operation were collected fromOctober,2010to December,2011in our hospital, including43males and18females. Among them, traffic accident accounted for40cases (66%) of thefractures, a crashing object for11cases (18%), machine twist injury for5cases (8%), fall for3cases (5%), and falling for2cases (3%). Patients agedfrom4to72years old, averaging37.3years. Patients were admitted from1to14hours after the injury with an average of5.30hours.Classification criteria of open fractures according to Gustilo: type I,0;type II,8cases (13.1%), type IIIa,16cases (26.2%), IIIb24cases (39.4%), type IIIc,13cases (21.3%).2Specimen collection cephalosporin antibiotic of first or second generationwas used to all the patients preoperatively. specimens were obtained duringdebridement and then were sent to culture the bacteria, the sample wasselected in the deep part where the tissue has been contused or necrotic, andthe fixed pattern depends on the type of open fracture and degree of pollution.The assessment of wound infection is determined by the swelling of thesurrounding wounds and purulent discharge. The bacterial culture and drugsensitive test are carried out in strict accordance with the principles of asepticoperation, and were compared with bacterial culture results in the operation.3Bacterial culture and drug susceptibility assessment The samples weresent to the hospital clinical laboratory for routine bacterial culture, which isseparate and cultivated in strict accordance with the "National ClinicalLaboratory Procedures". France bioMérieux Automated Microbiology Systemwas used for strains identification. K-B paper diffusion method was appliedfor antibacterial drug sensitivity experiment, and the results were interpretedaccording to the required standards of the United States Committee on clinicallaboratory standards (NCCLS). The lab environment quality was controlled bythe standard strains of Staphylococcus aureus A TCC25923, Escherichia coliA TCC25922, Pseudomonas aeruginosa A TCC27853.Results: Of the61patients, bacterium was separated and cultivated in14cases, and its positive rate is23%. Among them, one kind of bacteria wasisolated from12cases (85.7%), two from2cases (14.3%), and a total of eightof16types were isolated. The Gram-negative bacteria accounted for68.8%,which is most common in Pseudomonas aeruginosa; while Gram-positivebacteria accounted for31.3%, and the most common one is Staphylococcusaureus. Multidrug-resistant bacteria was not found and the most bacteriacultivated are sensitive to cephalosporin, carbapenem, Aminoglycosides andQuinolones antibiotics.Of the61patients after wound infection,69pathogenic bacteria wasseparated, including one kind of bacteria was isolated from53cases (86.9%), eight from2cases (13.1%), and a total of11types of species were isolated.The Gram-negative bacteria accounted for91.3%, which is most common inAcinetobacter baumannii of34(49.3%) among all the bacteria. Moreover, thePseudomonas aeruginosa accounted for15(21.7%), while Escherichia colirated7.2%. Gram-positive bacteria accounted for6(8.7%), and the mostcommon one is Staphylococcus aureus4(5.8%). It is worth noting that42outof69bacterias are multidrug resistant, which includes Acinetobacterbaumannii34(81%), MRSA4(9.6%), Escherichia coli of ESBLs2(4.8%),Pseudomonas aeruginosa1(2.3%)and bacterium vulgare1(2.3%). Thesemultidrug-resistant bacteria showed extensive resistance to most of theantibiotics like Penicillins, Cephalosporins, Aminoglycosides and so on.However, funtuntely, we found that third generation cephalosporin withenzyme inhibitors, such as Cefoperazone and sulbactam, Levofloxacin,presented lower resistance rate to multidrug-resistant Acinetobacter baumanniiand Escherichia coli of ESBLs, and most of them between sensitive andintermediate. In addition, the resistance rate of MRSA to vancomycin andLinezolid is zero. As well as the Escherichia coli to carbapenem andSulbactam with Cefoperazone.Conclusions: The bacteria of the debridement can rarely be cultivated,and culture results predictive value of postoperative bacterial infection is low.The postoperative infection of open fracture are most likely to be theGram-negative bacterial infections, resulting from Acinetobacter baumanniignerally of which the resistant organism rates highly. Nosoco-mial infectionmust be controlled rigourously, germiculture and drug sensitive test aresupposed to be done as soon as possible and suitable antibiotics should beselected accordingly, only in this way, can we manage to keep the infectionunder control.