骨科术后血流感染患者的临床特征及危险因素分析

Clinical characteristics and risk factors of blood stream infections after orthopedic surgery

目的探讨骨科术后发生血流感染(blood stream infections,BSI)患者的临床特征及病原菌耐药情况,明确BSI发生危险因素,为临床诊疗提供参考。方法回顾分析2017年1月—2019年12月6 348例骨科住院手术患者的临床资料,男3 598例,女2 750例;年龄18~98岁,平均66岁。收集患者资料,采取单因素及logistic回归分析BSI的危险因素,总结BSI病原菌分布、药敏试验结果以及不同年份骨科术后患者BSI发生情况、常见BSI继发感染部位。结果 6 348例患者中骨科术后106例(1.67%)发生BSI,其中继发感染71例(66.98%)。术后BSI患者病死率为1.89%,与非术后BSI患者(0.24%)相比,差异有统计学意义(χ^(2)=5.313,P=0.021)。2017、2018、2019年BSI发病率分别为1.18%、1.53%、2.17%,呈逐年升高趋势(趋势χ^(2)=6.610,P=0.037)。统计分析表明,创伤、住院时间≥14 d、急诊手术以及术后白细胞计数<4×109/L、血红蛋白≤90 g/L、白蛋白≤30 g/L、留置导尿管时间>24 h、使用深静脉导管、合并其他部位感染是骨科术后BSI发生的独立危险因素(P<0.05)。血液培养示革兰阳性菌56株(52.83%)、革兰阴性菌47株(44.34%)、真菌3株(2.83%),前3位病原菌依次为凝固酶阴性葡萄球菌36株(33.96%)、大肠埃希菌16株(15.09%)、金黄色葡萄球菌15株(14.15%)。大肠埃希菌、肺炎克雷伯菌中产超广谱β-内酰胺酶菌株检出率分别为56.25%(9/16)、44.44%(4/9),金黄色葡萄球菌、凝固酶阴性葡萄球菌中耐甲氧西林菌株检出率分别为46.67%(7/15)、72.22%(26/36)。结论骨科患者术后BSI由多因素所致,临床上应针对相关危险因素采取预防性措施,加强围术期风险评估;葡萄球菌、大肠埃希菌是骨科术后BSI中最常见致病菌,感染率及耐药菌均呈逐年上升趋势,因此需加强耐药性监测。

Objective To analyze the clinical characteristics, risk factors, and drug resistance of pathogenic bacteria in patients with blood stream infections(BSI) after orthopedic surgery, so as to provide reference and basis for clinical diagnosis and treatment. Methods A retrospective analysis was made on the clinical data of 6 348 orthopedic patients admitted for surgery between January 2017 and December 2019. There were 3 598 males and 2 750 females. Their age ranged from 18 to 98 years, with an average of 66 years. The data of patients were collected, and the risk factors of BSI were analyzed by univariate analysis and logistic regression analysis. The distribution of BSI pathogenic bacteria, the results of drug sensitivity test, the incidence of BSI in patients after orthopedic surgery in different years, and the common sites of BSI secondary infection were summarized. Results BSI occurred in 106(1.67%) of 6 348 patients after orthopedic surgery. There were 71 cases(66.98%) of secondary infection. The mortality of postoperative BSI patients was 1.89%,and the difference was significant when compared with that of non-postoperative BSI patients(0.24%)(χ^(2)=5.313,P=0.021). The incidences of BSI in 2017, 2018, and 2019 were 1.18%, 1.53%, and 2.17%, respectively, showing an increasing trend year by year(trend χ^(2)=6.610, P=0.037). Statistical analysis showed that the independent risk factors for BSI after orthopedic surgery(P<0.05) included the trauma, length of hospital stay≥14 days, emergency surgery,postoperative leukocyte counting<4×109/L, level of hemoglobin≤90 g/L, albumin≤30 g/L, the time of indwelling ureter>24 hours, use of deep vein catheter insertion, and merging other site infection. Blood culture showed 56 strains(52.83%) of Gram-positive bacteria, 47 strains(44.34%) of Gram-negative bacteria, and 3 strains(2.83%) of fungi. The top three pathogenic bacteria were coagulase negative Staphylococci(CNS;36 strains, 33.96%), Escherichia coli(16 strains, 15.09%),and Staphylococcus aureus(15 strains, 14.15%). The detection rates of extended-spectum β-lactamases producing strains of Escherichia coli and Klebsiella pneumoniae were 56.25%(9/16) and 44.44%(4/9), respectively. The detection rates of methicillin-resistant strains in Staphylococcus aureus and CNS were 46.67%(7/15) and 72.22%(26/36), respectively.Conclusion Postoperative BSI in orthopedic patients is caused by multiple factors. Preventive measures should be taken according to related risk factors and perioperative risk assessment should be strengthened. Staphylococcus and Escherichia coli are the most common pathogenic bacteria in BSI after orthopedic surgery. The infection rate and drug-resistant bacteria are increasing year by year. Therefore, drug resistance monitoring should be strengthened.