心脏外科术后深部胸骨切口感染的临床特点及病原菌耐药性分析

Clinical characteristics and pathogenic drug resistance analysis of deep sternal wound infection after cardiac surgery

目的观察心脏外科术后深部胸骨切口感染(deep sternal wound infection,DSWI)的临床特点,并进行病原菌耐药性分析。方法回顾性分析2012-2014年中国医科大学航空总医院心胸外科84例采用肌瓣修复重建手术治疗的心脏手术后DSWI患者(年龄≥18岁)的临床资料,并对DSWI患者的病原菌分布及其耐药性进行分析。结果 1Ⅱ型DSWI最多见(49/84,58.3%),Ⅰ型有17例(20.2%),Ⅲ型有18例(21.4%)。Ⅰ型和Ⅱ型DSWI患者具有典型的临床表现如发热、伤口裂开和/或脓性分泌物、手术区域自发性疼痛、血象升高等。Ⅰ型DSWI患者更易合并低蛋白血症(P<0.01),早期X线或CT扫描可发现纵隔增宽(P<0.01)。部分Ⅲ型DSWI患者仅表现为手术区域局部症状。237例(44.0%)患者有明确病原学诊断,最常见的病原菌为革兰阴性杆菌(Gram-negative bacilli,GNB;54.8%),其次为甲氧西林敏感金黄色葡萄球菌(23.7%);GNB中最常见的是铜绿假单胞菌,其次是鲍曼不动杆菌和阴沟肠杆菌。3铜绿假单胞菌对亚胺培南和美罗培南的耐药率均为18.2%,鲍曼不动杆菌对临床常用抗菌药物耐药率均在70%以上,阴沟肠杆菌对大部分常用抗菌药物未表现耐药性。金黄色葡萄球菌和表皮葡萄球菌对青霉素G的耐药率均为100%,对克林霉素的耐药率均在80%以上,但对替加环素、万古霉素和利奈唑胺未表现出耐药。结论 DSWI多发生在心脏术后1个月内,其中Ⅱ型DSWI最多见,且不同类型的DSWI主要临床表现不同;DSWI常见的病原菌为革兰阴性杆菌及金黄色葡萄球菌,且对常用抗菌药物的耐药率高。

Objective To investigate the clinical characteristics and drug resistance of deep sternal wound infection （DSWI） after cardiac surgery. Methods From January 2012 to December 2014, 84 patients （≥18 years old） with secondary DSWI after cardiac surgery underwent the pectoralis major muscle flap transposition in our department, and the clinical data were retrospectively analyzed. The distribution of pathogens in the patients with DSWI and the drug resistance of pathogens were analyzed. Results Among these 84 patients, 34 （40.5%） were females and the mean age was 54.6 ± 14.8. There were 49 （58.3%） patients with type Ⅱ DSWI, 17 （20.2%） patients with type I DSWI and 18 （21.4%） patients with type Ⅲ DSWI. Both type Ⅰ and type Ⅱ DSWI patients showed typical clinical manifestations, such as fever, purulent exudate with wound dehiscence, sternal instability, and spontaneous pain in the surgical area. But type I DSWI patients were more likely to be associated with hypoproteinemia （P 〈 0.01 ）, and early chest X- ray or computerized tomography （CT） showed mediastinal widening （P 〈 0.01 ）. Some patients with type Ⅱ DSWI showed only local symptoms at the surgical area. Microbiological diagnosis was available in 37 patients. The pathogens that were most commonly isolated in the patients with DSWI were Gram-negative bacilli （ GNB, 54.8% ）, followed by methicillin-sensitive Staphylococcus aureus （23.7%）. The most common pathogens m GNB were Pseudomonas aeruginosa, followed by Acinetobacter baumannii and Enterobacter cloacae. Pseudomonas aeruginosa resistant to imipenem and meropenem was 18. 2%. Acinetobacter baumannii resistance was very serious, and its resistance to the clinical commonly used antibiotics was more than 70%. Enterobacter cloacae did not show the resistance to the most commonly used antibiotics. Staphylococcus aureus and Staphylococcus epidermidis showed 100% resistance to penicillin G, more than 80% resistance to clindamycin, and no resistance to tigecycline, vancomycin and linezolid. Conclusion DSWI often occurs within 1 month after cardiac surgery. Type Ⅱ DSWI is the most common, and different types of DSWI exhibit different clinical features. The most common pathogens are GNB and Staphylococcus aureus, which have high resistance to commonly used antibiotics.