NICU新生儿败血症的临床特点和病原菌分析

Analyses of clinical feature and pathogen for septicemia in NICU

目的：探讨NICU新生儿败血症的临床特点、病原菌分布和药物敏感状况。方法：回顾性分析中山大学附属第一医院NICU1998年1月2007年12月确诊的34例败血症新生儿的临床资料。结果：34例新生儿均有程度不等的少吃、少哭、少动和体重不长,发热20例,休克10例,黄疸加重或延长9例,呼吸暂停7例,喂养不耐受6例,合并局部感染10例。动态血象显示WBC〈5×109/L（41.18%）比WBC〉20×109/L（8.82%）更普遍（P〈0.05）,起病时WBC和血小板计数均显著下降（P〈0.05）;CRP〉8 mg/L17例（17/24,70.83%）,CRP≤8 mg/L 7例（7/24,29.17%）。7例（29.17%）C-反应蛋白（CRP）于起病后1224 h才呈现异常升高。共分离细菌36株,主要有凝固酶阴性葡萄球菌14株（CNS,38.89%）、肺炎克雷伯菌12株（33.33%）、阴沟肠杆菌3株（8.33%）、肠球菌2株（5.56%）;100%CNS为耐甲氧西林菌株（MRCNS）,66.7%肺炎克雷伯菌为产超广谱β-内酰胺酶（ESBLs）菌株。药敏显示MRCNS和ESBLs均多重耐药,但分别对万古霉素和亚胺培南全部敏感。结论：CNS和肺炎克雷伯菌,特别是MRCNS和ESBLs是NICU败血症的两大主要致病菌,其临床症状呈多样化和非特异性,动态血象和CRP变化可协助早期诊断;减少侵入性操作、严格消毒隔离制度、重视医护人员手卫生、严格掌握三代头孢菌素和预防性抗生素的应用指征可减少MRCNS和ESBLs菌株的感染机会;万古霉素、亚胺培南可分别作为MRCNS和ESBLs败血症的首选抗生素。

Objective：To investigate the clinical features,pathogenic distribution and drug susceptibility for septicemia in neonatal intensive care unit（NICU）.Methods：The clinical data were retrospectively analyzed among 34 newborns with bacterial septicemia confirmed by blood culture admitted to the NICU from Jan 1998 to Dec 2007.Results：Of the total 34 cases,almost all the cases presented with decreased appetite,feeble cry,feeble activity and poor increase in weight,twenty cases（58.58%） had fever,ten cases（29.14%） had shock,nine cases（26.47%） had progressive or prolong jaundice,seven cases（20.59%） had apnea,six cases（17.65%） had feeding intolerance,and ten cases（29.14%） had local infections.In continuous blood routine,WBC lower than 5×109/L was more common than WBC higher than 20×109/L,the counts of WBC and platelet were all decreased significantly at the episode point（P〈0.05）.CRP were tested in 24 cases,of which showed higher than 8mg/l in seventeen cases（70.83%） and a late rise in seven cases（29.17%） at 12 to 24 hours after the episode.36 strains were isolated from the 34 septic neonates,of which 14 strains were coagulate-negative staphylococcus（CNS,38.89%）,12 strains were Klebsiela pneumonia（33.33%）,3 strains were E.cloacae（8.33%） and 2 strains（5.56%） were enterococcus.100% of CNS were methicillin-resistant strains（MRCNS） and 66.7% of Klebsiela pneumonia were extended-spectrum β-lactamase strains（ESBLs）.The results of drug allergic test showed that MRCNS and ESBLs were all multi-drug resistance,but were sensitive to vancomycin and imipenem respectively.Conclusion：CNS and Klebsiela pneumonia,especially MRCNS and ESBLs,show multi-drug resistance,are the two major pathogens for septicemia in NICU.The clinical manifestations are diverse and no special,continuous blood routine and CRP test are beneficial to early diagnosis.Sterilization and isolation measures,hand hygiene of the cares,control use of third generation cephalothin and preventive antibiotic can reduce the number of MRCNS and ESBLs.Vancomycin and imipenem are the first choice to MRCNS and ESBLs respectively.