11年间极低出生体重儿医院感染的临床分析

Analysis of very low birth weight infants with nosocomial infection within eleven years

目的 探讨新生儿重症监护病房极低出生体重儿（very low birth weight infant,VLBWI）医院感染的流行病学情况、临床特征、危险因素、结局及预防策略.方法 回顾性分析1998年1月1日至2008年12月31日11年间北京大学第三医院新生儿重症监护病房收治的出生体重＜1500 g且住院时间＞48 h的VLBWI的相关资料,按照是否发生医院感染,分为感染组和末感染组.应用SPSS 12.0统计软件先进行单因素分析,选择其中差异有统计学意义的因素再进行多因素Logistic回归分析,探讨VLBWI医院感染发生的危险因素,并总结其临床特征和结局,提出相关防治策略.结果 11年间收治符合本研究纳入标准的VLBWI共158例,平均出生体重（1263.8±155.5）g,平均胎龄（30.4±2.1）周,发生医院感染者56例,感染发生率为35.4%,与住院时间相关的医院感染发生率为14.4‰.共发生医院感染70例次,其中肺炎40例次（57.1%）、败血症22例次（31.4%）、鹅口疮4例次（5.8%）、结膜炎1例次（1.4%）、上呼吸道感染1例次（1.4%）、部位不明2例次（2.9%）.121份培养标本中共检出细菌41株,G杆菌23株,占56.1%;G-球菌19株,占46.3%.56例医院感染者平均住院时间长于未感染组,分别为（43.7±15.5）d和（26.3±14.4）d（t=-7.058,P＜0.01）;感染组与未感染组病死率分别为3.6%（2/56）和3.9%（4/102）,差异无统计学意义（x2=0.012,P＞0.05）.Logistic回归分析显示机械通气（OR=3.388,95%CI：1.656～6.932,P=0.001）和肠外营养（OR=7.054,95%CI：2.005～24.813,P=0.002）是发生医院感染的独立危险因素.结论 VLBWI医院感染发生率较高,要尽量避免使用机械通气和肠外营养,以尽可能减少医院感染的发生.

Objective To investigate the epidemiological and clinical characteristics, risk factors, outcome and prevention strategy of very low birth weight infant （VLBWI） with nosocomial infection in neonatal intensive care unit （NICU）. Methods The VLBWIs whose birth weight were less than 1500 g and hospital stays were more than 48 hours in NICU of Peking University Third Hospital from January 1, 1998 to December 31, 2008 were selected in this study. They were divided into nosocomial infection group and non-infection group. The clinical features and outcomes of nosocomial infection were summarized and the risk factors of which were analyzed with Logistic regression. Results There were 158 VLBWIs who fit for the criteria of our study during the eleven years, the mean birth weight was （1263.8± 155.5） g and the mean gestational age was （30.4±2.1） weeks. There were 70 times and 56 cases suffered from nosocomial infections. The incidence of nosocomial infection was 35.4% and hospital stay-related incidence was 14.4‰. Among 70 times of infections, there were 40（57.1%） pneumonia, 22（31.4%） septicemia, 4（5.8%） thrush, 1（1.4%）conjunctivitis, 1 （ 1.4%） upper respiratory tract infection and 2 （2.9%） unknown site infections.Forty-one strains of bacteria were isolated from 121 specimens, among which gram-negative bacillus accounted for 56.1% and gram-positive cocci for 46.3%. The duration of hospital stay of VLBWIs with nosocomial infection was significantly longer than that without [（43.7±15.5） d vs （26.3±14.4） d] （t = -7.058, P〈0.01）. The fatality rate of VLBWIs with and without nosocomial infection was 3.6% （2/56） and 3.9% （4/102）, and there was no significant difference （x2 = 0.012,P〉0.05）. Logistic regression showed that mechanical ventilation （OR = 3.388, 95% CI： 1.656-6.932, P=0.001） and parenteral nutrition （OR= 7.054, 95%CI： 2.005-24.813, P=0.002） were risk factors of nosocomial infection. Conclusions The incidence of nosocomial infection in VLBWIs in NICU is high. Mechanical ventilation and parenteral nutrition should be avoided and the duration of invasive operation and treatment should be shortened as much as possible to minimize the chances of nosocomial infection in VLBWIs.