新生儿重症监护病房的院内感染638例分析

目的调查NICU院内感染的发生情况,探讨其危险因素,为院内感染的防控提供依据。方法对我科2003年5月至2004年12月,住院的638例新生儿进行院内感染的监控,并进行分析和总结。结果638例新生儿中74例发生88次院内感染,发生率为11．6％;住院日相关的院内感染率为14．9／1000NICU病例一天;导管相关血行感染率为18／1000血管内导管一天（2／111）;呼吸机相关肺炎发生率为63．3／1000机械通气一天（15／237）;平均开始出现感染时间（7．98±4．58）d。发生院内感染者比未感染者的胎龄及出生体重低、住院时间延长。新生儿发生院内感染的危险因素包括胃肠外营养、出生体重≤1500g及呼吸机治疗等（P〈0．05）。感染部位中,以肺炎占首位（45．4％）。院内感染病死率为4．1％。入院后有细菌定植者较无定植者院内感染率高（Х^2=79．7,P〈0．001）。结论充分了解NICU中新生儿发生院内感染的高危因素、尽量减少肠外营养及侵袭性操作的次数和时间、明确NICU中患儿个体细菌的定植情况将有助于控制院内感染并对临床合理用药提供参考。

Clinical analysis of nosocomial infection in neonatal intensive care units

OBJECTIVE: Nosocomial infections (NIs) have become a matter of major concern in neonatal intensive care units (NICU). The objectives of this study were to investigate the incidence of nosocomial infections of newborn infants in NICU and to explore the risk factors and strategies of infection control. METHODS: The study enrolled 638 hospitalized newborn infants from Apr 2003 to Dec 2004. The clinical data, such as the clinical manifestation, the condition of colonized bacteria, were collected and analyzed by using SPSS software. RESULT: There were 88 times of nosocomial infections in 74 newborn infants. The overall incidence of nosocomial infections was 11.6%. The mean duration from admission to first episode of NI was 7.98 +/- 4.58 days. The incidence density was 14.9 per 1000 NICU patient-days. Catheter-correlated hematogenous infection rate was 18 per 1000 umbilical or central line-days; the ventilator-associated nosocomial pneumonia rate was 63.3 per 1000 ventilator days. The smaller the gestational age and the lower the birth weight, the higher the incidences of nosocomial infection. The duration of hospitalization was longer in these infected infants than those non-infected infants. Univariate analysis indicated that gestational age < or = 32 W, the parenteral nutrition, birth weight < or = 1500 g and mechanical ventilation, apnea, small for gestational age infant, central venous catheter (P < 0.05) were risk factors for NIs. Multivariate analysis identified 3 independent risk factions: the parenteral nutrition ([OR] = 7.185 [95% CI, 3.399 - 15.188]), birth weight < or = 1500 g ([OR] = 3.310 [95% CI, 1.100 - 9.963]) and mechanical ventilation ([OR] = 2.527 [95% CI, 1.092 - 5.850]). The most common infection was pneumonia (45.4%). The mortality rate of nosocomial infections was 4.1%. Bacterial surveillance was examined by nasopharyngeal and rectal swab culture immediately on hospital admission and then once a week. The incidence rate of NIs was 24.8% in patients whose nasopharyngeal and rectal swab culture indicated bacterial colonization, and 1.9% in patients without bacterial colonization (chi(2) = 79.7, P < 0.001). CONCLUSION: It is important to identify the high risk factors for nosocomial infections in newborn infants in NICU. Reducing the duration of the parenteral nutrition and the virulence manipulation as far as possible and getting the message of individual bacterial colonization in NICU may be conducive to decrease of the incidence of nosocomial infections and provide reference for rational clinical drug administration.