新生儿革兰氏阴性杆菌气道定植：与支气管肺发育不良严重程度的关联。

Neonatal airway colonization with gram-negative bacilli: association with severity of bronchopulmonary dysplasia.

作者信息

Cordero L, Ayers L W, Davis K

机构信息

Department of Pediatrics, Ohio State University Medical Center, Columbus 43210-1228, USA.

出版信息

Pediatr Infect Dis J. 1997 Jan;16(1):18-23. doi: 10.1097/00006454-199701000-00005.

DOI:10.1097/00006454-199701000-00005

PMID:9002095

Abstract

BACKGROUND

Airway colonization with Gram-negative bacilli (GNB) and Gram-positive cocci (GPC) is common in mechanically ventilated neonates. Whether GNB are related to nosocomial bloodstream infection (BSI) and/or to the severity of bronchopulmonary dysplasia (BPD) is unknown.

METHODS

We prospectively examine this relationship using a cohort design. Data from 260 < or = 1250-g birth weight inborn infants (1991 to 1995) intubated > or = 2 weeks included 917 serial tracheal cultures and 583 blood cultures. The severity of BPD was assessed by duration of mechanical ventilation, oxygen dependency at 36 weeks of postconceptional age and the use of home oxygen supplementation.

RESULTS

After 2 weeks of ventilation, 80% of the infants were colonized with GPC (Staphylococus epidermidis and Staphylococcus haemolyticus in 90% of the cases). Superimposed on 36% of these infants was GNB airway colonization with Klebsiella pneumoniae (25%), Enterobacter cloacae (25%), Escherichia coli (25%), Pseudomonas aeruginosa (10%), Serratia marcescen (10%), Acinetobacter baumannii and Haemophilus influenzae (5%). Comparison between 174 GPC- and 86 GNB-colonized infants showed that demographics, birth weight, gestational age, perinatal risk factors and mortality were similar. Fifteen percent of GNB-colonized infants developed BSI caused by GNB and 14% developed BSI caused by GPC. No significant temporal relationship between airway colonization and BSI was noted. GNB infants were ventilated longer and required oxygen at 36 weeks of postconceptional age and home oxygen supplementation twice as often as infants colonized only with GPC. GNB colonization was a predictor of severe BPD after controlling for ventilation. Ureaplasma colonization occurred in 28% of GNB-colonized and 33% of noncolonized infants and was not a predictor of BPD severity.

CONCLUSION

GNB airway colonization creates a moderate risk for BSI. Antibiotic treatment does not regularly eradicate GNB. GNB airway colonization is associated with severe BPD, but further studies will be necessary before therapeutic efforts to eradicate GNB from the airways should be undertaken.

摘要

背景

革兰氏阴性杆菌（GNB）和革兰氏阳性球菌（GPC）在机械通气的新生儿气道定植中很常见。GNB是否与医院获得性血流感染（BSI）和/或支气管肺发育不良（BPD）的严重程度相关尚不清楚。

方法

我们采用队列设计前瞻性地研究这种关系。对1991年至1995年出生体重≤1250克、插管≥2周的260例新生儿的数据进行分析，包括917次连续气管培养和583次血培养。通过机械通气时间、孕龄36周时的氧依赖情况以及家庭氧疗的使用来评估BPD的严重程度。

结果

通气2周后，80%的婴儿被GPC定植（90%的病例为表皮葡萄球菌和溶血葡萄球菌）。在这些婴儿中，36%同时合并GNB气道定植，其中肺炎克雷伯菌占25%、阴沟肠杆菌占25%、大肠杆菌占25%、铜绿假单胞菌占10%、黏质沙雷菌占10%、鲍曼不动杆菌和流感嗜血杆菌占5%。对174例GPC定植婴儿和86例GNB定植婴儿进行比较，结果显示人口统计学特征、出生体重、胎龄、围产期危险因素和死亡率相似。15%的GNB定植婴儿发生了由GNB引起的BSI，14%发生了由GPC引起的BSI。未发现气道定植与BSI之间存在明显的时间关系。与仅被GPC定植的婴儿相比，GNB定植的婴儿机械通气时间更长，孕龄36周时需要吸氧，且家庭氧疗的使用频率是前者的两倍。在控制通气因素后，GNB定植是严重BPD的一个预测指标。脲原体定植在28%的GNB定植婴儿和33%的非定植婴儿中出现，且不是BPD严重程度的预测指标。