加拿大新生儿重症监护室院内感染及其变化趋势对胎龄<33周早产儿预后的影响

败血症是新生儿重症监护室(NICU)的危重病症及造成新生儿死亡的重要原因之一,根据其发病时间,可分为早发(生后2 d 内)和晚发(生后2 d 后)。其中晚发的新生儿败血症,一般考虑为院内感染(NI)。胎龄越小,出生体重越低,NI 的发生率越高。NI 的发生率在加拿大各 NICU 之间差别较大,与各中心医护人员的相关诊疗行为密切相关。在国家卫生研究院"基于循证医学的医疗质量改进项目" 的推动下,2003~2009 年间加拿大全国 NICU 总的NI 率明显下降,但不同中心各自感染率的变化趋势仍极为不同。本研究纳入了加拿大全国共24 家 NICU 在2008~2012 年间所有收入院的胎龄<33 周的早产儿共18 961 名,探讨NI 率的变化趋势以及其与早产儿预后的关系。

Effects of nosocomial infection trends on neonatal outcomes in preterm infants <33 weeks of gestational age in Canadian NICUs

Objective To characterize recent trends of nosocomial infection (NI) among preterm infants admitted to Canadian Level 3 NICUs during 2008-2012, and its association with neonatal outcomes. Methods A retrospective observational cohort study was performed including infants born <33 weeks gestational age and admitted to 24 NICU sites participating in the Canadian Neonatal NetworkTM during 2008-2012. NICU sites were classified into three groups according to their baseline NI rates in 2008 [Low NI group (≤14%), Medium NI group (14.1%-19%) and High NI group (>19% )], and NICU sites were also classified according to their NI trend during 2008-2012 (decreased, null and increased). Trends in NI were further examined for each baseline-NI group. Trends for a composite outcome indicating mortality or severe morbidities (intraventricular hemorrhage grades ≥3 or periventricular leukomalacia, retinopathy of prematurity stages ≥3, bronchopulmonary dysplasia or necrotizing enterocolitis stages ≥2) were examined for each baseline-NI and trend-NI NICU site groups using multivariable logistic regression analyses adjusted for potential confounders. Results Baseline high NI group showed significantly decreased trends in NI rates, while for with medium or low baseline NI groups showed no significant trends in NI rates. The composite outcome (mortality during NICU stay or any severe neonatal morbidity such as intraventricular hemorrhage grades 3-4, periventricular leukomalacia, retinopathy of prematurity stages 3-5, bronchopulmonary dysplasia and necrotizing enterocolitis stages 2-3) decreased significantly for sites with decreased (OR=0.89, 95% CI=0.85-0.93) or null (OR=0.94, 95% CI=0.90-0.98) NI trends, but no significant trends in the composite outcome were detected for sites with increased NI rates. Conclusions The neonatal outcome is possibly influenced by NI rates and trend. The trend in the mortality and the risk of bronchopulmonary dysplasia, retinopathy of prematurity stage ≥3 and intraventricular hemorrhage >2 were significantly decreased for sites with decreased NI trend, suggesting that these improved outcomes may be associated with effort to decrease NI rate.