论文部分内容阅读
目的:探讨胎龄≤34周早产儿生后1周内降钙素原(procalcitonin，PCT)生理性波动规律及其对早发型脓毒症(early-onset sepsis，EOS)的诊断价值。方法:选择2017年1月至2018年12月山东省立医院东院区新生儿重症监护病房收治的胎龄≤34周早产儿进行回顾性分析。入选早产儿生后均进行PCT动态监测，根据是否发生EOS分为EOS组和非EOS组(无感染)。非EOS组早产儿应用多元线性回归分析围产期因素对PCT的影响，构建PCT日龄百分位参考曲线；并进一步按照胎龄分为<30周、30～31周、32～34周3个亚组进行PCT分层比较。EOS组早产儿应用贝叶斯定理计算PCT第95百分位数诊断EOS的敏感度、特异度、阳性预测值和阴性预测值。结果:研究期间共纳入胎龄≤34周早产儿216例，其中EOS组54例(25.0%)，非EOS组162例(75.0%)。多元回归分析显示胎龄≤34周早产儿PCT水平与检测日龄及胎龄相关，PCT在生后第1天达峰值(中位数5.38 ng/ml)后逐渐下降，至第4天降至儿童正常值(中位数0.44 ng/ml)；胎龄<30周组生后5 d内PCT水平(0～5 d中位数分别为0.35、6.98、5.64、2.74、0.87、0.50 ng/ml)明显高于胎龄30～31周组(0～5 d中位数分别为0.25、4.21、2.98、0.88、0.38、0.36 ng/ml)和胎龄32～34周组(0～5 d中位数分别为0.19、2.67、2.42、0.87、0.37、0.18 ng/ml)，生后6 d降至正常范围(中位数0.33 ng/ml)。日龄百分位曲线显示，生后1～3 d PCT第95百分位数分别为25.00、10.00、6.01 ng/ml，诊断EOS的特异度、阳性预测值均处于较高水平，其中第2天PCT为10.00 ng/ml的诊断价值最高(特异度99.1%、阳性预测值94.7%、敏感度33.3%、阴性预测值75.0%)。结论:胎龄≤34周早产儿生后PCT水平的生理性波动受胎龄、日龄影响，其中胎龄<30周早产儿生后5 d内PCT水平明显高于30～34周早产儿；生后第2天PCT界值为10.00 ng/ml诊断EOS的价值最高。“,”Objective:To study the physiological concentrations of procalcitonin (PCT) in preterm infants with gestational age (GA) less than 34 weeks (w) during the first week after birth and to assess its accuracy in detecting early-onset sepsis (EOS).Method:From January 2017 to December 2018, preterm infants with GA less than 34 w admitted to neonatal intensive care unit (NICU) of our hospital were included in this study. The preterms were assigned into EOS group and non-EOS group according to the diagnosis criteria of EOS. In the non-EOS group, multiple linear regression analysis was used to analyze the influence of perinatal factors on PCT, and a postnatal age-specific percentile-based reference curve for PCT from birth to 7 days after birth was established. Then PCT was compared among three subgroups according to GA(<30 w, 30~31 w, 32~34 w). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the 95th percentile (P95) of PCT for the diagnosis of EOS in the EOS group were calculated.Result:A total of 216 preterms were enrolled in the study, including 162 (75.0%) in the non-EOS group and 54(25.0%) in the EOS group. Multiple linear regression analysis indicated that PCT concentration was correlated with sampling time (postnatal age) and GA. The PCT concentration peaked on the first day after birth (median 5.38 ng/ml) and decreased thereafter to the normal range on the fourth day (median 0.44 ng/ml). Within the first 5 days after birth, the PCT concentration in GA<30 w subgroup (median PCT on 0~5 d were 0.35, 6.98, 5.64, 2.74, 0.87, and 0.50 ng/ml, respectively) were significantly higher than the 30~31w subgroup (median PCT on 0~5 d were 0.25, 4.21, 2.98, 0.88, 0.38, and 0.36 ng/ml, respectively) and the 32~34 w subgroup (median PCT on 0~5 d were 0.19, 2.67, 2.42, 0.87, 0.37, and 0.18 ng/ml, respectively), which decreased to the normal range on the 6th day after birth (median 0.33 ng/ml). The age-specific percentile-based reference curve showed high specificity and high PPV at P95 on the first (25.00 ng/ml), second (10.00 ng/ml) and third (6.01 ng/ml) day after birth. Among them, P95 (10.00 ng/ml) on the second day had the highest diagnostic value with specificity 99.1%, PPV 94.7%, sensitivity 33.3%, and NPV 75.0%.Conclusion:The physiological concentrations of PCT in preterms less than 34 w were correlated with GA and postnatal age. PCT concentration in preterms less than 30 w was significantly higher than 30~34 w within 5 days after birth. The PCT is 10.00 ng/ml on the second day after birth has the highest diagnostic value for EOS.