Engle W D, Rosenfeld C R, Mouzinho A, Risser R C, Zeray F, Sanchez P J
Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75235-9063, USA.
Pediatrics. 1997 Mar;99(3):E10. doi: 10.1542/peds.99.3.e10.
To study the effect of sepsis on circulating neutrophils in very low birth weight neonates and to assess the usefulness of recently revised reference ranges for circulating neutrophils in the diagnosis of sepsis in this population by comparison with previously reported reference ranges.
Neutrophil parameters (absolute total neutrophils, absolute total immature neutrophils, and the immature:total neutrophil proportion) were analyzed retrospectively in 202 sepsis episodes in 192 neonates (birth weight = 1055 +/- 246 g, X +/- SD; estimated gestational age = 29 +/- 2 weeks) between birth and 30 days of age. The percentage of values lying outside the reference ranges reported recently by Mouzinho et al and previously by Manroe et al were compared. To more accurately assess possible differences in specificity between the two reference ranges, neonates with early-onset group B streptococcal infection (n = 19) were compared with a matched control group (n = 51) using conditional logistic regression.
Greater sensitivity was observed using the previous reference ranges of Manroe et al over the entire study period (0 to 720 hours) both for the initial and the second complete blood count (CBC). The previous reference ranges also were more sensitive than the revised ranges for the initial CBC at 0 to 72 and at 73 to 720 hours and for infections attributable to coagulase-negative staphylococci. However, specificity in neonates without group B streptococcal infection was significantly greater with the revised reference ranges compared with those of Manroe et al (initial CBC, 73% vs 45%; serial CBCs, 59% vs 10%).
The observed differences in sensitivities may be of limited clinical significance because very low birth weight infants often are begun on antibiotic therapy regardless of laboratory values. However, the striking differences in specificity using the revised reference ranges suggest that these ranges may be clinically useful in determining length of antimicrobial therapy in infants in whom cultures remain sterile.
研究脓毒症对极低出生体重儿循环中性粒细胞的影响，并通过与先前报道的参考范围进行比较，评估最近修订的循环中性粒细胞参考范围在该人群脓毒症诊断中的实用性。
回顾性分析192例新生儿（出生体重 = 1055±246 g，X±SD；估计胎龄 = 29±2周）在出生至30日龄期间发生的202次脓毒症发作时的中性粒细胞参数（绝对总中性粒细胞、绝对总未成熟中性粒细胞以及未成熟:总中性粒细胞比例）。比较了Mouzinho等人最近报道的参考范围以及先前Manroe等人报道的参考范围之外的值的百分比。为了更准确地评估两个参考范围之间特异性的可能差异，使用条件逻辑回归将早发型B族链球菌感染的新生儿（n = 19）与匹配的对照组（n = 51）进行比较。
在整个研究期间（0至720小时），无论是首次还是第二次全血细胞计数（CBC），使用Manroe等人先前的参考范围观察到更高的敏感性。对于0至72小时以及73至720小时的首次CBC以及由凝固酶阴性葡萄球菌引起的感染，先前的参考范围也比修订后的范围更敏感。然而，与Manroe等人的参考范围相比，修订后的参考范围在无B族链球菌感染的新生儿中的特异性显著更高（首次CBC，73%对45%；系列CBC，59%对10%）。
观察到的敏感性差异可能具有有限的临床意义，因为极低出生体重儿通常无论实验室值如何都开始接受抗生素治疗。然而，使用修订后的参考范围在特异性方面的显著差异表明，这些范围可能在确定培养结果无菌的婴儿的抗菌治疗时长方面具有临床实用性。
