Mintegi Santiago, Benito Javier, Pijoan Jose Ignacio, Marañon Rafael, Peñalba Ana, Gonzalez Andres, Muñoz Gisela, Luaces Carles, Claret Gemma
Pediatric Emergency Department, Cruces Hospital, Bilbao, Spain.
Pediatr Emerg Care. 2010 Jul;26(7):470-4. doi: 10.1097/PEC.0b013e3181e582e4.
The prevalence of pneumonia in infants with high fever without source (FWS; temperature, > or =39.0 degrees C) and a white blood cell (WBC) count greater than 20 x 10(9)/L (occult pneumonia) has been reported to be 20% before the introduction of the 7-valent pneumococcal conjugated vaccine (PCV7). This is the main reason for carrying out chest x-ray (CXR) on infants with high FWS. The aims of this study were to establish the prevalence of occult pneumonia in well-appearing infants with high FWS (temperature, > or =39.0 degrees C) and a WBC count greater than 20 x 10(9)/L in the era of PCV7 and to analyze the value of WBC, absolute neutrophil count (ANC), and C-reactive protein (CRP) level as predictors of the risk of occult pneumonia in these patients.
We conducted a multicenter prospective study in 4 pediatric emergency departments including children younger than 36 months with FWS (temperature, > or =39.0 degrees C) and a WBC count higher than 20 x 10(9)/L on whom a CXR was performed in the absence of respiratory findings. Physicians completed a questionnaire when observing the infant, and the attending physician or, when in doubt, the radiologist interpreted the CXR. Multivariable binary logistic regression was used to estimate the adjusted relative influences of the aforementioned factors on the prevalence of radiological pneumonia.
During an entire year (September 2006 to September 2007), we included 188 infants (aged 1-36 months; 56.2% were males) with high FWS and a WBC count greater than 20 x 10(9)/L (range, 20-44.7 x 10(9)/L) on whom a CXR was performed. Of the 188 chest radiographs obtained, 37 (19.7%) were interpreted by the radiologist. Consolidation in the chest radiographs was detected in 25 (13.3%). The probability of an infant with high FWS and WBC of 20 x 10(9)/L or greater having pneumonia was related to 3 of the studied variables: age, ANC, and serum CRP level. The incidence of pneumonia increased with age (odds ratio [OR] of 2.62 for infants >12 months; 95% confidence interval [95% CI], 1.04-6.60), CRP level greater than 100 mg/L (OR, 3.18; 95% CI, 1.19-8.51), and ANC greater than 20 x 10(9)/L (OR, 3.52; 95% CI, 1.37-9.06). White blood cell count was not predictive of occult pneumonia when ANC was taken into account.
In the era of PCV7, the incidence of pneumonia in infants younger than 36 months with high FWS and WBC count greater than 20 x 10(9)/L seems to be lower than that previously reported. However, this is not a uniform group because the incidence of pneumonia increases in infants older than 12 months and with higher ANC and serum CRP level.
据报道，在引入7价肺炎球菌结合疫苗（PCV7）之前，无明确病因的高热（FWS；体温≥39.0℃）且白细胞（WBC）计数大于20×10⁹/L的婴儿（隐匿性肺炎）中肺炎的患病率为20%。这是对FWS高热婴儿进行胸部X线检查（CXR）的主要原因。本研究的目的是确定在PCV7时代，外观良好的FWS高热（体温≥39.0℃）且WBC计数大于20×10⁹/L的婴儿中隐匿性肺炎的患病率，并分析WBC、绝对中性粒细胞计数（ANC）和C反应蛋白（CRP）水平作为这些患者隐匿性肺炎风险预测指标的价值。
我们在4个儿科急诊科进行了一项多中心前瞻性研究，纳入36个月以下FWS高热（体温≥39.0℃）且WBC计数高于20×10⁹/L且无呼吸相关表现而接受CXR检查的儿童。医生在观察婴儿时填写问卷，由主治医师或在有疑问时由放射科医生解读CXR。采用多变量二元逻辑回归来估计上述因素对放射性肺炎患病率的校正相对影响。
在一整年（2006年9月至2007年9月）期间，我们纳入了188例FWS高热且WBC计数大于20×10⁹/L（范围为20 - 44.7×10⁹/L）并接受了CXR检查的婴儿（年龄1 - 36个月；56.2%为男性）。在获得的188张胸部X线片中，放射科医生解读了37张（19.7%）。胸部X线片发现实变的有25例（13.3%）。FWS高热且WBC为20×10⁹/L或更高的婴儿患肺炎的可能性与3个研究变量有关：年龄、ANC和血清CRP水平。肺炎发病率随年龄增加而升高（12个月以上婴儿的比值比[OR]为2.62；95%置信区间[95%CI]，1.04 - 6.60），CRP水平大于100mg/L（OR，3.18；95%CI，1.19 - 8.51），ANC大于20×10⁹/L（OR，3.52；95%CI，1.37 - 9.06）。当考虑ANC时，白细胞计数不能预测隐匿性肺炎。
在PCV7时代，36个月以下FWS高热且WBC计数大于20×10⁹/L的婴儿中肺炎的发病率似乎低于先前报道。然而，这不是一个均匀的群体，因为12个月以上以及ANC和血清CRP水平较高的婴儿肺炎发病率增加。
