Samraj Ravi S, Crotty Eric J, Wheeler Derek S
From the Division of Pediatric Critical Care, Shands Children's Hospital, UF Health, Gainesville, FL.
Divisions of Pediatric Radiology.
Pediatr Emerg Care. 2019 Oct;35(10):671-674. doi: 10.1097/PEC.0000000000001259.
Children with status asthmaticus (SA) often present with fever and are evaluated with chest radiographs (CXRs). In the absence of a confirmatory test for bacterial infection, antibiotics are started whenever there are radiological infiltrates or if there is a suspicion of pneumonia. We undertook this study to determine if serum procalcitonin (PCT) levels at admission are altered in critically ill children with SA. We also sought to determine if serum PCT levels are elevated in children with radiological infiltrates or in children who were treated with antibiotics.
This is a prospective single-center observational study evaluating serum PCT levels in critically ill children with SA. Study subjects included children 1 to 21 years old, admitted to a pediatric intensive care unit (PICU) with SA between March 2012 and April 2013. For the purposes of this study, patients whose CXRs were read by the radiologist as probable bacterial pneumonia was defined as having "radiological bacterial pneumonia," whereas patients who received antibiotics by the treating physician were defined as having "clinician-diagnosed pneumonia."
Sixty-one patients with a median age of 7.3 years (interquartile range, 4-10 years) were included in the study. Fifty-one percent were male. Average Pediatric Risk of Mortality III score was 2.7 (SD, 2.9). Three patients (5%) were determined to have radiological bacterial pneumonia, whereas 52 (85%) did not. Six patients (10%) were indeterminate. The mean PCT level for all patients was 0.65 (SD, 1.54) ng/mL, whereas the median PCT level was 0.3 ng/mL. There was no significant difference in the mean PCT levels between the patients with and without clinician-diagnosed pneumonia (0.33 [SD, 0.36] vs 0.69 [SD, 1.67], P = 0.44). Using a PCT cutoff level of 0.5 ng/mL, a significant association was found with the presence of fever (P = 0.004), but no significant association was found with the presence of CXR infiltrates, radiological bacterial pneumonia, hospital length of stay, PICU length of stay, Pediatric Risk of Mortality III scores, or receipt of antibiotics.
Serum PCT level was not elevated to greater than 0.5 ng/mL in 75% of this cohort of critically ill children with SA admitted to PICU. Presence of CXR infiltrates was not associated with higher PCT levels. Large clinical trials are needed to study the diagnostic and predictive role of PCT in this patient population.
哮喘持续状态（SA）患儿常伴有发热，需进行胸部X线片（CXR）检查。在缺乏细菌感染确诊检查的情况下，只要存在放射学浸润或怀疑有肺炎，就会开始使用抗生素。我们开展这项研究以确定入住重症监护病房的SA危重症患儿入院时血清降钙素原（PCT）水平是否发生改变。我们还试图确定有放射学浸润的患儿或接受抗生素治疗的患儿血清PCT水平是否升高。
这是一项前瞻性单中心观察性研究，评估SA危重症患儿的血清PCT水平。研究对象包括2012年3月至2013年4月间因SA入住儿科重症监护病房（PICU）的1至21岁儿童。在本研究中，放射科医生将CXR读片诊断为可能的细菌性肺炎的患者被定义为患有“放射学细菌性肺炎”，而接受治疗的医生给予抗生素治疗的患者被定义为患有“临床医生诊断的肺炎”。
61例患者纳入研究，中位年龄7.3岁（四分位间距4 - 10岁）。51%为男性。小儿死亡风险Ⅲ评分平均为2.7（标准差2.9）。3例患者（5%）被确定患有放射学细菌性肺炎，52例（85%）未患。6例患者（10%）情况不明。所有患者的平均PCT水平为每毫升0.65（标准差1.54）纳克，中位PCT水平为每毫升0.3纳克。有临床医生诊断的肺炎的患者与无该诊断的患者之间的平均PCT水平无显著差异（分别为每毫升0.33[标准差0.36]纳克和每毫升0.69[标准差1.67]纳克，P = 0.44）。使用0.5纳克/毫升的PCT临界值水平，发现与发热存在显著关联（P = 0.004），但与CXR浸润、放射学细菌性肺炎、住院时间、PICU住院时间、小儿死亡风险Ⅲ评分或是否接受抗生素治疗均无显著关联。
在入住PICU的这一队列SA危重症患儿中，75%的患儿血清PCT水平未升高至大于0.5纳克/毫升。CXR浸润的存在与较高的PCT水平无关。需要进行大型临床试验来研究PCT在该患者群体中的诊断和预测作用。
