Pfister Roman, Kochanek Matthias, Leygeber Timo, Brun-Buisson Christian, Cuquemelle Elise, Machado Mariana Benevides, Piacentini Enrique, Hammond Naomi E, Ingram Paul R, Michels Guido
Crit Care. 2014 Mar 10;18(2):R44. doi: 10.1186/cc13760.
Procalcitonin (PCT) is helpful for diagnosing bacterial infections. The diagnostic utility of PCT has not been examined thoroughly in critically ill patients with suspected H1N1 influenza.
Clinical characteristics and PCT were prospectively assessed in 46 patients with pneumonia admitted to medical ICUs during the 2009 and 2010 influenza seasons. An individual patient data meta-analysis was performed by combining our data with data from five other studies on the diagnostic utility of PCT in ICU patients with suspected 2009 pandemic influenza A(H1N1) virus infection identified by performing a systematic literature search.
PCT levels, measured within 24 hours of ICU admission, were significantly elevated in patients with bacterial pneumonia (isolated or coinfection with H1N1; n = 77) (median = 6.2 μg/L, interquartile range (IQR) = 0.9 to 20) than in patients with isolated H1N1 influenza pneumonia (n = 84; median = 0.56 μg/L, IQR = 0.18 to 3.33). The area under the curve of the receiver operating characteristic curve of PCT was 0.72 (95% confidence interval (CI) = 0.64 to 0.80; P < 0.0001) for diagnosis of bacterial pneumonia, but increased to 0.76 (95% CI = 0.68 to 0.85; P < 0.0001) when patients with hospital-acquired pneumonia and immune-compromising disorders were excluded. PCT at a cut-off of 0.5 μg/L had a sensitivity (95% CI) and a negative predictive value of 80.5% (69.9 to 88.7) and 73.2% (59.7 to 84.2) for diagnosis of bacterial pneumonia, respectively, which increased to 85.5% (73.3 to 93.5) and 82.2% (68.0 to 92.0) in patients without hospital acquired pneumonia or immune-compromising disorder.
In critically ill patients with pneumonia during the influenza season, PCT is a reasonably accurate marker for detection of bacterial pneumonia, particularly in patients with community-acquired disease and without immune-compromising disorders, but it might not be sufficient as a stand-alone marker for withholding antibiotic treatment.
降钙素原（PCT）有助于诊断细菌感染。对于疑似H1N1流感的重症患者，PCT的诊断效用尚未得到充分研究。
对2009年和2010年流感季节入住内科重症监护病房（ICU）的46例肺炎患者的临床特征和PCT进行前瞻性评估。通过将我们的数据与另外五项关于PCT在疑似2009年甲型H1N1大流行性流感病毒感染的ICU患者中的诊断效用的研究数据相结合，进行了个体患者数据荟萃分析。这些数据是通过系统文献检索确定的。
在ICU入院24小时内测量的PCT水平，在细菌性肺炎患者（单独感染或合并H1N1感染；n = 77）中显著升高（中位数 = 6.2 μg/L，四分位间距（IQR）= 0.9至20），高于单纯H1N1流感肺炎患者（n = 84；中位数 = 0.56 μg/L，IQR = 0.18至3.33）。PCT用于诊断细菌性肺炎的受试者工作特征曲线下面积为0.72（95%置信区间（CI）= 0.64至0.80；P < 0.0001），但在排除医院获得性肺炎和免疫功能低下疾病的患者后，该面积增加至0.76（95% CI = 0.68至0.85；P < 0.0001）。PCT截断值为0.5 μg/L时，诊断细菌性肺炎的灵敏度（95% CI）和阴性预测值分别为80.5%（69.9至88.7）和73.2%（59.7至84.2），在无医院获得性肺炎或免疫功能低下疾病的患者中分别增至85.5%（73.3至93.5）和82.2%（68.0至92.0）。
在流感季节患有肺炎的重症患者中，PCT是检测细菌性肺炎的一个相当准确的标志物，特别是在社区获得性疾病且无免疫功能低下疾病的患者中，但它可能不足以作为停用抗生素治疗的唯一标志物。
