Ramirez P, Garcia M A, Ferrer M, Aznar J, Valencia M, Sahuquillo J M, Menéndez R, Asenjo M A, Torres A
Intensive Care Unit, Universal Hospital La Fe.
Eur Respir J. 2008 Feb;31(2):356-62. doi: 10.1183/09031936.00086707. Epub 2007 Oct 24.
The utility of procalcitonin levels to improve the accuracy of clinical and microbiological parameters in diagnosing ventilator-associated pneumonia (VAP) was evaluated. Sequential measurement of procalcitonin and C-reactive protein levels and the calculation of the simplified Clinical Pulmonary Infection Scores (CPIS) were performed in 44 patients mechanically-ventilated for >48 h with neither active infection for the duration or suspicion of VAP. Patients who developed extrapulmonary infection were excluded. In total, 20 cases were suspected of having VAP and diagnosis was microbiologically confirmed in nine. In patients with confirmed VAP, procalcitonin levels were higher than in those without VAP. C-reactive protein levels and CPIS were lower in patients without suspected VAP, but could not discriminate confirmed and nonconfirmed suspicion of VAP. The best sensitivity and specificity (78 and 97%, respectively) corresponded to procalcitonin. The CPIS resulted in the same sensitivity, but had a lower specificity (80%). C-reactive protein had the worst sensitivity (56%), but a good specificity (91%). A CPIS >or=6 combined with serum levels of procalcitonin >or=2.99 ng.mL(-1) did not improve the sensitivity (67%), but resulted in 100% specificity. Procalcitonin might be useful in the diagnosis of ventilator-associated pneumonia. Combined values of Clinical Pulmonary Infection Scores and procalcitonin below the cut-off points excluded false-positive diagnoses of ventilator-associated pneumonia.
评估了降钙素原水平在提高诊断呼吸机相关性肺炎（VAP）的临床和微生物学参数准确性方面的效用。对44例机械通气超过48小时、在整个期间无活动性感染或无VAP怀疑的患者进行了降钙素原和C反应蛋白水平的连续测量，并计算简化临床肺部感染评分（CPIS）。排除发生肺外感染的患者。总共20例患者被怀疑患有VAP，其中9例经微生物学确诊。确诊VAP的患者降钙素原水平高于未患VAP的患者。未怀疑VAP的患者C反应蛋白水平和CPIS较低，但无法区分确诊和未确诊的VAP怀疑。最佳敏感性和特异性（分别为78%和97%）对应于降钙素原。CPIS的敏感性相同，但特异性较低（80%）。C反应蛋白的敏感性最差（56%），但特异性良好（91%）。CPIS≥6并结合血清降钙素原水平≥2.99 ng.mL⁻¹并未提高敏感性（67%），但特异性达到100%。降钙素原可能有助于呼吸机相关性肺炎的诊断。临床肺部感染评分和降钙素原低于切点的组合值可排除呼吸机相关性肺炎的假阳性诊断。
