Gauvin France, Dassa Clément, Chaïbou Mahamadou, Proulx François, Farrell Catherine Ann, Lacroix Jacques
Hópital Sainte-Justine, Montreal, Quebec, Canada.
Pediatr Crit Care Med. 2003 Oct;4(4):437-43. doi: 10.1097/01.PCC.0000090290.53959.F4.
To compare different methods for diagnosis of ventilator-associated pneumonia in intubated children.
Prospective epidemiologic study.
Pediatric intensive care unit of a tertiary care university hospital.
All consecutive pediatric intensive care unit patients <18 yrs of age with suspected ventilator-associated pneumonia.
For all patients, the following diagnostic methods were compared: 1) clinical data using Centers for Disease Control criteria; 2) blind protected bronchoalveolar lavage, evaluating quantitative cultures, bacterial index of >5, Gram stain, and presence of intracellular bacteria; and 3) nonquantitative cultures of endotracheal secretions. The reference standard used was clinical judgment of three independent experts (Delphi method) who retrospectively established by consensus the presence of ventilator-associated pneumonia based on clinical, microbiological, and radiologic data. Concordance between each diagnostic method and the reference standard was evaluated by concordance percentage and kappa score. Validity was evaluated using sensitivity, specificity, positive predictive value, negative predictive value, and global value.
A total of 30 patients were included in the study. According to the reference standard, ventilator-associated pneumonia occurred in 10 of 30 patients (33%). Bacterial index of >5 in bronchoalveolar secretions showed the best concordance compared with the reference standard (concordance, 83%; kappa, 0.61). Bacterial index of >5 also showed the best validity (sensitivity, 78%; specificity, 86%; positive predictive value, 70%; negative predictive value, 90%; global value, 90%). Intracellular bacteria and Gram stain from bronchoalveolar secretions were very specific (95% and 81%, respectively) but not sensitive (30% and 50%, respectively). Clinical criteria and endotracheal cultures were very sensitive (100% and 90%, respectively) but poorly specific (15% and 40%, respectively).
Our data show that the most reliable diagnostic method for ventilator-associated pneumonia is a bacterial index of >5, using blind protected bronchoalveolar lavage. Further studies should evaluate the validity of all these methods according to the gold standard (autopsy).
比较不同方法诊断插管儿童呼吸机相关性肺炎。
前瞻性流行病学研究。
一所三级大学医院的儿科重症监护病房。
所有18岁以下疑似呼吸机相关性肺炎的儿科重症监护病房连续患者。
对所有患者比较以下诊断方法：1）使用疾病控制中心标准的临床资料；2）盲法保护性支气管肺泡灌洗，评估定量培养、细菌指数>5、革兰染色及细胞内细菌的存在情况；3）气管内分泌物的非定量培养。所采用的参考标准为三位独立专家的临床判断（德尔菲法），他们根据临床、微生物学和放射学数据，通过共识回顾性确定呼吸机相关性肺炎的存在情况。通过一致性百分比和kappa值评估每种诊断方法与参考标准之间的一致性。使用敏感性、特异性、阳性预测值、阴性预测值和总体值评估有效性。
共30例患者纳入研究。根据参考标准，30例患者中有10例（33%）发生呼吸机相关性肺炎。支气管肺泡分泌物细菌指数>5与参考标准相比一致性最佳（一致性，83%；kappa值，0.61）。细菌指数>5有效性也最佳（敏感性，78%；特异性，86%；阳性预测值，70%；阴性预测值，90%；总体值，90%）。支气管肺泡分泌物中的细胞内细菌和革兰染色特异性很高（分别为95%和81%）但敏感性不佳（分别为30%和50%）。临床标准和气管内培养敏感性很高（分别为100%和90%）但特异性很差（分别为15%和40%）。
我们的数据表明，诊断呼吸机相关性肺炎最可靠的方法是采用盲法保护性支气管肺泡灌洗，细菌指数>5。进一步研究应根据金标准（尸检）评估所有这些方法的有效性。
