Millot Guillaume, Voisin Benoit, Loiez Caroline, Wallet Frédéric, Nseir Saad
CHU Lille, Critical Care Center, Lille, France.
CHU Lille, Laboratory of Bacteriology, Lille, France.
Ann Transl Med. 2017 Nov;5(22):451. doi: 10.21037/atm.2017.11.05.
Ventilator-associated pneumonia (VAP) is a frequent issue in intensive care units (ICU), with a major impact on morbidity, mortality and cost of care. VAP diagnosis remains challenging: traditional culture-based microbiological techniques are still the gold-standard, but are too slow to enable clinicians to improve prognosis with timely antimicrobial therapy adjustment. Prolonged exposure to inappropriate antibiotics has also been shown to increase the incidence of multi-drug-resistant organisms (MDROs). Point-of-care testing (POCT) tools are diagnostic testing methods that can be used at or near the bedside, with delays ranging from a couple minutes to a few hours. The use of POCTs for VAP could allow for faster diagnosis and antimicrobial therapy adjustments. Despite uncertainty regarding their diagnostic value, C-reactive protein (CRP) and procalcitonin (PCT) can be detected using POCTs in few minutes. In VAP, CRP showed a sensitivity of 56% to 88% and specificity of 86% to 91%; PCT showed a sensitivity of 78% to 100% and a specificity between 75% and 97% using non-POCT methods. Automated microscopy could also be used in clinical ICU setting, with reported sensitivity of 100% and specificity of 97%, allowing for antibiotic susceptibility testing (AST) in less than 12 h. Multiplex polymerase chain reaction (MPCR) could allow for identification and AST approximation through the detection of drug-resistance genes in about 6 h, with reported sensitivity of 89.2% and specificity of 97.1%; although use as POCT was shown to result in test failure in about 40% of samples. Despite being at an early development stage, exhalome analysis, which allows for non-invasive fast identification, and chromogenic tests, more suited for the detection of drug-resistance enzymes, are also promising techniques for POCT diagnosis of VAP.
呼吸机相关性肺炎(VAP)是重症监护病房(ICU)中常见的问题,对发病率、死亡率和护理成本有重大影响。VAP的诊断仍然具有挑战性:传统的基于培养的微生物学技术仍是金标准,但速度太慢,无法让临床医生通过及时调整抗菌治疗来改善预后。长期使用不恰当的抗生素也已被证明会增加多重耐药菌(MDRO)的发生率。即时检测(POCT)工具是可在床边或床边附近使用的诊断检测方法,检测延迟从几分钟到几小时不等。将POCT用于VAP诊断可实现更快的诊断和抗菌治疗调整。尽管其诊断价值存在不确定性,但C反应蛋白(CRP)和降钙素原(PCT)可通过POCT在几分钟内检测出来。在VAP中,使用非POCT方法时,CRP的灵敏度为56%至88%,特异性为86%至91%;PCT的灵敏度为78%至100%,特异性在75%至97%之间。自动显微镜检查也可用于临床ICU环境,报告的灵敏度为100%,特异性为97%,可在不到12小时内进行抗生素敏感性测试(AST)。多重聚合酶链反应(MPCR)可通过检测耐药基因在约6小时内实现病原体鉴定和AST近似评估,报告的灵敏度为89.2%,特异性为97.1%;不过,用作POCT时约40%的样本会检测失败。呼气分析处于早期开发阶段,可实现非侵入性快速鉴定,而显色试验更适合检测耐药酶,它们也是用于VAP的POCT诊断的有前景的技术。