The next generation of rapid point-of-care testing identification tools for ventilator-associated pneumonia

Abstract

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 drugresistance enzymes, are also promising techniques for POCT diagnosis of VAP.

Update of the treatment of nosocomial pneumonia in the ICU

“…The future use of rapid diagnostics is promising and will undoubtedly change our approaches to diagnosis and treatment of NP optimizing empiric antibiotic treatment. New tests have been developed such as multiplex polymerase chain reaction (MPCR), exhalome analysis and chromogenic tests [73].…”

“…The clinical severity of a suspected VAP makes intensivists start as soon as possible broad-spectrum antimicrobial therapy when, in fact, many patients treated do not have NP. Clinical scores, such as Clinical Pulmonary Infection Score (CPIS), or non-specific biomarkers such procalcitonin (PCT) and C-reactive protein (CRP) must be applied to begin or to stop antibiotic treatment as previously discussed [73]. Prolonged courses of antimicrobial therapy promote more resistance.…”

Assessment of levels of D‑dimer and interferon‑γ in pediatric patients with Mycoplasma pneumoniae pneumonia and its clinical implication

“…In this regard, the lab test is especially helpful in the diagnosis of MPP. Although D-dimer and interferon-γ (INF-γ) were reported to be associated with pneumonia in the literature, the diagnostic value and clinical implication of assessing both indicators in diagnosis of MPP in children were not reported ( 4 – 7 ). In this study, the serum levels of D-dimer and INF-γ in 185 pediatric patients with MPP and 92 healthy children were measured, to explore their associations with MPP and the clinical value of assessing both in diagnosis of MPP.…”

Assessment of a Loop-Mediated Isothermal Amplification (LAMP) Assay for the Rapid Detection of Pathogenic Bacteria from Respiratory Samples in Patients with Hospital-Acquired Pneumonia

“…The application of rapid diagnostic techniques to identify microbial pathogens seems to have a huge impact in the treatment of VAP, reducing inappropriate or unnecessary antimicrobial treatments and mortality in these patients [13,14]. Molecular biology techniques have allowed a faster diagnosis of VAP, especially in viral infections.…”