Diagnostic accuracy of pulmonary host inflammatory mediators in the exclusion of ventilator-acquired pneumonia. Issue 1 (8th October 2014)

• Record Type: Journal Article
• Authors: Hellyer, Thomas P; Morris, Andrew Conway; McAuley, Daniel F; Walsh, Timothy S; Anderson, Niall H; Singh, Suveer; Dark, Paul; Roy, Alistair I; Baudouin, Simon V; Wright, Stephen E; Perkins, Gavin D; Kefala, Kallirroi; Jeffels, Melinda; McMullan, Ronan; O'Kane, Cecilia M; Spencer, Craig; Laha, Shondipon; Robin, Nicole; Gossain, Savita; Gould, Kate; Ruchaud-Sparagano, Marie-Hélène; Scott, Jonathan; Browne, Emma M; MacFarlane, James G; Wiscombe, Sarah; Widdrington, John D; Dimmick, Ian; Laurenson, Ian F; Nauwelaers, Frans; Simpson, A John
• Is Part Of: Thorax. Volume 70:Issue 1(2015)
• Page Start: 41
• Page End: 47
• Publication Date: 2014-10-08
• Subjects: Pneumonia; Chest -- Diseases -- Periodicals; Thorax; Chest -- Diseases; Periodicals; Periodicals; 617.54
• DOI: 10.1136/thoraxjnl-2014-205766
• Languages: English
• ISSNs: 0040-6376

Abstract

Abstract : Background: Excessive use of empirical antibiotics is common in critically ill patients. Rapid biomarker-based exclusion of infection may improve antibiotic stewardship in ventilator-acquired pneumonia (VAP). However, successful validation of the usefulness of potential markers in this setting is exceptionally rare. Objectives: We sought to validate the capacity for specific host inflammatory mediators to exclude pneumonia in patients with suspected VAP. Methods: A prospective, multicentre, validation study of patients with suspected VAP was conducted in 12 intensive care units. VAP was confirmed following bronchoscopy by culture of a potential pathogen in bronchoalveolar lavage fluid (BALF) at >10 4 colony forming units per millilitre (cfu/mL). Interleukin-1 beta (IL-1β), IL-8, matrix metalloproteinase-8 (MMP-8), MMP-9 and human neutrophil elastase (HNE) were quantified in BALF. Diagnostic utility was determined for biomarkers individually and in combination. Results: Paired BALF culture and biomarker results were available for 150 patients. 53 patients (35%) had VAP and 97 (65%) patients formed the non-VAP group. All biomarkers were significantly higher in the VAP group (p<0.001). The area under the receiver operator characteristic curve for IL-1β was 0.81; IL-8, 0.74; MMP-8, 0.76; MMP-9, 0.79 and HNE, 0.78. A combination of IL-1β and IL-8, at the optimal cut-point, excluded VAP with a sensitivity of 100%, a specificity of 44.3% and a post-test probability of 0% (95% CI 0% to 9.2%). Conclusions: Low BALF IL-1β in combination with IL-8 confidently excludes VAP and could form a rapid biomarker-based rule-out test, with the potential to improve antibiotic stewardship.