Octane in exhaled breath to diagnose acute respiratory distress syndrome in invasively ventilated intensive care unit patients

Laura A Hagens; Nanon F L Heijnen; Marry R Smit; Alwin R M Verschueren; Tamara M E Nijsen; Inge Geven; Cristian N Presură; Ronald Rietman; Dominic W Fenn; Paul Brinkman; Marcus J Schultz; Dennis C J J Bergmans; Ronny M Schnabel; Lieuwe D J Bos

doi:10.1183/23120541.00214-2023

Octane in exhaled breath to diagnose acute respiratory distress syndrome in invasively ventilated intensive care unit patients

ERJ Open Res. 2023 Oct 16;9(5):00214-2023. doi: 10.1183/23120541.00214-2023. eCollection 2023 Sep.

Authors

Laura A Hagens¹, Nanon F L Heijnen², Marry R Smit¹, Alwin R M Verschueren³, Tamara M E Nijsen³, Inge Geven³, Cristian N Presură³, Ronald Rietman³, Dominic W Fenn^{4

5}, Paul Brinkman⁴, Marcus J Schultz^{1

6

7}, Dennis C J J Bergmans^{2

8}, Ronny M Schnabel², Lieuwe D J Bos^{1

4

5}

Affiliations

¹ Department of Intensive Care, Amsterdam UMC location University of Amsterdam, Amsterdam, The Netherlands.
² Department of Intensive Care, Maastricht University Medical Centre+, Maastricht, The Netherlands.
³ Sleep and Respiratory Solutions, Philips Research, Eindhoven, The Netherlands.
⁴ Department of Respiratory Medicine, Amsterdam UMC location University of Amsterdam, Amsterdam, The Netherlands.
⁵ Laboratory of Experimental Intensive Care and Anesthesiology (LEICA), Amsterdam UMC location University of Amsterdam, Amsterdam, The Netherlands.
⁶ Mahidol-Oxford Tropical Medicine Research Unit (MORU), Mahidol University, Bangkok, Thailand.
⁷ Nuffield Department of Medicine, University of Oxford, Oxford, UK.
⁸ School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University, Maastricht, The Netherlands.

Abstract

Background: The concentration of exhaled octane has been postulated as a reliable biomarker for acute respiratory distress syndrome (ARDS) using metabolomics analysis with gas chromatography and mass spectrometry (GC-MS). A point-of-care (POC) breath test was developed in recent years to accurately measure octane at the bedside. The aim of the present study was to validate the diagnostic accuracy of exhaled octane for ARDS using a POC breath test in invasively ventilated intensive care unit (ICU) patients.

Methods: This was an observational cohort study of consecutive patients receiving invasive ventilation for at least 24 h, recruited in two university ICUs. GC-MS and POC breath tests were used to quantify the exhaled octane concentration. ARDS was assessed by three experts following the Berlin definition and used as the reference standard. The area under the receiver operating characteristic curve (AUC) was used to assess diagnostic accuracy.

Results: 519 patients were included and 190 (37%) fulfilled the criteria for ARDS. The median (interquartile range) concentration of octane using the POC breath test was not significantly different between patients with ARDS (0.14 (0.05-0.37) ppb) and without ARDS (0.11 (0.06-0.26) ppb; p=0.64). The AUC for ARDS based on the octane concentration in exhaled breath using the POC breath test was 0.52 (95% CI 0.46-0.57). Analysis of exhaled octane with GC-MS showed similar results.

Conclusions: Octane in exhaled breath has insufficient diagnostic accuracy for ARDS. This disqualifies the use of octane as a biomarker in the diagnosis of ARDS and challenges most of the research performed up to now in the field of exhaled breath metabolomics.