Plasma Soluble Suppression of Tumerogenicity-2 Associates with Ventilator Liberation in Acute Hypoxemic Respiratory Failure.

Abstract

RATIONALE\nStandard physiologic assessments of extubation readiness in patients with acute hypoxemic respiratory failure (AHRF) may not reflect lung injury resolution and could adversely affect clinical decision-making and patient outcomes.\n\n\nOBJECTIVES\nWe hypothesized that elevations in inflammatory plasma biomarkers soluble suppression of tumerogenicity-2 (sST2) and interleukin-6 (IL-6) indicate ongoing lung injury in AHRF and better inform patient outcomes compared to standard clinical assessments.\n\n\nMETHODS\nWe measured daily plasma biomarkers and physiologic variables in 200 patients with AHRF for up to 9 days after intubation. We tested the associations of baseline values with the primary outcome of unassisted breathing at day 29. We analyzed the ability of serial biomarker measurements to inform successful ventilator liberation.\n\n\nMEASUREMENTS AND MAIN RESULTS\nBaseline sST2 concentrations were higher in patients dead or mechanically ventilated versus breathing unassisted at day 29 (491.7 ng/mL, IQR 294.5-670.1 ng/mL vs. 314.4 ng/mL, IQR 127.5-550.1 ng/mL, P = 0.0003). Higher sST2 concentrations over time were associated with decreased probability of ventilator liberation (HR 0.80 per log-unit increase, 95% CI 0.75-0.83, P = 0.03). Patients with higher sST2 concentrations on the day of liberation were more likely to fail liberation compared to patients who remained successfully liberated (320.9 ng/mL, IQR 181.1-495.6 ng/mL vs. 161.6 ng/mL, IQR 95.8-292.5 ng/mL, P = 0.002). Elevated sST2 concentrations on the day of liberation decreased the odds of successful liberation when adjusted for standard physiologic parameters (OR 0.325, 95% CI 0.119-0.885, P = 0.03). IL-6 levels did not associate with outcomes.\n\n\nCONCLUSIONS\nUsing sST2 concentrations to guide ventilator management may more accurately reflect underlying lung injury and outperform traditional measures of readiness for ventilator liberation.