Higher mini-BAL total protein concentration in early ARDS predicts faster resolution of lung injury measured by more ventilator-free days.

Pubmed ID: 28213470

Pubmed Central ID: PMC5451593

Journal: American journal of physiology. Lung cellular and molecular physiology

Publication Date: May 1, 2017

Affiliation: Department of Anesthesia, University of California, San Francisco; San Francisco, California; and.

MeSH Terms: Humans, Male, Female, Middle Aged, Treatment Outcome, Linear Models, Ventilators, Mechanical, Bronchoalveolar Lavage Fluid, Proteins, Biomarkers, Immunoglobulin M, Lung Injury, Respiratory Distress Syndrome

Grants: R37 HL051856, R01 HL110969, R01 HL131621, K23 HL133495, K24 HL133390, T32 HL007185, F32 HL124911, R01 HL051854

Authors: Matthay MA, Calfee CS, Liu KD, Zhuo H, Hendrickson CM, Abbott J

Cite As: Hendrickson CM, Abbott J, Zhuo H, Liu KD, Calfee CS, Matthay MA, NHLBI ARDS Network. Higher mini-BAL total protein concentration in early ARDS predicts faster resolution of lung injury measured by more ventilator-free days. Am J Physiol Lung Cell Mol Physiol 2017 May 1;312(5):L579-L585. Epub 2017 Feb 17.

Studies:

Acute Respiratory Distress Network (ARDSNet) Studies 06 and 08 Prospective, Randomized, Multicenter Trial of Aerosolized Albuterol Versus Placebo for the Treatment of Acute Lung Injury (ALTA)

Abstract

The protein concentration of alveolar edema fluid in acute respiratory distress syndrome (ARDS) is dynamic. It reflects alveolar flooding during acute injury, as well as fluid and protein clearance over time. We hypothesized that among ARDS patients treated with low tidal volume ventilation, higher concentrations of protein in mini-bronchoalveolar lavage (mBAL) samples would predict slower resolution of lung injury and worse clinical outcomes. Total protein and IgM concentrations in day 0 mBAL samples from 79 subjects enrolled in the aerosolized albuterol (ALTA) ARDS Network Albuterol Trial were measured by colorimetric assay and ELISA, respectively. Linear regression models were used to test the association of mBAL proteins with clinical outcomes and measures of length of illness, including ventilator-free days (VFDs). Median mBAL total protein concentration was 1,740 μg/ml [interquartile range (IQR): 890-3,170]. Each 500 μg/ml increase in day 0 mBAL total protein was associated with an additional 0.8 VFDs [95% confidence interval (CI): 0.05-1.6, P value = 0.038]. Median mBAL IgM concentration was 410 ng/ml (IQR: 340-500). Each 50 ng/ml increase in mBAL IgM was associated with an additional 1.1 VFDs (95% CI 0.2-2.1, P value = 0.022). These associations remained significant and were not attenuated in multivariate models adjusted for age, serum protein concentration, and vasopressor use in the 24 h before enrollment. Thus, higher mBAL total protein and IgM concentrations at day 0 are associated with more VFDs in patients with ARDS and may identify patients with preserved alveolar epithelial mechanisms for net alveolar fluid clearance.