LAUSR

OBJECTIVE Frailty is a state of systematic physiologic decline and reduced ability to recover from illness. There are no rapid quantitative biological measures to assess frailty. The study objective was to determine whether oxidation-reduction potential (ORP) is correlated with frailty score. METHODS This prospective, observational cohort study was performed using plasma samples of geriatric trauma patients (≥65 years) admitted to a level I trauma center. Frailty was measured with the Canadian Study of Health and Aging (CSHA) Clinical Frailty Scale (7-point scale; 1 = robust health and 7 = severely frail). Plasma ORP was determined using the RedoxSYS™ system to measure static ORP (aggregate measure of oxidative stress) and capacity ORP (antioxidant reserves; log transformed). Spearman rank correlation (presented as rs) and ordinal logistic regression (presented as adjusted odds ratios, AOR) were used to examine the unadjusted and adjusted relationship between frailty score and ORP values. RESULTS There were 93 geriatric trauma patients in our study. The majority (86%) had frailty scores 1-5, 11% were moderately frail and 3% were severely frail. There was a u-shaped relationship between ORP and frailty scale that became monotonic for scores 1-5. Each increase in frailty score demonstrated significant decreases in antioxidant reserves (log cORP rs = -0.26, p = 0.02) and nonsignificant increases in oxidative stress (sORP rs = 0.17, p = 0.15). After adjustment, variables significantly associated with frailty included log cORP (e.g., fewer antioxidant reserves, AOR: 0.70), age (AOR: 1.82), injury severity score (AOR: 0.50), admission lactate ≥2.5 mMol (AOR: 4.31), and alcohol use (AOR: 0.34). CONCLUSIONS The amount of antioxidant reserves (cORP) appears to be a quantitative marker to differentiate the degree of frailty ranging from robust health to mild frailty in geriatric trauma patients. We propose that direct quantification of frailty by way of a biomarker for oxidative reserves could have application in emergent trauma situations.