Disparities in Lung Protective Ventilation in the United States

Background: Lung-protective ventilation is often used in critically ill patients with acute respiratory failure, including those without acute respiratory distress syndrome. While disparities exist in the delivery of critical care based on gender, race, and insurance status, it is unknown whether there are disparities in the use of lung-protective ventilation. The objective of our study was to determine whether gender-, racial / ethnic-, or insurance status-based disparities exist in the use of lung-protective ventilation for critically ill mechanically ventilated patients in the United States (U.S.). Methods: : This was a secondary data analysis of the U.S. Critical Illness and Injury Trials Group Critical Illness Outcomes Study, a prospective multi-center cohort study conducted from 2010 - 2012. The dependent variable of interest was the proportion of patients receiving tidal volume > 8 mL/kg predicted body weight (PBW). The independent variables of interest were gender, insurance status, and race / ethnicity. Results: : Our primary analysis included 1,595 mechanically ventilated patients from 59 intensive care units (ICUs) in the U.S. Women were more likely to receive tidal volumes > 8 ml/kg PBW than men (odds ratio [OR] = 3.25, 95% confidence interval [CI] = 2.58 – 4.09), though this relationship was substantially weakened after adjusting for gender differences in height (OR = 1.26 95% CI = 0.94 – 1.71). The underinsured were significantly more likely to receive tidal volume > 8 ml/kg PBW than the insured in multivariable analysis (odds ratio = 1.54, 95% confidence interval = 1.16 – 2.04). The prescription of > 8 ml/kg PBW tidal volume did not differ by racial or ethnic categories. Conclusions: : In this prospective nationwide cohort of critically ill mechanically ventilated patients, women and the underinsured were less likely than their comparators to receive lung protective ventilation, with no apparent differences based on race / ethnicity alone. Differences in height between men and women do not fully explain this disparity. Future research should evaluate whether implicit bias affects tidal volume choice and other management decisions in critical care.