Cigarette smoking is the leading cause of preventable disease and death in the United States. Cardiovascular comorbidities associated with both active and secondhand cigarette smoking indicate the vascular toxicity of smoke exposure. Growing evidence supports the injurious effect of cigarette smoke on pulmonary endothelial cells and the roles of endothelial cell injury in development of acute respiratory distress syndrome (ARDS), emphysema, and pulmonary hypertension. This review summarizes results from studies of humans, preclinical animal models, and cultured endothelial cells that document toxicities of cigarette smoke exposure on pulmonary endothelial cell functions, including barrier dysfunction, endothelial activation and inflammation, apoptosis, and vasoactive mediator production. The discussion is focused on effects of cigarette smoke-induced endothelial injury in the development of ARDS, emphysema, and vascular remodeling in chronic obstructive pulmonary disease.

IMPORTANCE Pulse oximetry (SpO 2 ) is routinely used for transcutaneous monitoring of blood oxygenation, but it can overestimate actual oxygenation. This is more common in patients of racial and ethnic minority groups. The extent to which these discrepancies are associated with variations in treatment is not known. OBJECTIVE To determine if there are racial and ethnic disparities in supplemental oxygen administration associated with inconsistent pulse oximeter performance. DESIGN, SETTING, AND PARTICIPANTSThis retrospective cohort study was based on the Medical Information Mart for Intensive Care (MIMIC)-IV critical care data set. Included patients were documented with a race and ethnicity as Asian, Black, Hispanic, or White and were admitted to the intensive care unit (ICU) for at least 12 hours before needing advanced respiratory support, if any. Oxygenation levels and nasal cannula flow rates for up to 5 days from ICU admission or until the time of intubation, noninvasive positive pressure ventilation, high-flow nasal cannula, or tracheostomy were analyzed. MAIN OUTCOMES AND MEASURESThe primary outcome was time-weighted average supplemental oxygen rate. Covariates included race and ethnicity, sex, SpO 2 -hemoglobin oxygen saturation discrepancy, data duration, number and timing of blood gas tests on ICU days 1 to 3, partial pressure of carbon dioxide, hemoglobin level, average respiratory rate, Elixhauser comorbidity scores, and need for vasopressors or inotropes. RESULTSThis cohort included 3069 patients (mean [SD] age, 66.9 [13.5] years; 83 were Asian, 207 were Black, 112 were Hispanic, 2667 were White). In a multivariable linear regression, Asian (coefficient, 0.602; 95% CI, 0.263 to 0.941; P = .001), Black (coefficient, 0.919; 95% CI, 0.698 to 1.140; P < .001), and Hispanic (coefficient, 0.622; 95% CI, 0.329 to 0.915; P < .001) race and ethnicity were all associated with a higher SpO 2 for a given hemoglobin oxygen saturation. Asian (coefficient, −0.291; 95% CI, −0.546 to −0.035; P = .03), Black (coefficient, −0.294; 95% CI, −0.460 to −0.128; P = .001), and Hispanic (coefficient, −0.242; 95% CI, −0.463 to −0.020; P = .03) race and ethnicity were associated with lower average oxygen delivery rates. When controlling for the discrepancy between average SpO 2 and average hemoglobin oxygen saturation, race and ethnicity were not associated with oxygen delivery rate. This discrepancy mediated the effect of race and ethnicity (−0.157; 95% CI, −0.250 to −0.057; P = .002). CONCLUSIONS AND RELEVANCEIn this cohort study, Asian, Black, and Hispanic patients received less supplemental oxygen than White patients, and this was associated with differences in pulse oximeter performance, which may contribute to known race and ethnicity-based disparities in care.

Introduction and Objectives:The Life-Space Assessment can be used to measure a patient's level of mobility. This study evaluated the relationship between life-space mobility and frequency of hospitalization in the previous year and other clinical markers of health among adults with cystic fibrosis (CF). Methods: The Life-Space Assessment was administered to ambulatory adults with CF in clinic or by telephone. Life-space mobility was correlated with the most recent forced expiratory volume in one second as a percent of the predicted value (FEV1 % predicted), body mass index (BMI) and number of hospitalizations in the previous year. Results: Forty-eight subjects completed the Life-Space Assessment. Subjects had a life-space score of 88 Ϯ 26, FEV1 % predicted of 66% Ϯ 26% and BMI of 22.5 Ϯ 3.3. There was a statistically significant negative linear correlation between the number of times a subject was hospitalized in the previous year and life-space mobility (P = 0.001, R 2 = 0.20). This association was independent of FEV1 % predicted and BMI. Conclusion: The life-space mobility score is associated with frequency of hospitalization in adults with CF. A prospective study should be undertaken to assess the ability of the Life-Space Assessment to predict hospitalization and other outcomes in adults with CF.Please cite this paper as: Gottlieb ER, Smith EC, Wolfenden LL, Allman RM and Tangpricha V. Life-space mobility is associated with frequency of hospitalization in adults with cystic fibrosis. Clin Respir J 2011; 5: 245-251.Key words cystic fibrosis -life-space mobility -quality of life Correspondence Vin Tangpricha, MD,