Ventilatory And Respiratory Outcomes Are Impaired By Obesity In A Clinical Setting

Excess adiposity can alter breathing mechanics. Previous research has established relationships between obesity and asthma, sleep apnea, and minute ventilation. More relationships are likely to exist but require further investigation. PURPOSE: To identify the effect of obesity on ventilatory and respiratory diagnoses and outcomes in hospital patients. METHODS: We exported patient registries from two departments at a major Midwestern hospital: the emergency department (ED; n = 1,005) and trauma center (TC; n = 424). All patients were between 15 and 85 years of age and had a Glasgow Coma Scale score ≥ 14, enabling cogent reporting of health history. All TC patients were admitted for thoracic trauma, permitting analysis of obesity's effect on ventilatory treatments and outcomes. ED patients did not experience thoracic trauma. Linear and logistic regressions assessed the effect of obesity on respiratory rate, oximetry, diagnosis of respiratory disease, and use of mechanical ventilation. Confounding variables were held constant. RESULTS: Among ED patients, 30.9% were obese. Obesity was unrelated to sex (p = 0.642) and age (p = 0.963). However, sex (p = 0.002) and age (p < 0.001) predicted diagnosis of a respiratory disease; holding both constant, obesity predicted a 76.5% increase in the odds of diagnosis (p = 0.009). Holding sex (p = 0.044) and age (p < 0.001) constant, obesity predicted a 0.6% reduction in oxygen saturation (p < 0.001). Among TC patients, 26.8% were obese, and obesity was unrelated to sex (p = 0.673) and age (p = 0.727). Holding age (p = 0.023) and injury severity score (ISS; p = 0.071) constant, the odds of obese patients presenting with a pulmonary contusion were decreased by 45.6% (p = 0.027), possibly owing to insulation of impact. Despite less severe pulmonary injury, the odds of requiring mechanical ventilation were elevated by 120.9% (p = 0.015) while holding sex (p = 0.049) and ISS (p < 0.001) constant. The duration of ventilation was 3.4 days longer, but insignificant owing to wide variance. Holding ISS constant (p = 0.008), respiratory rate was 0.8 breaths per minute higher in obese patients (p = 0.020). CONCLUSION: These data support the hypothesis that obesity is a risk factor for several pulmonary abnormalities. Weight management may be an important component of long-term patient care in this population.