Introduction

Obesity is a major health problem worldwide. The number of overweight men and women in the US has risen steadily since 1960. According to the most recent epidemiological survey, a staggering 64.5% of the adult population in the US are overweight with 4.7% being morbidly obese. Obesity has been linked to increasing morbidity and mortality from numerous medical disorders including non-insulin dependent diabetes mellitus, hypertension, dyslipidemia, cardiovascular and cerebrovascular disease, and many malignancies. It is speculated that morbid obesity increases the incidence of complications in patients requiring hospitalization and this may be associated with an increased hospital length of stay and poorer outcome. As obesity has a major impact on the respiratory system it is likely that the increased morbidity and mortality of hospitalized obese patients is related to an increase in pulmonary complications. This chapter will review the impact of obesity on respiratory function, its associated morbidity and finally the particular clinical management.

Obesity and the respiratory system

Obese persons are at increase risk of developing respiratory complication such as atelectasis, pneumonia, pulmonary embolism, aspiration pneumonia and acute respiratory failure, particularly in the post-operative period (see Chapter 4). Obesity is the most common factor predisposing to the obstructive sleep apnea (OSA) syndrome.