ABSTRACT
Obesity is defined as an excessive accumulation of fat, with a resulting increase of body mass index (BMI) > 30 kg/m2. A BMI > 25 (overweight) represents a health-risk factor, and obesity is the most frequently found health risk in the United States, where more than one in three adults weigh 20% over the ideal value. The prevalence of obesity is 3.5 million in the United States (26% adults of 20-75 years), reaching 31% of the male and 35% of the female population. The prevalence of extreme obesity (BMI 40 kg/m2) has quadrupled and that of BMI 50 kg/m2 has increased fivefold (1). Obese patients frequently present with acute on chronic respiratory failure (CRF) in the emergency ward, or are discovered in a chronic status as they are investigated for suspicion of obstructive sleep apnea syndrome (OSAS), for assessment of CRF, or for preoperative evaluation.
