Subjects at high risk are defined as having 1 or more of the following co-morbid conditions: body mass index (BMI) between 30-40 kg/m2, inclusive, active smokers, chronic obstructive pulmonary disease (COPD), diabetes, immunosuppression, coronary artery disease, chronic corticosteroid use, low pre-operative serum albumin, advanced age, or renal insufficiency.