Ann Am Thorac Soc. 2017. May 16
The surgical patient population is increasingly elderly and comorbid and poses challenges to perioperative physicians. Accurate pre-operative risk stratification is important to direct perioperative care. Reduced aerobic fitness is associated with increased post-operative morbidity and mortality. Cardiopulmonary exercise testing is an integrated and dynamic test that gives an objective measure of aerobic fitness or functional capacity and identifies the cause of exercise intolerance. Cardiopulmonary exercise testing provides an individualized estimate of patient risk that can be used to predict post-operative morbidity and mortality. This technology can therefore be used to inform collaborative decision making and patient consent; to triage the patient to an appropriate peri-operative care environment; to diagnose unexpected comorbidity; to optimize medical co-morbidities pre-operatively and to direct individualized pre-operative exercise programmes. Functional capacity, evaluated as the anaerobic threshold and peak oxygen uptake (VO2peak) predicts post-operative morbidity and mortality in the majority of surgical cohort studies. The ventilatory equivalents for carbon dioxide (an index of gas exchange efficiency), is predictive of surgical outcome in some cohorts. Prospective cohort studies are needed to improve the precision of risk estimates for different patient groups and to clarify the best combination of variables to predict outcome. Early data suggests that preoperative exercise training improves fitness, reduces the debilitating effects of neoadjuvant chemotherapy and may improve clinical outcomes. Further research is required to identify the most effective type of training and the minimum duration required for a positive effect.