Effects of surgery on the function of the respiratory muscles.

The function of the respiratory muscles (RM) is affected positively or negatively by a variety of surgical procedures. Cardiac, thoracic and upper abdominal surgery impair the RM function and lead to postoperative complications such as hypoxia, atelectasis, aspiration and infections. Preoperative assessment of RM function is cardinal to avoid or attenuate these complications. Three types of surgical procedures, lung transplantation, lung volume reduction surgery and surgery for obesity have been shown to improve RM function. A mechanism by which these types of operation have shown beneficial effects on RM function is multifactorial, depending on geometrical factors, from the reduction of hyperinflation and those depending on changes on the control of breathing. Physicians dealing with postoperative care of patients should be aware of the pathophysiological mechanisms that impair or improve respiratory muscle function as a result of a surgery as well as of the therapeutic modalities.