Pathophysiology of the respiratory system related to anesthesia

The pathophysiology of the respiratory system can be viewed by simply evaluating the status of a functional residual capacity (FRC). More specifically, patients with airways that are characterized as extremely compliant or "floppy" will have an increased FRC, which is the hallmark of chronic obstructive pulmonary disease. Patients with noncompliant, "stiff" lungs suffer from a form of restrictive disease with a resultant reduction in the FRC. Hence, the implications for anesthesia care focus on the FRC; that is, raising the FRC in the restrictive disease patient and normalizing or preventing further increase in the FRC in the patient with chronic obstructive pulmonary disease.