Respiratory consequences of abdominal hernia in a patient with severe chronic obstructive pulmonary disease.

The diaphragm is the most important muscle of respiration. It is believed that the abdominal contents affect diaphragmatic contraction by helping determine its length tension state and by acting as a fulcrum for this muscle to lift the rib cage and thereby increase lung volume. In support of these concepts we describe a patient with severe chronic obstructive pulmonary disease and a large midline hernia of the abdomen who, when standing, had a gastric pressure (Pg) of 4 cm H2O and a maximal transdiaphragmatic pressure (Pdimax) of 14 cm H2O. This was associated with an O2 saturation of 82%, lower thoracic and upper abdominal paradoxical breathing, and severe dyspnea. Once the hernia was reduced there was a rise in Pg to 12 cm H2O, of Pdimax to 27 cm H2O, and of O2 saturation to 89%. There was normalization of the breathing pattern and a decrease in dyspnea. Reduction of this patient's abdominal hernia resulted in an increase in her exercise tolerance.