COMPARISON OF ESOPHAGEAL, TRACHEAL, AND MOUTH OCCLUSION PRESSURE IN PATIENTS WITH CHRONIC OBSTRUCTIVE PULMONARY-DISEASE DURING ACUTE RESPIRATORY-FAILURE

Abstract

In 14 acutely ill patients with chronic obstructive pulmonary disease [COPD] who were either intubated or breathed via a tracheostomy, pressures generated in the esophagus and trachea during the first 0.1 s of spontaneous inspiratory efforts against closed airway (P0.1) were measured. No significant difference was found between P0.1 in the trachea and esophagus, where it was measured at 2 balloon levels (distance from balloon tip to nares: 35 and 45 cm). In 4 of the patients esophageal and mouth occlusion pressures were also compared during mouth breathing, the orifice of tracheostomy being temporarily obstructed. Mouth P0.1 in the 4 patients averaged .apprx. 47% of the esophageal occlusion pressure (4.4 .+-. 1.7 vs. 8.9 .+-. 3.1 cm H2O, respectively). Because in patients with COPD with upper airways bypassed (tracheostomized or intubated) the changes in esophageal and tracheal pressure during occluded respiratory efforts were similar, the difference between esophageal and mouth occlusion pressure must be due to the tissue compliance of the oropharynx.