Comparison of intraesophageal balloon pressure measurements with a nasogastric-esophageal balloon system in volunteers.

Recently, an esophageal balloon incorporated into a nasogastric tube was designed that allowed measurement of intraesophageal pressure. To define the performance of this nasogastric-esophageal balloon (NG-EB) system, comparative measurements were made with a standard esophageal balloon while subjects were in the sitting, supine, and left lateral decubitus and right lateral decubitus positions. Values for dynamic pulmonary compliance, pulmonary resistance, and cough pressure were not statistically different between the two systems. Mean static deflation pressure-volume (P-V) curves using the NG-EB were shifted to the left of the esophageal balloon P-V curve in all body positions, but static lung compliance (CL) was not statistically different. For both balloon systems, CL showed no significant difference between sitting and right lateral decubitus positions. Results from this study indicate that the NG-EB system acceptably reflects esophageal balloon pressure measurements and should be useful in estimating lung and chest wall mechanics in acutely ill patients requiring mechanical ventilation.