2006 OPEN FORUM Abstracts
EVALUATION OF PATIENT WORK-OF-BREATHING ON AN ELECTRONIC SIMULATOR AND THE VIASYS AVEA USING ESOPHAGEAL PRESSURE MONITORING
Dan Neifert, Ty Barnett, Lutana Haan RRT,
Background: Esophageal pressure monitoring is used to measure the work-of-breathing (WOB) in patients. The Viasys Avea has an option to measure WOB using esophageal pressure monitoring. The WOB on the Viasys Avea was compared to the WOB on the Hans Rudolph Electronic Breathing Simulator (HR1101).
Method: A lung model (Bear Model 1000) that includes the pleural space, was used. The Avea was connected to the lung model with a standard circuit. An esophageal balloon was placed in the lung model and connected to the Avea. The lung model was then connected to the HR 1101 with a resistance of 5 cm H2O/L/sec., compliance of 60 mL/cm H2O and a respiratory rate of 15 breaths per minute. The HR 1101 amplitude (cm H2O) was changed from 2.0 to 40.0 in multiples of 3.0, simulating an increase in patient effort. Avea settings: CPAP 5 cm H2O, without pressure support. The WOB measured by the HR 1101 (WOB HR 1101) and WOB measured by the Avea (WOB Avea) were recorded.
Amplitude 2.0; WOB HR 1101 .19 j/L; WOB Avea 02 j/L
Amplitude 5.0; WOB HR 1101 .42 j/L; WOB Avea .12 j/L
Amplitude 8.0; WOB HR 1101 .67 j/L; WOB Avea .2 j/L
Amplitude 11.0; WOB HR 1101 .92 j/L; WOB Avea .29 j/L
Amplitude 14.0; WOB HR 1101 1.17 j/L; WOB Avea .36 j/L
Amplitude 17.0; WOB HR 1101 1.43 j/L; WOB Avea .49 j/L
Amplitude 20.0; WOB HR 1101 1.64 j/L; WOB Avea .53 j/L
Amplitude 23.0; WOB HR 1101 1.93 j/L; WOB Avea .66 j/L
Amplitude 26.0; WOB HR 1101 2.14 j/L; WOB Avea .76 j/L
Amplitude 29.0; WOB HR 1101 2.45 j/L; WOB Avea .86 j/L
Amplitude 32.0; WOB HR 1101 2.69 j/L; WOB Avea .92 j/L
Amplitude 35.0; WOB HR 1101 2.92 j/L; WOB Avea .97 j/L
Amplitude 38.0; WOB HR 1101 3.14 j/L; WOB Avea 1.0 j/L
Amplitude 40.0; WOB HR 1101 3.29 j/L; WOB Avea 1.02 j/L
Conclusion: As the Amplitude on the HR 1101 is increased, simulating an increase in patient inspiratory effort, the WOB HR 1101 and WOB Avea increase linearly. However, the difference between WOB HR 1101 and WOB Avea increases as amplitude increases. This difference may be cause by the way each system calculates WOB.