2002 OPEN FORUM Abstracts
Use of the Deltatrac II with the NPB 840 and NBP 7200 Ventilators
Allan Andrews, MS, RRT; Carl Haas, MLS, RRT; Ronald Dechert, MS, RRT; Critical Care Support Services, University of Michigan, Ann Arbor, MI
Background: Until recently resting energy expenditure (REE) calculations on ventilated patients were done using the Delta Trac II metabolic cart (SensorMedics Corporation, Yorba Linda, CA) in conjunction with the PB 7200 (Puritan Bennett, Inc., Carlsbad, CA), with acceptable results. The PB 840 is now our standard ventilator and it has been suggested that the 840 does not allow valid REE calculation. This study was done to compare the results obtained via the 7200 and those via the 840.
Methods: Ten normal subjects, breathing room air through a mouthpiece, had REEs calculated under 5 conditions; no support, PS=5 cm H20 via the 7200 and 840, and with a VT=0.7 L & f=2 via 7200 and 840. The order of testing was randomized and done in duplicate
Results: The figure shows minimal difference between 7200 and 840 for pressure (8 of 10 subjects) or volume (7 of 10) breaths. There was no significant difference (Wilcoxon Signed Ranks Test) in REEs for: 1) VC-840 vs. PS-840, 2) VC-7200 vs. PS-7200, 3) VC-840 vs. VC-7200, or $) PS-840 vs. PS-700.
Conclusions: Under these test conditions 1) There were no significant differences in REEs between the 840 or 7200, for either breath type; 2) most REEs were higher during mechanical ventilation. Due to the small sample size and limited variety of ventilator settings, further investigation is needed.