The Science Journal of the American Association for Respiratory Care

2011 OPEN FORUM Abstracts

THE USE OF INDIRECT CALORIMETRY MEASUREMENT FOR QUANTITATIVE ASSESSMENT OF PATIENT VENTILATOR/ASYNCHRONY.

Thomas H. Glass1, Beverly Mauer1, Jeremy Luedtke2, Robert Welsh2; 1Respiratory Care, William Beaumont Hospital, Royal Oak, MI; 2Surgical, William Beaumont Hospital, Royal Oak, MI

The Use of Indirect Calorimetry Measurement of REE & VO2ml/min for Quantitative Assessment of Patient Ventilator/Asynchrony Thomas Glass RRT, Beverly Mauer RRT, Jeremy Luedtke MD, Robert Welsh, MD, William Beaumont Hospital, Royal Oak, MI Background: The introduction of Indirect Calorimetry measurements in our Surgical Intensive Care Units was initially often met with an unusually high Resting Energy Expenditure (REE) with patients on APRV mode of ventilation. Once all possible technical variables were addressed, it was determined that the measurements were in fact accurate and that the patient's REE was elevated and appeared to be directly related to observed patient ventilator asynchrony. Once this suspected correlation between increased REE and patient/ventilator asynchrony was identified, we established a testing protocol for those patients who displayed at least one of the following criteria: 1) Delay or failure to wean 2) Graphic display of ventilator flow and/or pressure patterns consistent with asynchrony 3) Clinical display of increased respiratory effort. Methods and Materials: The Puritan Bennett 840 Ventilator was in use with all patients included in the study. The test equipment used for Indirect Calorimetry was the MedGraphics Ultima. The 840 ventilator was connected to a Bio-Med Devices Oxygen/Air blender during testing procedures to facilitate the stabilization of FIO2. The criteria for acceptable data reported during the study were: REE, VCO2 and VO2 covar < 10% for 25 minutes or an REE, VCO2 and VO2 covar < 5% for a 10 minute period. The testing procedures were conducted following the AARC Clinical Practice Guidelines for Indirect Calorimetry. Data collection was performed on 33 patients initially on APRV mode, displaying ventilator asynchrony with an accompanying increased REE. Follow-up testing was performed after they had been switched to another mode. Conclusion: In addition to the well-established utilization of Indirect Calorimetry for nutritional support, we have found the same data to be of significant value in determining ventilator setting/patient compatibility. We are continuing to assess the application of this information to modify ventilator management were indicated.
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Comparison of REE of Patients on APRV Verses Alternative Methods
There was a statistcally significant difference between the APRV REE and the non-APRV REE using a paired ttest p< 0.0001