The Science Journal of the American Association for Respiratory Care

2010 OPEN FORUM Abstracts


Carl D. Mottram, Jamal A. Awad, Mahamednur M. Harun, Katrina M. Hynes, Abdirashid S. Ibrahim, Muhamed D. Mursal, Paul D. Scanlon; Pulmonary and Critical Care, Mayo Clinic, Rochester, MN

Background: Cardiopulmonary exercise testing (CPET) involves monitoring numerous physiologic parameters, including blood pressure, for safety and diagnosis. Blood pressure (B/P) is typically measured using auscultation and a sphygmomanometer, but can also be measured using an arterial catheter connected to a pressure transducer (direct method). The B/P response to exercise is a critical measurement and can suggest a plethora of abnormalities depending on its response, yet it is subject to error. The Tango B/P system was designed to measure B/P during exercise testing by integrating a microphone into the cuff and capturing the R wave signal from the EGC system to further clarify the signal and minimize noise which can cause errors. The system also allows the user to listen to the Korotkoff sounds to manually determine the B/P along with displaying the automated B/P. The comparison of B/P measured non-invasively versus directly is not well characterized during CPET. In a single study, Rasmussen and colleagues reported that the mean systolic pressure difference (direct minus indirect) was +29 mmHg and the mean diastolic difference was +12.3 mmHg during exercise testing. Hypothesis: The Tango system accurately measures B/P automatically when compared to the manual method during exercise. The B/P measured non-invasively via the Tango versus the B/P measured with an arterial line has the same relationship of direct to indirect as in previously published data. Method: 14 subjects for whom a CPET with an arterial line was ordered as a clinical test were used in the comparison. In these subjects an arterial line is placed and B/P measured according to standard laboratory procedures. On the opposite arm as the catheter the non-invasive B/P system was placed according to the manufacture’s recommendations. B/P was recorded using both systems at rest and maximal exercise. Data were analyzed using Student t-test for comparability. Results: Table 1 Conclusion: During maximal CPET there is no significant difference between the B/P measured automatically and using the manual auditory method with the Tango system. The relationship of direct versus indirect measurement of B/P during exercise is consistent with previously published data for systolic pressure but demonstrates a dissimilar correlation in diastolic pressure with no substantial difference between the measurements. However the sample size is limited and would need further study to characterize this relationship. Sponsored Research - None Table 1