ASAIO CARDIOPULMONARY ABSTRACTS
INTRAAORTIC BALLOON PUMP (IABP) TIMING ERRORS IN ADULT PATIENTS
Delays and distortions of arterial pressure waveform landmarks for timing IABP inflation and deflation can introduce timing errors and misrepresentation of the resulting hemodynamics. It is hypothesized that timing errors contribute to reduced IABP efficacy by reducing diastolic augmentation and increasing rather than decreasing afterload.
Intraoperative hemodynamic data from 10 IABP patients were digitally recorded during cardiac surgery. High-fidelity, aortic root pressure (AoPr) and flow waveforms were recorded simultaneously with the arterial pressure (IABAoP) from the IABP fluid-filled lumen used to time IABP inflation and deflation. ECG and radial artery pressure (RadP) were recorded at the same time. The signals were post-processed to correct for electronic delays.
Inflation and deflation landmark delays were observed in aH patients. When comparing AoPr to IABAoP waveforms, delays ranged from 60 to 119 msec. Landmark delays in the RadP waveform were even greater (156 to 207 msec). Afterload increase was often seen in the AoPr when the IABAoP indicated afterload reduction. Waveform quality was often found to deteriorate within 12 hours of IABP placement resulting in inconsistent pressure trigger mode operation. When timing in one patient was switched from the IABAoP to the AoPr waveform, stroke volume increased 18% while afterload reduced 11 mm Hg. These findings demonstrate pervasive IABP timing errors when using standard arterial pressure monitoring. Furthermore, timing errors can be rectified and IABP efficacy improved by timing to high-fidelity pressure waveforms.Copyright © 2003 by the American Society for Artificial Internal Organs