Figure 32-10 Effect of small air bubbles within arterial pressure monitoring systems. Arterial pressure waveforms are displayed along with superimposed fast flush square-wave artifacts. A, The original monitoring system has an adequate dynamic response (natural frequency, 17 Hz; damping coefficient, 0.2). B, A small 0.1-mL air bubble added to the monitoring system produces a paradoxical increase in arterial blood pressure. Note the decreased natural frequency of the system. C, A larger 0.5-mL air bubble further degrades the dynamic response and produces spurious arterial hypotension. (Redrawn from Mark JB: Atlas of Cardiovascular Monitoring. New York, Churchill Livingstone, 1998, Fig. 9-14.)