Monitoring Distal Extremity Perfusion with the Pulse Amplitude Monitor during Vascular Reconstruction

One problem in vascular surgery today is the effective monitoring of blood flow to distal extremities before, during, and after a surgical reconstruction. Current methods of blood flow assessment such as periodic pulse palpation, skin signs, Doppler sounds, and capillary refill are neither continuous nor objectively comparable. Because of the qualitative nature of these methods, it is difficult to compare measurements taken by different people at different times, making a quick and appropriate response to changing perfusion requirements difficult. In order to address these problems, a system has been designed to monitor and document pulse amplitudes non-invasively. A pulse amplitude monitor system (Figure 1) consists of a pulse sensor and a waveform monitor (Impra, Tempe, AZ). The sensor (Figure 2) contains a piezoelectric film which is used to detect the slight mechanical oscillations of the arterial wall beneath the skin surface. This film is mounted on a compressible foam block which isolates the vibrations and maintains constant force on the skin. The sensor is taped over a distal pulse, typically that of the dorsalis pedis.