Figure 1 -.
Simultaneous fluctuations in arterial pressure (top) and plethysmographic (bottom) waveforms during mechanical ventilation. The systolic pressure and systolic plethysmographic component are maximal during inspiration and decline proportionally in expiration. Similarly, the arterial pulse pressure and plethysmographic amplitude are maximal during inspiration and minimal during expiration. Psmax, maximal arterial systolic pressure; Splethmax, maximal plethysmographic waveform systolic component; Psmin, minimal arterial systolic pressure; Splethmin, minimal plethysmographic waveform systolic component; Ppmax, maximal arterial pulse pressure; Pplethmax, maximal plethysmographic waveform amplitude; Ppmin, minimal arterial pulse pressure; Pplethmin, minimal plethysmographic waveform amplitude.