Figure 2From: Relation between respiratory variations in pulse oximetry plethysmographic waveform amplitude and arterial pulse pressure in ventilated patientsRelationship between ΔPOP and ΔPP. Empty circles indicate patients receiving vasopressor support, and empty squares indicate patients with severe hypotension. ΔPOP, respiratory variations in POP waveform amplitude; ΔPP, respiratory variations in systemic pulse pressure.Back to article page