Pulse pressure variation accurately predicts fluid responsiveness under controlled mechanical ventilation, with a gray zone between 9% and 13% requiring integration with functional hemodynamic tests.
This narrative review highlights the evolution and clinical utility of pulse pressure variation for predicting fluid responsiveness in perioperative and critical care settings.
Fluid administration remains one of the most common therapeutic interventions in surgical and critically ill patients. Both insufficient and excessive fluid delivery are associated with adverse outcomes, underscoring the need to predict fluid responsiveness rather than administer fluids empirically. In this context, pulse pressure variation (PPV) has evolved from a physiological observation into a key tool in perioperative and critical care hemodynamic management. PPV is based on cardiopulmonary interactions during positive-pressure ventilation, where cyclic changes in intrathoracic pressure induce predictable variations in stroke volume. Its amplitude reflects the position of the ventricles on the Frank–Starling curve, identifying patients likely to benefit from fluid administration. The widespread adoption of PPV has been facilitated by automated monitoring systems capable of continuously analyzing arterial waveform variations. Under controlled mechanical ventilation, sinus rhythm, adequate tidal volumes, and preserved cardiopulmonary mechanics, PPV accurately predicts fluid responsiveness. However, its reliability decreases when these conditions are not met, such as during spontaneous breathing, arrhythmias, low tidal volumes, or right ventricular dysfunction, requiring a more contextual interpretation. The introduction of the “gray zone” concept, typically between 9% and 13%, represents a major advance, acknowledging that intermediate values do not allow definitive classification. In these cases, PPV should be integrated with functional hemodynamic tests, such as passive leg raising or mini-fluid challenges. In the operating room, PPV is widely incorporated into goal-directed therapy strategies to optimize intravascular volume and maintain adequate perfusion. When applied under appropriate conditions, PPV-guided management improves hemodynamic stability and may reduce postoperative complications.
Matronola et al. (Wed,) conducted a review in Surgical and critically ill patients. Pulse pressure variation (PPV) was evaluated. Pulse pressure variation accurately predicts fluid responsiveness under controlled mechanical ventilation, with a gray zone between 9% and 13% requiring integration with functional hemodynamic tests.