Can we reliably use pulse pressure as a surrogate for stroke volume? Physiological background and potential clinical implications for shock resuscitation.

In critically ill patients, early hemodynamic assessment is essential for guiding shock resuscitation. While cardiac output (CO) is a key indicator of circulatory status, its measurement is often limited by technical and practical constraints. This perspective explores the physiological and clinical relevance of pulse pressure (PP) as a potential surrogate for stroke volume (SV), emphasizing its accessibility at the bedside. The paper discusses how factors such as arterial compliance, vascular tone, and pulse wave amplification influence the PP-SV relationship, often complicating interpretation in acute and complex hemodynamic states. It also examines the effects of vasopressors, vascular decoupling, and catheter site on PP measurements, particularly in septic shock. Despite its limitations, the review highlights how peripheral PP, when carefully interpreted, may aid in identifying low SV and guiding early resuscitation strategies.