The use of capillary refill time In adult critically ill patients: a narrative review on potentials, pitfalls, and perspectives.

The evolution of Capillary refill time (CRT) use in clinical medicine is interesting, transforming a simple bedside observation into a reliable tool for assessing tissue perfusion in critically ill patients. When Henry Beecher and colleagues first systematized CRT measurement in 1947, they recognized its potential as a rapid method to evaluate circulatory status in trauma casualties, establishing a foundational framework that would influence intensive care practice for decades to come. However, clinicians soon discovered that relying on visual inspection alone introduced troubling variability between observers and even within the same observer's assessments, with expertise and training significantly influencing measurement accuracy. This recognition of CRT's limitations sparked a concerted effort to transform the measurement from a purely subjective exercise into a standardized, objective clinical tool. Researchers systematically refined protocols by establishing consistent pressure application techniques, standardized measurement sites, and defined normal thresholds (approximately 3 s for healthy adults). These methodological advances set the stage for rigorous clinical validation. Subsequent research revealed that CRT correlated powerfully with microvascular blood flow and independently predicted mortality and organ dysfunction in septic patients. Meta-analyses encompassing over 60,000 patients confirmed that abnormal CRT carried substantially elevated mortality risk, particularly when measured using standardized techniques. More recently, the ANDROMEDA-SHOCK trials demonstrated that CRT could serve not merely as a prognostic marker but as an actionable resuscitation target. CRT is nowadays considered an adjunct bedside marker to guide fluid and vasopressor resuscitation in adults with sepsis and septic shock, supporting individualized hemodynamic strategies while reducing over-resuscitation risks.