Authors: Chala H et al.
Source: Canadian Journal of Anesthesia. Published January 13, 2026.
Summary:
This systematic review examined risk factors associated with a central-to-peripheral arterial blood pressure gradient (CPAPG) in adults, a phenomenon in which radial arterial pressures underestimate central arterial pressure. Such gradients can meaningfully distort hemodynamic interpretation and lead to inappropriate clinical decisions in the operating room and intensive care unit, where radial artery catheters are routinely used as the monitoring standard.
The authors reviewed 55 studies encompassing 5,598 adult patients with simultaneous radial and central arterial pressure monitoring across a variety of clinical contexts, including cardiopulmonary bypass, liver transplantation, and ICU care. Across these studies, 90 distinct potential risk factors were assessed, of which 36 showed a statistically significant association with CPAPG.
The most consistent and reproducible predictors were complex surgical procedures and smaller radial artery diameter, with every study assessing these factors demonstrating a significant association with CPAPG. Vasopressor use—particularly at higher doses—was frequently associated with pressure gradients, although results were heterogeneous, achieving statistical significance in approximately half of the studies examined.
Several demographic characteristics were identified as contributory in select studies, including older age, female sex, and shorter stature. These factors are thought to be indirect markers of smaller radial artery caliber, which may exaggerate pressure damping or amplification. Other reported contributors included hypothermia, low cardiac output states, cardiopulmonary bypass, severe illness, and altered vascular tone, though these factors demonstrated less consistent consensus across the literature.
Overall, the review highlights that CPAPG is common, multifactorial, and often predictable. In patients with multiple risk factors, reliance on radial arterial pressure alone may be misleading, particularly when precise blood pressure targets are critical.
What You Should Know:
Central-to-peripheral arterial pressure gradients are common and can substantially underestimate true central blood pressure, especially during complex surgery or critical illness. Recognizing high-risk patients allows clinicians to adjust monitoring strategies before management decisions are affected.
Key Points:
CPAPGs have been reported in up to three-quarters of monitored patients in some settings.
Complex procedures and small radial artery diameter are the most consistent predictors of CPAPG.
Vasopressor use frequently contributes to pressure gradients, though with variable consistency.
Demographic factors such as older age, female sex, and shorter height may increase risk.
Central arterial cannulation should be considered in patients with multiple risk factors to improve measurement accuracy.
Thank you to the Canadian Journal of Anesthesia / Journal canadien d’anesthésie for publishing this clinically relevant synthesis addressing a frequently overlooked but important limitation of radial arterial pressure monitoring.