Peripheral pULSe Assessment and Arterial pRessure (PULSAR) (PULSAR)

The presence or absence of palpable peripheral pulses is widely used as a rapid bedside indicator of circulatory status during trauma care, emergency medicine, intensive care, and cardiopulmonary resuscitation. Advanced Trauma Life Support (ATLS) teaching traditionally assumes that palpable pulses at different anatomical sites correspond to specific systolic blood pressure thresholds. However, these assumptions are based on limited evidence from small observational studies.

This international multicenter prospective observational cohort study aims to investigate the relationship between palpable carotid, femoral, and radial pulses and simultaneously measured arterial blood pressure in adult patients with circulatory shock or impending circulatory failure.

Patients receiving routine hemodynamic monitoring with non-invasive blood pressure (NIBP) and/or invasive arterial blood pressure (IBP) monitoring will be included. Pulse palpation will be performed during routine clinical care without altering treatment or management.

The primary objective is to determine the association between pulse palpability and measured systolic blood pressure. Secondary objectives include identifying blood pressure thresholds associated with pulse palpability, evaluating agreement between invasive and non-invasive blood pressure measurements, and assessing whether patient factors such as vascular disease or vasoactive medication use influence pulse palpability.