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

Association Between Palpable Peripheral Pulses and Arterial Blood Pressure in Patients With Circulatory Shock: An International Prospective Multicenter Observational Cohort Study

This prospective multicenter observational study aims to investigate the relationship between palpable peripheral pulses and simultaneously measured arterial blood pressure in adult patients with circulatory shock or impending circulatory failure. Peripheral pulse palpation is routinely used in emergency medicine, trauma care, critical care, and cardiopulmonary resuscitation as a rapid clinical assessment of circulation. However, the association between palpable pulses and actual arterial blood pressure remains poorly validated.

Patients treated in emergency departments, intensive care units, operating rooms, and other acute care settings will undergo routine pulse palpation at predefined anatomical locations including carotid, femoral, and radial arteries. Simultaneously measured non-invasive and/or invasive arterial blood pressure values will be recorded from routine clinical monitoring systems. Additional clinical variables relevant to circulatory status will also be collected.

The study seeks to define blood pressure thresholds associated with pulse palpability and evaluate the agreement between invasive and non-invasive blood pressure measurements in patients with circulatory shock.

Study Overview

• Status: Recruiting
• Conditions: Shock; Critical Illness; Hypotension; Hemodynamic Instability; Circulatory Shock
• Intervention / Treatment: Procedure: Peripheral Pulse Palpation

Detailed Description

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.

• Study Type: Observational
• Enrollment (Estimated): 5000

Contacts and Locations

• Study Contact: Name: Mattias Günther, MD PhD; Phone Number: 46812361000; Email: mattias.gunther@ki.se

Study Locations

• Sweden
  • Stockholm County
    • Stockholm, Stockholm County, Sweden, 11883
      • Recruiting
      • Region Stockholm, all hospitals
      • Contact: Mattias Günther, MD PhD; Phone Number: 46812361000; Email: mattias.gunther@ki.se

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Adult patients with circulatory shock or impending circulatory failure treated in emergency departments, intensive care units, operating rooms, trauma centers, and other acute care settings.

Description

Inclusion Criteria:

• Clinical signs of circulatory shock or impending circulatory failure
• Availability of non-invasive and/or invasive arterial blood pressure monitoring
• Pulse palpation possible without interfering with emergency care

Exclusion Criteria:

• Peripheral vascular conditions preventing reliable pulse palpation
• Major extremity amputation affecting assessment sites
• Clinical situations where study procedures interfere with life-saving treatment

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Patients With Circulatory Shock; Adult patients with clinical signs of circulatory shock or impending circulatory failure undergoing routine hemodynamic monitoring with non-invasive and/or invasive arterial blood pressure measurement during standard clinical care.	Procedure: Peripheral Pulse Palpation; Manual palpation of carotid, femoral, and radial pulses performed during routine clinical care in patients with circulatory instability. Simultaneous arterial blood pressure measurements are recorded from standard monitoring systems. No study-specific treatment or intervention is administered.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Association between palpable pulses and systolic arterial blood pressure	Relationship between palpable carotid, femoral, and radial pulses and simultaneously measured systolic arterial blood pressure.	During episodes of circulatory instability, up to 24 hours after inclusion

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Mean arterial pressure associated with pulse palpability	Relationship between pulse palpability and mean arterial pressure (MAP).	During episodes of circulatory instability, up to 24 hours after inclusion
Agreement between non-invasive and invasive blood pressure measurements	Agreement between oscillometric non-invasive blood pressure and invasive arterial blood pressure measurements.	During episodes of circulatory instability, up to 24 hours after inclusion
Effect of vascular disease and vasoactive medication on pulse palpability	Influence of peripheral vascular disease, atherosclerosis, age, and vasoactive medications on pulse palpability.	During hospital admission, up to 30 days

Collaborators and Investigators

• Sponsor: Region Stockholm

Publications and helpful links

General Publications

• Kim SH, Lilot M, Sidhu KS, Rinehart J, Yu Z, Canales C, Cannesson M. Accuracy and precision of continuous noninvasive arterial pressure monitoring compared with invasive arterial pressure: a systematic review and meta-analysis. Anesthesiology. 2014 May;120(5):1080-97. doi: 10.1097/ALN.0000000000000226.
• Gunther M, Dahlberg M, Rostami A, Azadali A, Arborelius UP, Linder F, Rostami E. Incidence, Demographics, and Outcomes of Penetrating Trauma in Sweden During the Past Decade. Front Neurol. 2021 Nov 15;12:730405. doi: 10.3389/fneur.2021.730405. eCollection 2021.

Study record dates

Study Major Dates

• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): June 1, 2031
• Study Completion (Estimated): December 31, 2031

Study Registration Dates

• First Submitted: May 13, 2026
• First Submitted That Met QC Criteria: May 19, 2026
• First Posted (Actual): May 27, 2026

Study Record Updates

• Last Update Posted (Actual): May 27, 2026
• Last Update Submitted That Met QC Criteria: May 19, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Hypotension; Trauma; Critical Care; Resuscitation; Hemodynamic Monitoring; Hemodynamic Instability; Arterial Blood Pressure; Circulatory Shock; Pulse Palpation; Peripheral Pulse
• Additional Relevant MeSH Terms: Vascular Diseases; Cardiovascular Diseases; Pathologic Processes; Disease Attributes; Pathological Conditions, Signs and Symptoms; Critical Illness; Wounds and Injuries; Hypotension; Shock
• Other Study ID Numbers: 2026-02475-01

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: Data sharing plans are currently undecided due to ongoing considerations regarding ethical approvals, multicenter collaboration agreements, and data protection regulations.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No