Checking the pulse in the 21st century: Interobserver reliability of carotid pulse detection by point-of-care ultrasound

Abstract

Introduction: Detection of a pulse is crucial to decision-making in the care of patients who are in cardiac arrest, however, the current standard of manual pulse palpation is unreliable. An emerging alternative is the use of point-of-care ultrasound (POCUS) for direct assessment of the carotid pulse. The primary objective of this study is to determine the interobserver reliability for physician interpretation of pre-recorded point-of-care ultrasound pulse-check clips for patients who are in cardiac arrest.

Methods: We conducted a web-based survey of residents and physicians working in an academic center. Participants were shown a tutorial demonstrating POCUS detection of the carotid pulse and then asked to interpret 15 carotid pulse ultrasound clips from patients who were in cardiac arrest. The primary outcome was interobserver reliability for carotid pulse assessment. Secondary outcomes included interobserver reliability stratified by physician role and POCUS experience, median tutorial and median pulse assessment duration. Interobserver reliability was determined by Krippendorff's ⍺.

Results: 68 participants completed the study, with a response rate of 75%. There was high interobserver reliability for pulse assessment amongst all study participants (⍺ = 0.874, 95% CI 0.869 to 0.879). All sub-groups had ⍺ greater than 0.8. Median tutorial duration was 35 s (IQR 29). Median pulse assessment duration was 6 s (IQR 5) with 76% of assessments completed within 10 s.

Conclusion: Interpretation of the carotid pulse by POCUS showed high interobserver reliability. Further work must be done to determine the performance of POCUS pulse assessment in real-time for patients who are in cardiac arrest.

Keywords: Cardiac arrest; Point-of-care ultrasound; Pulse check.