Using Digital Biomarkers for Objective Assessment of Perfusionists' Workload and Acute Stress During Cardiac Surgery

Area of Science:

• Physiological monitoring in healthcare
• Human factors in surgery
• Cardiovascular research

Background:

• The cardiac operating room (OR) is a complex, high-risk environment.
• Perfusionists play a critical role during cardiopulmonary bypass (CPB), managing patient perfusion and coordinating with the surgical team.
• Objective measures are needed to assess perfusionist workload and stress.

Purpose of the Study:

• To investigate objective digital biomarkers of perfusionist workload and stress using heart rate variability (HRV) metrics.
• To explore the relationship between HRV parameters and validated self-report measures of workload and stress.
• To identify HRV biomarkers suitable for real-time cognitive support systems.

Main Methods:

• Utilized wearable physiological sensors to capture HRV metrics in a real cardiac OR.
• Collected self-report data for surgical task workload (SURG-TLX) and acute stress (STAI-SF).
• Analyzed correlations between HRV parameters, workload, stress, and surgical outcomes (e.g., bypass time, hospital stay).

Main Results:

• The frequency-domain HRV parameter HF relative power - FFT (%) showed the strongest association with task workload (r = -0.491, p = 0.003).
• The time-domain HRV parameter RMSSD (ms) demonstrated the strongest correlation with acute stress (r = -0.489, p = 0.005).
• Some HRV biomarkers were also linked to bypass time and patient length of stay.

Conclusions:

• HRV metrics can serve as objective digital biomarkers for perfusionist workload and stress in the cardiac OR.
• Specific HRV parameters, HF relative power and RMSSD, are promising indicators of workload and stress, respectively.
• Findings support the development of real-time cognitive support systems for surgical teams based on HRV monitoring.