Heart Rate Variability as a Marker of Stress in Trainee Performance of Critical Procedures

Sunday, March 22, 2026

12:15 PM - 1:15 PM Central Time

Location: Connections Central - RST 12

AE

Alana M. Engelbrecht, MD (she/her/hers)

Resident Physician
Children's National Hospital, District of Columbia

Disclosure(s): No relevant financial relationship(s) to disclose.
GB

Gabrielle Baylon, MD (she/her/hers)

Children's National Medical Center, District of Columbia

Disclosure(s): No relevant financial relationship(s) to disclose.
PD

Pallavi Dwivedi, MS, MPH

Statistician
Children National Hospital

Disclosure information not submitted.
LS

Lamia Soghier, MD, MEd

Professor of Pediatrics
Children's National Hospital

Disclosure information not submitted.
Amy H.J Wolfe, MD, MEd

Childrens National Health Systems, District of Columbia

Disclosure(s): No relevant financial relationship(s) to disclose.

Introduction: Heart rate variability (HRV) is an objective measure of physiologic stress. Although HRV has been studied in physicians during simulated procedures, data on pediatric critical care trainees performing real-time procedures are limited. This study aimed to: 1) quantify physiologic stress during high-stakes intensive care unit (ICU) procedures compared to baseline and 2) compare subjective and objective measures of stress experienced while performing these procedures.

Methods: This prospective observational study enrolled pediatric ICU trainees performing clinically indicated intubations, arterial lines, and central venous lines (CVL). Participants wore a Hexoskin vest to record continuous ECG data for HRV analysis. Baseline HRV was compared to HRV during procedures using a paired t-test/Wilcoxon rank test. Standard HRV metrics were calculated, including the Low-Frequency to High-Frequency Ratio (LF/HF), RMSSD (Root Mean Square of Successive Differences), Standard Deviation (SD) of NN intervals (SDNN), and SD2/SD1. Subjective stress (e.g. workload) was measured with the validated NASA-Task Load Index (NASA-TLX). Associations between HRV and NASA-TLX scores were assessed using the Pearson/Spearman’s rank correlation coefficient.

Results: Study participants included 1 resident (6.3%) and 7 fellows (93.8%) who performed 16 procedures (2 intubations, 7 CVLs, 7 A-lines) on 13 patients. There was a statistically significant change in mean trainee procedural HRV compared to baseline for all parameters except LF/HF reflecting increased sympathetic tone and parasympathetic withdrawal. Comparison of the mean baseline vs. procedural HRV was notable for increased LF/HF (4.79 vs. 6.67; p=0.07), increased SD2/SD1 (2.76 vs. 4.06; p= < 0.001), decreased RMSSD (34.53 vs. 17.28; p= < 0.001) and decreased SDNN (47.12 vs. 34.22; p=0.003) consistent with increased procedural stress. The mean NASA-TLX score (out of 100) was 55.16 (SD 17.38) reflecting high workload (e.g. stress). The difference between NASA-TLX scores and percent change in HRV during procedures was not statistically significant.

Conclusions: Trainees experience increased physiologic stress when performing emergent procedures in the ICU. Future directions aim to increase sample size and correlate HRV measures to procedural success and difficulty.