Association Between Heart Rate Variability and Inflammatory Biomarkers in Critically Ill Children

Author: Colleen M Badke1, Michael S Carroll, Debra E Weese-Mayer, L Nelson Sanchez-Pinto
Affiliation: <sup>1</sup> Division of Critical Care Medicine, Department of Pediatrics, Ann &amp; Robert H. Lurie Children&#x27;s Hospital of Chicago, Chicago, IL. Department of Pediatrics, Northwestern University Feinberg School of Medicine, Chicago, IL. Department of Pediatrics, Stanley Manne Children&#x27;s Research Institute, Chicago, IL. Data Analytics and Reporting, Ann &amp; Robert H. Lurie Children&#x27;s Hospital of Chicago, Chicago, IL. Division of Autonomic Medicine, Ann &amp; Robert H. Lurie Children&#x27;s Hospital of Chicago, Chicago, IL.
Conference/Journal: Pediatr Crit Care Med
Date published: 2022 Mar 16
Other: Special Notes: doi: 10.1097/PCC.0000000000002936. , Word Count: 246


Objectives:
The autonomic nervous system (ANS) can both modulate and be modulated by the inflammatory response during critical illness. We aimed to determine whether heart rate variability (HRV), a measure of ANS function, is associated with proinflammatory biomarker levels in critically ill children.

Design:
Two cohorts were analyzed. The first was a prospective observational cohort from August 2018 to August 2020 who had plasma proinflammatory cytokine measurements within 72 hours of admission, including tumor necrosis factor-α, interleukin (IL)-1β, IL-6, and IL-8. The second was a retrospective cohort from June 2012 to August 2020 who had at least one C-reactive protein (CRP) measurement within 72 hours of admission.

Setting:
Forty-six-bed PICU.

Patients:
Critically ill children in either cohort who had continuous heart rate data available from the bedside monitors.

Interventions:
None.

Measurements and main results:
Sixty-two patients were included in the prospective cohort and 599 patients in the retrospective cohort. HRV was measured using the age-adjusted integer heart rate variability (HRVi), which is the SD of the heart rate sampled every 1 second over 5 consecutive minutes. The median HRVi was measured in the 12-hour period ending 30 minutes prior to inflammatory biomarker collection. HRVi was inversely correlated with IL-6, IL-8, and CRP levels (p ≤ 0.02); correlation with IL-8 and CRP persisted after adjusting for Pediatric Risk of Mortality III and age, and median HR and age (p < 0.001).

Conclusions:
HRVi is inversely correlated with IL-6, IL-8, and CRP. Further studies are needed to validate this measure as a proxy for a proinflammatory state.


PMID: 35293369 DOI: 10.1097/PCC.0000000000002936