Epinephrine-induced Effects on Cerebral Microcirculation and Oxygenation Dynamics Using Multimodal Monitoring and Functional Photoacoustic Microscopy

Authors

Dong Zhang
Wei Wang
Xiaoyi Zhu
Ran Li
Wei Liu
Maomao Chen
Tri Vu
Laiming Jiang
Qifa Zhou
Cody L Evans
Dennis A Turner
Huaxin Sheng
Jerrold H Levy
Jianwen Luo
Wei Yang
Junjie Yao
Ulrike Hoffmann

Language

English

Publication Date

8-1-2023

Journal

Anesthesiology

DOI

10.1097/ALN.0000000000004592

PMID

37079748

PMCID

PMC11672663

PubMedCentral® Posted Date

12-27-2024

PubMedCentral® Full Text Version

Author MSS

Abstract

Background: The administration of epinephrine after severe refractory hypotension, shock, or cardiac arrest restores systemic blood flow and major vessel perfusion but may worsen cerebral microvascular perfusion and oxygen delivery through vasoconstriction. The authors hypothesized that epinephrine induces significant microvascular constriction in the brain, with increased severity after repetitive dosing and in the aged brain, eventually leading to tissue hypoxia.

Methods: The authors investigated the effects of intravenous epinephrine administration in healthy young and aged C57Bl/6 mice on cerebral microvascular blood flow and oxygen delivery using multimodal in vivo imaging, including functional photoacoustic microscopy, brain tissue oxygen sensing, and follow-up histologic assessment.

Results: The authors report three main findings. First, after epinephrine administration, microvessels exhibited severe immediate vasoconstriction (57 ± 6% of baseline at 6 min, P < 0.0001, n = 6) that outlasted the concurrent increase in arterial blood pressure, while larger vessels demonstrated an initial increase in flow (108 ± 6% of baseline at 6 min, P = 0.02, n = 6). Second, oxyhemoglobin decreased significantly within cerebral vessels with a more pronounced effect in smaller vessels (microvessels to 69 ± 8% of baseline at 6 min, P < 0.0001, n = 6). Third, oxyhemoglobin desaturation did not indicate brain hypoxia; on the contrary, brain tissue oxygen increased after epinephrine application (from 31 ± 11 mmHg at baseline to 56 ± 12 mmHg, 80% increase, P = 0.01, n = 12). In the aged brains, microvascular constriction was less prominent yet slower to recover compared to young brains, but tissue oxygenation was increased, confirming relative hyperoxia.

Conclusions: Intravenous application of epinephrine induced marked cerebral microvascular constriction, intravascular hemoglobin desaturation, and paradoxically, an increase in brain tissue oxygen levels, likely due to reduced transit time heterogeneity.

Keywords

Mice, Animals, Microcirculation, Oxyhemoglobins, Microscopy, Epinephrine, Oxygen, Cerebrovascular Circulation

Published Open-Access

yes

Recommended Citation

Zhang, Dong; Wang, Wei; Zhu, Xiaoyi; et al., "Epinephrine-induced Effects on Cerebral Microcirculation and Oxygenation Dynamics Using Multimodal Monitoring and Functional Photoacoustic Microscopy" (2023). Faculty, Staff and Student Publications. 6682.
https://digitalcommons.library.tmc.edu/uthgsbs_docs/6682