Blood-brain Barrier Permeability May Influence Vasopressor Effects in Anesthetized Patients With Brain Tumor: An Analysis of Magnetic Resonance Imaging Data

Mads Rasmussen; Klaus U Koch; Ulrick S Espelund; Niwar Mohamad; Anders R Korshøj; Niels Juul; Hugo Angleys; Lingzhong Meng; Leif Østergaard; Irene K Mikkelsen

doi:10.1097/ANA.0000000000000948

Blood-brain Barrier Permeability May Influence Vasopressor Effects in Anesthetized Patients With Brain Tumor: An Analysis of Magnetic Resonance Imaging Data

J Neurosurg Anesthesiol. 2023 Dec 8. doi: 10.1097/ANA.0000000000000948. Online ahead of print.

Authors

Mads Rasmussen^{1

2}, Klaus U Koch^{3

2}, Ulrick S Espelund^{2

4}, Niwar Mohamad¹, Anders R Korshøj^{5

2}, Niels Juul¹, Hugo Angleys⁶, Lingzhong Meng⁷, Leif Østergaard⁶, Irene K Mikkelsen⁶

Affiliations

¹ Department of Anesthesiology, Section of Neuroanesthesia.
² Department of Clinical Medicine, Aarhus University, Aarhus.
³ Department of Intensive Care Medicine.
⁴ Department of Anesthesiology, Horsens Regional Hospital, Horsens, Denmark.
⁵ Department of Neurosurgery, Aarhus University Hospital.
⁶ Center of Functionally Integrative Neuroscience (CFIN), Department of Clinical Medicine, Aarhus University, Aarhus.
⁷ Department of Anesthesia, Indiana University School of Medicine, Indianapolis, IN.

PMID: 38082495
DOI: 10.1097/ANA.0000000000000948

Abstract

Objective: This is a secondary analysis of data from a previous study of anesthetized brain tumor patients receiving ephedrine or phenylephrine infusions. 18 patients with magnetic imaging verified tumor contrast enhancement were included. We hypothesized that vasopressors induce microcirculatory flow changes, characterized by increased capillary transit time heterogeneity (CTH) and decreased mean transit time (MTT), in brain regions exhibiting BBB leakage.

Methods: This is a secondary analysis of data from a previous study of anesthetized brain tumor patients receiving ephedrine or phenylephrine infusions. 18 patients with magnetic imaging verified tumor contrast enhancement were included. Postvasopressor to prevasopressor ratios of CTH, MTT, relative transit time heterogeneity (RTH), cerebral blood flow (CBF), cerebral blood volume, and oxygen extraction fraction (OEF) were calculated in tumor, peritumoral, hippocampal, and contralateral grey matter regions. Comparisons were made between brain regions and vasopressors.

Results: During phenylephrine infusion, ratios of CTH, RTH, and CBF were greater, and ratios of MTT and OEF were lower, in the tumor region with contrast leakage compared with corresponding contralateral grey matter ratios. During ephedrine infusion, ratios of CTH, MTT, RTH, CBF, and cerebral blood volume were higher in the tumor region with leakage compared with contralateral grey matter ratios. In addition, the ratio of CBF was higher in all regions, the ratio of RTH was lower in the leaking tumor region, and the ratio of OEF was lower in peritumoral, hippocampal, and grey matter regions with ephedrine compared with phenylephrine.

Conclusions: Vasopressors can induce distinct microcirculatory flow alterations in regions with compromised brain tumor barrier or BBB. Ephedrine, a combined α and β-adrenergic agonist, appears to result in fewer flow alterations and less impact on tissue oxygenation compared with phenylephrine, a pure α-adrenergic agonist.