Page 48 - Effects of radiotherapy and hyperbaric oxygen therapy on oral microcirculation Renee Helmers

Chapter 2
Administering supplementary oxygen in the form of either NB hyperoxia or HBOT is used with an intention to treat conditions in which hypoxia, infection, and/or poor tissue vasculature are central to an underlying pathology. Despite mechanical and pharmacological strategies for stabilizing metabolism and resetting tissue regulatory mechanisms in treatment-refractory pathologies, oxygen therapy is not without consequences and should be administered with caution. Under- or over-treating with oxygen is risky particularly because no consensus exists indicating the exact adequate clinical levels for achieving medically beneficial results. Nonetheless, supplementary oxygen is routinely administered in patients with adequate oxygen saturation levels with the belief that it will improve oxygen delivery in patients with distressed tissues afflicted by ischemic insults. In view of the clinical relevance of the present research model, bedside microvascular perfusion assessments have identified the oral microcirculation in recent years as an important prognostic ROI for clinical and translational monitoring of both disease pathophysiology and the course of therapeutic response.
Conclusions
We report for the first time the application of SDFI inside a multiplace HB chamber for continuous monitoring and measurement of sublingual mucosa microcirculation. The present research model demonstrated the feasibility of performing intrabarochamber microcirculation data acquisitions simultaneously for local and systemically derived parameters under influence of changing barometric and hyperoxic conditions. Within the scope of the experiments presented in this report, the effects of NB and HB hyperoxia on microcirculation parameters in healthy subjects indicate reversibility in microvascular perfusion in the presence of steady cardiovascular function. To assess whether these observations hold true for other tissues and/or other pathophysiological conditions further investigation is warranted.
Acknowledgments
The authors thank the staff of the Department of Hyperbaric Medicine for their kind assistance during the late hours operating the hyperbaric tank for these investigations. Important note: The investigators of this study do not claim, nor do the results of this study suggest, that it is safe to use a MicroScan (Sidestream Dark-Field Video Microscopy system) in pressurized oxygen
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