Effect of hyperbaric oxygen on flow-mediated vasodilation: an ultrasound study

The purpose of this study was to investigate the effect of hyperbaric oxygen (HBO) treatment on flow-mediated vasodilation (FMD) by ultrasound examination.

We studied 14 young patients without cardiovascular problems who underwent HBO treatment. The indications for HBO treatment were osteomyelitis (n = 8), Crohn disease (n = 2), perianal abscesses (n = 2), lingual artery embolization (n = 1), and aseptic necrosis (n = 1). The ultrasound evaluation for FMD was performed before HBO treatment, after 1 session of HBO treatment, and after 10 sessions of HBO treatment. The right brachial artery FMD response was evaluated by the mean of the baseline right brachial artery diameter, absolute change in the diameter before and after cuff inflation/deflation, and percent change in the diameter.

Statistical analysis showed a significant change in the preinflation right brachial artery diameter before (mean +/- SD, 3.6 +/- 0.54 mm) and after (3.76 +/- 0.56 mm) 10 sessions of HBO treatment (P < .05). The absolute changes in the right brachial artery diameter before and after cuff inflation/deflation (0.36 +/- 0.2 mm before HBO treatment, 0.37 +/- 0.22 mm after 1 session of HBO treatment, and 0.38 +/- 0.21 mm after 10 sessions) and percent change in FMD (10% +/- 5.8% before HBO treatment, 10.6% +/- 7.5% after 1 session of HBO treatment, and 10.6% +/- 7.7% after 10 sessions) after induction of a hyperemic response by cuff inflation were not statistically significant (P > .05).

Hyperbaric oxygen treatment did not have an immediate effect on FMD (absolute change in the right brachial artery diameter after cuff inflation/deflation); however, the right brachial artery diameter increased after 10 sessions of HBO treatment. This may suggest chronic stress on the vascular endothelium after HBO.