Effect of hyperbaric oxygen on cerebral oxygen saturation in patients with sub-acute traumatic brain injury

Introduction

How hyperbaric oxygen (HBO) affects injured brain tissue is not yet confirmed. We suppose that HBO could make the oxygen stay longer in the injured tissue, because of poor circulation or perfusion of blood in the injured area. This mechanism may help to explain the longer effect of HBO, after HBO treatment. That is the purpose of our study.

Methods

Patients suffering from sub-acute traumatic brain injury, who would be treated with HBO, were enrolled in the study. They were divided into two groups: frontal lobe lesion and nonfrontal lobe lesion groups (n = 20) depending on their iconography check (X-CT or MR). The regional cerebral oxygen saturation (rSO₂) was measured by a Somanetics INVOS 5100 monitor before and after 90 minutes treatment with HBO (15 minutes compression, 40 minutes breathing oxygen of FiO₂ 99% by mask, 10 minutes rest, 15 minutes decompression). Meanwhile, the arterial blood was sampled to measure blood gas analysis and cytokine.

Results

The parameter of rSO₂ showed no significant difference following HBO treatment in two groups (t = 0.352, P > 0.05); however, there were inconceivable results in blood gas analysis. Partial pressure of oxygen (PaO₂) was significantly decreased after HBO treatment (P < 0.05), although these changes did not take effect on the clinical manifestation. Otherwise, the measurement of cytokines (TNF, IL-1) before and after HBO has no difference (P > 0.05) in all groups.

Conclusions

HBO has no effect on brain oxygen saturation, after HBO treatment. But PaO₂ was significantly decreased following HBO. The mechanism needs to be studied further.

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