Department of Anesthesiology, Xijing Hospital, The Fourth Military Medical University, Xi'an, China.
Eur J Pain. 2012 Sep;16(8):1094-105. doi: 10.1002/j.1532-2149.2012.00113.x.
Neuropathic pain after nerve injury is severe and intractable, and current drug and non-drug therapies offer very limited pain relief. Hyperbaric oxygen (HBO 2) has been clinically used for protection of the nervous system after acute injury. We investigated whether HBO 2 treatment could prevent and/or attenuate neuropathic pain in animals and in patients.
Mechanical allodynia and thermal hyperalgesia and neurochemical alterations of neuropathic pain were analysed in male, adult, Sprague-Dawley rats with sciatic nerve injury. Clinical trials were conducted in patients with idiopathic trigeminal neuralgia.
Repetitive HBO 2 treatment [a combination of pressure at 3 atmosphere absolute (ATA) and pure oxygen] greatly inhibited behavioural signs of neuropathic pain manifested as thermal hyperalgesia and mechanical allodynia. Such an HBO 2 treatment also inhibited nerve injury-induced induction of c-Fos and activation of astrocytes and increased phosphorylation of NR2B receptor and the subsequent Ca 2+-dependent signals in rats. Neither high pressure (up to 3 ATA) nor pure oxygen alone resulted in analgesic effect. In clinical trials, one course of HBO 2 therapy (10 consecutive days) produced a rapid-onset, dose-dependent and long-lasting analgesic effects evidenced by the decreased doses of carbamazepine required for keeping patient pain at a minimum and decreased scores of visual analogue scales, which was used for patient's self-evaluation.
These findings support that HBO 2 therapy is an effective approach for treating neuropathic pain in both animals and human beings and suggest that neural protection, anti-inflammation and inhibition of nerve injury-induced altered neural activity may contribute to the analgesic effect of HBO 2 therapy.
神经损伤后的神经性疼痛严重且难以治疗，目前的药物和非药物疗法提供的止痛效果非常有限。高压氧（HBO 2）已在临床用于急性损伤后对神经系统的保护。我们研究了 HBO 2 治疗是否可以预防和/或减轻动物和患者的神经性疼痛。
分析雄性成年 Sprague-Dawley 大鼠坐骨神经损伤后的机械性痛觉过敏和热痛觉过敏以及神经性疼痛的神经化学改变。在特发性三叉神经痛患者中进行了临床试验。
重复 HBO 2 治疗（3 个大气压绝对压力（ATA）和纯氧的组合）极大地抑制了神经性疼痛的行为表现，表现为热痛觉过敏和机械性痛觉过敏。这种 HBO 2 治疗还抑制了神经损伤诱导的 c-Fos 诱导、星形胶质细胞激活以及磷酸化 NR2B 受体和随后的 Ca 2+依赖性信号的增加。单纯高压（高达 3 ATA）或纯氧均无镇痛作用。在临床试验中，一个疗程的 HBO 2 治疗（连续 10 天）产生了快速、剂量依赖性和持久的镇痛效果，表现为卡马西平的剂量减少，以保持患者疼痛最小，以及视觉模拟量表评分降低，这用于患者的自我评估。
这些发现支持 HBO 2 治疗是治疗动物和人类神经性疼痛的有效方法，并表明神经保护、抗炎和抑制神经损伤诱导的神经活动改变可能有助于 HBO 2 治疗的镇痛效果。
