Takács J
Abteilung für Anästhesie und Intensivmedizin, Berufsgenossenschaftliche Unfallklinik Tübingen.
Anasthesiol Intensivmed Notfallmed Schmerzther. 1996 Oct;31(8):525-8.
The neurotoxicity of nitrous oxide ("laughing gas") had already been observed in 1956 when using N2O in the long-term sedation of tetanus patients. In 1967 Parbrook described leukopenic effects during long-term exposure to N2O. It was only in 1978 that further studies were conducted on myeloneuropathies and myelodepression under the influence of N2O. The basic cause is vitamin B12 deficiency and the irreversible oxidation of coenzyme B12 by N2O. Between 1986 and 1995 eight cases of acute funicular myelosis associated with latent vitamin B12 deficiency subsequent to nitrous oxide anaesthesia were reported. In our hospital, two further patients now have this disease. Two observations must be emphasised when assessing the 10 patients mentioned above: 1. There was no long-term exposure to N2O (> 6 hrs); the periods of anaesthesia were between 1.5 and 3.5 hrs. 2. Vitamin B12 deficiency was not known preoperatively, and there was no marked pernicious anaemia, so that the only pointers to the risk patients were supplied by the mean corpuscular haemoglobin (MCH) and the mean corpuscular volume (MCV) of the blood picture.
1956年，在使用一氧化二氮（“笑气”）对破伤风患者进行长期镇静时，就已经观察到了其神经毒性。1967年，帕布鲁克描述了长期接触一氧化二氮期间的白细胞减少效应。直到1978年，才在一氧化二氮的影响下对骨髓神经病和骨髓抑制进行了进一步研究。其根本原因是维生素B12缺乏以及一氧化二氮对辅酶B12的不可逆氧化。1986年至1995年期间，报告了8例与一氧化二氮麻醉后潜在维生素B12缺乏相关的急性脊髓病病例。在我们医院，现在又有两名患者患有这种疾病。在评估上述10名患者时，必须强调两点：1. 没有长期接触一氧化二氮（>6小时）；麻醉时间在1.5至3.5小时之间。2. 术前不知道维生素B12缺乏，也没有明显的恶性贫血，因此血液检查中的平均红细胞血红蛋白（MCH）和平均红细胞体积（MCV）是提示患者存在风险的唯一指标。
