脑外伤后脑脊液乳酸、丙酮酸变化的临床意义

Clinical significance of change of the lactic and pyruvic acid in CSF after head injury

对29冽严重脑外病人在伤后或术后24小时内和第3天测定了脑脊液和静脉血乳酸、丙酮酸含量同时进行了持续颅内压监测。 结果表明,脑脊液乳酸水平和乳酸/丙酮酸比值的增高是反映脑的病态氧化还原状态的可靠生化指标,它对判断脑外伤病情的轻重和估计预后有重要价值。脑脊液乳酸含量与颅内压之间呈密切的正相关关系。静脉血内乳酸、丙酮酸含量的变化不能完全反映脑的氧化——还原状态,不能,作为判断预后的指标。

The lactic and pyruvic acid in serum and CSF were determined in 29 patients with severe head injury within 24 hours and on the third day after injury. All patients underwent conti- nuous intracranial pressure monitoring. The results showed that CSF lactate level and alctate/pyruvate ratio would be reliable biochemical indicaters of the redox state of the brain tissue and were valuable to indicate the severity and to predict the prognosis of cerebral injury. The prognosis was grave when CSF lactate level raised over 4 mmol/L and CSF laetate/pyrurate ratio was higher than 20. When the CSF lactate level was more than 6mmol/L, usually the patient couldn't he survived.Significant correlation was found between intracranial pressure and CSF lactate. And the in(?)racranial pressure increased when the CSF lactate level raised.A persistent rise of CSF lactate level and lactate/pyruvate ratio suggested de(?)erioration with progressive increase of intracranial pressure and cerebral hypoxia.The venous lactate and pyruvate levels coundn't indicate the redox state of the brain and were not correlated with the outcome.