Department of Neurosurgery, National Institute of Neurological and Allied Sciences, Bansbari, Kathmandu, Nepal.
World Neurosurg. 2011 Sep-Oct;76(3-4):355-60. doi: 10.1016/j.wneu.2011.03.042.
Hyponatremia is common in patients with traumatic brain injury (TBI). This study aims at ascertaining the incidence of hyponatremia in TBI with its etiologic diagnosis, biochemical confirmation, and severity correlation with initial Glasgow Coma Scale (GCS) score and computed tomography (CT) abnormality.
All patients more than 20 years old with severe and moderate TBI and the mild ones with CT abnormality were included. Daily sodium level was monitored for 14 days. Central venous pressure (CVP) was measured for assessment of volume status. Fractional excretion of uric acid (FEUA) was measured in all patients with hyponatremia, both before and after its correction.
Of 40 consecutive patients, 33 remained for analysis. Hyponatremia was seen in 9 (27.2%) patients, of whom 6 developed it within the first week. Mean duration of hyponatremia was 1.78 days. We found that 5 patients had an elevated CVP consistent with the syndrome of inappropriate antidiuretic hormone (SIADH), whereas 3 had low CVP consistent with cerebral salt wasting syndrome (CSWS) and 1 had an equivocal reading. Measurement of FEUA did not show consistent pattern to suggest a biochemical distinction. There were 33.3% each of mild and moderate, and 16.6% of severe TBI among hyponatremic patients. Hyponatremia was seen in Rotterdam CT scores I to IV in increasing incidence (r = 0.983, P = 0.017), whereas it had no significant correlation with initial GCS (r = 0.756, P = 0.455).
Hyponatremia due to SIADH is more common in TBI. FEUA measurement is not consistent enough to make a distinction between SIADH and CSWS. CT scoring of severity is more predictive of hyponatremia than initial GCS.
低钠血症在创伤性脑损伤（TBI）患者中很常见。本研究旨在确定 TBI 患者低钠血症的发生率及其病因诊断、生化确认，并与初始格拉斯哥昏迷量表（GCS）评分和计算机断层扫描（CT）异常的严重程度相关。
纳入年龄大于 20 岁的重度和中度 TBI 患者，以及 CT 异常的轻度 TBI 患者。监测患者 14 天的每日钠水平。测量中心静脉压（CVP）以评估容量状态。对所有低钠血症患者（无论是否已纠正）均测量尿尿酸排泄分数（FEUA）。
40 例连续患者中，33 例纳入分析。9 例（27.2%）患者出现低钠血症，其中 6 例在第一周内发生。低钠血症的平均持续时间为 1.78 天。我们发现，5 例患者 CVP 升高，符合抗利尿激素分泌不当综合征（SIADH），3 例患者 CVP 降低，符合脑性盐耗综合征（CSWS），1 例患者 CVP 结果不确定。FEUA 测量结果没有一致的模式表明存在生化差异。低钠血症患者中轻度、中度和重度 TBI 各占 33.3%，16.6%。低钠血症患者的 Rotterdam CT 评分从 I 到 IV 呈递增趋势（r=0.983，P=0.017），但与初始 GCS 无显著相关性（r=0.756，P=0.455）。
SIADH 引起的低钠血症在 TBI 中更为常见。FEUA 测量结果不一致，无法区分 SIADH 和 CSWS。CT 严重程度评分比初始 GCS 更能预测低钠血症。
