Damaraju S C, Rajshekhar V, Chandy M J
Department of Neurological Sciences, Christian Medical College and Hospital, Vellore, India.
Neurosurgery. 1997 Feb;40(2):312-6; discussion 316-7. doi: 10.1097/00006123-199702000-00015.
We had previously suggested a protocol for the management of neurosurgical patients with hyponatremia and natriuresis that was based on their volume status as determined by actual blood volume measurements. All patients in that study were found to be hypovolemic or normovolemic and responded, within 72 hours, to salt and fluid replacement. In the present study, the validity of that protocol was tested using central venous pressure as the sole measure of volume status of patients with hyponatremia and natriuresis.
Twenty-five consecutive patients (26 cases) who fulfilled the inclusion criteria typically used to diagnose the syndrome of inappropriate secretion of antidiuretic hormone were included in the study. Central venous pressure was used to classify patients as hypovolemic (< 5 cm of water), normovolemic (6-10 cm of water), or hypervolemic (> 11 cm of water). Hypovolemic patients were given fluids (50 ml/kg/d) and salt (12 g/d). Normovolemic patients were given normal fluid with 12 g of salt per day. In addition, patients with anemia (hematocrit, < 27%) were administered whole blood. The end point was a serum sodium of more than or equal to 130 mEq/L measured in two consecutive samples 12 hours apart or 72 hours after entry into the study. If the serum sodium was less than 130 mEq/L at the end of 72 hours, the clinical condition of the patient determined further management.
Nineteen of 25 patients (26 cases) were hypovolemic, the rest were normovolemic. No patient was hypervolemic. Nineteen of 25 patients (26 cases) attained normal serum sodium values within 72 hours, and an additional 3 responded within the next 36 hours (108 h after entry into the study). One patient who was discharged on request had normalized her serum sodium a week later. Among the three nonresponders, who were severely hypovolemic, as revealed by blood volume measurement, and responded to increased fluid and salt administration. One was normovolemic and responded to increased salt administration. There were no complications related to the therapy.
Hyponatremia with natriuresis in the neurosurgical setting responds to salt and fluid replacement guided by the patients' volume status as determined by the central venous pressure. This study also offers further indirect evidence to suggest that the syndrome of hyponatremia with natriuresis is most often caused by "cerebral salt wasting" rather than by the syndrome of inappropriate secretion of antidiuretic hormone.
我们之前曾提出一种针对神经外科低钠血症和钠尿症患者的管理方案，该方案基于通过实际血容量测量确定的患者容量状态。该研究中的所有患者均被发现为低血容量或血容量正常，并在72小时内对补充盐和液体有反应。在本研究中，使用中心静脉压作为低钠血症和钠尿症患者容量状态的唯一测量指标，对该方案的有效性进行了测试。
本研究纳入了连续25例（26例次）符合常用于诊断抗利尿激素分泌异常综合征的纳入标准的患者。使用中心静脉压将患者分类为低血容量（<5cm水柱）、血容量正常（6 - 10cm水柱）或高血容量（>11cm水柱）。低血容量患者给予液体（50ml/kg/d）和盐（12g/d）。血容量正常的患者给予含12g盐的正常液体。此外，贫血（血细胞比容<27%）的患者输注全血。终点是在相隔12小时的两个连续样本中测得的血清钠≥130mEq/L，或在进入研究后72小时测得。如果在72小时结束时血清钠<130mEq/L，则根据患者的临床情况决定进一步的管理措施。
25例患者（26例次）中有19例为低血容量，其余为血容量正常。无高血容量患者。25例患者（26例次）中有19例在72小时内血清钠值恢复正常，另外3例在接下来的36小时内（进入研究后108小时）恢复正常。1例应要求出院的患者在一周后血清钠恢复正常。在3例无反应者中，经血容量测量显示为严重低血容量，对增加液体和盐的输注有反应。1例血容量正常，对增加盐的输注有反应。治疗无相关并发症。
神经外科环境中的低钠血症伴钠尿症对根据中心静脉压确定的患者容量状态指导下的盐和液体补充有反应。本研究还提供了进一步的间接证据，表明低钠血症伴钠尿症综合征最常由“脑性盐耗损”而非抗利尿激素分泌异常综合征引起。
