Department of Endocrinology, Diabetes and Metabolism, Christian Medical College, Vellore, Tamil Nadu, India.
Department of Biostatistics, Christian Medical College, Vellore, Tamil Nadu, India.
Neurol India. 2020 Mar-Apr;68(2):340-345. doi: 10.4103/0028-3886.280637.
Delayed hyponatremia is a serious complication seen after pituitary surgery. We document the incidence, presentation, outcome and risk factors for this condition.
This was a retrospective study involving 222 patients operated for nonfunctioning pituitary macroadenomas between 2007-2016. Delayed hyponatremia was defined as serum sodium <135 mmol/L, occurring after the third post-operative day. Hyponatremia was categorized as mild (134-130 mmol/L), moderate (129-125 mmol/L) and severe (<125 mmol/L). All patients received intravenous (0.9%) saline, intravenous hydrocortisone and 12g oral salt over 24 hours. Patients with severe hyponatremia were given 3% saline.
Fifty eight patients (26%) developed delayed hyponatremia; thirty (13.5%) had severe hyponatremia. Delayed hyponatremia usually (43.1%) occurred on the seventh post-operative day (range, 3-15 days). Most patients (81%) remained asymptomatic; 11 patients developed vomiting (5), seizures (3), lethargy (1), fever (1) and paralytic ileus (1). One patient developed status epilepticus. Patients who manifest symptoms had lower sodium levels as compared to those who did not have symptoms (mean 117.7 mmol/L vs. 123 mmol/L; P < 0.01). Male gender (P = 0.002) and intra-operative CSF leak (P = 0.003) were risk factors for developing delayed hyponatremia. Other factors like, age, pre-operative cortisol levels, extent of resection and post-operative diabetes insipidus did not correlate with the occurrence of delayed hyponatremia. Patients who maintained their mean serum sodium levels >138 mmol/L (day 1-day 3) were unlikely to develop delayed hyponatremia (sensitivity, 55.2% and specificity, 83.9%), positive predictive value, 63.2% [confidence interval (CI) 48, 76.7%] and negative predictive value, 78.8% (CI 70.6, 85.5%). In most patients (57%) hyponatremia was corrected within 48 hours (h).
We recommend routine serum sodium testing on the seventh post-operative day for all patients undergoing pituitary surgery. Most patients remain asymptomatic and unless they are detected early they can go on to develop serious complications.
延迟性低钠血症是垂体手术后的一种严重并发症。我们记录了这种情况的发生率、表现、结果和危险因素。
这是一项回顾性研究，涉及 2007 年至 2016 年间接受非功能性垂体大腺瘤手术的 222 例患者。术后第 3 天出现血清钠<135mmol/L 定义为延迟性低钠血症。低钠血症分为轻度（134-130mmol/L）、中度（129-125mmol/L）和重度（<125mmol/L）。所有患者在 24 小时内接受静脉（0.9%）生理盐水、静脉注射氢化可的松和口服 12g 盐。严重低钠血症患者给予 3%盐水。
58 例（26%）患者发生延迟性低钠血症；30 例（13.5%）患者发生严重低钠血症。延迟性低钠血症通常（43.1%）发生在术后第 7 天（范围 3-15 天）。大多数患者（81%）无症状；11 例出现呕吐（5 例）、癫痫（3 例）、昏睡（1 例）、发热（1 例）和麻痹性肠梗阻（1 例）。1 例患者发生癫痫持续状态。有症状的患者的钠水平低于无症状患者（平均 117.7mmol/L 与 123mmol/L；P<0.01）。男性（P=0.002）和术中脑脊液漏（P=0.003）是发生延迟性低钠血症的危险因素。其他因素，如年龄、术前皮质醇水平、切除范围和术后尿崩症与延迟性低钠血症的发生无关。在第 1 天至第 3 天期间保持平均血清钠水平>138mmol/L 的患者不太可能发生延迟性低钠血症（敏感性 55.2%，特异性 83.9%），阳性预测值为 63.2%（置信区间 48-76.7%），阴性预测值为 78.8%（置信区间 70.6-85.5%）。大多数患者（57%）在 48 小时内纠正低钠血症。
我们建议所有接受垂体手术的患者术后第 7 天常规检测血清钠。大多数患者无症状，除非早期发现，否则可能会出现严重并发症。
