钠、钙和镁：抽搐、惊厥和变得平坦

🧠 为什么重要

SODIUM，正常值 135 至 145：HYPONATREMIA（低钠血症）会引起头痛、恶心、意识混乱和惊厥，原因包括体液过多、SIADH、利尿剂或低渗液体；按病因治疗，体液过多或 SIADH 时限制液体，利尿剂等导致体液丢失时用等渗（0.9%）saline；严重时给予高渗 saline，缓慢升高钠，一般不超过 8 至 10 mEq/L（24 小时内），因为快速纠正会导致渗透性脱髓鞘。HYPERNATREMIA（高钠血症）会引起口渴、黏膜干燥、坐立不安和惊厥，原因包括脱水或尿崩症；用低渗液体缓慢纠正，以避免脑水肿。CALCIUM，正常值约 9 至 10.5 mg/dL：HYPOCALCEMIA（低钙血症）见于甲状腺或甲状旁腺手术后、维生素 D 不足、胰腺炎或肾脏疾病时，会引起麻刺感、肌肉痉挛、TETANY（手足搐搦）、喉痉挛、CHVOSTEK'S sign 阳性（面部抽动）和 TROUSSEAU'S sign 阳性（袖带加压时腕部痉挛），以及 QT 间期延长；用 IV calcium gluconate 治疗，甲状腺切除术后要将其备在床旁。HYPERCALCEMIA（高钙血症）源于甲状旁腺功能亢进、癌症和长期制动，会引起嗜睡、便秘、肾结石、肌无力和 QT 间期缩短；用补液、袢利尿剂、calcitonin 和 bisphosphonates 治疗。MAGNESIUM，正常值约 1.5 至 2.5 mEq/L：HYPOMAGNESEMIA（低镁血症）常见于酒精使用障碍和营养不良，会引起震颤、反射亢进、手足搐搦和 torsades de pointes；HYPERMAGNESEMIA（高镁血症）源于肾衰竭或输注 magnesium，会引起反射消失、嗜睡、低血压、心动过缓和呼吸抑制，治疗是停用 magnesium 并给予 calcium gluconate。

SODIUM, normal 135 to 145: HYPONATREMIA causes headache, nausea, confusion and seizures, from fluid excess, SIADH, diuretics or hypotonic fluids; treat by cause, with fluid restriction for fluid excess or SIADH and isotonic (0.9%) saline for fluid loss such as from diuretics; when severe, give hypertonic saline, raising sodium slowly, generally no more than 8 to 10 mEq/L in 24 hours, because rapid correction causes osmotic demyelination. HYPERNATREMIA causes thirst, dry mucous membranes, restlessness and seizures, from dehydration or diabetes insipidus; correct slowly with hypotonic fluids to avoid cerebral edema. CALCIUM, normal about 9 to 10.5 mg/dL: HYPOCALCEMIA, after thyroid or parathyroid surgery, with low vitamin D, pancreatitis or kidney disease, causes tingling, muscle cramps, TETANY, laryngospasm, a positive CHVOSTEK'S sign (facial twitch) and TROUSSEAU'S sign (carpal spasm with a cuff), and a prolonged QT; treat with IV calcium gluconate and keep it at the bedside after thyroidectomy. HYPERCALCEMIA, from hyperparathyroidism, cancer and immobility, causes lethargy, constipation, kidney stones, muscle weakness and a shortened QT; treat with fluids, loop diuretics, calcitonin and bisphosphonates. MAGNESIUM, normal about 1.5 to 2.5 mEq/L: HYPOMAGNESEMIA, common in alcohol use disorder and malnutrition, causes tremors, hyperreflexia, tetany and torsades de pointes; HYPERMAGNESEMIA, from kidney failure or magnesium infusions, causes loss of reflexes, lethargy, hypotension, bradycardia and respiratory depression, treated by stopping magnesium and giving calcium gluconate.

🏥 真实场景

🦋 甲状腺切除术后十二小时，一位患者主诉口周和指尖有麻刺感。护士在耳前轻叩，患者的嘴唇抽动。手术中甲状旁腺受到了干扰，钙正在下降。按方案已备在床旁的 calcium gluconate 被给予患者。未经治疗的低钙血症的下一步喉痉挛，就这样没有发生。

🦋 Twelve hours after a thyroidectomy a client reports tingling around the mouth and in the fingertips. The nurse taps in front of the ear and the client's lip twitches. The parathyroid glands were disturbed during surgery and calcium is falling. Calcium gluconate, already at the bedside per protocol, is given. Laryngospasm, the next step in untreated hypocalcemia, never happens.

📌 要点总结

• 低钠血症：意识混乱和惊厥；纠正速度每天不超过 8 至 10 mEq/LHyponatremia: confusion and seizures; correct no faster than 8 to 10 mEq/L a day
• 低钙血症：Chvostek's、Trousseau's、手足搐搦；甲状腺切除术后床旁备 calcium gluconateHypocalcemia: Chvostek's, Trousseau's, tetany; calcium gluconate at the bedside after thyroidectomy
• 高镁血症：反射消失和呼吸缓慢；停掉输液，给予 calcium gluconateHypermagnesemia: lost reflexes and slow breathing; stop the drip, give calcium gluconate

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