Sunyecz L, Mirtallo J M
Department of Pharmacy Services, Shadyside Hospital, Pittsburgh, PA 15232.
Clin Pharm. 1993 Feb;12(2):138-49.
A case of hyponatremia and then hypernatremia in a hospitalized patient receiving total parenteral nutrition (TPN) is described, and the etiologies, diagnoses, and treatments of hyponatremia and hypernatremia are reviewed. A 23-year-old man whose left leg had been amputated after a motorcycle accident required parenteral nutrition because of an ileus. After developing sepsis, he was given antimicrobials administered in standard dilutions of 5% dextrose injection, contributing 3 L of free water a day to his fluid intake. The patient subsequently became hyponatremic, and the sodium content of the TPN solution was increased to 140 meq/L. Multiple doses of furosemide and albumin were administered because of weight gain and edema of the lower extremity. After 14 days, all antimicrobial therapy was discontinued, and 2 days later the patient became hypernatremic. The sodium content of the TPN solution was decreased and then eliminated. Because of a 16-kg weight loss, diuretic therapy was stopped. This patient's hyponatremia was caused by administration of large amounts of sodium-free fluids (i.e., antimicrobials in 5% dextrose injection). The most appropriate management would have been to change the fluids in which the antimicrobials were diluted, with no change in the sodium content of the TPN solution. The patient's subsequent hypernatremia is best explained by a loss of free water. To manage this condition, it would have been appropriate to administer 5% dextrose injection to replace the free-water loss. Once the patient had reached baseline weight and therapy with the diuretic had been discontinued, maintenance therapy with 0.45% sodium chloride injection would have been beneficial. No change in the TPN sodium content should have been required. It is important to recognize all factors that predispose patients receiving TPN to hyponatremia and hypernatremia. Although the focus is often on the sodium content of the TPN solution, sodium and fluid can be administered by other means, including medication admixtures and maintenance intravenous fluids.
本文描述了一例接受全胃肠外营养（TPN）的住院患者先出现低钠血症而后又出现高钠血症的病例，并对低钠血症和高钠血症的病因、诊断及治疗进行了综述。一名23岁男性在摩托车事故后左腿截肢，因肠梗阻需要胃肠外营养。发生败血症后，给予其按标准稀释于5%葡萄糖注射液中的抗菌药物，每天为其液体摄入量贡献3L游离水。该患者随后出现低钠血症，TPN溶液的钠含量增至140mEq/L。因体重增加和下肢水肿，多次给予呋塞米和白蛋白。14天后，停用所有抗菌治疗，2天后患者出现高钠血症。TPN溶液的钠含量降低然后停用。由于体重减轻16kg，停止利尿治疗。该患者的低钠血症是由于给予大量无钠液体（即溶于5%葡萄糖注射液中的抗菌药物）所致。最恰当的处理方法本应是更换稀释抗菌药物的液体，而TPN溶液的钠含量不变。该患者随后出现的高钠血症最好用游离水丢失来解释。为处理这种情况，给予5%葡萄糖注射液以补充游离水丢失本应是合适的。一旦患者达到基线体重且停止利尿治疗，给予0.45%氯化钠注射液进行维持治疗会有益处。TPN的钠含量本不应改变。认识到所有使接受TPN的患者易发生低钠血症和高钠血症的因素很重要。尽管关注点通常在于TPN溶液的钠含量，但钠和液体可通过其他方式给予，包括药物混合液和维持性静脉输液。
