Access: Acid-Base, Fluids, and Electrolytes - part 3

Điều trị hạ natri máu Hypovolemic • Ngừng thuốc lợi tiểu, thiệt hại GI đúng, và mở rộng khối lượng ECF với nước muối bình thường • ECF thâm hụt khối lượng thay thế để loại trừ phát hành AVP nonosmotic và thúc đẩy tối đa pha loãng nước tiểu • Thay thế một thứ ba của Na + thâm hụt hơn đầu tiên 6-12 h | DISORDERS OF WATER BALANCE 85 TABLE 3-28 Treatment of Hypovolemic Hyponatremia Discontinue diuretics correct GI losses and expand ECF volume with normal saline ECF volume deficit is replaced to eliminate nonosmotic AVP release and promote maximally dilute urine Replace one-third of the Na deficit over the first 6-12 h and the remainder over the ensuing 24-48 h Na deficit total body water X 140 - current serum Na K deficits must be corrected in the setting of hypokalemia Abbreviations GI gastrointestinal ECF extracellular fluid AVP arginine vasopressin TABLE 3-29 Treatment of Euvolemic Hyponatremia Water restriction is used in the asymptomatic patient Fluid restriction rarely increases serum Na by more than mEq L per day Demeclocycline 600-1200 mg day is used for incurable SIADH providing that the patient has normal liver function Conivaptan hydrochloride injection 20 mg load followed by 20 mg IV over 24 h is a V1a V2 receptor antagonist that was recently approved for SIADH Oral vasopressin receptor antagonists are in clinical trials and may be useful for therapy of SIADH in the future Abbreviations SIADH syndrome of inappropriate antidiuretic hormone 86 DISORDERS OF WATER BALANCE TABLE 3-30 Treatment of Hypervolemic Hyponatremia Hypervolemia is managed with salt and water restriction An increase in cardiac output will suppress AVP release in CHF Large volume paracentesis albumin infusion and water restriction reduces hyponatremia in cirrhotics Abbreviations AVP arginine vasopressin CHF congestive heart failure TABLE 3-31 Example of Change in TBW to Correct Hypervolemic Hyponatremia A 75-kg man has a total body water of 45 L and a serum Na of 115 mEq L Desired TBW actual serum Na normal serum Na X current TBW Desired TBW 115 140 X 45 L L 45 L - L L must be lost to restore serum Na to 140 mEq L Abbreviation TBW total body water DISORDERS OF WATER BALANCE 87 TABLE 3-32 Important Concepts in Therapy of Hyponatremia A fear of CPM delays appropriate .