Management of Hyponatremia and Clinical Use of Vasopressin Antagonists

Vasopressin receptor antagonist use in a neurologic rehabilitation center

BACKGROUND/OBJECTIVE

To report successful use of a modified protocol of vasopressin receptor antagonist for effective and safe treatment of hyponatremia in a complexly ill patient in the neurorehabilitation setting.

DESIGN

Case report.

PARTICIPANTS/METHODS

A 57-year-old man with tetraparesis and protracted hyponatremia resistant to standard therapies.

RESULTS

This patient's rehabilitation from epidural abscess-induced tetraplegia was complicated by symptomatic hyponatremia. The pathophysiology was multifactorial. The course was prolonged, and several therapeutic endeavors failed. Intravenous infusions of vasopressin receptor antagonist induced and maintained eunatremia. The pace of the patient's recovery improved, and he was discharged with substantial neurologic recovery. No central nervous system toxicities of the treatments were observed.

CONCLUSION

Intravenous vasopressin receptor antagonist is an effective and safe treatment for hyponatremia in the rehabilitation setting if the dosage and monitoring protocols are modified in accordance with the physiology of the patient with spinal cord injury.

Hyponatremia in neurosurgical patients: clinical guidelines development

OBJECTIVE

Neurosurgical patients have a high risk of hyponatremia and associated complications. We critically evaluated the existing literature to identify the determinants for the development of hyponatremia and which management strategies provided the best outcomes.

METHODS

A multidisciplinary panel in the areas of neurosurgery, nephrology, critical care medicine, endocrinology, pharmacy, and nursing summarized and classified hyponatremia literature scientific studies published in English from 1950 through 2008. The panel's recommendations were used to create an evaluation and treatment protocol for hyponatremia in neurosurgical patients at the University of Florida.

RESULTS

Hyponatremia should be further investigated and treated when the serum sodium level is less than 131 mmol/L (class II). Evaluation of hyponatremia should include a combination of physical examination findings, basic laboratory studies, and invasive monitoring when available (class III). Obtaining levels of hormones such as antidiuretic hormone and natriuretic peptides is not supported by the literature (class III). Treatment of hyponatremia should be based on severity of symptoms (class III). The serum sodium level should not be corrected by more than 10 mmol/L/d (class III). Cerebral salt wasting should be treated with replacement of serum sodium and intravenous fluids (class III). Fludrocortisone may be considered in the treatment of hyponatremia in subarachnoid hemorrhage patients at risk of vasospasm (class I). Hydrocortisone may be used to prevent natriuresis in subarachnoid hemorrhage patients (class I). Hyponatremia in subarachnoid hemorrhage patients at risk of vasospasm should not be treated with fluid restriction (class II). Syndrome of inappropriate antidiuretic hormone may be treated with urea, diuretics, lithium, demeclocycline, and/or fluid restriction (class III).

CONCLUSION

The summarized literature on the evaluation and treatment of hyponatremia was used to develop practice management recommendations for hyponatremia in the neurosurgical population. However, the practice management recommendations relied heavily on expert opinion because of a paucity of class I evidence literature on hyponatremia.

Electrolyte complications of malignancy

A thorough working knowledge of the diagnosis and treatment of life-threatening electrolyte abnormalities in cancer patients, especially hyponatremia, hypoglycemia, and hypercalcemia, is essential to the successful practice of emergency medicine. Although most minor abnormalities have no specific treatment, severe clinical manifestations of several notable electrolytes occur with significant frequency in the setting of malignancy. The treatment of life-threatening electrolyte abnormalities is reviewed here. Promising future treatments directed at the underlying physiology are also introduced.