Salt Toxicity: A Systematic Review and Case Reports.

INTRODUCTION

Salt toxicity is a rare form of hypernatremia that typically occurs after a single massive ingestion of salt over a short period of time (minutes/hours). It is a dangerous imbalance capable of causing significant neurological injury; quick recognition of salt toxicity is crucial to allow treatment before permanent brain injury occurs. The purpose of this review is to assist emergency nurses in gaining knowledge on the causes, pathophysiology, symptoms, and treatment of salt toxicity.

METHODS

A systematic search for case reports of hypernatremia due to salt toxicity was conducted in the PubMed and Scopus electronic databases. The search terms used were salt, sodium, hypernatremia, toxicity, poisoning, case reports, case series, and cases. The following were the inclusion criteria: publication dates between January 1, 2000, and September 30, 2019; evidence of an acute large oral or gastric tube ingestion of salt over a short period of time (minutes/hours); admission for treatment within hours of the event; laboratory verification of hypernatremia; and full-text article available electronically in English. The following were the exclusion criteria: an unclear history, high salt consumption over a period of days, high sodium intake via the intravenous route, and breast feeding.

RESULTS

Only 15 cases met the inclusion criteria for the review. Patients described in the case reports ranged in age from 5 days to 73 years. Forty percent of the patients were children less than 15 years old. Of the 14 cases with known outcomes, 50% were fatal. The most frequent causes of salt toxicity were salt water emetics, intentional administration of large quantities of salt to a child by a caregiver, and suicide attempts. Among the other causes were unintentional salt overload in infant formula, an exorcism ritual, and a college prank.

DISCUSSION

Findings from this review of 15 case reports in which a large salt load was ingested over a short period of time suggest that salt toxicity is a rare condition associated with high mortality. In addition, salt toxicity can occur in patients of all ages for a variety of reasons; the most frequently identified reasons in this review were use of salt water as an emetic and child abuse by the intentional administration of a high salt load by a caregiver. For patients whose massive exposure to salt is recent (such as minutes to hours), rapidly reducing the serum sodium concentration may prevent irreversible neurological injury.