There Is More to Salt Than Just a Pinch of Sodium

Ab-normal saline in abnormal kidney function: risks and alternatives

Intravenous 0.9% saline has saved countless lives since it was introduced over a century ago. It remains the most widespread crystalloid in both adult and pediatric practice. However, in recent years, evidence of deleterious effects is accruing. These include increased mortality, acute kidney injury (AKI), metabolic acidosis, and coagulopathy. The predominant cause for these sequelae appears to be the excess chloride concentration of 0.9% saline relative to plasma. This has led to development of balanced isotonic solutions such as PlasmaLyte. This review summarizes current evidence for adverse effects of chloride-rich intravenous fluid and considers whether 0.9% saline should still be used in 2018 or abandoned as a historical treatment in favor of balanced crystalloid solutions.

Dietary Salt Restriction in Heart Failure: Where Is the Evidence?

Several dietary guidelines, health organizations and government policies recommend population-wide sodium restriction to prevent hypertension and related comorbidities like heart failure (HF). The current European Society of Cardiology and American College of Cardiology/American Heart Association Heart Failure guidelines recommend restricting sodium in HF patients. However, these recommendations are based on expert opinion (level C), leading to wide variability in application and lack of consensus among providers pertaining to dietary salt restriction. To evaluate the strength of current evidences to recommend dietary salt restriction among HF patients, we performed a comprehensive literature review and explored the safety and efficacy of such recommendations.

The hidden hand of chloride in hypertension

Among the environmental factors that affect blood pressure, dietary sodium chloride has been studied the most, and there is general consensus that increased sodium chloride intake increases blood pressure. There is accruing evidence that chloride may have a role in blood pressure regulation which may perhaps be even more important than that of Na⁺. Though more than 85 % of Na⁺ is consumed as sodium chloride, there is evidence that Na⁺ and Cl⁻ concentrations do not go necessarily hand in hand since they may originate from different sources. Hence, elucidating the role of Cl⁻ as an independent player in blood pressure regulation will have clinical and public health implications in addition to advancing our understanding of electrolyte-mediated blood pressure regulation. In this review, we describe the evidence that support an independent role for Cl⁻ on hypertension and cardiovascular health.