Consensus document on the management of hyponatraemia of the Acqua Group of the Spanish Society of Endocrinology and Nutrition.

INTRODUCTION: Hyponatremia is the most prevalent electrolyte disorder in the outpatient and inpatient settings. Despite this frequency, hyponatremia, including severe hyponatremia, is frequently underestimated and inadequately treated, thus highlighting the need to produce consensus documents and clinical practice guidelines geared towards improving the diagnostic and therapeutic approach to it in a structured fashion. MATERIAL AND METHODS: Members of the Acqua Group of the Spanish Society of Endocrinology and Nutrition (SEEN) met using a networking methodology over a period of 20 months (between October 2019 and August 2021) with the aim of discussing and developing an updated guideline for the management of hyponatraemia. A literature search of the available scientific evidence for each section presented in this document was performed. RESULTS: A document with 8 sections was produced, which sets out to provide updated guidance on the most clinically relevant questions in the management of hyponatraemia. The management of severe hyponatraemia is based on the i.v. administration of a 3% hypertonic solution. For the management of chronic euvolemic hyponatraemia, algorithms for the initiation of treatment with the two pharmacological therapeutic options currently available in Spain are presented: urea and tolvaptan. CONCLUSIONS: This document sets out to simplify the approach to and the treatment of hyponatraemia, making it easier to learn and thus improve the clinical approach to hyponatremia.

Development of hyponatremia in non-critical patients receiving total parenteral nutrition: A prospective, multicenter study.

BACKGROUND & AIMS: Hyponatremia is frequent in hospitalized patients, especially in those receiving total parenteral nutrition (TPN). Furthermore, the presence of hyponatremia is associated with increased morbimortality in both groups. The goal of this study is to describe the prevalence of hyponatremia developing during TPN in non-critical patients, and identify risk factors for its appearance. METHODS: This prospective multicenter study involved 19 Spanish hospitals. Noncritically-ill patients prescribed TPN over a 9-month period were studied. Variables analyzed demographic characteristics, prior comorbidities, drug therapy, PN composition, additional iv fluids, and serum sodium levels. RESULTS: A total of 543 patients were recruited, 60.2% males. Age: 67 (IR 57-76). Of 466/543 who were eunatremic when starting TPN, 18% developed hyponatremia (serum sodium < 135 mmol/L) during TPN. Independent risk factors identified by logistic regression analysis: female (OR 1.74 [95% CI = 1.04-2.92], p = 0.036); severe malnutrition (OR 2.15 [95% CI = 1.16-4.35], p = 0.033); opiates (OR 1.97 [95% CI = 1.10-3.73], p = 0.036); and nausea/vomiting (OR 1.75 [95% CI = 1.04-2.94], p = 0.036). CONCLUSIONS: Previously eunatremic patients frequently develop hyponatremia while receiving TPN. In this group, severe malnutrition is an independent risk factor for hyponatremia, as well as previously described risk factors: opiates, nausea/vomiting, and female gender.