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

Abstract

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.

Keywords: Hyponatremia; Hyponatremia risk factors; Severe malnutrition; Total parenteral nutrition.