Urea treatment in fluid restriction-refractory hyponatraemia

Hyponatraemia is a frequent condition in hospitalized patients and is linked to higher mortality rates. Current international guidelines offer inconsistent recommendations about using urea to treat this condition. While some studies suggest urea may help, there is no consensus on its role in specific cases. Prior research has shown that fluid restriction is a standard first-line approach, but it is not always effective. This gap motivated a closer look at urea as an alternative. No prior work had resolved whether urea could safely raise sodium levels in patients who do not respond to fluid restriction. The lack of clear evidence on urea’s effectiveness and safety in such cases remains a challenge. This uncertainty drove the need for a retrospective analysis of urea use in a real-world hospital setting. Understanding urea’s potential could help guide treatment decisions in difficult cases of hyponatraemia.

This study aimed to evaluate the safety and effectiveness of urea in treating hyponatraemia that does not respond to fluid restriction. The focus was on patients with conditions like SIADH who are unable to tolerate or have failed fluid restriction. The researchers sought to determine if urea could achieve a target serum sodium level within 72 hours. They also wanted to assess the frequency and severity of side effects. The motivation was to provide evidence-based guidance for clinicians. Urea is not widely used, and its role in this context remains unclear. The study aimed to fill this knowledge gap by analyzing real-world data. The goal was to support or challenge the use of urea in this clinical scenario.

The researchers conducted a retrospective review of urea use in patients admitted to a tertiary hospital between 2016 and 2017. They focused on patients with hyponatraemia who were treated with urea. The primary outcome was the proportion of patients achieving a serum sodium level of at least 130 mmol/L within 72 hours. They collected data on patient demographics, underlying causes of hyponatraemia, and treatment history. Urea was used in 78 treatment episodes across 69 patients. The study compared the sodium change after urea treatment with prior therapies. They also recorded any side effects and adverse outcomes. The approach allowed for a real-world assessment of urea’s impact in a clinical setting.

Urea treatment was used in 78 episodes across 69 patients. The median age was 67, and 41% were female. Most patients had hyponatraemia due to SIADH, with CNS pathology being the most common cause. The median lowest sodium level was 122 mmol/L. Fluid restriction was the first-line treatment in 65.4% of cases. Urea was used as first-line in 21.8% and second-line in 78.2%. Fifty treatment episodes (64.1%) achieved a serum sodium level of at least 130 mmol/L within 72 hours. Patients who received urea after other treatments showed a mean sodium increase of 6.9 mmol/L at 72 hours. This was significantly greater than the change with prior treatments, which was -1.0 mmol/L. Seventeen patients (22.7%) experienced side effects, mostly distaste. No severe side effects or overcorrection occurred.

The authors suggest that urea is a safe and effective treatment for hyponatraemia that does not respond to fluid restriction. They propose that urea may be a suitable option for patients with SIADH and moderate to severe hyponatraemia who cannot tolerate or have failed fluid restriction. The study found that urea can help achieve a target sodium level within 72 hours in a majority of cases. The researchers propose that a starting dose of at least 30 g per day may be appropriate. They suggest that urea offers a better sodium response than prior treatments in some patients. The authors note that side effects were mild and did not lead to serious complications. They propose that urea should be considered as a second-line treatment in these cases. The findings support the potential role of urea in managing refractory hyponatraemia.