Are Further Interventions Needed to Prevent and Manage Hospital-Acquired Hyponatraemia? A Nationwide Cross-Sectional Survey of IV Fluid Prescribing Practices

Efficacy and safety of isotonic versus hypotonic intravenous maintenance fluids in hospitalized children: an updated systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Iatrogenic hyponatremia is a common complication following intravenous maintenance fluid therapy (IV-MFT) in hospitalized children. Despite the American Academy of Pediatrics' 2018 recommendations, IV-MFT prescribing practices still vary considerably.

OBJECTIVES

This meta-analysis aimed to compare the safety and efficacy of isotonic versus hypotonic IV-MFT in hospitalized children.

DATA SOURCES

We searched PubMed, Scopus, Web of Science, and Cochrane Central from inception to October 1, 2022.

STUDY ELIGIBILITY CRITERIA

We included randomized controlled trials (RCTs) comparing isotonic versus hypotonic IV-MFT in hospitalized children, either with medical or surgical conditions. Our primary outcome was hyponatremia following IV-MFT. Secondary outcomes included hypernatremia, serum sodium, serum potassium, serum osmolarity, blood pH, blood sugar, serum creatinine, serum chloride, urinary sodium, length of hospital stay, and adverse outcomes.

STUDY APPRAISAL AND SYNTHESIS METHODS

Random-effects models were used to pool the extracted data. We performed our analysis based on the duration of fluid administration (i.e., ≤ 24 and > 24 h). The Grades of Recommendations Assessment Development and Evaluation (GRADE) scale was used to evaluate the strength and level of evidence for recommendations.

RESULTS

A total of 33 RCTs, comprising 5049 patients were included. Isotonic IV-MFT significantly reduced the risk of mild hyponatremia at both ≤ 24 h (RR = 0.38, 95% CI [0.30, 0.48], P < 0.00001; high quality of evidence) and > 24 h (RR = 0.47, 95% CI [0.37, 0.62], P < 0.00001; high quality of evidence). This protective effect of isotonic fluid was maintained in most examined subgroups. Isotonic IV-MFT significantly increased the risk of hypernatremia in neonates (RR = 3.74, 95% CI [1.42, 9.85], P = 0.008). In addition, it significantly increased serum creatinine at ≤ 24 h (MD = 0.89, 95% CI [0.84, 0.94], P < 0.00001) and decreased blood pH (MD = -0.05, 95% CI [-0.08 to -0.02], P = 0.0006). Mean serum sodium, serum osmolarity, and serum chloride were lower in the hypotonic group at ≤ 24 h. The two fluids were comparable in terms of serum potassium, length of hospital stay, blood sugar, and the risk of adverse outcomes.

LIMITATIONS

The main limitation of our study was the heterogeneity of the included studies.

CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS

Isotonic IV-MFT was superior to the hypotonic one in reducing the risk of iatrogenic hyponatremia in hospitalized children. However, it increases the risk of hypernatremia in neonates and may lead to renal dysfunction. Given that the risk of hypernatremia is not important even in the neonates, we propose to use balanced isotonic IV-MFT in hospitalized children as it is better tolerated by the kidneys than 0.9% saline.

SYSTEMATIC REVIEW REGISTRATION NUMBER

CRD42022372359. Graphical abstract A higher resolution version of the Graphical abstract is available as Supplementary information.

Impact of a Treatment Guide on Intravenous Fluids in Minimising the Risk of Hospital-Acquired Hyponatraemia in Denmark

Hypotonic intravenous (IV) fluids are associated with an increased risk of hospital-acquired hyponatraemia, eventually leading to brain injury and death. We evaluated the effectiveness of a treatment guide to improve prescribing practices of IV fluids. We conducted a before-and-after cross-sectional survey among physicians working at Danish emergency departments. The primary outcome was prescribing practices of IV fluids. Participants were asked which IV fluid they would select in four clinical scenarios. We applied multivariate logistic regression models to estimate the odds ratio of selecting hypotonic fluids. Secondary outcomes included knowledge about IV fluids and hyponatraemia, and the receipt, reading, and usefulness of the treatment guide. After the intervention, about a third (47/154) reported that they would use hypotonic fluids in patients with increased intracranial pressure, and a quarter (39/154) would use hypotonic maintenance fluids in children, both of which are against guideline recommendations. A total of 46% selected the correct fluid, a 3% hypertonic saline solution for a patient with hyponatraemia and severe neurological symptoms. None of the knowledge questions met the predefined criteria of success of 80% correct answers. Of the respondents, 22% had received the treatment guide. Since the implementation failed, we recommend improving distribution by applying methods from implementation science.

A cross-sectional survey of knowledge pertaining to IV fluid therapy and hyponatraemia among nurses working at emergency departments in Denmark

INTRODUCTION

Inappropriate fluid therapy may induce or worsen existing hyponatraemia with potentially life-threatening consequences. Nurses have an important role in assisting physicians in IV fluid prescribing. However, research is lacking in Denmark about nurses' knowledge pertaining to IV fluid therapy and hyponatraemia.

METHODS

An explorative cross-sectional survey was performed among Danish emergency department nurses in Spring 2019. Knowledge about IV fluid therapy was assessed for three common clinical scenarios, and multiple-choice questions were used to measure knowledge about hyponatraemia.

RESULTS

112 nurses responded to all scenario questions corresponding to 6.2% (112/1815) of the total population of nurses working at emergency departments in Denmark. In two of the three scenarios, a minority of nurses (8-10%) inappropriately selected hypotonic fluids. Nearly one third (31%) selected a hypotonic fluid for a patient with meningitis, which is against guideline recommendations. The study revealed limited knowledge about severe symptoms of hyponatraemia, patients at high risk, and hyperglycaemia-induced hyponatraemia.

CONCLUSION

In accordance with guideline recommendation, the majority of nurses did not select hypotonic fluids in three clinical scenarios commonly encountered in the emergency department. However, when setting up an educational program, further awareness is needed regarding symptoms of hyponatraemia, high-risk patients, and hyperglycaemia-induced hyponatraemia.

Fluid Rate Is Important As Much As Fluid Tonicity: An Experimental Study

Objective

There is no study evaluating the effect on plasma osmolality of both fluid tonicity and high fluid rate at the same time. The aim of this experimental study was to determine the change in the plasma osmolality by different fluid tonicity and rate, and to suggest the safest and the most appropriate fluids based on the plasma osmolality for medical situations requiring fluid therapy with high or maintenance rates.

Materials and methods

The rats were randomly divided into seven groups (six rats in each group): [D₅] D₅ administered at 100 ml/kg/24h; [D₅150] D₅ administered at 150 ml/kg/24h; [D₅(½)100] D₅ 0.45% NaCl administered at 100 ml/kg/24h; [D₅(½)150] D₅ 0.45% NaCl administered at 150 ml/kg/24h; [D₅(1)100] D₅ 0.9% NaCl administered at 100 ml/kg/24h; [D₅(1)150] D5 0.9% NaCl administered at 150 ml/kg/24h; [Control group] non-treated control rats. Intracardiac blood samples were collected from all the groups at the end of 24 h.

Results

[D₅(1)150] and [D5(½)100] were the group closest to the control group in terms of both sodium (P = .937; P = .699, respectively) and effective osmolality (P = 1, P = .818, respectively).

Conclusion

Our results showed that 0.9% NaCl and 0.45% NaCl solutions might be the safest and the most appropriate fluids to maintain normal plasma osmolality in medical situations requiring fluid therapy with high or maintenance rates, respectively.