Comparison of isotonic versus hypotonic intravenous fluid for maintenance fluid therapy in neonates more than or equal to 34 weeks of gestational age - a randomized clinical trial

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.

Higher versus lower sodium intake for preterm infants

BACKGROUND

Infants born preterm are at increased risk of early hypernatraemia (above-normal blood sodium levels) and late hyponatraemia (below-normal blood sodium levels). There are concerns that imbalances of sodium intake may impact neonatal morbidities, growth and developmental outcomes.

OBJECTIVES

To determine the effects of higher versus lower sodium supplementation in preterm infants.

SEARCH METHODS

We searched CENTRAL in February 2023; and MEDLINE, Embase and trials registries in March and April 2022. We checked reference lists of included studies and systematic reviews where subject matter related to the intervention or population examined in this review. We compared early (< 7 days following birth), late (≥ 7 days following birth), and early and late sodium supplementation, separately.

SELECTION CRITERIA

We included randomised, quasi-randomised or cluster-randomised controlled trials that compared nutritional supplementation that included higher versus lower sodium supplementation in parenteral or enteral intake, or both. Eligible participants were preterm infants born before 37 weeks' gestational age or with a birth weight less than 2500 grams, or both. We excluded studies that had prespecified differential water intakes between groups.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility and risk of bias, and extracted data. We used the GRADE approach to assess the certainty of evidence.

MAIN RESULTS

We included nine studies in total. However, we were unable to extract data from one study (20 infants); some studies contributed to more than one comparison. Eight studies (241 infants) were available for quantitative meta-analysis. Four studies (103 infants) compared early higher versus lower sodium intake, and four studies (138 infants) compared late higher versus lower sodium intake. Two studies (103 infants) compared intermediate sodium supplementation (≥ 3 mmol/kg/day to < 5 mmol/kg/day) versus no supplementation, and two studies (52 infants) compared higher sodium supplementation (≥ 5 mmol/kg/day) versus no supplementation. We assessed only two studies (63 infants) as low risk of bias. Early (less than seven days following birth) higher versus lower sodium intake Early higher versus lower sodium intake may not affect mortality (risk ratio (RR) 1.02, 95% confidence interval (CI) 0.38 to 2.72; I2 = 0%; 3 studies, 83 infants; low-certainty evidence). Neurodevelopmental follow-up was not reported. Early higher versus lower sodium intake may lead to a similar incidence of hyponatraemia < 130 mmol/L (RR 0.68, 95% CI 0.40 to 1.13; I2 = 0%; 3 studies, 83 infants; low-certainty evidence) but an increased incidence of hypernatraemia ≥ 150 mmol/L (RR 1.62, 95% CI 1.00 to 2.65; I2 = 0%; 4 studies, 103 infants; risk difference (RD) 0.17, 95% CI 0.01 to 0.34; number needed to treat for an additional harmful outcome 6, 95% CI 3 to 100; low-certainty evidence). Postnatal growth failure was not reported. The evidence is uncertain for an effect on necrotising enterocolitis (RR 4.60, 95% CI 0.23 to 90.84; 1 study, 46 infants; very low-certainty evidence). Chronic lung disease at 36 weeks was not reported. Late (seven days or more following birth) higher versus lower sodium intake Late higher versus lower sodium intake may not affect mortality (RR 0.13, 95% CI 0.01 to 2.20; 1 study, 49 infants; very low-certainty evidence). Neurodevelopmental follow-up was not reported. Late higher versus lower sodium intake may reduce the incidence of hyponatraemia < 130 mmol/L (RR 0.13, 95% CI 0.03 to 0.50; I2 = 0%; 2 studies, 69 infants; RD -0.42, 95% CI -0.59 to -0.24; number needed to treat for an additional beneficial outcome 2, 95% CI 2 to 4; low-certainty evidence). The evidence is uncertain for an effect on hypernatraemia ≥ 150 mmol/L (RR 7.88, 95% CI 0.43 to 144.81; I2 = 0%; 2 studies, 69 infants; very low-certainty evidence). A single small study reported that later higher versus lower sodium intake may reduce the incidence of postnatal growth failure (RR 0.25, 95% CI 0.09 to 0.69; 1 study; 29 infants; low-certainty evidence). The evidence is uncertain for an effect on necrotising enterocolitis (RR 0.07, 95% CI 0.00 to 1.25; 1 study, 49 infants; very low-certainty evidence) and chronic lung disease (RR 2.03, 95% CI 0.80 to 5.20; 1 study, 49 infants; very low-certainty evidence). Early and late (day 1 to 28 after birth) higher versus lower sodium intake for preterm infants Early and late higher versus lower sodium intake may not have an effect on hypernatraemia ≥ 150 mmol/L (RR 2.50, 95% CI 0.63 to 10.00; 1 study, 20 infants; very low-certainty evidence). No other outcomes were reported.

AUTHORS' CONCLUSIONS

Early (< 7 days following birth) higher sodium supplementation may result in an increased incidence of hypernatraemia and may result in a similar incidence of hyponatraemia compared to lower supplementation. We are uncertain if there are any effects on mortality or neonatal morbidity. Growth and longer-term development outcomes were largely unreported in trials of early sodium supplementation. Late (≥ 7 days following birth) higher sodium supplementation may reduce the incidence of hyponatraemia. We are uncertain if late higher intake affects the incidence of hypernatraemia compared to lower supplementation. Late higher sodium intake may reduce postnatal growth failure. We are uncertain if late higher sodium intake affects mortality, other neonatal morbidities or longer-term development. We are uncertain if early and late higher versus lower sodium supplementation affects outcomes.

Randomised controlled trials in child and adolescent health in 2023

In the year July 2022 to June 2023 there were 501 publications from randomised controlled trials (RCTs) in child and adolescent health in developing countries identified through a standardised search strategy that has been going for 20 years. This year, trials addressed the widest range of diseases and conditions that affect the health, development and well-being of children, newborns, adolescents and mothers. RCTs reflected old, neglected and new problems, the changing epidemiology of child health, social and economic circumstances in many countries, local and global priorities of low-income and middle-income countries, environmental causes of poor child health, and inequities. The RCTs tested new and refined treatments, diagnostics, vaccines, holistic management, and prevention approaches, and explored many outcomes, including mortality, nutrition, psychosocial measures, and neurodevelopment. The studies were conducted in numerous hospitals and healthcare clinics, schools, and communities, including among some of the world's most disadvantaged populations in humanitarian and refugee emergencies. Some studies are of the highest quality, and others fall short. Many RCTs will influence guidelines, practice and policies for years to come.

Korean Society of Nephrology 2022 recommendations on controversial issues in diagnosis and management of hyponatremia

The Korean Society for Electrolyte and Blood Pressure Research, in collaboration with the Korean Society of Nephrology, has published a clinical practice guideline (CPG) document for hyponatremia treatment. The document is based on an extensive evidence-based review of the diagnosis, evaluation, and treatment of hyponatremia with the multidisciplinary participation of representative experts in hyponatremia with methodologist support for guideline development. This CPG consists of 12 recommendations (two for diagnosis, eight for treatment, and two for special situations) based on eight detailed topics and nine key questions. Each recommendation begins with statements graded by the strength of the recommendations and the quality of the evidence. Each statement is followed by rationale supporting the recommendations. The committee issued conditional recommendations in favor of rapid intermittent bolus administration of hypertonic saline in severe hyponatremia, the use of vasopressin receptor antagonists in heart failure with hypervolemic hyponatremia, and syndrome of inappropriate antidiuresis with moderate to severe hyponatremia, the individualization of desmopressin use, and strong recommendation on the administration of isotonic fluids as maintenance fluid therapy in hospitalized pediatric patients. We hope that this CPG will provide useful recommendations in practice, with the aim of providing clinical support for shared decision-making to improve patient outcomes.

Korean Society of Nephrology 2022 Recommendations on controversial issues in diagnosis and management of hyponatremia

The Korean Society for Electrolyte and Blood Pressure Research, in collaboration with the Korean Society of Nephrology, has published a clinical practice guideline (CPG) document for hyponatremia treatment. The document is based on an extensive evidence-based review of the diagnosis, evaluation, and treatment of hyponatremia with the multidisciplinary participation of representative experts in hyponatremia with methodologist support for guideline development. This CPG consists of 12 recommendations (two for diagnosis, eight for treatment, and two for special situations) based on eight detailed topics and nine key questions. Each recommendation begins with statements graded by the strength of the recommendations and the quality of the evidence. Each statement is followed by rationale supporting the recommendations. The committee issued conditional recommendations in favor of rapid intermittent bolus administration of hypertonic saline in severe hyponatremia, the use of vasopressin receptor antagonists in heart failure with hypervolemic hyponatremia, and syndrome of inappropriate antidiuresis with moderate to severe hyponatremia, the individualization of desmopressin use, and strong recommendation on the administration of isotonic fluids as maintenance fluid therapy in hospitalized pediatric patients. We hope that this CPG will provide useful recommendations in practice, with the aim of providing clinical support for shared decision-making to improve patient outcomes.