A randomized controlled trial of isotonic versus hypotonic maintenance intravenous fluids in hospitalized children

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.

Crystalloid Solutions in Hospital: A Review of Existing Literature

Intravenous fluids (IVF) like normal saline (NS) and Ringer's lactate (RL) are often crucial in the management of hospitalized patients. Mishandling these fluids can lead to complications in about 20% of patients receiving them. In this review, we present the current evidence through the identification of observational studies and randomized trials that observed the optimal use of IVF. We found that NS may cause hyperchloremic metabolic acidosis in surgical patients, but there is no clear difference in mortality and long-term outcomes between NS and balanced crystalloids. Critically ill patients, particularly those in sepsis, benefit from balanced crystalloids, as high chloride content fluids like NS increase the risk of complications and mortality. In pancreatitis, NS has been shown to increase the risk of ICU admission when compared to RL; however, there is no significant difference in long-term outcomes and mortality between the fluids. RL is preferred for burns due to its isotonicity and lack of protein, preventing edema formation in an already dehydrated state. Plasma-lyte may resolve diabetic ketoacidosis faster, while prolonged NS use can lead to metabolic acidosis, acute kidney injury, and cerebral edema. In conclusion, NS, RL, and plasma-lyte are the most commonly used isotonic IVF in the hospital population. Incorrect choice of fluids in a different clinical scenario can lead to worse outcomes.

ESPNIC clinical practice guidelines: intravenous maintenance fluid therapy in acute and critically ill children- a systematic review and meta-analysis

PURPOSE

Intravenous maintenance fluid therapy (IV-MFT) prescribing in acute and critically ill children is very variable among pediatric health care professionals. In order to provide up to date IV-MFT guidelines, the European Society of Pediatric and Neonatal Intensive Care (ESPNIC) undertook a systematic review to answer the following five main questions about IV-MFT: (i) the indications for use (ii) the role of isotonic fluid (iii) the role of balanced solutions (iv) IV fluid composition (calcium, magnesium, potassium, glucose and micronutrients) and v) and the optimal amount of fluid.

METHODS

A multidisciplinary expert group within ESPNIC conducted this systematic review using the Scottish Intercollegiate Guidelines Network (SIGN) grading method. Five databases were searched for studies that answered these questions, in acute and critically children (from 37 weeks gestational age to 18 years), published until November 2020. The quality of evidence and risk of bias were assessed, and meta-analyses were undertaken when appropriate. A series of recommendations was derived and voted on by the expert group to achieve consensus through two voting rounds.

RESULTS

56 papers met the inclusion criteria, and 16 recommendations were produced. Outcome reporting was inconsistent among studies. Recommendations generated were based on a heterogeneous level of evidence, but consensus within the expert group was high. "Strong consensus" was reached for 11/16 (69%) and "consensus" for 5/16 (31%) of the recommendations.

CONCLUSIONS

Key recommendations are to use isotonic balanced solutions providing glucose to restrict IV-MFT infusion volumes in most hospitalized children and to regularly monitor plasma electrolyte levels, serum glucose and fluid balance.

Do we overestimate intravenous fluid therapy needs? Adverse effects related to isotonic solutions during pediatric hospital admissions

INTRODUCTION

Maintenance intravenous fluids are frequently used in hospitalised pediatric patients. The aim of the study was to describe the adverse effects of isotonic fluid therapy in hospitalised patients, and its prevalence based on the rate of infusion.

MATERIALS AND METHODS

A prospective clinical observational study was designed. We included hospitalised patients between 3 months-old and 15-years-old were included with 0,9% isotonic solutions with 5% glucose within the first 24 h of administration. They were divided into two groups, depending on the quantity of liquid they received (restricted <100% vs 100% maintenance needs). Clinical data and laboratory findings were recorded in two different times (T0 when they were admitted to hospital and T1 within the first 24 h of administration).

RESULTS

The study included 84 patients, 33 received <100% maintenance needs and 51 patients received around 100%. The main adverse effects notified in the first 24 h of administration were hyperchloremia >110 mEq/L (16.6%) and oedema (19%). Oedema was more frequent in patients with lower age (p < 0,01). The hyperchloremia at 24 h of intravenous fluids was an independent risk factor of developing oedema (OR 1,73 (1,0-3,8), p = 0,06).

CONCLUSION

The use of isotonic fluids is not free from adverse effects, probably related to the rate of infusion and more likely to appear in infants. It`s necessary more studies that review the correct estimation of intravenous fluid needs in hospitalized children.

Perioperative fluid management in children: an updated review

Background: Perioperative fluid management in children has been a major topic for debate. Objectives: Our aim is to review the current evidence on perioperative fluid management in children including: type of fluid, administration rates, preoperative fluid intake and monitoring techniques. Design: Narrative review. Method: Following the PRISMA-S guidelines we performed a search (2010-March 2022) in databases Medline (through PubMed) and Cochrane Library. 4297 citations were found and screened by two independent researchers. After screening, 64 articles were withheld for our review. Results: The perioperative administration of isotonic fluids is safer than hypotonic solutions, concerning the development of hyponatremia. A balanced isotonic solution with 1-2,5% glucose should be used as perioperative maintenance IV fluid in children (1 month to 18 years). Colloids can be used in children when inadequate effect in volume correction is achieved with crystalloids. The preferred synthetic colloid for children is a third generation HES in a balanced solution. To date, most clinicians use the “4-2-1 rule” for calculating fluid rate. This may not be the optimal fluid rate, as little research has been done. Preoperative fasting for clear fluids should be limited to 1 hour, children should even be encouraged to drink up until 1 hour before induction. Respiratory variation of aortic blood flow peak velocity (ΔVpeak) with echocardiography is currently the most reliable technique for evaluating fluid responsiveness in children.

Efficacy and Safety of Isotonic and Hypotonic Intravenous Maintenance Fluids in Hospitalised Children: A Systematic Review and Meta-Analysis of Randomised Controlled Trials

Hyponatraemia is a known complication in hospitalised children receiving maintenance intravenous fluid. Several studies have been published to investigate the efficacy and safety of intravenous fluids in children. However, there is still an ongoing debate regarding the ideal solution to be used in the paediatric population. Therefore, the aim of this meta-analysis was to investigate the safety and efficacy of administering isotonic versus hypotonic intravenous maintenance fluid in hospitalised children. An extensive search was undertaken on PubMed, Web of Science, Scopus, ScienceDirect, Google Scholar and Cochrane Library on 28 December 2020. Only randomised controlled trials (RCTs) were included. We used the random-effects model for all analyses. Risk ratio (RR) and mean difference with 95% confidence intervals (CIs) were used for dichotomous and continuous outcomes, respectively. The quality of each study was assessed using the Joanna Briggs Institute critical appraisal tool for RCTs. This study is registered with PROSPERO (CRD42021229067). Twenty-two RCTs with a total of 3795 participants were included. The studies encompassed surgical and medical patients admitted to intensive care unit as well as to general wards. We found that hypotonic fluid significantly increases the risk of hyponatremia at both ≤24 h (RR 0.34; 95% CI: 0.26–0.43, p < 0.00001) and >24 h (RR 0.48; 95% CI: 0.36–0.64, p < 0.00001). Isotonic fluid increases the risk of hypernatraemia at ≤24 h (RR 2.15; 95% CI: 1.24–3.73, p = 0.006). The prevalence of hyponatraemia was also higher in the hypotonic group at both ≤24 h (5.7% vs. 23.3%) and >24 h (6.0% vs. 26.3%). There was no statistically significant difference in the risk of developing adverse outcomes between the two groups. Mean serum and urine sodium as well as serum osmolality/osmolarity was lower in the hypotonic group. Isotonic solution is protective against the development of hyponatraemia while hypotonic solution increases the risk of hyponatraemia.

Risk of Electrolyte Disorders in Acutely Ill Children Receiving Commercially Available Plasmalike Isotonic Fluids: A Randomized Clinical Trial

IMPORTANCE

The use of isotonic fluid therapy is currently recommended in children, but there is limited evidence of optimal fluid therapy in acutely ill children.

OBJECTIVE

To evaluate the risk for electrolyte disorders, including hyponatremia, hypernatremia, and hypokalemia, and the risk of fluid retention in acutely ill children receiving commercially available plasmalike isotonic fluid therapy.

DESIGN, SETTING, AND PARTICIPANTS

This unblinded, randomized clinical pragmatic trial was conducted at the pediatric emergency department of Oulu University Hospital, Finland, from October 3, 2016, through April 15, 2019. Eligible study subjects (N = 614) were between 6 months and 12 years of age, required hospitalization due to an acute illness, and needed intravenous fluid therapy. Exclusion criteria included a plasma sodium concentration of less than 130 mmol/L or greater than 150 mmol/L on admission; a plasma potassium concentration of less than 3.0 mmol/L on admission; clinical need of fluid therapy with 10% glucose solution; a history of diabetes, diabetic ketoacidosis, or diabetes insipidus; a need for renal replacement therapy; severe liver disease; pediatric cancer requiring protocol-determined chemotherapy hydration; and inborn errors of metabolism. All outcomes and samples size were prespecified except those clearly marked as exploratory post hoc analyses. All analyses were intention to treat.

INTERVENTIONS

Acutely ill children were randomized to receive commercially available plasmalike isotonic fluid therapy (140 mmol/L of sodium and 5 mmol/L potassium in 5% dextrose) or moderately hypotonic fluid therapy (80 mmol/L sodium and 20 mmol/L potassium in 5% dextrose).

MAIN OUTCOMES AND MEASURES

The primary outcome was the proportion of children with any clinically significant electrolyte disorder, defined as hypokalemia less than 3.5 mmol/L, hypernatremia greater than 148 mmol/L, or hyponatremia less than 132 mmol/L during hospitalization due to acute illness. The main secondary outcomes were the proportion of children with severe hypokalemia and weight change.

RESULTS

There were 614 total study subjects (mean [SD] age, 4.0 [3.1] years; 315 children were boys [51%] and all 614 were Finnish speaking [100%]). Clinically significant electrolyte disorder was more common in children receiving plasmalike isotonic fluid therapy (61 of 308 patients [20%]) compared with those receiving moderately hypotonic fluid therapy (9 of 306 patients [2.9%]; 95% CI of the difference, 12%-22%; P < .001). The risk of developing electrolyte disorder was 6.7-fold greater in children receiving isotonic fluid therapy. Hypokalemia developed in 57 patients (19%) and hypernatremia developed in 4 patients (1.3%) receiving plasmalike isotonic fluid therapy. Weight change was greater in children receiving isotonic, plasmalike fluid therapy compared with those receiving mildly hypotonic fluids (mean weight gain, 279 vs 195 g; 95% CI, 16-154 g; P = .02).

CONCLUSIONS AND RELEVANCE

In this randomized clinical trial, commercially available plasmalike isotonic fluid therapy markedly increased the risk for clinically significant electrolyte disorders, mostly due to hypokalemia, in acutely ill children compared with previously widely used moderately hypotonic fluid therapy containing 20 mmol/L of potassium.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT02926989.

Association Between Hyponatremia and Maintenance Intravenous Solutions in Critically Ill Children: A Retrospective Observational Study

Objetive: We sought to determine the association between maintenance intravenous solutions and the presence of hyponatremia in children in pediatric intensive care (PICU). Materials and Methods: An analytical observational study in children hospitalized in the PICU between January 2015 and December 2018. Patients who received maintenance fluids within the first 48 h after admission and who had at least two serum sodium levels drawn during this time were included. Measurements and Main Results: A total of 1,668 patients were admitted to the PICU during the study period, 503 of whom met the inclusion criteria. The median age was 24 months (IQR 8-96) and 50.9% were female. Altogether, 24.1% of the children developed hyponatremia; it was more frequent in those who received hypotonic solutions (63 vs. 37%; OR 1.41 95% CI 0.92, 2.15 p = 0.106), who also had a longer hospital stay (20 vs. 14 days, difference in means 8 days, 95% CI 2.67, 13.3, p = 0.001). Children who received loop diuretics and those who were post-operative had a greater risk of developing hyponatremia if they received hypotonic solutions (aOR 2.1 95% CI 1.41, 3.0, p = 0.000). Those with balanced isotonic solutions had a lower risk of developing hyponatremia (aOR 0.59 95% CI 0.35, 0.99, p = 0.004) and hyperchloremia (aOR 0.51 95% CI 0.34, 0.77, p = 0.000), adjusted for disease severity. A greater risk of death was found in the group with severe hyponatremia <130 mEq/L (aOR 9.75 95% CI 1.64-58.15; p = 0.01). Conclusions: Hyponatremia associated with the use of hypotonic maintenance solutions occurs in one out of four children in intensive care. The use of these solutions is associated with a longer hospital stay, and the main risk groups are post-operative patients and those who receive loop diuretics. Clinical studies are needed to determine which maintenance solutions have the greatest efficacy and safety in critically ill children.

Isotonic versus hypotonic saline as maintenance intravenous fluid therapy in children under 5 years of age admitted to general paediatric wards: a randomised controlled trial

Background: To prevent the risk of iatrogenic hyponatraemia in hospitalised children, isotonic fluid has been recommended as maintenance intravenous fluid (IVF). There are few studies which compare half normal saline with normal saline as maintenance IVF in general paediatric wards.Aim: To compare the safety and efficacy of half normal saline with normal saline as maintenance IVF in general paediatric wards.Methods: Children aged between 3 months and 5 years with an anticipated requirement for IVF for 24 h were randomised to receive either half normal saline (0.45% saline in 5% dextrose) or normal saline (0.9% saline in 5% dextrose). The primary objective was to compare the incidence of hyponatraemia (serum sodium <135 mmol/L with a decrease from baseline of at least 4 mmol/L) at 24 h in children receiving half normal saline with those receiving normal saline. Secondary objectives were to compare the incidence of moderate (sodium <130 mmol/L), severe (sodium <125 mmol/L) and symptomatic hyponatraemia, change in serum sodium level from baseline and the incidence of hypernatraemia.Results: A total of 168 children were randomised to receive either normal saline (n = 84) or half normal saline (n = 84). More than two-thirds of the children were suffering from respiratory diseases (pneumonia and bronchiolitis) and diseases of the nervous system (meningoencephalitis, febrile seizures and epilepsy). The incidence of hyponatraemia at 12 h in children receiving half normal saline was similar to that in those receiving normal saline (6 vs 4.8%; Relative risk (RR) 1.2; 95% CI 0.3.0-4.8; p = 0.73). Although the incidence of hyponatraemia at 24 h in children receiving half normal saline was higher than in those receiving normal saline, the difference was not statistically significant (14.3 vs 6%; RR 2.6; 95% CI 0.9-7.8; p = 0.07). One child in the isotonic group and one in the hypotonic group developed moderate and severe hyponatraemia, respectively. There was no significant difference in the incidence of hypernatraemia between two groups (RR 0.7; 95% CI 0.16-3.3).Conclusion: Half-normal saline as maintenance IVF does not result in a significantly increased risk of hyponatraemia in general paediatric ward patients under 5 years of age.

Hypotonic versus isotonic maintenance fluid administration in the pediatric surgical patient. Semin Pediatr Surg 2019;28:43-46. [PMID: 30824133 DOI: 10.1053/j.sempedsurg.2019.01.007]

Intravenous fluid administration has been occurring for well over one hundred years for a variety of pediatric disease processes. Surprisingly, clinicians have yet to agree upon a standardized intravenous solution. There is ongoing debate regarding the administration of isotonic versus hypotonic fluids as maintenance solutions. In this article, we will review what is known about different maintenance solutions, discuss the potential complications with their use, and summarize the available evidence to help guide clinicians in their choice of maintenance fluids for their patients.

Clinical Practice Guideline: Maintenance Intravenous Fluids in Children

Maintenance intravenous fluids (IVFs) are used to provide critical supportive care for children who are acutely ill. IVFs are required if sufficient fluids cannot be provided by using enteral administration for reasons such as gastrointestinal illness, respiratory compromise, neurologic impairment, a perioperative state, or being moribund from an acute or chronic illness. Despite the common use of maintenance IVFs, there is high variability in fluid prescribing practices and a lack of guidelines for fluid composition administration and electrolyte monitoring. The administration of hypotonic IVFs has been the standard in pediatrics. Concerns have been raised that this approach results in a high incidence of hyponatremia and that isotonic IVFs could prevent the development of hyponatremia. Our goal in this guideline is to provide an evidence-based approach for choosing the tonicity of maintenance IVFs in most patients from 28 days to 18 years of age who require maintenance IVFs. This guideline applies to children in surgical (postoperative) and medical acute-care settings, including critical care and the general inpatient ward. Patients with neurosurgical disorders, congenital or acquired cardiac disease, hepatic disease, cancer, renal dysfunction, diabetes insipidus, voluminous watery diarrhea, or severe burns; neonates who are younger than 28 days old or in the NICU; and adolescents older than 18 years old are excluded. We specifically address the tonicity of maintenance IVFs in children.The Key Action Statement of the subcommittee is as follows:1A: The American Academy of Pediatrics recommends that patients 28 days to 18 years of age requiring maintenance IVFs should receive isotonic solutions with appropriate potassium chloride and dextrose because they significantly decrease the risk of developing hyponatremia (evidence quality: A; recommendation strength: strong).

[A comparison of post-surgical plasma glucose levels in patients on fluids with different glucose concentrations]

OBJECTIVE

To compare plasma glucose levels and incidence of hyperglycaemia in the post-operative period after general surgery using fluids with different glucose.

METHODOLOGY

A randomised, open-label, non-blind, clinical trial was conducted on patients admitted to Paediatric Intensive Care Unit after elective surgery. The inclusion criteria were from 6 months to 14 years of age, with a weight greater than 6kg, onset glucose level >60mg/dL, and a signed informed consent, with no oral intake and maintenance intravenous fluid therapy using fluids with 3.3% or 5% glucose. Plasma glucose levels were measured before surgery, on admission, and 8, 24, and 48h, with the mean glucose levels and incidence of hyperglycaemia (glucose level >150mg/dL) in both groups being compared.

RESULTS

A total of 60 patients received glucose/saline 1/3 (51mEq/L sodium and 33g/L glucose), and 70 glucose/saline 5/0.9% (154mEq/L sodium and 50g/L glucose). Mean glucose levels were higher in the group receiving glucose 5%, with no statistical difference. There was no significant difference in the incidence of hyperglycaemia; 8h: 26% in the 3.3% group vs. 21.3% in the 5% group (P=.63); 24h: 20% vs. 22.7% (P=.8); and 48h: 19% vs. 23.1% (P=.78).

CONCLUSIONS

The use of fluids with 3.3% glucose in the post-operative period of general surgery maintains mean glucose levels in a similar range to that of patients receiving fluids with 5% glucose, with no difference in the incidence of hyperglycaemia.

In children requiring intravenous fluid for hydration maintenance, which out of hypotonic saline and isotonic saline is less likely to result in the development of hyponatraemia?

The administration of intravenous fluids remains a common intervention for hospitalised children. Commonly used hypotonic fluids administered at maintenance rates provide 2-4 mmol/kg/day of sodium. Being hypotonic, the development of hyponatraemia remains a risk. The consequences of hyponatraemia are not insignificant, with possibilities of irreversible neurological morbidity and mortality. There is currently no clear consensus on the optimal composition of fluids to be used for intravenous rehydration. A review of the available literature suggests that children who receive isotonic fluid have a lower risk of developing hyponatraemia, regardless of the rate of administration. This result is most applicable in the first 24 h of administration in a wide age group of paediatric patients with varying severities of illness.

Hospital-acquired Hyponatremia in Pediatric Intensive Care Unit

Objective:

The objective of the study was to evaluate the etiology of hospital-acquired hyponatremia (HAH) and its effects on morbidity and mortality in the Pediatric Intensive Care Unit (PICU) patients.

Design:

This study design was a prospective observational case–control study.

Setting:

this study was conducted at tertiary care PICU.

Materials and Methods:

All consecutive cases admitted with at least one measured serum sodium (P_Na) value were evaluated. Those with normal admission P_Na were followed till they develop hyponatremia (P_Na < 35 mEq/L) 7 days or PICU discharge whichever was earlier.

Results:

During the study period, 123 (19.6%) cases developed HAH and 126 patients remained isonatremic (control group). The admission P_Na 138.8 ± 3.03 mEq/L decreased to 132 ± 2.58 mEq/L (drop of 6.68 ± 3.39 mEq/L, P < 0.001) in HAH cases. The use of antidiuretic hormone (ADH)-stimulating drugs (odds ratio [OR]: 2.83, P = 0.01), postsurgical status (OR: 2.95, P = 0.006), and fluid intake ml/kg (OR: 1.0, P = 0.001) were found to be significant risk factors in HAH group on multivariate analysis. HAH cases had prolonged PICU stay (P = 0.000) and mechanical ventilation (P = 0.01), but no difference in the mortality when compared to controls.

Conclusions:

HAH is associated with increased fluid intake, presence of ADH-stimulating drugs or conditions, and postsurgical status and has an adverse effect on the outcome of PICU patients.

Intravenous fluids: balancing solutions

The topic of intravenous (IV) fluids may be regarded as “reverse nephrology”, because nephrologists usually treat to remove fluids rather than to infuse them. However, because nephrology is deeply rooted in fluid, electrolyte, and acid-base balance, IV fluids belong in the realm of our specialty. The field of IV fluid therapy is in motion due to the increasing use of balanced crystalloids, partly fueled by the advent of new solutions. This review aims to capture these recent developments by critically evaluating the current evidence base. It will review both indications and complications of IV fluid therapy, including the characteristics of the currently available solutions. It will also cover the use of IV fluids in specific settings such as kidney transplantation and pediatrics. Finally, this review will address the pathogenesis of saline-induced hyperchloremic acidosis, its potential effect on outcomes, and the question if this should lead to a definitive switch to balanced solutions.

A prospective trial comparing isotonic with hypotonic maintenance fluids for prevention of hospital-acquired hyponatraemia

BACKGROUND

Recent literature suggests that hypotonic fluids increase the risk of hospital-acquired hyponatraemia; despite this, hypotonic fluids are widely used.

OBJECTIVES

To compare the change in serum sodium following the use of hypotonic (0.3% saline, 0.45% saline) or isotonic (0.9% saline) intravenous (IV) maintenance solutions in hospitalised children.

STUDY DESIGN

This was a randomised controlled trial. Children aged 3 months to 15 years with medical or surgical disorders were randomised to receive one of three maintenance IV fluids: two hypotonic solutions (3.3% dextrose in 0.3% saline or 5% dextrose in 0.45% saline) and one isotonic solution (5% dextrose in 0.9% saline). The primary outcome was serum sodium levels at 8 hours. Secondary outcomes included the incidence of hospital-acquired hyponatraemia, adverse events attributable to IV solutions and length of hospital stay.

RESULTS

151 children were assigned randomly to receive 0.3% saline (n = 49), 0.45% saline (n = 50) or 0.9% saline (n = 52). Baseline characteristics were similar for the three groups. At 8 hours, mean (SD) serum sodium was lower in the hypotonic solutions groups [0.3% saline 134.65 (1.9) mmol/L, 0.45% saline 134.90 (2.3) mmol/L than 0.9% saline 137.98 (2.8) mmol/L] (P < 0.0001). The incidence of hospital-acquired hyponatraemia was higher in the hypotonic groups [0.3% saline 10/49 (20.4%), 0.45% saline 11/50 (22%) than 0.9% saline 1/52 (1.9%), P = 0.006). There were no differences in other adverse effects or length of hospital stay between the groups.

CONCLUSION

Hypotonic IV solutions increase the incidence of hospital-acquired hyponatraemia. Isotonic solutions are a safer alternative.

Suitable intravenous fluid for preventing dysnatremia in children with gastroenteritis; a randomized clinical trial

Introduction: Gastroenteritis (GE) is one of the most common pediatric diseases. Hyponatremia commonly occurs by administering hypotonic fluids to GE and hospitalized children. Yet, there is no consensus on the ideal method of treatment.

Objectives: we aimed to assess suitable intravenous (IV) fluid for preventing dysnatremia in children with GE.

Patients and Methods: This is a double blind randomized clinical trial, which was conducted on infants of 6 months up to 14 years children with GE. Children were randomly assigned in 2 different groups. Group A; received 20 cc/kg 0.9% isotonic saline as a bolus, and 0.45% hypotonic saline as sum of maintenance fluid and volume deficit. Group B was treated with the same bolus and 0.9% isotonic saline with 20 mEq/L KCl as sum of maintenance fluid and volume deficit. Blood and urine samples were taken at admission, 4 and 24 hours. Data were analyzed by independent t test, Mann-Whitney U test, Friedmann test, chi-square and 2-tailed repeated measurements by SPSS version 19.

Results: Baseline hyponatremia and isonatremia were detected in 24 (31.5%) and 51 (67.1%) patients, respectively. Mean level of sodium at T0, T4 and T 24 mentioned no significant difference between groups. No hypernatremia was noted by administering isotonic saline. Results showed that 4 and 24 hours after administration isotonic saline, the mean plasma sodium differed significantly in baseline hyponatremic patients. However, no significant difference was noted after 4 and 24 hours in group A.

Conclusion: According to the considerable effect of isotonic saline on hyponatremic patients, it seems that administering isotonic fluids regardless of the types of dysnatremia can be recommended to lessen clinicians’ conflicting decision-making in selecting an appropriate fluid.

Perioperative fluid management and postoperative hyponatremia in children

Intravenous (IV) fluids are used ubiquitously when children undergo surgical procedures. Until recently, Holliday and Segar's guidelines for calculating maintenance fluids dictated fluid management strategies in postoperative pediatric patients. An increased recognition of hospital-acquired hyponatremia and its associated morbidity has led to a critical re-examination of IV fluid management in this population. Postsurgical patients are at high risk of developing hyponatremia due to the presence of non-osmotic stimuli for antidiuretic hormone release. Recent studies have established that, as they are administered in current practice, hypotonic maintenance fluids are associated with increased rates of hyponatremia. The best available data demonstrate that administration of isotonic fluid reduces hyponatremic risk. In this review, we discuss the collective data available on the subject and offer guidelines for fluid management and therapeutic monitoring.

The effect of NaCl 0.9% and NaCl 0.45% on sodium, chloride, and acid-base balance in a PICU population

OBJECTIVES

To study the effect of two intravenous maintenance fluids on plasma sodium (Na), and acid-base balance in pediatric intensive care patients during the first 24h of hospitalization.

METHODS

A prospective randomized controlled study was performed, which allocated 233 patients to groups: (A) NaCl 0.9% or (B) NaCl 0.45%. Patients were aged 1 day to 18 years, had normal electrolyte concentrations, and suffered an acute insult (medical/surgical).

MAIN OUTCOME MEASURED

change in plasma sodium. Parametric tests: t-tests, ANOVA, X(2) statistical significance level was set at α=0.05.

RESULTS

Group A (n=130): serum Na increased by 2.91 (±3.9)mmol/L at 24h (p<0.01); 2% patients had Na higher than 150 mmol/L. Mean urinary Na: 106.6 (±56.8)mmol/L. No change in pH at 0 and 24h. Group B (n=103): serum Na did not display statistically significant changes. Fifteen percent of the patients had Na<135 mmol/L at 24h. The two fluids had different effects on respiratory and post-operative situations.

CONCLUSIONS

The use of saline 0.9% was associated with a lower incidence of electrolyte disturbances.

Isotonic versus hypotonic saline solution for maintenance intravenous fluid therapy in children: a systematic review

BACKGROUND

The administration of hypotonic saline solution for maintenance intravenous fluid (IVF) therapy has been the standard of care, but recent evidence has shown this treatment to be associated with hyponatremia-related complications. The aim of this systematic review was to determine which IVF, i.e., a hypotonic or an isotonic saline solution, poses less risk for the development of hyponatremia among hospitalized children who require maintenance IVF therapy.

METHODS

Medline, Cochrane Library, LILACS, Current Controlled Trials, reference lists, and abstract proceedings were searched for randomized controlled trials (RCTs) comparing hypotonic and isotonic saline solutions for maintenance IVF therapy in hospitalized children. Two reviewers independently assessed all potentially relevant studies and subsequently extracted data and evaluated the methodological quality of the RCTs. Studies were then combined and analyzed using a random effects model.

RESULTS

Eleven RCTs met the inclusion criteria. Our analysis of these 11 RCTs showed that among hospitalized children receiving maintenance IVF therapy, isotonic solutions significantly decreased the risk of developing hyponatremia [relative risk (RR) 0.50, 95% confidence interval (CI) 0.40-0.62] without significantly increasing the risk for hypernatremia (RR 0.83, 95% CI 0.41-1.67).

CONCLUSIONS

Current evidence does not support the standard practice of prescribing a hypotonic saline solution as maintenance IVF therapy to hospitalized children. Although there is no single IVF composition ideal for all children, an isotonic saline solution does appear to be the safer choice when maintenance IVF therapy is used in the general pediatric population.

140 mmol/L of sodium versus 77 mmol/L of sodium in maintenance intravenous fluid therapy for children in hospital (PIMS): a randomised controlled double-blind trial

BACKGROUND

Use of hypotonic intravenous fluid to maintain hydration in children in hospital has been associated with hyponatraemia, leading to neurological morbidity and mortality. We aimed to assess whether use of fluid solutions with a higher sodium concentration reduced the risk of hyponatraemia compared with use of hypotonic solutions.

METHODS

We did a randomised controlled double-blind trial of children admitted to The Royal Children's Hospital (Melbourne, VIC, Australia) who needed intravenous maintenance hydration for 6 h or longer. With an online randomisation system that used unequal block sizes, we randomly assigned patients (1:1) to receive either isotonic intravenous fluid containing 140 mmol/L of sodium (Na140) or hypotonic fluid containing 77 mmol/L of sodium (Na77) for 72 h or until their intravenous fluid rate decreased to lower than 50% of the standard maintenance rate. We stratified assignment by baseline sodium concentrations. Study investigators, treating clinicians, nurses, and patients were masked to treatment assignment. The primary outcome was occurrence of hyponatraemia (serum sodium concentration <135 mmol/L with a decrease of at least 3 mmol/L from baseline) during the treatment period, analysed by intention to treat. The trial was registered with the Australian New Zealand Clinical Trials Registry, number ACTRN1260900924257.

FINDINGS

Between Feb 2, 2010, and Jan 29, 2013, we randomly assigned 690 patients. Of these patients, primary outcome data were available for 319 who received Na140 and 322 who received Na77. Fewer patients given Na140 than those given Na77 developed hyponatraemia (12 patients [4%] vs 35 [11%]; odds ratio [OR] 0·31, 95% CI 0·16-0·61; p=0·001). No clinically apparent cerebral oedema occurred in either group. Eight patients in the Na140 group (two potentially related to intravenous fluid) and four in the Na77 group (none related to intravenous fluid) developed serious adverse events during the treatment period. One patient in the Na140 had seizures during the treatment period compared with seven who received Na77.

INTERPRETATION

Use of isotonic intravenous fluid with a sodium concentration of 140 mmol/L had a lower risk of hyponatraemia without an increase in adverse effects than did fluid containing 77 mmol/L of sodium. An isotonic fluid should be used as intravenous fluid for maintenance hydration in children.

FUNDING

National Health and Medical Research Council, Murdoch Childrens Research Institute, The Royal Children's Hospital, and the Australian and New Zealand College of Anaesthetists.

The efficacy of isotonic and hypotonic intravenous maintenance fluid for pediatric patients: a meta-analysis of randomized controlled trials

AIM

This study aimed to analyze the effect of isotonic versus hypotonic solution as intravenous maintenance fluid on level of plasma sodium in hospitalized children.

METHODS

A fully recursive literature search in May 2013 was conducted in PubMed and EMBASE to identify potentially relevant randomized controlled trials. Jadad score and allocation concealment were adopted to evaluate the methodological quality of each trial. RevMan5.2 was used for statistical analysis.

RESULTS

Eight randomized controlled trials with 752 patients were included. Combined analysis showed a significant lower risk of hyponatremia with isotonic solution (odds ratio, 0.36; 95% confidence interval, 0.26-0.51). The isotonic intravenous maintenance did not increase the possibility of hypernatremia (odds ratio, 0.86; 95% confidence interval, 0.36-2.06).

CONCLUSIONS

The meta-analysis revealed that there was potential risk of hyponatremia for routine infusion of hypotonic maintenance fluid. The use of isotonic solution was warranted in hospitalized pediatric patients.

Isotonic intravenous maintenance fluid reduces hospital acquired hyponatremia in young children with central nervous system infections

OBJECTIVE

To find the appropriate type of intravenous fluid (isotonic vs. hypotonic saline in 5 % dextrose) for empiric maintenance fluid therapy in children with central nervous system (CNS) infections that reduces the incidence of hospital acquired hyponatremia.

METHODS

This blinded randomized controlled trial included hospitalized children aged 3 mo to 5 y with suspected CNS infections requiring intravenous maintenance fluid for at least 24 h. The subjects were randomized to receive 0.9 % saline (Group-A), 0.45 % saline (Group-B) and 0.18 % saline (Group-C) at standard maintenance rate. The outcome measures were proportion of patients developing hyponatremia (serum sodium < 135 mmol/L) after 24 h and serum sodium values at 6, 12, 18, 24 h of receiving maintenance fluids.

RESULTS

Of the 92 patients enrolled, 31, 30 and 31 patients were randomized to Group A, B and C, respectively. Majority (60.7 %) of the patients in Group-C developed hyponatremia compared with 7.1 % of the children in Group-A and 46.1 % in Group-B. During first 24 h of fluid administration successive fall in the serum sodium values was observed in patients receiving hypotonic fluids. The risk of developing hyponatremia was nearly 6½ (95 % confidence interval (CI) 1.6-26) to 8.5 (95 % CI 2.16-33.39) times more in patients who received hypotonic saline compared to those who received isotonic saline.

CONCLUSIONS

Administration of 0.9 % saline in 5 % dextrose as intravenous maintenance fluid in children with CNS infection leads to significantly less incidence of hyponatremia when compared to that with hypotonic fluids.

Isotonic versus hypotonic solutions for maintenance intravenous fluid administration in children

BACKGROUND

Maintenance intravenous fluids are frequently used in hospitalised children who cannot maintain adequate hydration through enteral intake. Traditionally used hypotonic fluids have been associated with hyponatraemia and subsequent morbidity and mortality. Use of isotonic fluid has been proposed to reduce complications.

OBJECTIVES

To establish and compare the risk of hyponatraemia by systematically reviewing studies where isotonic is compared with hypotonic intravenous fluid for maintenance purposes in children.Secondly, to compare the risk of hypernatraemia, the effect on mean serum sodium concentration and the rate of attributable adverse effects of both fluid types in children.

SEARCH METHODS

We ran the search on 17 June 2013. We searched the Cochrane Injuries Group Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library), MEDLINE (OvidSP), Embase (OvidSP), and ISI Web of Science. We also searched clinical trials registers and screened reference lists. We updated this search in October 2014 but these results have not yet been incorporated.

SELECTION CRITERIA

We included randomised controlled trials that compared isotonic versus hypotonic intravenous fluids for maintenance hydration in children.

DATA COLLECTION AND ANALYSIS

At least two authors assessed and extracted data for each trial. We presented dichotomous outcomes as risk ratios (RR) with 95% confidence intervals (CIs) and continuous outcomes as mean differences with 95% CIs.

MAIN RESULTS

Ten studies met the inclusion criteria, with a total of 1106 patients. The majority of the studies were performed in surgical or intensive care populations (or both). There was considerable variation in the composition of intravenous fluid, particularly hypotonic fluid, used in the studies. There was a low risk of bias for most of the included studies. Ten studies provided data for our primary outcome, a total of 449 patients in the analysis received isotonic fluid, while 521 received hypotonic fluid. Those who received isotonic fluid had a substantially lower risk of hyponatraemia (17% versus 34%; RR 0.48; 95% CI 0.38 to 0.60, high quality evidence). It is unclear whether there is an increased risk of hypernatraemia when isotonic fluids are used (4% versus 3%; RR 1.24; 95% CI 0.65 to 2.38, nine studies, 937 participants, low quality evidence), although the absolute number of patients developing hypernatraemia was low. Most studies had safety restrictions included in their methodology, preventing detailed investigation of serious adverse events.

AUTHORS' CONCLUSIONS

Isotonic intravenous maintenance fluids with sodium concentrations similar to that of plasma reduce the risk of hyponatraemia when compared with hypotonic intravenous fluids. These results apply for the first 24 hours of administration in a wide group of primarily surgical paediatric patients with varying severities of illness.

Hypotonic versus isotonic fluids in hospitalized children: a systematic review and meta-analysis

OBJECTIVE

To determine whether the use of hypotonic vs isotonic maintenance fluids confers an increased risk of hyponatremia in hospitalized children.

STUDY DESIGN

A search of MEDLINE (1946 to January 2013), the Cochrane Central Registry (1991 to December 2012), Cumulative Index for Nursing and Allied Health Literature (1990 to December 2012), and Pediatric Academic Societies (2000-2012) abstracts was conducted using the terms "hypotonic fluids/saline/solutions" and "isotonic fluids/saline/solutions," and citations were reviewed using a predefined protocol. Data on the primary and secondary outcomes were extracted from original articles by 2 authors independently. Meta-analyses of the primary and secondary outcomes were performed when possible.

RESULTS

A total of 1634 citations were screened. Ten studies (n = 893) identified as independent randomized controlled trials were included. Five studies examined subjects in the intensive care unit setting, including 4 on regular wards and 1 in a mixed setting. In hospitalized children receiving maintenance intravenous fluids, hyponatremia was seen more often in those receiving hypotonic fluids than in those receiving isotonic fluids, with an overall relative risk of 2.37 (95% CI, 1.72-3.26). Receipt of hypotonic fluids was associated with a relative risk of moderate hyponatremia (<130 mmol/L) of 6.1 (95% CI, 2.2-17.3). A subgroup analysis of hypotonic fluids with half-normal saline found a relative risk of hyponatremia of 2.42 (95% CI, 1.32-4.45).

CONCLUSION

In hospitalized children in intensive care and postoperative settings, the administration of hypotonic maintenance fluids increases the risk of hyponatremia when compared with administration of isotonic fluids. For patients on general wards, insufficient data are available based on the reviewed studies, and individual risk factors must be assessed.

Stabilisation and Transport of the Critically Ill Child

Since the Department of Health Report ‘Paediatric Intensive Care: A framework for the future’ in 1997, paediatric intensive care services have been centralised and 24-hour retrieval services developed. However, all hospitals admitting critically ill children must be able to resuscitate and stabilise prior to retrieval, and occasionally undertake the ‘time-critical’ transfers themselves. This article reviews the clinical and organisational skills involved in the retrieval process, and also suggests ways in which knowledge and skills can be maintained.

Isotonic versus hypotonic maintenance IV fluids in hospitalized children: a meta-analysis

OBJECTIVE

To assess evidence from randomized controlled trials (RCTs) on the safety of isotonic versus hypotonic intravenous (IV) maintenance fluids in hospitalized children.

METHODS

We searched PubMed, Embase, Cochrane Library, and clinicaltrials.gov (up to April 11, 2013) for RCTs that compared isotonic to hypotonic maintenance IV fluid therapy in hospitalized children. Relative risk (RR), weighted mean differences, and 95% confidence intervals (CIs) were calculated based on the effects on plasma sodium (pNa). The risk of developing hyponatremia (pNa <136 mmol/L), severe hyponatremia (pNa <130 mmol/L), and hypernatremia (pNa >145 mmol/L) was evaluated. We adopted a random-effects model in all meta-analyses. Sensitivity analyses by missing data were also performed.

RESULTS

Ten RCTs were included in this review. The meta-analysis showed significantly higher risk of hypotonic IV fluids for developing hyponatremia (RR 2.24, 95% CI 1.52 to 3.31) and severe hyponatremia (RR 5.29, 95% CI 1.74 to 16.06). There was a significantly greater fall in pNa in children who received hypotonic IV fluids (-3.49 mmol/L versus isotonic IV fluids, 95% CI -5.63 to -1.35). No significant difference was found between the 2 interventions in the risk of hypernatremia (RR 0.73, 95% CI 0.22 to 2.48). None of the findings was sensitive to imputation of missing data.

CONCLUSIONS

Isotonic fluids are safer than hypotonic fluids in hospitalized children requiring maintenance IV fluid therapy in terms of pNa.

Association between maintenance fluid tonicity and hospital-acquired hyponatremia

OBJECTIVE

To evaluate whether the administration of hypotonic fluids compared with isotonic fluids is associated with a greater risk for hyponatremia in hospitalized children.

STUDY DESIGN

Informatics-enabled cohort study of all hospitalizations at Lucile Packard Children's Hospital between April 2009 and March 2011. Extraction and analysis of electronic medical record data identified normonatremic hospitalized children who received either hypotonic or isotonic intravenous maintenance fluids upon admission. The primary exposure was the administration of hypotonic maintenance fluids, and the primary outcome was the development of hyponatremia (serum sodium <135 mEq/L).

RESULTS

A total of 1048 normonatremic children received either hypotonic (n = 674) or isotonic (n = 374) maintenance fluids upon admission. Hyponatremia developed in 260 (38.6%) children who received hypotonic fluids and 104 (27.8%) of those who received isotonic fluids (unadjusted OR 1.63; 95% CI 1.24-2.15, P < .001). After we controlled for intergroup differences and potential confounders, patients receiving hypotonic fluids remained more likely to develop hyponatremia (aOR 1.37, 95% CI 1.03-1.84). Multivariable analysis identified additional factors associated with the development of hyponatremia, including surgical admission (aOR 1.44, 95% CI 1.09-1.91), cardiac admitting diagnosis (aOR 2.08, 95% CI 1.34-3.20), and hematology/oncology admitting diagnosis (aOR 2.37, 95% CI 1.74-3.25).

CONCLUSIONS

Hyponatremia was common regardless of maintenance fluid tonicity; however, the administration of hypotonic maintenance fluids compared with isotonic fluids was associated with a greater risk of developing hospital-acquired hyponatremia. Additional clinical characteristics modified the hyponatremic effect of hypotonic fluid, and it is possible that optimal maintenance fluid therapy now requires a more individualized approach.

Hospital-acquired hyponatremia in pediatric patients: a review of the literature

Hypotonic intravenous (IV) fluids in children are a mainstay of therapy based on a recommendation made in 1957 by Holliday and Segar. Since that time, hospital-acquired hyponatremia caused by hypotonic IV fluids has been found to be an additional risk factor in the cause of death and neurological impairment in acutely ill children. This article reviews and critically evaluates the literature regarding the association of hyponatremia and hypotonic IV fluids in pediatric hospitalized, postoperative, and critical care patients.

Risk of acute hyponatremia in hospitalized children and youth receiving maintenance intravenous fluids

Hospital-acquired acute hyponatremia is increasingly recognized as a cause of morbidity and mortality in children. It has been attributed primarily to the use of hypotonic intravenous (IV) fluids to maintain fluid and electrolyte requirements. This practice point outlines current understanding of the problem and summarizes recent research dealing with this issue. Detailed recommendations are made for the prescription of IV maintenance fluids in children between one month and 18 years of age. The use of isotonic fluid (D5W.0.9% NaCl) is recommended in most circumstances. Hypotonic IV fluids containing less than 0.45% NaCl should not be used to provide routine IV fluid maintenance requirements.