Hypotonic and isotonic intravenous maintenance fluids in hospitalised paediatric patients: a randomised controlled trial

Antimicrobial Functionalization of Silicone-graft-poly(N-vinylimidazole) Catheters

In this work, we present the modification of a medical-grade silicone catheter with the N-vinylimidazole monomer using the grafting-from method at room temperature and induced by gamma rays. The catheters were modified by varying the monomer concentration (20-100 vol%) and the irradiation dose (20-100 kGy). Unlike the pristine material, the grafted poly(N-vinylimidazole) chains provided the catheter with hydrophilicity and pH response. This change allowed for the functionalization of the catheters to endow it with antimicrobial features. Thus, the quaternization of amines with iodomethane and bromoethane was performed, as well as the immobilization of silver and ampicillin. The inhibitory capacity of these materials, functionalized with antimicrobial agents, was challenged against Escherichia coli and Staphylococcus aureus strains, showing variable results, where loaded ampicillin was amply better at eliminating bacteria.

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.

Perioperative water and electrolyte balance and water homeostasis regulation in children with acute surgery

BACKGROUND

Hospital-acquired hyponatremia remains a feared event in patients receiving hypotonic fluid therapy. Our objectives were to assess post-operative plasma-sodium concentration and to provide a physiological explanation for plasma-sodium levels over time in children with acute appendicitis.

METHODS

Thirteen normonatremic (plasma-sodium ≥135 mmol/L) children (8 males), median age 12.3 (IQR 11.5-13.5) years participated in this prospective observational study (ACTRN12621000587808). Urine was collected and analyzed. Blood tests, including renin, aldosterone, arginine-vasopressin, and circulating nitric oxide substrates were determined on admission, at induction of anesthesia, and at the end of surgery.

RESULTS

On admission, participants were assumed to be mildly dehydrated and were prescribed 50 mL/kg of Ringer's acetate intravenously followed by half-isotonic saline as maintenance fluid therapy. Blood tests, urinary indices, plasma levels of aldosterone, arginine-vasopressin, and net water-electrolyte balance indicated that participants were dehydrated on admission. Although nearly 50% of participants still had arginine-vasopressin levels that would have been expected to produce maximum antidiuresis at the end of surgery, electrolyte-free water clearance indicated that almost all participants were able to excrete net free water. No participant became hyponatremic.

CONCLUSIONS

The use of moderately hypotonic fluid therapy after correction of extracellular fluid deficit is not necessarily associated with post-operative hyponatremia.

IMPACT

Our observations show that in acutely ill normonatremic children not only the composition but also the amount of volume infused influence on the risk of hyponatremia. Our observations also suggest that perioperative administration of hypotonic fluid therapy is followed by a tendency towards hyponatremia if extracellular fluid depletion is left untreated. After correcting extracellular deficit almost all patients were able to excrete net free water. This occurred despite nearly 50% of the cohort having high circulating plasma levels of arginine-vasopressin at the end of surgery, suggesting a phenomenon of renal escape from arginine-vasopressin-induced antidiuresis.

Postoperative free water administration is associated with dysnatremia after congenital heart disease surgery in infants

Dysnatremia after congenital heart disease (CHD) surgery is common. European guidelines on intraoperative fluid therapy in children recommend isotonic solutions to avoid hyponatremia, but prolonged cardiopulmonary bypass and administration of high sodium-containing solutions (i.e., blood products and sodium bicarbonate) are associated with postoperative hypernatremia. The aim of the study was to describe fluid composition prior to and during the development of postoperative dysnatremia. A retrospective observational, single-center study including infants undergoing CHD surgery. Demographics and clinical characteristics were registered. Highest and lowest plasma sodium values were recorded and associations with perioperative fluid administration, blood products, crystalloids, and colloids were explored in relation to three perioperative periods. Postoperative dysnatremia occurred in nearly 50% of infants within 48 h after surgery. Hypernatremia was mainly associated with administration of blood products (median [IQR]: 50.5 [28.4-95.5] vs. 34.5 [18.5-61.1] mL/kg; p = 0.001), and lower free water load (1.6 [1.1-2.2] mL/kg/h; p = 0.01). Hyponatremia was associated with a higher free water load (2.3 [1.7-3.3] vs. 1.8 [1.4-2.5] mL/kg/h; p = 0.001) and positive fluid balance. On postoperative day 1, hyponatremia was associated with higher volumes of free water (2.0 [1.5-2.8] vs. 1.3 [1.1-1.8] mL/kg/h; p < 0.001) and human albumin, despite a larger diuresis and more negative daily fluid balance. Postoperative hyponatremia occurred in 30% of infants despite restrictive volumes of hypotonic maintenance fluid, whereas hypernatremia was mainly associated with blood product transfusion. Individualized fluid therapy, with continuous reassessment to reduce the occurrence of postoperative dysnatremia is mandatory in pediatric cardiac surgery. Prospective studies to evaluate fluid therapy in pediatric cardiac surgery patients are warranted.

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.

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.

Postoperative dysnatremia in infants after open-heart surgery occurs frequently and is associated with prolonged intensive care length of stay

BACKGROUND

Dysnatremia after surgery for congenital heart disease (CHD) is well known and has been associated with prolonged pediatric intensive care unit length of stay (PICU-LOS). Fluctuations in plasma sodium levels occur perioperatively. The primary aim of the study was to evaluate the occurrence of dysnatremia during the first 48 h after surgery and whether it was associated with PICU-LOS. The secondary aim was to evaluate if the degree of sodium fluctuations was associated with PICU-LOS.

METHODS

A retrospective observational, single-center study including infants undergoing surgery for CHD. The highest and lowest plasma sodium value was registered for the prespecified time periods. PICU-LOS was analyzed in relation to the occurrence of dysnatremia and the degree of plasma sodium fluctuations. The occurrence of dysnatremia was evaluated in relation to surgical procedure and fluid administration.

RESULTS

Two hundred and thirty infants who underwent 249 surgical procedures were included. Dysnatremia developed in more than 60% within 48 h after surgery. Infants with normonatremia had a 40%-50% shorter PICU-LOS among children in RACHS-1 category 3-6, compared with infants developing either hypo- or hyper-/hyponatremia within 48 h after surgery (p = .006). Infants who had a decline of plasma sodium >11 mmol/L had almost double the PICU-LOS compared to those with a decline of <8 mmol/L.

CONCLUSION

Dysnatremias were common after surgery for CHD and associated with prolonged PICU-LOS. The degree of decline in plasma sodium was significantly associated with PICU-LOS. Fluid administration both in terms of volume and components (blood products and crystalloids) as well as diuresis were related to the occurrence of dysnatremias.

Severe hospital-acquired hyponatremia in acutely ill children receiving moderately hypotonic fluids

BACKGROUND

Hypotonic fluids have been associated with hospital-acquired hyponatremia. The incidence of life-threatening severe hyponatremia associated with hypotonic fluids has not been evaluated.

METHODS

This was a population-based cohort study of 46,518 acutely ill children 15 years of age or under who visited the pediatric emergency department (ED) at Oulu University Hospital, Finland, between 2007 and 2017. We retrieved all electrolyte measurements from the comprehensive electronic laboratory system and reviewed medical records for all patients with severe hyponatremia.

RESULTS

The overall occurrence of severe hyponatremia (serum sodium < 125 mmol/L) was found in 27 out of 46,518 acutely ill children (0.06%, 95% confidence interval 0.04-0.08%). After admission, severe hyponatremia developed in seven of 6,984 children receiving moderately hypotonic fluid therapy (0.1%, 95% confidence interval 0.04-0.2%), usually within 8 h of admission. All children who developed severe hyponatremia during hospitalization were severely ill.

CONCLUSION

In this register-based cohort study of children presenting to the ED, severe hyponatremia developed in one of 998 acutely ill children receiving moderately hypotonic fluid therapy. A higher resolution version of the Graphical abstract is available as Supplementary information.

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.

Maintenance fluid management in pediatrics: Current practice and quality improvement achievements

The long-standing use of hypotonic fluids in pediatric maintenance fluids has been challenged in recent years due to concerns over iatrogenic hyponatremia causing morbidity and mortality. Newer research has highlighted the safety of isotonic fluid alternatives. The American Academy of Pediatrics published an evidenced-based Clinical Practice Guideline in December of 2018 (Feld et al., 2018) to support the routine use of isotonic solutions in pediatric maintenance fluids. This article will also highlight relevant history, current practice, and a quality improvement project to standardize isotonic fluid use in the inpatient pediatric setting.

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.