Full Volume Isotonic (0.9%) vs. Two-Thirds Volume Hypotonic (0.18%) Intravenous Maintenance Fluids in Preventing Hyponatremia in Children Admitted to Pediatric Intensive Care Unit-A Randomized Controlled Study

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.

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.

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.

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.

Hyponatraemia in a Lao paediatric intensive care unit: Prevalence, associations and intravenous fluid use

AIM

Hyponatraemia is a common and potentially deadly complication affecting hospitalised children world-wide. Hypotonic intravenous fluids can be a significant exacerbating factor. Exclusive use of isotonic fluids, coupled with rigorous blood monitoring, has proven effective in reducing hyponatraemia in developed settings. In developing countries, where hyponatraemia is often more common and severe, different factors may contribute to its incidence and detection. We aimed to determine the prevalence and disease associations of hyponatraemia and describe the intravenous maintenance fluid prescribing practices in a Lao paediatric intensive care unit.

METHODS

We conducted a cross-sectional study of 164 children aged 1 month to 15 years admitted to intensive care at a tertiary centre in Lao People's Democratic Republic (PDR) and recorded their serum sodium and clinical data at admission and on two subsequent days.

RESULTS

Hyponatraemia was detected in 41% (67/164, confidence interval 34-48%) of children, the majority of which was mild (34%, 56/164) and present at admission (35%, 55/158). Hyponatraemia was more common in malnourished children (odds ratio (OR) 2.3, P = 0.012) and females (OR 1.9, P = 0.045). Hyponatraemia correlated with death or expected death after discharge (OR 2.2, P = 0.015); 88% received maintenance intravenous fluids, with 67% of those receiving a hypotonic solution. Electrolyte testing was only performed in 20% (9/46) of patients outside the study protocol.

CONCLUSIONS

Hyponatraemia is highly prevalent in critically ill children in Lao PDR, as is the continued use of hypotonic intravenous fluids. With financial and practical barriers to safely detecting and monitoring electrolyte disorders in this setting, this local audit can help promote testing and has already encouraged changes to fluid prescribing.

Fluid Management Practices After Surgery for Congenital Heart Disease: A Worldwide Survey

OBJECTIVES

To determine common practice for fluid management after cardiac surgery for congenital heart disease among pediatric cardiac intensivists.

DESIGN

A survey consisting of 17 questions about fluid management practices after pediatric cardiac surgery. Distribution was done by email, social media, World Federation of Pediatric Intensive and Critical Care Societies website, and World Federation of Pediatric Intensive and Critical Care Societies newsletter using the electronic survey distribution and collection system Research Electronic Data Capture.

SETTING

PICUs around the world.

SUBJECTS

Pediatric intensivists managing children after surgery for congenital heart disease.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

One-hundred eight responses from 18 countries and six continents were received. The most common prescribed fluids for IV maintenance are isotonic solutions, mainly NaCl 0.9% (42%); followed by hypotonic fluids (33%) and balanced crystalloids solutions (14%). The majority of the respondents limit total fluid intake to 50% during the first 24 hours after cardiac surgery. The most frequently used fluid as first choice for resuscitation is NaCl 0.9% (44%), the second most frequent choice are colloids (27%). Furthermore, 64% of respondents switch to a second fluid for ongoing resuscitation, 76% of these choose a colloid. Albumin 5% is the most commonly used colloid (61%). Almost all respondents (96%) agree there is a need for research on this topic.

CONCLUSIONS

Our survey demonstrates great variation in fluid management practices, not only for maintenance fluids but also for volume resuscitation. Despite the lack of evidence, colloids are frequently administered. The results highlight the need for further research and evidence-based guidelines on this topic.