The relationship between arginine vasopressin levels and hyponatremia following a percutaneous renal biopsy in children receiving hypotonic or isotonic intravenous fluids

Perioperative fluid therapy and intraoperative blood loss in children

Fluid and blood administration are required during surgery in children. The type, amount and tonicity of the intravenous fluids is an important aspect to be considered during anaesthesia management. The physiological differences between adults and children regarding the body water and blood volume needs to be understood. We performed a PUBMED search for English language articles using keywords including 'children', 'intravenous fluid therapy', 'crystalloids', 'colloids', 'fluid homeostasis', 'Starling equation', 'Donnan effect', 'blood loss', 'estimation of blood loss', 'blood management program'. This review discusses the physiological basis, historical background, risk of hyponatraemia, need of glucose in the intravenous fluids as well as the recent concepts in blood transfusion as related to children.

Syndrome of Inappropriate Antidiuresis

The syndrome of inappropriate antidiuresis (SIAD) is a common cause of hyponatremia in hospitalized children. SIAD refers to euvolemic hyponatremia due to nonphysiologic stimuli for arginine vasopressin production in the absence of renal or endocrine dysfunction. SIAD can be broadly classified as a result of tumors, pulmonary or central nervous system disorders, medications, or other causes such as infection, inflammation, and the postoperative state. The presence of hypouricemia with an elevated fractional excretion of urate can aid in the diagnosis. Treatment options include fluid restriction, intravenous saline solutions, oral sodium supplements, loop diuretics, oral urea, and vasopressin receptor antagonists (vaptans).

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.

Hypotonic fluid reduce serum sodium compared to isotonic fluids during anesthesia induction in pediatric patients undergoing maxillofacial surgery-type of infusion affects blood electrolytes and glucose: an observational study

Background

Reportedly, administration of hypotonic fluids containing 30.8–74 mEq/L sodium with 5 % glucose may lead to serious hyponatremia or hyperglycemia. In Japan, hypotonic fluids containing 90 mEq/L sodium with 2.6 % glucose are commonly used. We compared blood electrolyte balance and blood glucose concentration with the use of isotonic (140 mEq/L sodium with 1 % glucose) versus hypotonic fluids in pediatric patients.

Methods

We studied 77 children aged 5 months to 2 years who underwent oro-maxillofacial surgery and dental treatment under general anesthesia. Patients were categorized according to the fluids infused (hypotonic or isotonic). Blood samples were obtained from the dorsalis pedis artery between the conclusion of anesthesia induction and commencement of surgery. We compared blood sodium, potassium and glucose concentrations in the two fluid groups during the pre-anesthesia and post-anesthesia-induction periods.

Results

There were no significant differences in pre-anesthesia values between isotonic (n = 35) and hypotonic groups (n = 42). There were significant differences between isotonic and hypotonic groups in post-anesthesia-induction concentrations of sodium (isotonic, 138.7 ± 1.4 mEq/L; hypotonic, 137.5 ± 1.3 mEq/L; p = 0.0003) and glucose (isotonic, 88.0 ± 9.4 mg/dL; hypotonic, 109.9 ± 18.4 mg/dL; p < 0.0001), while potassium concentrations were not significantly different (isotonic, 4.0 ± 0.3 mEq/L; hypotonic, 4.0 ± 0.2 mEq/L; p = 0.6615) between the two groups.

Conclusion

Isotonic solution administration enables avoidance of serum sodium reduction and serum glucose elevation in infants, and may therefore enhance patient safety in comparison with hypotonic solutions.

Trial registration

University Hospital Medical Information Network Clinical Trials Registry (UMIN000014648), registration 25 July 2014.

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.

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.

Intravenous fluid management for the acutely ill child

PURPOSE OF REVIEW

To review the principles of prescribing intravenous fluids (IVFs) to the acutely ill child and of adjusting sodium composition and fluid rate to prevent disorders in serum sodium or volume status from occurring.

RECENT FINDINGS

Recent data have revealed that the historic approach of administering hypotonic IVFs results in a high incidence of hospital-acquired hyponatremia in children. The majority of hospitalized children requiring IVFs are at risk for developing hyponatremia from numerous stimuli for arginine vasopressin (AVP) production, such as volume depletion, pain, stress, nausea, vomiting, respiratory or central nervous system (CNS) disorders, or the postoperative state. Multiple recent prospective studies in over 600 children have demonstrated that hypotonic fluids cause acute hyponatremia, whereas 0.9% sodium chloride (NaCl) effectively prevents it. 0.9% NaCl is the most appropriate IVF for the majority of hospitalized children. Fluid and sodium restriction will be needed for children with edematous or oliguric states and hypotonic fluids needed for children with urinary or extra-renal free water losses or hypernatremia.

SUMMARY

Hypotonic fluids should not be administered routinely in children due to the risk of hospital-acquired hyponatremia. 0.9% NaCl is the preferred IVF for the vast majority of hospitalized children.