In a new evidence-based clinical guideline, the American Academy of Pediatrics (AAP) recommends isotonic intravenous fluids (IVFs) with appropriate potassium chloride and dextrose for most children aged 28 days to 18 years who require maintenance IVFs. Isotonic IVFs reduce the risk for hyponatremia, which can cause excess fluid in the brain, resulting in potentially fatal swelling and other neurologic damage, the authors say. Hyponatremia (serum sodium concentration <135 mEq/L) is the most frequently seen electrolyte abnormality in hospitalized patients, affecting approximately 15% to 30% of children and adults. "The administration of hypotonic IVF has been the standard in pediatrics. Concerns have been raised that this approach results in a high incidence of hyponatremia and that isotonic IVF could prevent the development of hyponatremia," the authors write. Whereas previous guidelines were based primarily on expert opinion, the new guidelines are based on high-quality evidence and have been given a strong recommendation rating. "Using an evidence-based approach, recommendations for optimal sodium composition of maintenance IVFs are provided to prevent hyponatremia and acute or permanent neurologic impairment related to it," write Leonard G. Feld, MD, PhD, MMM, FAAP, and colleagues from the AAP's Subcommittee on Fluid and Electrolyte Therapy. The committee published the clinical guideline online November 26 and in the December 2018 issue of Pediatrics. The group gathered a multidisciplinary subcommittee of medical experts and wrote the guidelines after an extensive research review. The guideline is appropriate for children in surgical (postoperative) and medical acute-care settings, including critical care and the general inpatient unit. It excludes patients at higher risk for hyponatremia, including those 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 or in the neonatal intensive care unit; and adolescents older than 18 years because most of the prospective studies reviewed for this guideline excluded these subsets of patients or failed to include patients with these specific high-risk diagnoses. The authors explain the four phases of fluid therapy — resuscitative, titration, maintenance, and convalescent — and specific issues associated with each. They also discuss the tonicity of dextrose and the physiologic effects of different IVF components. Even patients receiving isotonic maintenance IVFs have significant risk for hyponatremia, the authors warn. "If patients receiving isotonic maintenance IVFs develop hyponatremia, they should be evaluated to determine if they are receiving other sources of free water or if they may have syndrome of inappropriate antidiuresis (SIAD) and/or an adrenal insufficiency. If hypernatremia develops (plasma sodium >144 mEq/L), patients should be evaluated for renal dysfunction or extrarenal free-water losses, the authors write. Source
