Running Wide Open: Strong Evidence for Bolus Fluids Selection in Pediatric Sepsis*

Abstract

crutinizing long-established practices in medicine is foundational to the culture of continuous improvement, yet requires surprising amounts of energy, diligence, and commitment. IV fluid (IVF) administration, both as a bolus dose to restore compromised circulatory volume, and as maintenance IVF, seem particularly prone to this type of clinical inertia. Although this is true across medicine (1), pediatricians are often forced to make decisions with smaller trials, and use more indirect evidence, generally from adult trials. Data from 1992 were cited as the turning point that informed the 2018 guidelines from the American Academy of Pediatrics which changed the Academy's guidance on maintenance IVF from hypotonic fluids to isotonic fluids for risk of hyponatremia development (2, 3).Similarly, the choice of bolus fluids in the early management of sepsis is an area of historical controversy in both adult and pediatric practice, where normal saline (NS) has long been the preferred agent. Despite emerging data that balanced crystalloid (BC) fluids with more physiologic concentrations of sodium, potassium, and chloride were safe (4-8), multiple myths persisted about the potassium content causing hyperkalemia and sodium lactate precipitating lactic acidosis and interfering with lactic acid measurements (5, 9-11).In reality, there is no evidenced-based advantage of NS over BC in bolus IVF administration. In fact, a modern IVF researcher with a clean slate, tasked with designing a resuscitation fluid, would doubtless constitute a fluid with physiologic tonicity (BC) not hypertonicity (NS), physiologic chloride concentration (BC) not hyperchloremia (NS), and physiologic pH (BC) not acidic fluid (NS).Beyond academic thought experiments, there exists published data systematically supporting the use of BC as a bolus fluid in the critically ill adult population. Potura et al (4) showed that patients receiving BC had less hyperchloremia, acidosis, and required less vasopressor support. Weinberg et al (5) showed patients receiving NS were more likely to develop hyperkalemia, hyperchloremia, and metabolic acidosis. Semler et al (8) in the groundbreaking Isotonic Solutions and Major Adverse Renal Events Trial (SMART) trial, took these findings further, demonstrating adverse clinical outcomes attributable to NS bolus administration: in critically ill adults, receiving BC was associated with a lower rate of the composite outcome of death, new renal replacement therapy (RRT), or persistent renal dysfunction. This trial enrolled over 15,000 patients in a multicenter, double-blinded randomized clinical trial (RCT) that rapidly changed fluid administration practices for critically ill adult patients.It is notable that, while we are staunch believers of the adage that children are not simply small adults, this wisdom may not apply in this particular scenario. Kidneys, after all, have been shown to be functionally equivalent organs *See also p. 1449.