When a child arrives at the emergency department (ED) with sepsis, one of the first treatments they receive is intravenous (IV) fluids. For decades, clinicians have debated which kind of IV fluid works best. A new PECARN-led trial finally has an answer: it doesn’t seem to matter.
The PRoMPT BOLUS trial, published in the New England Journal of Medicine, compared the two most common IV fluids used to treat children with septic shock and found them equally safe and effective [1].
Study Design
PRoMPT BOLUS is the largest pediatric sepsis fluid trial of its kind to date. Balamuth et al. enrolled more than 9,000 children, ages 2 months to under 18 years, across 47 emergency departments in five countries. It was a collaborative effort across three pediatric research networks: PECARN in the United States, PERC in Canada, and PREDICT in Australia and New Zealand.
Children with suspected septic shock were randomly assigned to receive one of two IV fluids during their resuscitation:
- 0.9% saline, the most commonly used IV fluid worldwide, which contains more chloride than the body’s own fluid
- Balanced fluids (such as lactated Ringer’s), which more closely match the body’s natural electrolyte balance
The study’s main outcome was a combined measure of serious kidney problems or death within 30 days of treatment.
Results
Outcomes were nearly identical between groups. Serious kidney problems or death occurred in 3.4% of children who received balanced fluids and 3.0% of children who received saline, a difference that was neither statistically nor clinically meaningful [1]. There were also no differences in mortality, length of hospital stay, or other safety outcomes.
Although saline produced slightly more biochemical changes (such as higher chloride levels in the blood), these did not translate into worse clinical outcomes for the children who received it.
Why This Matters
For years, smaller studies and adult data hinted that balanced fluids might be safer than saline. Major guidelines reflected that uncertainty by only weakly favoring balanced fluids and calling for more definitive trials. PRoMPT BOLUS provides that definitive evidence in children: either fluid is a reasonable choice.
This is good news for clinicians and for global health equity. Balanced fluids are not always available, especially in lower-resource settings. The trial’s findings mean that emergency teams everywhere can use whichever IV fluid is on hand without concern that they are giving inferior care.
Take Home Message
For children in the ED with suspected septic shock, both 0.9% saline and balanced IV fluids are equally safe and effective. The most important factors remain early recognition of sepsis and prompt treatment, not the specific fluid chosen.
Why is this important for patients and caregivers
- Sepsis is a life-threatening reaction to infection. When a child has sepsis, IV fluids are one of the first and most important treatments.
- This study compared the two most common IV fluids and found that both work equally well. Your child’s care team can choose the one that is most readily available without compromising safety.
- What matters most is recognizing the signs of sepsis early (such as a high fever, rapid breathing, lethargy, or unusual irritability) and seeking emergency care quickly.
Interested in other PECARN research?
A few recent PECARN studies covered on the PECARN and ALiEM blogs:
- Not All Kids Are Triaged Equally: Disparities in Pediatric Behavioral Health ED Triage — Hoffmann et al, JAMA Network Open, 2026. Triage errors in pediatric behavioral health visits are common, and Hispanic, Black, and Spanish-speaking children are undertriaged more often than their peers. Read more on ALiEM and PECARN.
- The End of Routine Lumbar Punctures for the Febrile Infant 28 Days and Younger? — Burstein et al, JAMA, 2025. An updated PECARN rule helps clinicians safely avoid routine lumbar punctures in many young febrile infants. Read more on ALiEM and PECARN.
- PECARN Cervical Spine Injury Prediction Rule — Leonard et al, Lancet Child & Adolescent Health, 2024. A validated decision rule for safely clearing the cervical spine in injured children. Read more on ALiEM and PECARN.
References
- Balamuth F, Weiss SL, Long E, et al; PRoMPT BOLUS Investigators of the PECARN, PERC, and PREDICT Networks. Balanced fluid or 0.9% saline in children treated for septic shock. N Engl J Med. Published online April 24, 2026. PMID: 42028918. doi:10.1056/NEJMoa2601969
