Written by Joshua Belfer
Spoon Feed
In children with suspected septic shock, balanced crystalloids did not reduce the incidence of death, new renal-replacement therapy, or persistent kidney dysfunction compared with 0.9% saline, suggesting either fluid is reasonable for initial ED resuscitation.
A landmark trial with a surprisingly practical answer
Fluid choice in pediatric sepsis has often generated strong opinions, mostly because 0.9% saline can cause hyperchloremia and metabolic acidosis, while balanced fluids more closely resemble plasma composition. The PRoMPT BOLUS trial was designed to answer whether those biochemical differences actually matter clinically. This pragmatic, international randomized trial enrolled children 2 months to <18 years old with suspected septic shock and abnormal perfusion across 47 EDs in 5 countries, comparing balanced fluids with 0.9% saline for resuscitation and maintenance fluids for up to 48 hours.
Among 8,482 analyzed patients, a primary outcome event—a composite of death, new renal-replacement therapy, or persistent kidney dysfunction, all at 30 days—occurred in 3.4% of the balanced-fluid group vs. 3.0% of the saline group, with no significant difference (RR 1.10; 95%CI 0.88–1.40, p=0.85). Mortality, hospital length of stay, and hospital-free days were also similar. Balanced fluids reduced hyperchloremia (31% vs. 49%) and hypernatremia (1.8% vs. 3.1%), though hyperlactatemia was slightly more common (20% vs. 17%), but these lab differences did not translate into patient-centered benefit.
The major limitation is that the event rate was lower than expected, reducing power to detect small differences. The authors also note that the study may not fully exclude benefit in the sickest children, where point estimates favored balanced fluids in some analyses.
How will this change my practice?
There was a lot of anticipation for the results of this study, which was the largest acute care interventional trial ever conducted in pediatrics. Personally, as someone who helped to enroll during fellowship and as an attending, I was very curious what the study would reveal. I think a good way to frame the results is that it is practice-settling, not necessarily practice-changing. For most children with suspected septic shock in the ED, I would not delay resuscitation or overthink the fluid bag. Use what is immediately available, compatible, and appropriate for the patient. If LR or Plasma-Lyte is ready, great. If saline is what’s hanging, also fine. The priority remains early recognition, timely antibiotics, appropriate fluid resuscitation, reassessment, and vasoactive drugs when needed. Balanced fluids still make physiologic sense in some scenarios, especially when giving large volumes or trying to avoid hyperchloremia, but this trial makes it hard to argue that balanced fluids should be mandatory for all pediatric septic shock resuscitations. The bag probably matters less than the bedside care around it.
Source
Balanced Fluid or 0.9% Saline in Children Treated for Septic Shock. N Engl J Med. 2026 Apr 24:10.1056/NEJMoa2601969. doi: 10.1056/NEJMoa2601969. Epub ahead of print. PMID: 42028918; PMCID: PMC13134814.
