Design: Pragmatic, multinational randomised trial (PRoMPT BOLUS)
Population: 8,482 children aged 2 months to <18 years with suspected septic shock, 47 EDs in 5 countries
Primary outcome: Major adverse kidney events at 30 days (death, new RRT, persistent kidney dysfunction)
Effect: 3.4% vs 3.0%, RR 1.10 (95% CI 0.88–1.40)

PRoMPT BOLUS was a pragmatic trial at 47 emergency departments in five countries, published in April 2026. Children aged 2 months to 18 years with suspected septic shock and abnormal perfusion were randomised to resuscitation with balanced crystalloid or 0.9% saline for up to 48 hours. After withdrawals, 8,482 were analysed.

The primary outcome — death, new renal replacement therapy or persistent kidney dysfunction at 30 days — occurred in 3.4% with balanced fluid and 3.0% with saline (difference 0.4 points, 95% CI −0.5 to 1.3; RR 1.10, 0.88–1.40). Hospital-free days were identical. Saline caused more hyperchloraemia (49% vs 31%) and hypernatraemia (3.1% vs 1.8%); balanced fluid more hyperlactataemia (19.8% vs 16.7%). Other adverse events did not differ.

The theoretical kidney harm of saline's chloride load did not translate into worse outcomes in children. For emergency departments where balanced solutions are costly or unavailable, saline is an acceptable choice. What matters more is recognising shock early and giving the right volume.

Use either 0.9% saline or a balanced crystalloid for fluid resuscitation in paediatric septic shock.
Do not delay resuscitation to find a balanced solution.
Expect hyperchloraemia with saline; it did not translate into kidney harm here.
Reassess after each bolus for signs of fluid overload — hepatomegaly, crackles, rising work of breathing.
Give antibiotics within the first hour; fluid choice is secondary to timing.

Why it matters

It removes pressure to switch to more expensive balanced solutions in paediatric emergency care, which matters where resources are tight.

The statistics, in plain English

The confidence interval for the difference (−0.5 to +1.3 points) is narrow and centred near zero, so a clinically meaningful benefit of balanced fluid is effectively ruled out.