Nomogram‐Based Admission Model to Predict Early Hypovolaemic Shock in Paediatric Nephrotic Syndrome: Derivation and Internal Validation

AIM: Hypovolaemic shock (HS) is an uncommon but life-threatening complication in paediatric nephrotic syndrome (NS), yet current guidelines lack a quantitative admission-time instrument to flag high-risk children. We aimed to develop and internally validate a simple model for early HS using routinely available clinical-laboratory data. METHODS: We performed a single-centre observational study including 258 children with NS admitted to a tertiary paediatric hospital. HS within 24-h of admission was the outcome. Candidate predictors were routine admission variables. Multivariable logistic regression was used to derive a parsimonious model, which was presented as a nomogram. Internal validation and clinical utility were assessed using cross-validation and decision-curve analysis (DCA). RESULTS: HS occurred in 37/258 (14.3%). The final 4-variable model retained age, haematocrit, serum albumin and serum sodium. Two markers remained strongly and independently associated with HS: serum albumin, OR = 2.17 per 1 g/L decrease (95% CI 1.68-3.07; p < 0.001); and serum sodium, OR = 5.79 per 5 mmol/L decrease (95% CI 1.86-22.75; p = 0.006). Age (OR 0.90 per year) and haematocrit (OR 1.47 per +5%) modestly improved discrimination. Apparent discrimination was excellent (AUC = 0.966; 95% CI 0.945-0.988; Brier 0.049) and remained high on cross-validation (AUC = 0.959; 95% CI 0.934-0.983; Brier 0.055). DCA showed a higher net benefit of the model than 'treat all' or 'treat none' between 20% and 50% risk. CONCLUSION: A four-variable admission nomogram can stratify early HS risk in children with NS using routine data. External multicentre validation remains necessary.