Acute kidney injury in children hospitalised for febrile urinary tract infection

Infants with a congenital anomaly of the kidney and urinary tract sometimes present with hyponatremia, hyperkalemia, and metabolic acidosis due to under-responsiveness to aldosterone, hereafter referred to as secondary pseudo-hypoaldosteronism. The purpose of this report is to investigate pseudo-hypoaldosteronism in infant urinary tract infection. A systematic review was conducted following PRISMA guidelines after PROSPERO (CRD42022364210) registration. The National Library of Medicine, Excerpta Medica, Web of Science, and Google Scholar without limitations were used. Inclusion criteria involved pediatric cases with documented overt pseudo-hypoaldosteronism linked to urinary tract infection. Data extraction included demographics, clinical features, laboratory parameters, management, and course. Fifty-seven reports were selected, detailing 124 cases: 95 boys and 29 girls, 10 months or less of age (80% of cases were 4 months or less of age). The cases exhibited hyponatremia, hyperkalemia, acidosis, and activated renin-angiotensin II-aldosterone system. An impaired kidney function was found in approximately every third case. Management included antibiotics, fluids, and, occasionally, emergency treatment of hyperkalemia, hyponatremia, or acidosis. The recovery time averaged 1 week for electrolyte, acid–base imbalance, and kidney function. Notably, anomalies of the kidney and urinary tract were identified in 105 (85%) cases.Conclusions:This review expands the understanding of overt transient pseudo-hypoaldosteronism complicating urinary tract infection. Management involves antimicrobials, fluid replacement, and consideration of electrolyte imbalances. Raising awareness of this condition within pediatric hospitalists is desirable. What is Known: • Infants affected by a congenital anomaly of the kidney and urinary tract may present with clinical and laboratory features resembling primary pseudo-hypoaldosteronism.• Identical features occasionally occur in infant urinary tract infection. What is New: • Most cases of secondary pseudo-hypoaldosteronism associated with a urinary tract infection are concurrently affected by a congenital anomaly of the kidney and urinary tract.• Treatment with antibiotics and parenteral fluids typically results in the normalization of sodium, potassium, bicarbonate, and creatinine within approximately 1 week.

Transient secondary pseudo-hypoaldosteronism in infants with urinary tract infections: systematic literature review

Betti,

Lavagno,

Bianchetti

et al. 2024

Heart rate to identify non-febrile children with dehydration and acute kidney injury in emergency department: a prospective validation study

Marzuillo,

Rivetti,

Galeone

et al. 2024

We previously developed and retrospectively validated the estimated percentage of heart rate variation (EHRV) as a predictor of the composite outcome of ≥ 5% dehydration and/or acute kidney injury (AKI) in non-febrile children. The current study aimed to prospectively validate EHRV as a predictor for dehydration or AKI in a different cohort of children attending the Pediatric Emergency Department. From July 2022 to August 2023, 256 pediatric patients aged 0–18 years attending the Pediatric Emergency Department were enrolled. EHRV was calculated as follows: [(HR at admission − 50th percentile of HR for age and sex)/HR at admission] × 100. Dehydration was categorized as < 5% or ≥ 5% fluid deficit. AKI was defined according to KDIGO creatinine criteria. Statistical analyses included receiver-operating characteristic (ROC) curves and logistic regression analysis. Among enrolled patients, 52 had ≥ 5% dehydration, 50 had AKI, and 16 had both conditions. EHRV demonstrated significant predictive ability for both ≥ 5% dehydration (AUROC = 0.71; 95% confidence interval (CI), 0.63–0.78; p < 0.001) and AKI (AUROC = 0.78; 95% CI, 0.71–0.84; p < 0.001). An EHRV > 24.5% was associated with an increased odds ratio (OR), adjusted for confounders, of ≥ 5% dehydration (OR = 3.5; 95% CI, 1.6–8.0; p = 0.003) and AKI (OR = 3.4; 95% CI, 1.6–7.3; p = 0.002). The sensitivity and specificity of this cut-off were 34% and 83% for ≥ 5% dehydration and 36% and 84% for AKI, respectively.Conclusions: This study prospectively validates the clinical utility of EHRV in predicting dehydration and AKI in a pediatric emergency care setting. An EHRV > 24.5% could serve as a marker for suspecting dehydration or AKI. Further validation across diverse patient populations and settings is needed. What is Known:• An increased heart rate (HR) is a readily detectable sign of dehydration in children.• In a retrospective validation cohort, an estimated HR variation (EHRV) greater than 24.5% compared to the 50th percentile of HR was predictive of ≥ 5% dehydration and/or acute kidney injury (AKI) in non-febrile patients. What is New:• We prospectively validated the clinical utility of EHRV in predicting dehydration and AKI in a pediatric emergency care setting.• We confirmed that an EHRV greater than 24.5% is associated with increased odds of ≥ 5% dehydration and AKI.

Prevalence of and factors associated with Na + /K + imbalances in a population of children hospitalized with febrile urinary tract infection

Marzuillo,

Guarino,

Annicchiarico Petruzzelli

et al. 2024

We aimed to assess the prevalence of and factors associated with Na + /K + imbalances in children hospitalized for febrile urinary tract infection (fUTI). This retrospective Italian multicenter study included children aged 18 years or younger (median age = 0.5 years) who were discharged with a primary diagnosis of fUTI. Na + /K + imbalances were classified as hyponatremia (sodium < 135 mEq/L), hypernatremia (sodium > 145 mEq/L), hypokalemia (potassium < 3.5 mEq/L), hyperkalemia (potassium > 5.5 mEq/L), and concurrent hyponatremia and hyperkalemia, in the absence of evidence of hemolyzed blood samples. Among the 849 enrolled children, 23% had hyponatremia, 6.4% had hyperkalemia, 2.9% had concurrent hyponatremia and hyperkalemia, 0.7% had hypokalemia, and 0.4% had hypernatremia. In the multiple logistic regression analysis, after applying the Bonferroni correction, only C-reactive protein (C-RP) levels were significantly associated with hyponatremia (OR = 1.04; 95% CI: 1.02–1.06; p < 0.001), only age was significantly associated with hyperkalemia (OR = 1.7; 95% CI: 1.1–2.7; p = 0.01), and only CAKUT was significantly associated with concurrent hyponatremia and hyperkalemia (OR = 4.3; 95% CI: 1.7–10.8; p = 0.002). Even after adjusting for the presence of kidney hypoplasia, abnormal renal echogenicity, pelvi-caliceal dilation, ureteral dilation, uroepithelial thickening of the renal pelvis, bladder abnormalities, pathogen other than E. coli, concurrent hyponatremia and hyperkalemia persisted significantly associated with CAKUT (OR = 3.6; 95% CI: 1.2–10.9; p = 0.02).Conclusion: Hyponatremia was the most common Na + /K + imbalance in children hospitalized for fUTI, followed by hyperkalemia and concurrent hyponatremia and hyperkalemia. C-RP levels were most strongly associated with hyponatremia, age with hyperkalemia, and CAKUT with concurrent hyponatremia and hyperkalemia (suggestive of transient secondary pseudo-hypoaldosteronism). Therefore, in children who develop concurrent hyponatremia and hyperkalemia during the course of a fUTI, an underlying CAKUT could be suspected. What is known:• Na+ and K+ abnormalities can occur in patients hospitalized for febrile urinary tract infection (fUTI).• Concurrent hyponatremia and hyperkalemia during fUTI may suggest transient secondary pseudo-hypoaldosteronism (TPHA), for which limited data on prevalence are available.What is new:• The most common Na+/K+ imbalance in children hospitalized with fUTI was hyponatremia (23%), followed by hyperkalemia (6.4%), concurrent hyponatremia and hyperkalemia (2.9%), hypokalemia (0.7%), and hypernatremia (0.4%).• Concurrent hyponatremia and hyperkalemia were mainly associated with CAKUT, while hyponatremia alone correlated with high C-reactive protein and hyperkalemia alone with younger age. In cases of concurrent hyponatremia and hyperkalemia during fUTI, an underlying CAKUT should be suspected.