Hyponatremia and hyperkalemia in infants with acute pyelonephritis

Laboratory Analysis of the Renal Function Changes Under Long-Term Exposure to Extremely Low Ambient Temperatures: Case Report

The study subject was a healthy, 47-year-old man, a low temperature Guinness World Record holder. He spent 50 days alone in Rovaniemi, Lapland, and functioned in the ambient temperature ranging from +2°C to -37°C. He did not use sources of heat, he did not eat warm meals or drink hot water, and did not dry his clothes. He slept in an igloo, on an ice cover of 20-30 cm. He spent 10 hours a day in a sleeping bag and for the remaining time he walked, skied, or rode a bicycle, and practiced swimming. The aim of the study was a laboratory assessment of renal capacity in a man exposed to long-term extremely low ambient temperatures. The study was approved by the Ethical Committee at the Regional Medical Chamber in Krakow, Poland (approval No.: 194/KBL/OIL/2019). Twice during the observation, urine and blood were collected and analyzed: before and after the prolonged exposure to extremely low ambient temperatures. Changes were seen in many blood and urine parameters, but in urine, they were more significant. In urine, decreased values of sodium (by 53.9%), potassium (by 22.6%), creatinine (by 65.5%), urea (by 61.3%), uric acid (by 58.4%), and protein (by 50%) were observed. Neutrophil gelatinase-associated lipocalin (NGAL) increased by 34%. Absence of calcium oxalate excretion was reported relative to the value before the exposure to cold. In blood, increased values of interleukin-6 (by 60%) and β-2-microglobulin (by 26.9%) were observed. Erythropoietin decreased by 22.4%. No changes were noted in estimated glomerular filtration rate. The study subject lost 10 kg in weight. On the basis of the results obtained during the observation, it can be determined that the probable cause of changes in the laboratory results of the subject was the diet used, and not a dysfunction of the excretory system. The body weight loss and activation of compensating mechanisms focused on saving vitally important diet components, caused by the insufficient diet, exclude the theory of a negative effect of exposure to extremely low temperatures on renal filtration function.

Blood analysis for screening of electrolyte and kidney function alterations in patients with febrile urinary tract infection

AIM

To describe the prevalence, severity, risk factors, and clinical relevance of electrolyte disturbances and acute kidney injury (AKI) during febrile urinary tract infection (fUTI).

METHODS

Retrospective observational study of well/fair-appearing patients between 2 months and 16 years, with no previous relevant medical history, diagnosed with fUTI in the paediatric emergency department (PED) with subsequent microbiological confirmation. Analytical alteration (AA) data were considered: AKI (creatinine elevation × 1.5 the median for age), plasma sodium alteration (≤130 or ≥150 mEq/L), and potassium alteration (≤3 or ≥6 mEq/L).

RESULTS

We included 590 patients, 17.8% presented AA (13 hyponatremia, 7 hyperkalaemia, and 87 AKI). No patient presented severe analytic alterations or a higher frequency of symptoms potentially attributable to these alterations (seizures, irritability, or lethargy). Risk factors associated with these AA were clinical dehydration (OR = 3.5 95% CI: 1.04-11.7; p = 0.044) and presenting a temperature >39°C (OR = 1.9 95% CI: 1.14-3.1; p = 0.013).

CONCLUSIONS

Electrolyte and renal function disturbances are infrequent in the previously healthy paediatric population with a fUTI. If present, they are asymptomatic and not severe. Based on our results, performing systematic blood analysis to rule out AA appears no longer justified, especially in the absence of risk factors.

Pseudo-hypoaldosteronism secondary to infantile urinary tract infections: role of ultrasound

Background

The biochemical hallmarks of transient pseudo-hypoaldosteronism associated with a pyelonephritis include hyponatremia, hyperkalemia, and acidosis. We tested if the kidney-urinary tract ultrasound helps in predicting the diagnosis of overt pseudo-hypoaldosteronism in infants with a pyelonephritis.

Cases presentation

Between 2013 and 2020, we managed 71 previously healthy infants 4 weeks to 24 months of age with a pyelonephritis (42 males and 29 females) and made the biochemical diagnosis of pseudo-hypoaldosteronism in 17 (24%). Infants with and without pseudo-hypoaldosteronism did not significantly differ with respect to the prevalence of kidney-urinary tract ultrasound abnormalities, graded by means of the UTD classification system of urinary tract abnormalities.

Conclusions

Kidney-urinary tract ultrasound is almost routinely obtained in children with a febrile urinary tract infection. Our experience does not support the hypothesis that ultrasound might be relevant for the diagnosis of overt transient pseudo-hypoaldosteronism in babies affected by a urinary tract infection. Our data confirm the assumption that negative studies may be important for advancing clinical practice.

Association of Electrolyte Changes and Inflammatory Markers with Renal Involvement in Children with Febrile UTI

Background: We need some simpler, cheaper, and less burdensome tools to investigate the severity of renal parenchymal involvement in children with clinical pyelonephritis. Objectives: The present study was designed to investigate the relationship between electrolyte changes with renal involvement as documented by dimercaptosuccinic acid (DMSA) scan in children with febrile urinary tract infection (UTI). Methods: This is a retrospective cohort study, involving 158 children aged two months to 14 years with febrile UTI admitted to Taleghani Hospital in Gorgan from 2018 to 2019. Their documents in hospital were analyzed. They were divided into two groups with positive or negative defects on DMSA scan. Clinical and laboratory data were studied. Statistical analysis was performed using SPSS version 18. Data were analyzed using independent t-test with normal distribution of variables, otherwise chi-square test was used. The statistical significance level of the study was considered 0.05. Results: Among the 158 children, 78 patients (49.4%) had normal DMSA scan results, and 80 patients (50.6%) had an abnormal result. The mean age in month was not different between the two groups. In patients with positive renal cortical defects on DMSA Scintigraphy (group 2), ESR was significantly higher than the first group (P < 0.05). The mean serum Na level in the second group was lower than in the first group; however, it was only slightly significant (P = 0.058). The two groups showed no difference with respect to serum potassium, urine specific gravity (SG), WBC count, and the duration of fever (P > 0.05). The frequency distribution of proteinuria was not different between the two groups (P = 0.836). Conclusions: We suggest that increased ESR, positive CRP, and the presence of reflux can predict renal parenchymal involvement in children with febrile UTI as evidenced by a positive finding on DMSA scan, and the presence of hyponatremia has a little predictive value in this regard.

Hyponatremia in childhood urinary tract infection

Acute urinary tract infection (UTI) is the most common bacterial infection in childhood. Although hyponatremia was described in ~ 2/3 of these children, its clinical significance is still unclear. Herein, we evaluated the prevalence and clinical implications of hyponatremia in children hospitalized with a UTI. Medical records of previously healthy children hospitalized between January 2011 and December 2016 with UTI were retrospectively reviewed. Patients (median age 5.5 months) were divided into two groups according to their sodium levels: normonatremia (Na ≥ 135 mEq/L) and hyponatremia (Na < 135 mEq/L). Hyponatremia diagnosed on admission was found in 114/219 children (49%). Hyponatremic patients experienced a more severe disease manifested by a longer hospital stay (3.8 vs 3.4 days, p = 0.003), a higher prevalence of abnormal findings on renal ultrasound (10 vs 2, p = 0.01), higher C-reactive protein (CRP) levels (8.6 vs 3.4 mg/dl, p = <0.001), and a negative correlation between sodium levels and CRP (r = - 0.38, p < 0.001).Conclusion:Hyponatremia occurs frequently in children hospitalized with UTI and is associated with elevated inflammatory markers and a more severe disease course. What is Known: • Hyponatremia, one of the most common electrolyte abnormalities, occurs in approximately 1/3 of hospitalized children and in 2/3 of children with pyelonephritis. • In certain cases of various medical conditions, hyponatremia has been shown to correlate with disease severity. What is New: • Hyponatremia in hospitalized children with UTI correlates with elevated inflammatory markers and a more severe disease course.

Na(+), K(+), Cl(-), acid-base or H2O homeostasis in children with urinary tract infections: a narrative review

Guidelines on the diagnosis and management of urinary tract infections in childhood do not address the issue of abnormalities in Na(+), K(+), Cl(-) and acid-base balance. We have conducted a narrative review of the literature with the aim to describe the underlying mechanisms of these abnormalities and to suggest therapeutic maneuvers. Abnormalities in Na(+), K(+), Cl(-) and acid-base balance are common in newborns and infants and uncommon in children of more than 3 years of age. Such abnormalities may result from factitious laboratory results, from signs and symptoms (such as excessive sweating, poor fluid intake, vomiting and passage of loose stools) of the infection itself, from a renal dysfunction, from improper parenteral fluid management or from the prescribed antimicrobials. In addition, two transient renal tubular dysfunctions may occur in infants with infectious renal parenchymal involvement: a reduced capacity to concentrate urine and pseudohypoaldosteronism secondary to renal tubular unresponsiveness to aldosterone that presents with hyponatremia, hyperkalemia and acidosis. In addition to antimicrobials, volume resuscitation with an isotonic solution is required in these children. In secondary pseudohypoaldosteronism, isotonic solutions (such as 0.9 % saline or lactated Ringer) correct not only the volume depletion but also the hyperkalemia and acidosis. In conclusion, our review suggests that in infants with infectious renal parenchymal involvement, non-renal and renal causes concur to cause fluid volume depletion and abnormalities in electrolyte and acid-base balance, most frequently hyponatremia.

Neonatal renal venous thrombosis followed by secondary pseudohypoaldosteronism

A male infant was diagnosed as having renal venous thrombosis (RVT) in association with bilateral flank masses, macroscopic hematuria, and thrombocytopenia. In the course of supportive treatment, hyponatremia, hyperkalemia, and metabolic acidosis became prominent. Plasma renin activity (PRA) and aldosterone increased markedly. Treatment with sufficient sodium chloride and sodium bicarbonate intake was effective. It is important to note that tubular damage by RVT causes secondary pseudohypoaldosteronism.

Hyponatremia may reflect severe inflammation in children with febrile urinary tract infection

BACKGROUND

Hyponatremia is the most common electrolyte abnormality in clinical practice, but little is known about the association between febrile urinary tract infection (UTI) and hyponatremia or its significance to clinical outcomes.

METHODS

Data from 140 children with febrile UTI between 2000 and 2010 were retrospectively analyzed. Laboratory examinations [white blood cell (WBC) count, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and serum sodium concentration], renal ultrasonography, (99m)Technetium-dimercaptosuccinic acid (DMSA) scintigraphy, and voiding cystourethrogram were performed. Culture growing >50,000 colonies of one single bacterial species on a urine sample obtained by catheter or >100,000 colonies on two clean-catch samples was required to establish diagnosis of UTI.

RESULTS

In children with renal cortical defects diagnosed after DMSA scintigraphy (group 1), duration of fever was significantly longer (P = 0.038) and WBC (P = 0.047) and CRP (P < 0.0001) levels significantly higher than in those without renal cortical defects (group 2). However, serum sodium levels were significantly lower in group 1 than group 2 (135.9 ± 2.4 vs 137.4 ± 2.7 mEq/L, P = 0.007). Hyponatremia (serum sodium ≤ 135 mEq/L) was also more frequent in group 1 than in group 2 (74.1 % vs 45.3 %, P = 0.012). Serum sodium concentration was negatively correlated with WBC count (r = -0.156, P = 0.011) and CRP levels (r = -0.160, P= 0.028).

CONCLUSIONS

Our study indicates that hyponatremia may be a substantial inflammatory marker and is significantly and independently associated with the degree of inflammation in children with febrile UTI.

Pseudohypoaldosteronism type 1: a rare cause of severe dyselectrolytemia and cardiovascular collapse in neonates

Severe hyperkalemia is a medical emergency and occurs due to a variety of underlying illnesses. We present a 7 day old neonate who presented with life threatening hyperkalemia due to pseudohypoaldosteronism type 1 (PHA1). The clinical picture resembled congenital adrenal hyperplasia (CAH). Very aggressive management including peritoneal dialysis was required to control hyperkalemia. It is important to differentiate PHA1 from CAH since the former does not respond to corticosteroid therapy and may require peritoneal dialysis for control of hyperkalemia. A discussion on the types, clinical course, and management of pseudohypoaldosteronism type 1 is presented.

Electrolyte disturbances in acute pyelonephritis

The aim of this study was to determine whether renal unresponsiveness to aldosterone associated with hyperkalemia is present in infants with acute pyelonephritis in the absence of significant urinary tract anomalies and to describe the clinical characteristics of patients presenting an inadequate renal response to hyperkalemia. The patient cohort comprised 113 infants with acute pyelonephritis (APN), based on the criteria of a temperature >38°C and significant bacteriuria. Serum and urine electrolytes, creatinine, osmolality, and renal tubular function tests were performed at diagnosis. The findings were compared to those present in 75 children who had fever without significant bacteriuria. Hyperkalemia (>5.5 mmol/L) was observed in infants with an APN diagnosis, who exhibited a lower transtubular potassium concentration gradient (TTKG) and a higher fractional sodium excretion. We defined inadequate renal response to hyperkalemia as the combination of hyperkalemia and TTKG below the normal range established for the age of the subject. Infants presenting an inadequate response to hyperkalemia were younger and associated more frequently with an APN diagnosis. This alteration could be explained by the renal interstitial inflammation present in acute pyelonephritis and the immaturity of the renal tubular responsiveness to aldosterone due to infancy in the absence of urinary tract infection or obstruction.

Transient Pseudohypoaldosteronism due to Urinary Tract Infection in Infancy: A Report of 4 Cases

Hyponatremia with hyperkalemia in infancy is an uncommon but life-threatening occurrence. In the first weeks of life, this scenario is often associated with aldosterone deficiency due to salt-wasting congenital adrenal hyperplasia. However, alternative diagnoses involving inadequate mineralocorticoid secretion or action must be considered, particularly for infants one month of age or older. We report four infants who presented with profound hyponatremia accompanied by urinary tract infection, ultimately leading to the diagnosis of transient pseudohypoaldosteronism. Our cases provide support for the idea that the renal tubular resistance to aldosterone is due to urinary tract infection itself rather than to underlying urinary tract anomalies typically found in these infants. Awareness of this condition is important so that serum aldosterone, urine sodium, and urine cultures may be obtained immediately in any infant presenting with hyponatremia and hyperkalemia in whom a diagnosis of congenital adrenal hyperplasia was not found. Adequate replacement with intravenous saline and antibiotic therapy is sufficient to correct sodium levels over 24–48 hours.