Nonosmotic secretion of arginine vasopressin and salt loss in hyponatremia in Kawasaki disease

A Conspectus of Euvolemic Hyponatremia, Its Various Etiologies, and Treatment Modalities: A Comprehensive Review of the Literature

Hyponatremia is the most prevalent electrolyte imbalance encountered among hospitalized patients, athletes, the elderly, patients with chronic ailments, postoperative patients, and a few asymptomatic individuals. Clinical manifestations of hyponatremia can be diverse, with characteristic neurological symptoms. Depending on in-depth medical history, physical examination (including volume status assessment), laboratory investigation, and drug history, patients can be classified broadly as undergoing hypervolemic, euvolemic, or hypovolemic hyponatremia. However, patients with hypervolemic hyponatremia often present with distinctive signs such as edema or ascites, and the clinical presentation of hypovolemic and euvolemic hyponatremia poses significant challenges for clinicians. The convolution in clinical manifestations of patients is due to the varied etiologies of euvolemic hyponatremia, such as syndrome of inappropriate antidiuretic hormone secretion (SIADH), adrenocortical insufficiency, hypothyroidism, psychogenic polydipsia, different classes of drugs (chemotherapeutics, antipsychotics, antidepressants), endurance exercise events, and reset osmostat syndrome (ROS). The management of hyponatremia depends on the rate of hyponatremia onset, duration, severity of symptoms, levels of serum sodium, and underlying comorbidities. Over the last decade, the clinical understanding of hyponatremia has been scattered due to the introduction of innovative laboratory markers and new drugs. This article will be a conspectus of all the recent advancements in the field of diagnosis, investigations, management, and associations of hyponatremia, along with traditional clinical practices. Subsequently, a holistic overview has been laid out for the clinicians to better understand and identify knowledge deficiencies on this topic.

Incidence and Severity of Community- and Hospital-Acquired Hyponatremia in Pediatrics

Hyponatremia is the most common electrolyte disturbance in hospitalized children, with a reported incidence of 15-30%, but its overall incidence and severity are not well known. The objective of our study was to determine the incidence, severity, and associated risk factors of community- and hospital-acquired hyponatremia on a general pediatric ward. Data of 5550 children admitted from June 2012 to December 2019 on plasma sodium and discharge diagnosis were analyzed by logistic regression model. Clinically relevant diagnostic groups were created. Hyponatremia was classified as mild, moderate, and severe. The incidence of community- and hospital-acquired hyponatremia was 15.8% and 1.4%, respectively. Most of the cases were mild (90.8%) to moderate (8.6%), with only two cases of severe community-acquired hyponatremia. There were no clinical complications in any of the hyponatremic children. Age and diagnosis at discharge were principal factors significantly correlated with hyponatremia. Community-acquired hyponatremia is more common than hospital-acquired hyponatremia in clinical practice. Severe cases of both types are rare. Children from 2 to 11 years of age presenting with infections, cardiovascular disorders, and gastrointestinal disorders are at risk of developing hyponatremia.

[Association between duration of fever before treatment and intravenous immunoglobulin resistance in Kawasaki disease]

OBJECTIVES

To examine the association between duration of fever before intravenous immunoglobulin (IVIG) treatment and IVIG resistance in children with Kawasaki disease (KD).

METHODS

A retrospective analysis was performed on the medical data of 317 children with KD who were admitted from January 2018 to December 2020. According to the duration of fever before IVIG treatment, they were divided into two groups: short fever duration group (≤4 days) with 92 children and long fever duration group (>4 days) with 225 children. According to the presence or absence of IVIG resistance, each group was further divided into a drug-resistance group and a non-drug-resistance group. Baseline data and laboratory results were compared between groups. A multivariate logistic regression analysis was used to identify the influencing factors for IVIG resistance.

RESULTS

In the short fever duration group, 19 children (20.7%) had IVIG resistance and 5 children (5.4%) had coronary artery aneurysm, and in the long fever duration group, 22 children (9.8%) had IVIG resistance and 19 children (8.4%) had coronary artery aneurysm, suggesting that the short fever duration group had a significantly higher rate of IVIG resistance than the long fever duration group (P<0.05), while there was no significant difference in the incidence rate of coronary artery aneurysm between the two groups (P>0.05). In the short fever duration group, compared with the children without drug resistance, the children with drug resistance had a significantly lower level of blood sodium and significantly higher levels of procalcitonin, C-reactive protein, and N-terminal B-type natriuretic peptide before treatment (P<0.05). In the long fever duration group, the children with drug resistance had significantly lower levels of blood sodium and creatine kinase before treatment than those without drug resistance (P<0.05). The multivariate logistic regression analysis showed that a reduction in blood sodium level was associated with IVIG resistance in the long fever duration group (P<0.05).

CONCLUSIONS

IVIG resistance in children with KD varies with the duration of fever before treatment. A reduction in blood sodium is associated with IVIG resistance in KD children with a duration of fever of >4 days before treatment.

Serum sodium level is inversely correlated with body temperature in children

BACKGROUND

Several studies have demonstrated that non-osmotic antidiuretic hormone activity contributes to the development of hyponatremia in children with common febrile diseases. However, the relationship between hyponatremia and body temperature has remained unclear. We therefore examined this relationship in children with common diseases.

METHODS

In this retrospective case study based on a chart review, 1,973 children presenting with acute illnesses at Hirakata City Hospital between November 2008 and October 2009, and for whom blood test data were available, were enrolled. The median age of this cohort was 2.7 years and the mean serum sodium concentration was 136.4 mEq/L; 454 patients showed hyponatremia (<135 mEq/L). The patients were classified into four groups on the basis of body temperature, <37 °C, 37 °C (37.0-37.9 °C), 38 °C (38.0-38.9 °C) and ≥39 °C, and their serum sodium concentration was compared.

RESULTS

The mean sodium level was significantly lower in febrile (135.9 mEq/L) than in non-febrile (138.5 mEq/L) patients. The mean serum sodium levels in the four temperature groups were, in ascending order, 138.5 mEq/L (95% CI, 138.3-138.8 mEq/L), 137.3 mEq/L (137.1-137.5 mEq/L), 136.1 mEq/L (135.8-136.3 mEq/L) and 134.6 mEq/L (134.4-134.9 mEq/L), respectively. The serum sodium level in each individual temperature range became significantly lower as body temperature increased (P < 0.001).

CONCLUSIONS

There is a clear inverse correlation between serum sodium level and body temperature in children with common febrile diseases, and fever may play an important role in this relationship.

Sodium-containing versus sodium-trace preparations of IVIG for children with Kawasaki disease in the acute phase

Kawasaki disease (KD) is an acute systemic vasculitis that most commonly causes acquired cardiac disease in children in developed countries. The most highly recommended treatment for KD is 2 g/kg intravenous immunoglobulin (IVIG). There are two types of IVIG, sodium-containing (high-Na) and sodium-trace (low-Na) preparations. However, few studies have compared the effects of these two preparations for superiority. The purpose of this study was to compare outcomes between high and low-Na IVIG preparations in KD children using a national inpatient database in Japan. We used the Diagnostic Procedure Combination database to identify KD patients treated with IVIG between 2010 and 2017. We identified those receiving high and low-Na preparations of IVIG as an initial treatment. Outcomes included proportion of coronary artery abnormalities (CAA), IVIG resistance, adverse effects, length of stay, and medical cost. Propensity score-matched analyses were conducted to compare the outcomes between the two groups. Instrumental variable analyses were performed to confirm the results. We identified 42,345 patients with KD. There were significant differences in proportions of CAA (2.8% vs. 3.2%; p = 0.031) and IVIG resistance (17% vs. 18%, p = 0.001) between the two groups. However, there were no significant differences in length of stay or medical cost. The instrumental variable analysis confirmed the same results as the propensity score analysis.Conclusion: The present study suggests that high-Na IVIG is potentially effective for reducing the proportion of CAA in KD patients. Prospective studies are warranted to confirm the effectiveness observed in this study. What is Known: • For treatments of Kawasaki Disease in acute phase, intravenous immunoglobulin have been the most recommended to reduce fever early and prevent complications of coronary artery abnormalities. There are two types of IVIG preparations, sodium-containing IVIG and sodium-trace IVIG. However, few studies have performed comparisons to determine which preparation of IVIG is superior. What is New: • The present findings suggest that high-Na IVIG is associated with reductions in the proportions of CAAs and IVIG resistance in KD patients.

Serum sodium level associated with coronary artery lesions in patients with Kawasaki disease

INTRODUCTION/OBJECTIVES

Hyponatremia is a potential risk factor for the development of coronary artery lesions (CALs) identified after acute Kawasaki disease (KD). However, the serum sodium distribution corresponding to the reference intervals differs between infants (< 1 year of age) and older children. We hypothesized the association of serum sodium level with CAL complications differs between infants and older patients with KD.

METHODS

We analyzed 21,610 population-based patients who developed KD throughout Japan during 2013-2014. We performed multivariable logistic regression analyses to evaluate the association between serum sodium and CAL complications. Additionally, we stratified the serum sodium distribution associated with CAL complications by infants and older patients.

RESULTS

CALs were identified in 158 (3.6%) infants and 302 (1.8%) older patients. Infants were more likely to develop CALs when within the normal sodium range compared with older patients (75% vs. 29%), whereas most older patients developed CALs with a sodium level lower than the reference interval. Serum sodium ≤ 130 mEq/L indicated significantly higher risk for development of CALs in both groups (adjusted odds ratio [95% confidence intervals] = 3.21 [1.65-6.25] in infants and 1.74 [1.18-2.57] in older patients).

CONCLUSIONS

Serum sodium distribution associated with CAL complications differed greatly between infants and older patients. Older patients developed CALs with sodium levels lower than the reference interval; however, among infants, hyponatremia was not necessarily a risk factor for developing coronary artery lesion. When considering risk assessments for CALs using serum sodium levels, infants with KD should be distinguished from older patients. Key Points • Hyponatremia is a potential risk factor for the development of coronary artery lesions (CALs) among patients with Kawasaki disease. • However, the serum sodium distribution corresponding to the reference intervals differs between infants (< 1 year of age) and older children. • Most infants developed CALs within the normal sodium range, whereas older patients developed at a range lower than the reference interval. • These findings highlight that when considering risk assessments for CALs using serum sodium levels, infants should be distinguished from older patients.