Hyponatremia is one of the most commonly encountered electrolyte disorders in emergency department (ED). Seasonal fluctuations of the prevalence of hyponatremia has been reported. We investigated the impact of age on the seasonal prevalence of hyponatremia in the emergency department in Japan. Total of 8377 patients presented to the ED between January 2015 and December 2016 were reviewed. The adult group aged between 18 and 64 years old consisted of 3656 patients and the elderly group aged over 65 years consisted of 4721 patients. Information collected included age, sex, serum sodium, and serum creatinine. Hyponatremia was defined as a serum sodium leve1 < 135 mEq/L and severe hyponatremia was defined as a serum sodium level < 125 mEq/L. Prevalence of hyponatremia was significantly higher in the elderly group than in the adult group (17.0% vs. 5.7%, p < 0.001). Similarly, the prevalence of severe hyponatremia was significantly higher in the elderly group than in the adult group (1.9% vs. 0.3%, p < 0.001). Prevalence of hyponatremia and severe hyponatremia was significantly higher in the elderly group than in the adult group in all seasons. In the elderly group, there was a significant correlation between weather high temperature during summer and prevalence of hyponatremia (r = 0.510, p = 0.011). There was a major impact of age on the seasonal prevalence of hyponatremia and severe hyponatremia. Strategies to prevent hyponatremia and severe hyponatremia should be taken especially in the elderly patients during summer.

Background: Hypernatremia is one of the most commonly encountered electrolyte disorders in the emergency department (ED). Few studies have reported the seasonal fluctuations of the prevalence of hypernatremia with conflicting results. We investigated the seasonal prevalence of hypernatremia in an emergency department in Japan. Methods: A total of 12,598 patients presented to the ED between January 2015 and December 2017 were reviewed. The adult group aged between 18 and 64 years old consisted of 5427 patients and the elderly group aged over 65 years consisted of 7171 patients. Information collected included age, sex, serum sodium, and serum creatinine. Hypernatremia was defined as a serum sodium leve1 > 145 mEq/L, and moderate to severe hypernatremia was defined as a serum sodium level ≥ 150 mEq/L. Results: The prevalence of hypernatremia was significantly higher in the elderly group than in the adult group (2.6% vs. 0.7%; p < 0.001). Similarly, the prevalence of moderate to severe hypernatremia was significantly higher in the elderly group than in the adult group (1.0% vs. 0.1%; p < 0.001). The prevalence of hypernatremia and moderate to severe hypernatremia was significantly higher in the elderly group than in the adult group in all seasons. In the elderly group, the seasonal prevalence of moderate to severe hypernatremia was significantly higher during the winter. Also, there was a correlation between weather temperature and the prevalence of moderate to severe hypernatremia in the elderly group (r = − 0.34, p = 0.04). Conclusions: Hypernatremia is prevalent in the elderly and the prevalence is highest during the winter. Special attention should be paid in the elderly patients to prevent hypernatremia especially in the winter.

IgA nephropathy is the most common cause of idiopathic glomerulonephritis in the developed world. Although this disorder was initially thought to follow a benign course, it is now recognized that slow progression to end-stage renal disease occurs in up to 50% of affected patients. The two major clinical presentations of IgA nephropathy are gross hematuria and persistent asymptomatic microscopic hematuria with or without mild to moderate proteinuria, which can also be seen in nutcracker syndrome caused by nutcracker phenomenon. The nutcracker phenomenon refers to the compression of the left renal vein between the abdominal aorta and the superior mesenteric artery with impaired blood outflow accompanied by distention of the distal portion of the vein. Nutcracker syndrome is the clinical manifestation of nutcracker phenomenon characterized by a wide spectrum of symptoms, such as hematuria, orthostatic proteinuria, pain or gonadal vein syndrome, and varicoceles.

Various stresses including ischemia are known to up-regulate renal L-FABP gene expression and increase the urinary excretion of L-FABP. In diabetic patients with anemia, the urinary excretion of L-FABP is significantly increased. We studied the clinical significance of urinary L-FABP and its relationship with anemia in non-diabetic patients. A total of 156 patients were studied in this retrospective cross-sectional analysis. The associations between anemia and urinary L-FABP levels, and the predictors of urinary L-FABP levels in non-diabetic patients were evaluated. Urinary L-FABP levels were significantly higher in patients with anemia compared to those in patients without anemia. Similarly, the urinary L-FABP levels were significantly higher in patients with albuminuria compared to those in patients without albuminuria. Urinary L-FABP levels correlated with urinary albumin-to-creatinine ratios, estimated glomerular filtration rates, body mass index, and hemoglobin levels. Multivariate linear regression analysis determined that hemoglobin levels (β = -0.249, P = 0.001) and urinary albumin-to-creatinine ratios (β = 0.349, P < 0.001) were significant predictors of urinary L-FABP levels. Urinary L-FABP is strongly associated with anemia in non-diabetic patients.

Background and Aims: Hypokalemia is one of the most common problems in the emergency department (ED). Severe hypokalemia, defined as a serum potassium level ≤2.5 mEq/L, is a relatively uncommon electrolyte disorder, and few studies have reported its prevalence, etiology, symptoms, and management in the ED. Therefore, we aimed to investigate them in this study.Methods: This retrospective single‐center study included adult patients whose serum potassium levels were measured in the ED between 2012 and 2019. Data including age, sex, serum potassium levels, and serum creatinine levels were collected from the electronic medical records.Results: The serum potassium levels of 21,616 adult patients were measured. The median age of these patients was 73 years (range: 57–83 years), and 38% were men. The prevalence of severe hypokalemia was 0.4%. The most common symptom of symptomatic severe hypokalemia was weakness (p = 0.001). Malnutrition, use of Japanese herbal medicine, and use of diuretics were the main causes of severe hypokalemia. Sixty‐one patients (70%) underwent electrocardiography. Fifty‐nine patients (68%) received treatment for severe hypokalemia within one day of the visit.Conclusion: The management of severe hypokalemia in the ED may be suboptimal. Emergency physicians should be vigilant to avoid missing hypokalemia.