Unveiling the Patterns of Water Diuresis in Profound Hyponatremia Management in Intensive Care Unit Settings.

BACKGROUND: Hyponatremia treatment guidelines recommend avoiding excessive increases in serum sodium concentration (s[Na]) to prevent osmotic demyelination syndrome. Although an unexpected rise in s[Na] has been attributed to water diuresis during the treatment of hyponatremia, clinical courses of water diuresis are unclear. We conducted this study to investigate the clinical characteristics of water diuresis during profound hyponatremia management. METHODS: In this retrospective observational study, we examined patients with profound hyponatremia (s[Na] ≤120 mEq/L) admitted to the intensive care unit of a Japanese hospital. The manifestation of water diuresis was defined as a urine volume ≥2 ml/kg/h and a urinary sodium plus potassium concentration (u[Na+K]) ≤50 mEq/L. We analyzed changes in urine volume and u[Na+K] over time for patients experiencing water diuresis. This analysis employed a mixed-effects model with spline terms for time, and the results are graphically presented. RESULTS: Among 47 eligible patients, 30 (64%) met the criteria for water diuresis. The etiologies of hyponatremia were drug-related hyponatremia (n=10; 33%), primary polydipsia (n=8; 27%), hypovolemic hyponatremia (n=7; 23%), syndrome of inappropriate secretion of antidiuresis (n=7; 23%), and acute heart failure (n=1; 3%). Among patients with water diuresis, 27 (90%) experienced the manifestation of water diuresis within 24 hours after the start of correction. The increased urine volume and decreased u[Na+K] levels began several hours before the peak manifestation of water diuresis. Within 6 hours after the manifestation of water diuresis, 29 patients (97%) received electrolyte-free infusions and 14 (47%) received desmopressin. One patient (3%) with water diuresis experienced overcorrection. CONCLUSIONS: Water diuresis is common during the treatment for profound hyponatremia and typically occurs within the first 24 hours, preceded by changes in urinary characteristics. Early detection and prompt response to water diuresis through urine monitoring during the early periods of hyponatremia treatment may be effective for managing water diuresis.

Renal Immune-related Adverse Event of Pembrolizumab Masked by Pemetrexed.

A Japanese woman in her 60s developed a kidney injury 9 weeks after treatment with pemetrexed, carboplatin, and pembrolizumab for stage IV lung adenocarcinoma. A renal biopsy showed chronic tubulointerstitial damage with minimal focal interstitial inflammation, consistent with pemetrexed-induced nephropathy; thus, pemetrexed was withdrawn. However, the kidney injury continued to worsen. A repeated biopsy showed severe acute tubulointerstitial nephritis, suggestive of a pembrolizumab-induced immune-related adverse event (irAE). The worsening after pemetrexed discontinuation suggested that the irAE had already begun, as the first biopsy showed focal inflammation. This case suggests thatcombining immune checkpoints and chemotherapy requires considering concurrent drug-induced nephrotoxicity.

Predictive correction of serum sodium concentration with formulas derived from the Edelman equation in patients with severe hyponatremia.

Severe hyponatremia can cause life-threatening cerebral edema. Treatment comprises rapid elevation of serum sodium concentration; however, overcorrection can result in osmotic demyelination. This study investigated potential factors, including predictive correction based on the Edelman equation, associated with appropriate correction in 221 patients with a serum sodium concentration ≤ 120 mEq/L who were admitted to a hospital in Nagoya, Japan. Appropriate correction was defined as an elevation in serum sodium concentration in the range of 4-10 mEq/L in the first 24 h and within 18 mEq/L in the first 48 h after the start of the correction. Appropriate corrections were made in 132 (59.7%) of the 221 patients. Multivariate analysis revealed that predictive correction with an infusate and fluid loss formula derived from the Edelman equation was associated with appropriate correction of serum sodium concentration (adjusted odds ratio, 7.84; 95% confidence interval, 2.97-20.64). Relative without its use, the predictive equation results in a lower proportion of undercorrection (14.3% vs. 48.0%, respectively) and overcorrection (1.0% vs. 12.2%, respectively). These results suggest that predictive correction of serum sodium concentrations using the formula derived from the Edelman equation can play an essential role in the appropriate management of patients with severe hyponatremia.

Combined light chain crystalline tubulopathy, podocytopathy, and histiocytosis associated with Bence-Jones κ protein diagnosed via immuno-electron microscopy.

We herein report a case of a combined crystalline light chain tubulopathy, podocytopathy, histiocytosis, and cast nephropathy in a patient with monoclonal gammopathy of renal significance (MGRS). A 66-year-old female with impaired renal function was referred to our department. Despite intravenous fluid resuscitation, the kidney function worsened progressively; thus, a kidney biopsy was performed. The kidney biopsy revealed light chain proximal tubulopathy (LCPT) with crystals, light chain crystal podocytopathy (LCCP), crystal-storing histiocytosis (CSH), and light chain cast nephropathy (LCCN). Of note, LCCP and CSH were diagnosed via electron microscopy. Serum and urine immunoelectrophoresis (IEP) revealed the presence of monoclonal Bence-Jones protein and free κ light chains. Bone marrow aspiration showed < 10% plasma cell proliferation. Thus, we had encountered a rare case in which a variety of kidney lesions were combined with MGRS. Most of the LCPT, LCCP, and CSH cases show monoclonal IgG κ, while our case showed Bence-Jones protein κ.

Fatal and extensive multiorgan hemorrhages in anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis: An autopsy case report.

INTRODUCTION: Anti-melanoma differentiation-associated gene 5 antibody (anti-MDA5 Ab) is an autoantigen associated with dermatomyositis (DM). Anti-MDA5 Ab-positive DM patients frequently exhibit clinically amyopathic dermatomyositis (CADM), and develop rapidly progressive interstitial lung disease (RPILD). Even with early detection and potent combination immunosuppressive therapy, anti-MDA5 Ab-positive DM patients have a poor prognosis. In the present case report, we present a rare autopsy case of a patient with anti-MDA5 Ab DM with RPILD who exhibited diffuse alveolar damage (DAD) patterning in lung specimens, and extensive hemorrhages in multiple organs. PATIENT CONCERNS: An 82-year-old Japanese man admitted with bacterial pneumonia was subsequently diagnosed with anti-MDA5 Ab-positive DM based on skin manifestations (mechanic's hand, ulcerated palmar papules, and flagellate erythema), myositis, interstitial pneumonia, and elevation of anti-MDA5 Ab titer. DIAGNOSIS: The patient was diagnosed with anti-MDA5 Ab DM, complicated with RPILD. INTERVENTIONS: The patient received potent immunosuppressive therapy consisting of pulse methylpredonisolone at a dose of 1000 mg for 3 days, followed by prednisolone at 60 mg/d, a 1000 mg pulse of intravenous cyclophosphamide (IVCY), and oral tacrolimus at 6 mg/d. Intravenous immunoglobulin (IVIG) at a dose of 400 mg/kg/d for 5 days was subsequently administered. OUTCOMES: Despite triple immunosuppressive therapy and IVIG, the patients' respiratory status deteriorated, and the patient died of respiratory failure on the twelfth day after admission. An autopsy revealed pulmonary DAD and multiorgan hemorrhages, including the left iliopsoas muscle, gastric and bowl mucosa, spleen, and left adrenal gland. LESSONS: Multiorgan hemorrhages may be a fatal complication in anti-MDA5 Ab DM patients.

The Type of Vascular Access and the Incidence of Mortality in Japanese Dialysis Patients.

Objective The National Kidney Foundation (NKF) Kidney Disease Outcome Quality Initiative (KDOQI) guidelines have recommended the use of arteriovenous fistula (AVF) at the initiation of dialysis. However, there are significant differences in the dialysis environments of Japan and the United States, and there are few people who receive hemodialysis via a central venous catheter (CVC) in Japan. The aim of the present study was to examine the association between the type of vascular access at the initiation of dialysis and the incidence of mortality in Japan. Methods This study was a prospective, multicenter, cohort study. The data was collected by the Aichi Cohort study of Prognosis in Patients newly initiated into dialysis (AICOPP) in which 18 Japanese tertiary care centers participated. The present study enrolled 1,524 patients who were newly introduced to dialysis (the patients started maintenance dialysis between October 2011 and September 2013). After excluding 183 patients with missing data, 1,341 patients were enrolled. The Cox proportional hazards model was used to evaluate mortality based on the type of vascular access. The types of vascular access were divided into four categories: AVF, arteriovenous graft (AVG), CVC changed to AVF during the course (CAVF), CVC changed to AVG during the course (CAVG). Results A multivariate analysis revealed that AVG, CAVF and CAVG were associated with a higher risk of mortality in comparison to AVF [hazard ratio (HR), 1.60; p=0.048; HR, 2.26; p=0.003; and HR, 2.45; p=0.001, respectively]. Conclusion The research proved that the survival rate among patients in whom hemodialysis was initiated with AVF was significantly higher than that in patients in whom hemodialysis was initiated with AVG or CVC.

A Fatal Case of Metformin-associated Lactic Acidosis.

A 72-year-old woman with a history of type 2 diabetes mellitus was brought to the ER with metformin-associated lactic acidosis. She received continuous hemofiltration and hemodialysis, but the laboratory analyses showed no improvement. She died 11 hours after admission. Metformin is minimally bound to proteins and is readily dialyzable, but a prolonged period of dialysis is required, because metformin has a very large distribution volume and is distributed to multiple compartments. The peak blood metformin level was 432 mg/L in this case, which is one of the highest metformin concentrations ever reported, and eight hours of hemodialysis were not sufficient to reduce the serum level.