Differences in peritoneal solute transport rates in peritoneal dialysis.

BACKGROUND: Ultrafiltration failure associated with peritoneal membrane dysfunction is one of the main complications for patients on long-term peritoneal dialysis (PD). The dialysate-to-plasma concentration ratio (D/P) of creatinine is widely used to assess peritoneal membrane function. However, other small-sized solutes have not been studied in detail as potential indicators of peritoneal permeability. METHODS: We studied the D/Ps of small, middle-sized and large molecules in peritoneal equilibration tests in 50 PD patients. We applied metabolomic analysis of comprehensive small molecular metabolites using capillary electrophoresis time-of-flight mass spectrometry. RESULTS: D/Ps of middle-sized and large molecules correlated positively with D/P creatinine. Most D/Ps of small molecules correlated positively with D/P creatinine. Among 38 small molecules contained in the dialysate, urea, citrulline and choline showed significantly lower ability to permeate than creatinine. In the relationship between D/Ps of creatinine and small molecules, regression coefficients of three molecules were less than 0.3, representing no correlation to D/P creatinine. Five molecules showed negative regression coefficients. Among these molecules, hippurate and 3-indoxyl sulfate showed relatively high teinpro binding rates, which may affect permeability. Serum concentrations of two molecules were higher in the Low Kt/V group, mainly due to high protein binding rates. CONCLUSIONS: D/Ps of some molecules did not correlate with D/P creatinine. Factors other than molecular weight, such as charge and protein binding rate, are involved in peritoneal transport rates. Metabolomic analysis appears useful to analyze small molecular uremic toxins, which could accumulate in PD patients, and the status of peritoneal membrane transport for each molecule.

Dapagliflozin induced hypernatremia via osmotic diuresis: a case report.

Sodium-glucose cotransporter 2 (SGLT2) inhibitors have been widely used. They inhibit proximal tubular glucose reabsorption, resulting in glycosuria. Herein, we report the case of a 65-year-old woman who presented with hypernatremia during the perioperative period of a subarachnoid hemorrhage. The patient continued to take dapagliflozin postoperatively and subsequently developed severe hypernatremia. Based on the urinalysis findings, we diagnosed osmotic diuresis due to glycosuria as contributing to hypernatremia. Hypernatremia improved with the discontinuation of dapagliflozin and the administration of a hypotonic infusion. In the perioperative period, physicians should discontinue SGLT2 inhibitors owing to concerns about the development of hypernatremia.

Hypernatremic chloride-depletion metabolic alkalosis successfully treated with high cation-gap amino acids: a case report.

Normal saline (NS) is recommended for the treatment of chloride-depletion alkalosis (CDA). However, its use in patients with drinking water restrictions or fluid volume deficiencies may lead to hypernatremia. We report the case of a 42-year-old Japanese man with ileus due to sigmoidal volvulus, who presented with CDA. After endoscopic decompression, NS was administered to treat the CDA. Despite the administration of NS, CDA persisted and hypernatremia developed. The infusion was then changed to high cation-gap amino acids (HCG-AA), which improved both metabolic alkalosis and hypernatremia. Thus, HCG-AA may be useful for the treatment of hypernatremia in patients with CDA.

A case of C3 glomerulopathy with nephritis-associated plasmin receptor positivity without a history of streptococcal infection.

A 17-year-old lady was diagnosed with proteinuria and microscopic hematuria within the prior 2 years to this presentation. Further tests revealed nephrotic syndrome with hematuria and hypocomplementemia. Renal histopathology showed membranoproliferative glomerulonephritis. Immunostaining and electron microscopy, suggested C3 glomerulonephritis (C3GN). Nephritis-associated plasmin receptor (NAPlr) and plasmin activity (PA), markers of infection-related glomerulonephritis, were identified in the aforementioned pathology specimens. There are several reports suggesting a causal relationship between group A streptococcal infection and C3 glomerulopathy (C3G). There are many intractable cases, whereas some have responded to immunosuppressive therapy, as did our case. However, there is currently no established gold standard treatment for this disease. We herein report a case of C3G with glomerular positive NAPlr and PA despite the absence of a streptococcal infection. Accumulation of cases such as this may help advance treatment by clarifying the etiology and pathogenic mechanism of C3G and future prognosis.

A rare cause of acute kidney injury with chronic myelomonocytic leukemia.

An 80-year-old man with myelodysplastic syndrome developed acute kidney injury (AKI) and peripheral blood monocyte-dominant leukocytosis. Glomerular disease was suspected from urinalysis, which showed proteinuria and microscopic hematuria with red cell casts. Eventually, he died of respiratory failure, after which a postmortem was performed. In the glomeruli, the extracapillary space was filled with numerous mononuclear cells and erythrocytes. At first interpretation, the glomerular findings appeared to represent cellular crescents. However, immunostaining revealed that the extracapillary mononuclear cells were in fact leukemic cells. Furthermore, tubular injury due to marked accumulation of lysozyme was also recognized together with infiltration of leukemic cells in the interstitium. The diagnosis of kidney infiltration by chronic myelomonocytic leukemia (CMML) and lysozyme-induced tubular injury was eventually made. Our case is the first report showing extracapillary infiltration of leukemic cells by immunostaining. In addition, lysozyme-induced tubular injury is a forgotten cause of kidney injury in patients with CMML. This case teaches us the rare and forgotten causes of AKI with CMML.

Pilsicainide Intoxication with Neuropsychiatric Symptoms Treated with Continuous Hemodiafiltration.

A 72-year-old lady with atrial fibrillation and chronic renal failure was hospitalized due to bradycardic shock with electrocardiographic QRS prolongation. She had experienced limb shaking two days before hospitalization, and additionally developed hallucinations one day before admission. Pilsicainide intoxication was diagnosed from a review of her medications and electrocardiographic findings. Consequently, continuous hemodiafiltration was performed resulting in a resolution of the hallucinations and the QRS prolongation. This is a rare case of psychiatric symptoms caused by pilsicainide intoxication. It is important to know the mode of excretion of a drug and to adjust its dose, so that such drug-related incidents can be avoided.

Successful Treatment of Peritoneal Dialysis-related Peritonitis due to Mycobacterium iranicum.

A 68-year-old man on peritoneal dialysis (PD) was hospitalized with the clinical picture of peritonitis. The patient was diagnosed with peritonitis caused by nontuberculous mycobacteria (NTM) according to positive Ziehl-Neelsen staining and negative Mycobacterium tuberculosis polymerase chain reaction results. Oral levofloxacin and clarithromycin, and later intraperitoneal imipenem were started. According to the anti-NTM susceptibility test results, oral minocycline was administered. The patient was treated for 6 months. He recovered without PD catheter removal; thus, PD was successfully continued. A genetic analysis identified the isolate as Mycobacterium iranicum. This is the first report of PD-related peritonitis caused by M. iranicum.

Successful treatment of Cryptococcus laurentii peritonitis in a patient on peritoneal dialysis.

A 32-year-old man on peritoneal dialysis (PD) was hospitalized for seven days due to fever. A diagnosis of yeast-like fungal peritonitis was made by Gram staining. The patient was started on intravenous micafungin and oral fluconazole therapy following removal of the PD catheter. A fungal pathogen was isolated from the peritoneal fluid and identified as Cryptococcus species. Based on antifungal susceptibility testing, the treatment was changed to voriconazole and continued for 3 months. A genetic analysis identified the isolate as Cryptococcus laurentii (C. laurentii). This patient was diagnosed with C. laurentii PD-related peritonitis and was successfully treated with voriconazole and removal of the PD catheter.

Evaluation for hypoperfusion distal to arteriovenous vascular access using skin perfusion pressure in fingers.

PURPOSE: The usefulness of skin perfusion pressure (SPP) measurement in the assessment of critical ischemia of the lower limb has previously been established. This study investigated whether finger SPP measurement is useful to evaluate hypoperfusion distal to arteriovenous vascular access in dialysis patients. METHODS: Seventeen asymptomatic hemodialysis patients with upper extremity arteriovenous access and 17 non-dialysis control patients were prospectively examined. SPP in the thumb, the middle finger and the little finger of both hands was measured. The bilateral difference of the mean SPP of the three fingers was evaluated. RESULTS: The mean difference of SPP between the contralateral and the arteriovenous access sides among hemodialysis patients (33±2 5 mmHg) was significantly larger than the mean difference of SPP between the left and the right hands among control patients (1.0±6.0 mmHg, p<0.01). CONCLUSIONS: This report shows the potential usefulness of SPP measurement to evaluate hypoperfusion distal to arteriovenous vascular access.