Urinary chemokine C-X-C motif ligand 16 and endostatin as predictors of tubulointerstitial fibrosis in patients with advanced diabetic kidney disease.

BACKGROUND: Interstitial fibrosis and tubular atrophy (IFTA) is a well-recognized risk factor for poor renal outcome in patients with diabetic kidney disease (DKD). However, a noninvasive biomarker for IFTA is currently lacking. The purpose of this study was to identify urinary markers of IFTA and to determine their clinical relevance as predictors of renal prognosis. METHODS: Seventy patients with biopsy-proven isolated DKD were enrolled in this study. We measured multiple urinary inflammatory cytokines and chemokines by multiplex enzyme-linked immunosorbent assay in these patients and evaluated their association with various pathologic features and renal outcomes. RESULTS: Patients enrolled in this study exhibited advanced DKD at the time of renal biopsy, characterized by moderate to severe renal dysfunction [mean estimated glomerular filtration rate (eGFR) 36.1 mL/min/1.73 m2] and heavy proteinuria (mean urinary protein:creatinine ratio 7.8 g/g creatinine). Clinicopathologic analysis revealed that higher IFTA scores were associated with worse baseline eGFR (P < 0.001) and poor renal outcome (P = 0.002), whereas glomerular injury scores were not. Among measured urinary inflammatory markers, C-X-C motif ligand 16 (CXCL16) and endostatin showed strong correlations with IFTA scores (P = 0.001 and P < 0.001, respectively), and patients with higher levels of urinary CXCL16 and/or endostatin experienced significantly rapid renal progression compared with other patients (P < 0.001). Finally, increased urinary CXCL16 and endostatin were independent risk factors for poor renal outcome after multivariate adjustments (95% confidence interval 1.070-3.455, P = 0.029). CONCLUSIONS: Urinary CXCL16 and endostatin could reflect the degree of IFTA and serve as biomarkers of renal outcome in patients with advanced DKD.

Effect of Hemodialysis on Peripapillary Choroidal Thickness Measured by Swept-Source Optical Coherence Tomography.

PURPOSE: The aim was to investigate the effects of hemodialysis (HD) on peripapillary choroidal thickness (PCT) by swept-source optical coherence tomography and on other ophthalmologic parameters in patients with end-stage kidney disease. MATERIALS AND METHODS: This was a prospective observational study. The authors evaluated 29 patients who underwent HD for end-stage kidney disease. Detailed ophthalmologic examinations and swept-source optical coherence tomography were performed immediately before and after HD. PCT was measured using the modification tool in the built-in OCT image viewer program. Changes in PCT before and after HD were statistically analyzed. RESULTS: The average PCT significantly decreased from 127.3±49.2 µm before HD to 117.1±50.9 µm after HD (P<0.001). A significant correlation was found between changes in PCT and macular choroidal thickness (ρ=0.547, P=0.002). Changes in mean ocular perfusion pressure did not significantly correlate with changes in PCT (ρ=-0.049, P=0.803). CONCLUSIONS: PCT significantly decreased after HD. HD could influence the optic nerve head and its surrounding structures.

Late Onset Nephrogenic Systemic Fibrosis in a Patient with Stage 3 Chronic Kidney Disease: a Case Report.

Nephrogenic systemic fibrosis (NSF) is a progressive systemic fibrosing disease that may occur after gadolinium contrast exposure. It can lead to severe complications and even death. NSF is highly prevalent among patients with advanced chronic kidney disease (CKD). In this report, however, we describe the case of a patient with NSF that occurred during early CKD. A 65-year-old man with stage 3a CKD was transferred to our hospital because of lower extremity edema. The medical history revealed that he was exposed to gadolinium 185 days earlier, and the result of his tibial skin biopsy was consistent with NSF. The patient underwent a combined therapy with ultraviolet-A1 phototherapy and methotrexate and steroid therapy for 6 months. The combined therapy stopped the systemic progression of NSF.

New oral spherical carbon adsorbent effectively reduces serum indoxyl sulfate levels in moderate to advanced chronic kidney disease patients: a multicenter, prospective, open-label study.

BACKGROUND: Elevated levels of serum indoxyl sulfate (IS) have been linked to cardiovascular complications in patients with chronic kidney disease (CKD). Oral sorbent therapy using spherical carbons selectively attenuates IS accumulation in CKD patients. This study aimed to investigate whether oral administration of a new oral spherical carbon adsorbent (OSCA), reduces serum IS levels in moderate to severe CKD patients. METHODS: This prospective, multicenter, open-label study enrolled patients with CKD stages 3-5. Patients were prescribed OSCA for 8 weeks (6 g daily in 3 doses) in addition to standard management. Serum IS levels were measured at baseline and 4 and 8 weeks of treatment with OSCA. RESULTS: A total of 118 patients were enrolled and 87 eligible patients completed 8 weeks of study. The mean age of the study subjects was 62.8 ± 13.7 years, and 80.5% were male. Baseline levels of serum IS were negatively correlated with estimated glomerular filtration rate (eGFR) (r = - 0.406, P < 0.001) and increased with increasing CKD stages (stage 3, 0.21 ± 0.21 mg/dL; stage 4, 0.54 ± 0.52 mg/dL; stage 5, 1.15 ± 054 mg/dL; P for trend = 0.001). The patients showed significant reduction in serum total IS levels as early as 4 weeks after OSCA treatment (22.5 ± 13.9% reduction from baseline, P < 0.001) and up to 8 weeks (31.9 ± 33.7% reduction from baseline, P < 0.001). This reduction effect was noted regardless of age, kidney function, or diabetes. No severe adverse effects were reported. Gastrointestinal symptoms were the most commonly reported adverse effects. In total, 21 patients withdrew from the study, with dyspepsia due to heavy pill burden as the most common reason. The medication compliance rate was 84.7 ± 21.2% (min 9%, max 101%) for 8 weeks among those who completed the study. CONCLUSIONS: OSCA effectively reduced serum IS levels in moderate to severe CKD patients. Gastrointestinal symptoms were the most commonly reported complications, but no treatment-related severe adverse effects were reported. TRIAL REGISTRATION: Clinical Research Information Service ( KCT0001875 . 14 December 2015.).

Cancer incidence according to the National Health Information Database in Korean patients with end-stage renal disease receiving hemodialysis.

BACKGROUND/AIMS: The aim of this study was to investigate incidence, survival, and risk factors of cancer in end-stage renal disease (ESRD) patients with hemodialysis using information from the National Health Information Database (NHID). METHODS: Using the NHID, we identified ESRD patients who started maintenance hemodialysis between 2003 and 2005 in Korea. Patients were followed from initiation of hemodialysis to renal transplantation, death, or December 31, 2016, whichever came first. We calculated the incidence, survival, and risk factors of cancer. RESULTS: Of the total 14,382 ESRD patients, 1,124 (7.82%; men:women, 728:396) were diagnosed with cancer during follow-up. The mean duration from the start of hemodialysis to new cancer identification was 64.40 ± 41.81 months. Significant risk factors for the development of new cancer were old age, male sex, and liver disease. Conversely, patients with diabetes showed low risk for new cancer. The colorectum (17.31%) was the most common primary site of cancer in men, followed by the liver (15.8%), stomach (14.29%), lung (13.6%), and kidney (10.3%). In women, the colorectum (14.65%) was also the most common primary site of cancer, followed by the breast (12.88%), thyroid (12.63%), stomach (10.86%), and lung (8.08%). According to the primary site of cancer, breast cancer showed the longest median survival duration (130.93 months), followed by thyroid, kidney, colorectum, bladder, stomach, liver, and lung cancer. On multivariate analyses, overall survival was affected by age and diabetes. CONCLUSION: The cancer incidence of chronic hemodialysis patients was relatively high. Thus, careful monitoring and a specific cancer screening program are needed for chronic hemodialysis patients.

Development of objective indicators for quantitative analysis of sodium intake: the sodium to potassium ratio of second-void urine is correlated with 24-hour urinary sodium excretion.

BACKGROUND/OBJECTIVES: To date, sodium intake has been evaluated based on spot urine instead of 24-hour (hr) urine collection. Nevertheless, the optimal method for assessing daily sodium intake remains unclear. SUBJECTS/METHODS: Fifteen male (age 32.7 ± 6.5 years) participants were offered 3 meals with a total of 9-10 g salt over 24 hours, and 24-hr urine was collected from the second-void urine of the first day to the first-void urine of the second day. Twenty-four-hr urinary sodium (24UNa) was estimated using Tanaka's equation and the Korean formula, and spot urine Na, potassium (K), chloride (Cl), urea nitrogen (UN), creatinine (Cr), specific gravity (SG) and osmolality (Osm) were measured. The ratios of urinary Na to other parameters were calculated, and correlations with total measured 24UNa were identified. RESULTS: Average 24-hr urine volume was 1,403 ± 475 mL, and measured 24UNa was 143.9 ± 42.1 mEq (range, 87.1-239.4 mEq). Measured 24UNa was significantly correlated with urinary Na/UN (r = 0.560, P < 0.01), urinary Na/Osm (r = 0.510, P < 0.01), urinary Na/Cr (r = 0.392, P < 0.01), urinary Na/K (r = 0.290, P < 0.01), 24UNa estimated using Tanaka's equation (r = 0.452, P < 0.01) and the Korean formula (r = 0.414, P < 0.01), age (r = 0.548, P < 0.01), weight (r = 0.497, P < 0.01), and height (r = 0.393, P < 0.01) in all spot urine samples. Estimated 24UNa based on the second-void spot urine of the first day tended to be more closely correlated with measured 24UNa than were estimates from the other spot urine samples. The significant parameters correlated with the second-void urine of the first day were urinary Na/K (r = 0.647, P < 0.01), urinary Na/Cr (r = 0.558, P < 0.05), and estimated 24UNa using Tanaka's equation (r = 0.616, P < 0.05) and the Korean formula (r = 0.588, P < 0.05). CONCLUSIONS: Second-void urine is more reliable than first-void urine for estimating 24UNa. Urinary Na/K in the second-void urine on the first day is significantly correlated with 24UNa. Further studies are needed to establish the most reliable index and the optimal time of urine sampling for predicting 24UNa.

Effect of Hemodialysis on Anterior Chamber Angle Measured by Anterior Segment Optical Coherence Tomography.

PURPOSE: To investigate the effect of hemodialysis (HD) on the anterior chamber angle by anterior segment optical coherence tomography (ASOCT) and other ophthalmologic parameters in patients with end-stage kidney disease (ESKD). METHODS: A prospective observational study was performed on 20 patients who underwent HD for ESKD. Anterior chamber angle images were obtained by 16 mm line scan of ASOCT. The angle opening distance (AOD) and the trabecular-iris space area (TISA) were determined using the ImageJ program. Additional 12 mm horizontal and 9 mm vertical wide-field scans centered on the posterior pole were performed for the measurement of peripapillary retinal nerve fiber layer (pRNFL) thickness and macular ganglion cell-inner plexiform layer (mGCIPL) thickness. Changes in intraocular pressure (IOP), AOD, TISA, pRNFL thickness, and mGCIPL thickness before and after HD were statistically analyzed. RESULTS: The IOP decreased significantly from 17.5 ± 3.4 before HD to 16.2 ± 2.3 after HD (P=0.017). There was a statistically significant decrease in AOD 750 and TISA 750 (P=0.005 and P=0.007, respectively). AOD 500 and TISA 500 also decreased, which was almost statistically significant (P=0.061 and P=0.081, respectively). Mean pRNFL thickness and mGCIPL thickness did not show significant change after HD. CONCLUSION: We observed a significant decrease in IOP and anterior chamber angle measurements after HD. Our study suggests that HD can influence the anterior segment structure of eyes.

Evaluation of changes in choroidal thickness and the choroidal vascularity index after hemodialysis in patients with end-stage renal disease by using swept-source optical coherence tomography.

To evaluate the effect of hemodialysis on choroidal thickness and the choroidal vascularity index (CVI) in patients with end-stage renal disease (ESRD) by using swept-source optical coherence tomography.Thirty-two eyes of 32 patients with ESRD undergoing hemodialysis were recruited prospectively. Detailed ophthalmologic examinations and swept-source optical coherence tomography were performed immediately before and after hemodialysis. Choroidal thickness maps were generated automatically by using built-in software. The CVI was calculated using binarized choroidal optical coherence tomography images. Systemic parameters such as body weight and blood pressure were also measured. The changes in systemic and ocular parameters during hemodialysis were evaluated. Subjects were divided into 2 groups (diabetes mellitus [DM] vs non-diabetes mellitus) for subgroup analysis.Total choroidal thickness showed a significant overall decrease after hemodialysis (-10.9 ±â€Š14.0, P <.001). In the subgroup analysis, total choroidal thickness significantly decreased in both patients with DM (-11.3 ±â€Š13.6, P = .004) and those without (-10.6 ±â€Š14.9, P = .020), but the reduction of choroidal thickness was observed in more subfields in patients with DM than in those without. The CVI did not significantly change after hemodialysis (P = .717). No significant systemic and ocular factors affected the changes in total choroidal thicknesses.Choroidal thickness significantly decreased after hemodialysis in most subfields regardless of the presence of DM. Peri-hemodialysis choroidal changes could be considered in the management of patients with ESRD. Swept-source optical coherence tomography can provide ample and reliable quantitative data for monitoring ocular hemodynamic changes.

Effect of acute intradialytic aerobic and resistance exercise on one-day blood pressure in patients undergoing hemodialysis: a pilot study.

BACKGROUND: Hypertension and intradialytic hypotension are independent risk factors for mortality in hemodialysis patients. We hypothesized that intradialytic exercise would increase blood pressure (BP) during dialysis and decrease it during the postdialytic period. The present study aimed to investigate the effect of acute intradialytic exercise on BP both during dialysis and for 20 hours postdialysis, and to detect any differences in effects of aerobic exercise (AE), resistance exercise (RE), and usual care (UC-the control condition). METHODS: Eleven patients undergoing maintenance hemodialysis performed two complete sets of AE or RE, with a 1-hour rest between the sets. The patients performed AE, RE and UC over three consecutive weeks at 7-day intervals. Intradialytic BP was measured using an oscillometric BP monitor (N.=11), and ambulatory BP was measured for 20 hours after each dialysis session using an ambulatory BP monitor (N.=8). RESULTS: The mean BP of the patients in the AE and RE interventions increased during exercise (P<0.05), with the exception of the first set of AE. However, only RE increased BP significantly compared with UC (P<0.05). Following dialysis, daytime ambulatory BP was significantly lower after AE and RE than after UC (P<0.05). CONCLUSIONS: Acute intradialytic exercise interventions are effective in increasing BP during dialysis and decreasing daytime ambulatory BP after dialysis. Longer observation periods and larger sample sizes will be needed to confirm our findings. Also further studies should be performed on patients prone to intradialytic hypotension.

Optical coherence tomography angiography analysis of changes in the retina and the choroid after haemodialysis.

The purpose of this study is to evaluate the effect of haemodialysis on perfused vessel density, choroidal thickness (CT), and retinal thickness in end-stage renal disease (ESRD) using swept-source optical coherence tomography angiography (SS-OCTA). We studied twenty-nine eyes of 29 ESRD patients by ophthalmologic examination and SS-OCTA before and after haemodialysis. The colour-coded perfusion density maps were generated and perfused vessel density was calculated. Changes in systemic and other ocular parameters such as retinal and choroidal thickness were measured and analysed. Total perfused vessel density decreased significantly after haemodialysis in the choriocapillaris; it was not significantly different in the superficial capillary plexus (SCP) and the deep capillary plexus (DCP). Total CT decreased significantly, but total retinal thickness was not significantly different. There was no significant correlation between choriocapillaris perfused vessel density and CT. The reduction in choriocapillaris perfused vessel density correlated with the decrease in systolic and mean arterial blood pressures. The decrease in CT correlated with the ultrafiltration volume. There were no significant systemic and ocular factors affecting change in retinal thickness and perfused vessel density of SCP and DCP. This is the first study to assess the effect of haemodialysis on blood flow changes using SS-OCTA; changes may be more prominent in the choroidal compared to the retinal layer.

Safety and Efficacy of Tolvaptan in Korean Patients with Hyponatremia Caused by the Syndrome of Inappropriate Antidiuretic Hormone.

BACKGROUND: The aim of this multicenter study was to evaluate the safety and efficacy of tolvaptan (TLV) in Korean patients with the syndrome of inappropriate secretion of antidiuretic hormone (SIADH). METHODS: Of 51 enrolled patients with SIADH, 39 patients (16 female patients, aged 70.8 ± 11.3 years) were included in an intention to treat analysis. All patients received 15 mg/day as the initial dose, and the dose was then increased up to 60 mg/day (as needed) until day 4. RESULTS: Serum sodium increased significantly from baseline during the first 24 hours (126.8 ± 4.3 vs. 133.7 ± 3.8 mmol/L, P < 0.001), rose gradually between days 1 and 4 (133.7 ± 3.8 vs. 135.6 ± 3.6 mmol/L, P < 0.05), and then plateaued until day 11 (136.7 ± 4.5 mmol/L). The correlation between the change in serum sodium for the first 24 hours and initial serum sodium concentration was significant (r = -0.602, P < 0.001). In severe hyponatremia (< 125 mmol/L), the change was significantly higher (11.1 ± 4.8 mmol/L) than in moderate (6.4 ± 2.5 mmol/L, P < 0.05) or mild hyponatremia (4.3 ± 3.3 mmol/L, P < 0.01). In addition, logistic regression analysis showed that body weight (odds ratio [OR], 0.858; 95% confidence interval [CI], 0.775-0.976; P = 0.020) and body mass index (BMI) (OR, 0.692; 95% CI, 0.500-0.956; P = 0.026) were associated with rapid correction. No serious adverse events were reported, but in 13% of patients hyponatremia was overcorrected. CONCLUSION: TLV is effective in correcting hyponatremia and well-tolerated in Korean patients with SIADH. However, those with low body weight, low BMI or severe hyponatremia, could be vulnerable to overcorrection with the initial dose of 15 mg TLV.

Effects of aristolochic acid I and/or hypokalemia on tubular damage in C57BL/6 rat with aristolochic acid nephropathy.

Background/Aims: This study was designed to investigate the roles of aristolochic acid I (AA-I) and hypokalemia in acute aristolochic acid nephropathy (AAN). METHODS: After an adaptation period (1 week), a total of 40 C57BL/6 mice (male, 8 weeks old) were divided into four groups: I (control group), II (low potassium [K] diet), III (normal K diet with administration of AA-I [10 mg/kg weight]), and IV (low K diet with AA-I). After collecting 24 hours of urine at 2 weeks, the mice were sacrificed, and their blood and kidneys were obtained to perform immunochemical staining and/or Western blot analysis. RESULTS: Proteinuria, glycosuria, and increased fractional excretion of sodium and K were prominent in groups III and IV (p < 0.05). Diffuse swelling and poor staining of collecting duct epithelial cells were evident in the medullas of group II. Typical lesions of toxic acute tubular injury were prominent in the cortices of groups III and IV. Α-Smooth muscle actin (α-SMA) was higher in the cortices of the mice in groups III and IV versus group II (p < 0.05), and higher in the medullas of group IV than groups I and III (p < 0.05). E-cadherin was higher in the cortices of groups III and IV compared to group I (p < 0.05). The F4/80 value was higher in the cortices and medullas of groups II, III, and IV compared to group I (p < 0.05), particularly in the case of group II. Conclusions: AA-I can induce acquired Fanconi syndrome in the acute stage of AAN. Macrophages appear to play a key role in the pathogenesis of AAN and hypokalemic nephropathy. It remains uncertain whether hypokalemia plays any role in AAN and hypokalemia.

Clinicopathological features of diabetic and nondiabetic renal diseases in type 2 diabetic patients with nephrotic-range proteinuria.

Heavy proteinuria with or without features of nephrotic syndrome is associated with many primary and systemic diseases. For diabetic patients, distinguishing nondiabetic renal disease (NDRD) from diabetic nephropathy (DN) is important in choosing treatment modalities and determining renal prognosis. However, clinical relevance of heavy proteinuria is inconsistent with clinical DN assessments. This study investigated the clinicopathological features and renal outcomes of DN and NDRD in type 2 diabetic patients with nephrotic-range proteinuria.We enrolled 220 cases of type 2 diabetic patients who underwent renal biopsy. They were grouped according to the presence of nephritic-range proteinuria and pathological features. Baseline characteristics, laboratory findings, types of pathological diagnosis, and renal outcomes were analyzed in patients with heavy proteinuria.Upon kidney biopsy, 129 patients (58.6%) showed nephritic-range proteinuria. Patients with heavy proteinuria (an average urine protein-to-creatinine ratio of 10,008 ±â€Š7307 mg/gCr) showed lower serum albumin levels and higher total cholesterol levels, but did not show any difference in age, duration of diabetes, renal function, or the presence of retinopathy compared with those with mild-to-moderate proteinuria (an average urine protein-to-creatinine ratio of 1581 ±â€Š979 mg/gCr). Renal biopsy revealed that the prevalence of NDRD was 37.2% in patients with heavy proteinuria, which was significantly lower than that in patients with mild-to-moderate proteinuria (63.7%). The most common pathological types of NDRD were membranous nephropathy (41.7%), IgA nephropathy (14.6%), and minimal change disease (10.4%). NDRD patients showed lower prevalence of diabetic retinopathy and better kidney function irrespective of proteinuria. Immunosuppressive treatment was administered more frequently in patients with heavy proteinuria (56.3%) compared with patients with mild-to-moderate proteinuria (20%) because of the pathological differences according to the amount of proteinuria. Renal outcomes were significantly worse in patients with DN than in patients with NDRD.DN patients with heavy proteinuria exhibited different prevalence of NDRD and worse prognosis. Renal biopsy in type 2 diabetic patients should be more extensively considered to accurately diagnose NDRD, guide further management, and predict renal outcomes, especially in patients with nephrotic-range proteinuria.

Does hypokalemia contribute to acute kidney injury in chronic laxative abuse?

Prolonged hypokalemia from chronic laxative abuse is recognized as the cause of chronic tubulointerstitial disease, known as "hypokalemic nephropathy," but it is not clear whether it contributes to acute kidney injury (AKI). A 42-year-old woman with a history of chronic kidney disease as a result of chronic laxative abuse from a purging type of anorexia nervosa (AN-P), developed an anuric AKI requiring hemodialysis and a mild AKI 2 months later. Both episodes of AKI involved severe to moderate hypokalemia (1.2 and 2.7 mmol/L, respectively), volume depletion, and mild rhabdomyolysis. The histologic findings of the first AKI revealed the remnants of acute tubular necrosis with advanced chronic tubulointerstitial nephritis and ischemic glomerular injury. Along with these observations, the intertwined relationship among precipitants of recurrent AKI in AN-P is discussed, and then we postulate a contributory role of hypokalemia involved in the pathophysiology of the renal ischemia-induced AKI.

Identification of perirenal or renal splenosis from undetermined masses: case report and review of the literature.

The incidental finding of tumor-llke perirenal or renal splenosis (PRS) creates a challenge to the renal physicians, because its benign nature has to be distinguished from a malignancy. This paper describes the case of a 40-year-old man referred from a local clinic for further evaluation of an incidental finding of left abdominal masses by ultrasonogram suspecting neoplasm, but was eventually confirmed as PRS by obtaining a history of splenectomy that pointed to splenosis and subsequently by a fusion image from single photon emission computed tomography using 99mTc-labelled heat-denatured erythrocytes and computed tomography (hybrid SPECT/CT). In addition, a review of 27 cases of PRS in a MEDLINE search including the present case revealed the following: all the masses were found incidentally and were associated with a history of previous splenectomy or splenic injury; the initial impressions were neoplastic tumor/PRS (n = 9), PRS (n = 10), and neoplastic tumor without consideration of splenosis (n = 8); surgical exploration was undertaken in all the 8 cases of suspected neoplastic tumor only, whereas non-invasive radiological or radionuclide imaging confirmed splenosis in the rest of the cases (n = 19). To avoid unnecessary tests and invasive surgery for undetermined perirenal or renal masses accompanying previous splenic injury, we stress the paramount importance of careful history-taking, physical examination, and a high index of suspicion for splenosis. Also, fusion imaging of hybrid SPECT/CT was reconfirmed as a useful diagnostic technique for accurately detecting and localizing splenic tissues by PRS.

[A case of isolated small intestinal wall calcification on patient with continuous ambulatory peritoneal dialysis].

The metastatic calcification is defined as the deposition of calcium salt in normal tissue with an abnormal serum biochemical environment, such as chronic kidney disease, hyperparathyroidism, and hypercalcemia related with malignancy. Although the metastatic calcification can develop in any organs and tissues, presenting its symptoms and complications are rare. Thus a few cases have been reported. This case shows the metastatic calcification of the small intestine without any peritoneal and mesenteric vascular calcification which was early diagnosed by computed tomography and mesenteric angiography in a patient with abdominal pain, receiving continuous ambulatory peritoneal dialysis due to end stage renal disease. The clinician should early consider the metastatic calcification as differential diagnosis when unidentified calcifications are noted in simple abdominal X-ray such as in the present case, and promptly confirm it by using appropriate diagnostic tests in order to prevent its complications and progression.

Electrolyte imbalances and nephrocalcinosis in acute phosphate poisoning on chronic type 1 renal tubular acidosis due to Sjögren's syndrome.

Although renal calcium crystal deposits (nephrocalcinosis) may occur in acute phosphate poisoning as well as type 1 renal tubular acidosis (RTA), hyperphosphatemic hypocalcemia is common in the former while normocalcemic hypokalemia is typical in the latter. Here, as a unique coexistence of these two seperated clinical entities, we report a 30-yr-old woman presenting with carpal spasm related to hypocalcemia (ionized calcium of 1.90 mM/L) due to acute phosphate poisoning after oral sodium phosphate bowel preparation, which resolved rapidly after calcium gluconate intravenously. Subsequently, type 1 RTA due to Sjögren's syndrome was unveiled by sustained hypokalemia (3.3 to 3.4 mEq/L), persistent alkaline urine pH (> 6.0) despite metabolic acidosis, and medullary nephrocalcinosis. Through this case report, the differential points of nephrocalcinosis and electrolyte imbalances between them are discussed, and focused more on diagnostic tests and managements of type 1 RTA.

Unintended cannulation of the subclavian artery in a 65-year-old-female for temporary hemodialysis vascular access: management and prevention.

Ultrasound-guided cannulation of a large-bore catheter into the internal jugular vein was performed to provide temporary hemodialysis vascular access for uremia in a 65-yr-old woman with acute renal failure and sepsis superimposed on chronic renal failure. Despite the absence of any clinical evidence such as bleeding or hematoma during the procedure, a chest x-ray and computed tomographic angiogram of the neck showed that the catheter had inadvertently been inserted into the subclavian artery. Without immediately removing the catheter and applying manual external compression, the arterial misplacement of the hemodialysis catheter was successfully managed by open surgical repair. The present case suggests that attention needs to be paid to preventing iatrogenic arterial cannulation during central vein catheterization with a large-bore catheter and to the management of its potentially devastating complications, since central vein catheterization is frequently performed by nephrologists as a common clinical procedure to provide temporary hemodialysis vascular access.

Does the exposure of urine samples to air affect diagnostic tests for urine acidification?

BACKGROUND AND OBJECTIVES: For accurate measurement of pH, urine collection under oil to limit the escape of CO(2) on air exposure is recommended. This study aims to test the hypothesis that urine collection under oil is not necessary in acidic urine in which bicarbonate and CO(2) are minor buffers, because loss of CO(2) would have little effect on its pH. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: One hundred consecutive random urine samples were collected under oil and analyzed for pH, pCO(2), and HCO(3)(-) immediately and after 5 minutes of vigorous shaking in uncovered flasks to allow CO(2) escape. RESULTS: The pH values in 97 unshaken samples ranged from 5.03 to 6.83. With shaking, urine pCO(2) decreased by 76%, whereas urine HCO(3)(-) decreased by 60%. Meanwhile, urine baseline median pH (interquartile range) of 5.84 (5.44-6.25) increased to 5.93 (5.50-6.54) after shaking (ΔpH=0.12 [0.07-0.29], P<0.001). ΔpH with pH≤6.0 was significantly lower than the ΔpH with pH>6.0 (0.08 [0.05-0.12] versus 0.36 [0.23-0.51], P<0.001). Overall, the lower the baseline pH, the smaller the ΔpH. CONCLUSIONS: The calculation of buffer reactions in a hypothetical acidic urine predicted a negligible effect on urine pH on loss of CO(2) by air exposure, which was empirically proven by the experimental study. Therefore, exposure of urine to air does not substantially alter the results of diagnostic tests for urine acidification, and urine collection under oil is not necessary.