Sang-Woong Han

Therapeutic Approach to Hyperkalemia

The foremost step in the initial clinical management of hyperkalemia is to decide whether a hyperkalemic patient requires immediate treatment to avoid a life-threatening situation (serum potassium concentration >6.0 mEq/l and EKG changes). When the decision for urgent treatment of hyperkalemia is based on EKG changes, an important caveat for clinicians is that absent or atypical EKG changes do not exclude the necessity for immediate intervention. Once an urgent situation has being handled with intravenous push of a 10% calcium salt, the initiation of short-term measures can be launched by either a single or combined regimen of the three agents that cause a transcellular shift of potassium – insulin with glucose, β2-agonist (albuterol), and NaHCO3. As the first choice among these available options, we favor an intravenous bolus of 10 units of insulin with 50 ml of 50% glucose alone or in combination with 10–20 mg of albuterol by nebulizer. These can be repeated as required until the institution of hemodialysis. The combination of insulin with glucose and NaHCO3 as an another option needs further clarification for its additive effects. However, NaHCO3 has lost its favor because of its poor efficacy as a potassium-lowering agent when used alone. The next step is to remove potassium from the body – diuretics (furosemide), cation exchange resin (kayexelate) with sorbitol, and dialysis (preferably hemodialysis). The final important step for the managements of hyperkalemia is a long-term plan to prevent its recurrence or worsening. In addition to every effort to elucidate underlying causes and pathophysiologic mechanisms for hyperkalemia, an extensive search must be made to uncover overt or sometimes covert medications that may have led to the development of hyperkalemia. Furthermore, one must obtain detailed dietary and medical history of hyperkalemic patients.

Lessons from 30 years' data of Korean end-stage renal disease registry, 1985-2015

The Korean Society of Nephrology (KSN) launched a nationwide official survey program about dialysis therapy in 1985. Nowadays, the accumulated data for 30 years by this “Insan Prof. Min Memorial end-stage renal disease (ESRD) Registry” program have been providing the essential information for dialysis clinical practice, academic nephrology research, and health management policy. We reviewed 30 years of data to identify important changes and implications for the future improvement of dialysis therapy in Korea. Hemodialysis patients, especially diabetics and elderly patients have increased in number very rapidly during recent years in Korea. The Korean prevalence rate of ESRD patients was about 70% of the United States and about 50% of Japan according to the international comparisons in the annual data report of United States Renal Data System. The blood pressure control, anemia control, and dialysis adequacy have continuously improved year by year. The importance of calcium and phosphorus control has also been increasing because of the increase in long-term dialysis patients. In addition, chronic dialysis complications should be closely monitored and dialysis modifications, such as hemodiafiltration therapy, might be considered. Because of the increase of private clinics and nursing hospitals in dialysis practice, the role of dialysis specialists and continuing education are thought to be essential. For strict cost-effective dialysis control of increasing elderly, diabetic, and long-term dialysis patients, the KSN ESRD patient registration should be run by the KSN and health ministry in cooperation, in which the dialysis fee reimbursement should be accompanied.

Cerebral infarction as a complication of nephrotic syndrome: a case report with a review of the literature.

Arterial thrombosis is relatively rare compared with venous thrombosis in nephrotic syndrome. However, the assessment of its pathogenesis and risk factors in individual patient with nephrotic syndrome is necessary to allow appropriate prophylactic management because it is a potentially serious problem. Hereby, with review of the literature, we report a case of a 53 yr-old man with cerebral infarction associated with nephrotic syndrome due to focal segmental glomerulosclerosis during the course of treatments with diuretics and steroid. It reveals that the hypercoagulable state in nephrotic syndrome can be associated with cerebral infarction in adults. Prophylactic anticoagulants can be considered to reduce the risk of serious cerebral infarction in nephrotic patients with risk factors such as severe hypoalbuminemia and on diuretics or steroid treatment, even in young patients regardless of types of underlying glomerular diseases.

Combined Therapy of Cilazapril and Losartan Has No Additive Effects in Ameliorating Adriamycin-Induced Glomerulopathy

Aims: Effects of the blockade of renin-angiotensin system (RAS), by angiotensin-converting enzyme inhibitor (ACEi), type 1 angiotensin II receptor blocker (ARB), or a combination of both, were evaluated in Adriamycin (ADR)-induced glomerulopathy. Methods: Male Sprague-Dawley rats (180–250 g) were induced of glomerulopathy by treatment with ADR (2 mg/kg, i.v.). Six weeks later, they were treated with cilazapril (1 mg/kg/day) and/or losartan (10 mg/kg/day) for an additional 6 weeks. Results: The urinary excretion of protein progressively increased following the treatment with ADR, which was prevented by ACEi, ARB, and a combination of both. Similarly, the glomerulopathy assessed by glomerulosclerosis index was also ameliorated by ACEi or ARB. However, combined therapy of both ACEi and ARB was without an additional effect (Control 1.4 ± 0.4%, ADR 10.7 ± 2.7%**, ACEi 0.8 ± 0.4%, ARB 2.6 ± 1.0%, ACEi+ARB 1.7 ± 1.5%, ** p < 0.01 vs. Control). The expression of transforming growth factor-β1 was increased following the treatment with ADR (1.4 ± 0.07-fold, p < 0.05 vs. Control), however, the degree of which was similarly blunted by either ACEi, ARB, or the combination of both. The expression of type 1 angiotensin II receptor mRNA increased following the treatment with ADR, the degree of which was further upregulated by ACEi and decreased by ARB to the control level (ADR 1.3 ± 0.06-fold*, ACEi 1.8 ± 0.05-fold***, ARB 1.0 ± 0.04-fold, * p < 0.05 and *** p < 0.001 vs. Control). The combined therapy of ACEi and ARB still showed an upregulation of type 1 angiotensin II receptor mRNA, however, of which degree was mitigated compared with that induced by ACEi alone (ACEi+ARB 1.5 ± 0.04-fold, ** p < 0.01 vs. Control). On the contrary, the expression of type 2 angiotensin II receptor mRNA was downregulated following the treatment with ADR, which was similarly restored to the control level by ACEi, ARB, and a combination of both (ADR 0.5 ± 0.08-fold**, ACEi 1.0 ± 0.06-fold, ARB 1.0 ± 0.05-fold, ACEi+ARB 1.0 ± 0.05-fold, ** p < 0.01 vs. Control). Conclusion: It is suggested that combined therapy of ACEi and ARB with relatively high or maximal doses of each drug has no additive or synergistic benefits on the progression of ADR-induced glomerulopathy. Effects of RAS blockade may in part be related to differential regulation of type 1 and type 2 angiotensin II receptors.

Serum calcium and phosphorus levels in patients undergoing maintenance hemodialysis: A multicentre study in Korea.

Background In many countries, nephrologists follow clinical practice guidelines for mineral bone disorders to control secondary hyperparathyroidism (SHPT) associated with abnormal serum calcium (Ca) and phosphorus (P) levels in patients undergoing maintenance hemodialysis (MHD). The Kidney Disease Outcomes Quality Initiative (KDOQI) Guidelines have long been used in Korea, and this study was undertaken to investigate the current status of serum Ca and P control in MHD patients. Methods Data were collected from a total of 1,018 patients undergoing MHD without intercurrent illness, in 17 hemodialysis centers throughout the country. Serum levels of Ca, P, and intact parathyroid hormone (iPTH) were measured over 1 year, and the average values were retrospectively analyzed. Results Serum levels of Ca, P, and the Ca×P product were 9.1±0.7 mg/dL, 5.3±1.4 mg/dL, and 48.0±13.6 mg2/dL2, respectively. However, the percentages of patients with Ca, P, and Ca × P product levels within the KDOQI guideline ranges were 58.7%, 51.0%, and 70.7%, respectively. Of the 1,018 patients, 270 (26.5%) had iPTH >300 pg/mL (uncontrolled SHPT), whereas 435 patients (42.7%) showed iPTH <150 pg/mL. Patients with uncontrolled SHPT had significantly higher values of serum Ca, P, and Ca×P product than those with iPTH ≤300 pg/mL. Conclusion Despite the current clinical practice guidelines, SHPT seems to be inadequately controlled in many MHD patients. Uncontrolled SHPT was associated with higher levels of serum Ca, P, and Ca × P product, suggestive of the importance of SHPT management.

Polyuria with the Concurrent manifestation of Central Diabetes Insipidus (CDI) & Type 2 Diabetes Mellitus (DM)

We report a rare case of the concurrent manifestation of central diabetes insipidus (CDI) and type 2 diabetes mellitus (DM). A 56 year-old man was diagnosed as a type 2 DM on the basis of hyperglycemia with polyuria and polydipsia at a local clinic two months ago and started an oral hypoglycemic medication, but resulted in no symptomatic improvement at all. Upon admission to the university hospital, the patients initial fasting blood sugar level was 140 mg/dL, and he showed polydipsic and polyuric conditions more than 8 L urine/day. Despite the hyperglycemia controlled with metformin and diet, his symptoms persisted. Further investigations including water deprivation test confirmed the coexisting CDI of unknown origin, and the patients symptoms including an intense thirst were markedly improved by desmopressin nasal spray (10 µg/day). The possibility of a common origin of CDI and type 2 DM is raised in a review of the few relevant adult cases in the literature.

Varying Dialysate Bicarbonate Concentrations in Maintenance Hemodialysis Patients Affect Post-dialysis Alkalosis but not Pre-dialysis Acidosis

This study aimed to assess the effects of different dialysate bicarbonate concentrations in correcting acid-base imbalance in 53 stable hemodialysis patients in a university-hemodialysis unit. Three different bicarbonate concentrations were assigned, i.e. 25 mEq/L in 10, 30 mEq/L in 30, and 35 mEq/L in 13 patients. Blood gas analyses from arterial line blood samples before and after dialysis in the mid-week were performed for the determination of pH and serum bicarbonate (HCO3-) concentration. The mean values of predialysis arterial HCO3- were mildly acidotic in all 3 groups, but not significantly different among them, whereas those of post-dialysis arterial HCO3- were alkalotic, especially in the group of 35 mEq/L as compared with the other two groups. The mean blood pH was not significantly different among the 3 groups. As expected, there was a positive correlation between pre-dialysis pH and post-dialysis pH (r=0.45, p=0.001), and pre-dialysis HCO3- and post-dialysis HCO3- (r=0.58, p=0.000), but with a negative correlation between pre-dialysis HCO3- and the increment of intradialytic HCO3- following hemodialysis (r=-0.46, p=0.001). In conclusion, this study shows that the impact of conventional dialysate bicarbonate concentrations ranging from 25 to 35 mEq/L is not quite different on the mild degree of predialysis acidemia, but the degree of postdialysis alkalemia is more prominent in higher bicarbonate concentrations. Base supply by hemodialysis alone does not seem to be the main factor to determine the predialysis acidosis in end-stage renal disease patients on chronic maintenance hemodialysis.

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.

Serum sodium levels and patient outcomes in an ambulatory clinic-based chronic kidney disease cohort.

Background: Chronic kidney disease (CKD) patients are prone to both hypo- and hypernatremia. Little has been published on the epidemiology of hypo- and hypernatremia in ambulatory patients with non-dialysis CKD. Methods: Data collected in two contemporaneous CKD cohort studies, the Renal Research Institute (RRI)-CKD study (n = 834) and the Study of Treatment of Renal Insufficiency: Data and Evaluation (STRIDE) (n = 1,348) were combined and analyzed to study the association between serum sodium (Na+) and clinical outcomes. Results: Baseline estimated glomerular filtration rate (eGFR) and Na+ were 26 ± 11 ml/min/1.73 m2 and 140.2 ± 3.4 mEq/l, respectively. The prevalence of Na+ ≤135 mEq/l and ≥144 mEq/l was 6 and 16%, respectively. Higher baseline Na+ was significantly associated with male sex, older age, systolic blood pressure, BMI, serum albumin, presence of heart failure, and lower eGFR. The risk of end-stage renal disease (ESRD) was marginally significantly higher among patients with Na+ ≤135 mEq/l, compared with 140< Na+ <144 mEq/l (referent), in time-dependent models (adjusted hazard ratio, HR = 1.52, p = 0.06). Mortality risk was significantly greater at 135< Na+ ≤140 mEq/l (adjusted HR = 1.68, p = 0.02) and Na+ ≥144 mEq/l (adjusted HR = 2.01, p = 0.01). Conclusion: CKD patients with Na+ ≤135 mEq/l were at a higher risk for progression to ESRD, whereas both lower and higher Na+ levels were associated with a higher risk of mortality. While caring for CKD patients, greater attention to serum sodium levels by clinicians is warranted and could potentially help improve patient outcomes.

Metabolic Alkalosis From Unsuspected Ingestion: Use of Urine pH and Anion Gap

Underlying causes of metabolic alkalosis may be evident from history, evaluation of effective circulatory volume, and measurement of urine chloride concentration. However, identification of causes may be difficult for certain conditions associated with clandestine behaviors, such as surreptitious vomiting, use of drugs or herbal supplements with mineralocorticoid activity, abuse of laxatives or diuretics, and long-term use of alkalis. In these circumstances, clinicians often are bewildered by unexplained metabolic alkalosis from an incomplete history or persistent deception by the patient, leading to misdiagnosis and poor outcome. We present a case of severe metabolic alkalosis and hypokalemia with a borderline urine chloride concentration in an alcoholic patient treated with a thiazide. The cause of the patients metabolic alkalosis eventually was linked to surreptitious ingestion of baking soda. This case highlights the necessity of a high index of suspicion for the diverse clandestine behaviors that can cause metabolic alkalosis and the usefulness of urine pH and anion gap in its differential diagnosis.