Congenital nephrogenic diabetes insipidus treated with acetazolamide

Congenital nephrogenic diabetes insipidus (CNDI) is a rare disorder. The condition is characterised by an inability of distal nephron segments to respond to normal or raised concentrations of serum antidiuretic hormone. In this report, we describe the case of a 13-year-old male known with CNDI who experienced a pedestrian vehicle accident leading to coma following a head injury. Intra-operatively, severe hypernatraemia and polyuria were observed. Following an inadequate response to conventional therapy, acetazolamide was prescribed resulting in an immediate response to therapy. To the best of our knowledge, acetazolamide has not been previously documented as a therapeutic option for CNDI. Additional research is necessary before considering the recommendation of acetazolamide for cases of NDI that do not respond adequately to conventional treatments.

Distal renal tubular acidosis in a patient with Hashimoto's thyroiditis: a case report

Renal tubular acidosis (RTA) is a rare disorder that can be inherited or acquired, and results in an inability of the kidneys to maintain normal acid-base balance. We present a case of recurrent, severe hypokalaemia and rhabdomyolysis in a young woman who had an associated normal anion gap metabolic acidosis and was subsequently diagnosed with distal RTA associated with Hashimoto's thyroiditis. Distal RTA associated with Hashimoto's thyroiditis is rare and probably develops because of autoimmune-mediated mechanisms, causing an inability of the H⁺-ATPase pump in alpha-intercalated cells of the cortical collecting duct to secrete H⁺, with subsequent failure of urinary acidification. In this case, this hypothesis was supported by the exclusion of common genetic mutations associated with distal RTA. We illustrate that utilizing a systematic, physiology-based approach for challenging electrolyte and acid-base disorders enables identification of the root cause and underlying disease mechanisms.

Aspergillus fumigatus: a rare cause of peritonitis in a peritoneal dialysis patient (a case report)

Although fungal organisms remain an uncommon cause of peritonitis in patients undergoing peritoneal dialysis, it carries significant morbidity and mortality. We describe a 36-year-old woman who presented with peritoneal dialysis-related peritonitis caused by dual infection with Staphylococcus caprae and Aspergillus fumigatus and discuss the challenges that were confronted regarding microbiological diagnosis and the selection of optimal antifungal treatment with subsequent successful resumption of peritoneal dialysis.

Outcomes of hospitalised patients with hyperkalaemia at a South African tertiary healthcare centre

BACKGROUND

Hyperkalaemia is a common electrolyte disorder in hospitalised patients. There is a lack of data from Africa on the prevalence, causes and outcomes of patients with hyperkalaemia. We aimed to identify the frequency of hyperkalaemia in hospitalised adults, and to identify any risk factors for in-hospital death.

METHODS

We conducted a retrospective cohort study of 1921 adult patients admitted to hospital with hyperkalaemia (potassium concentration ([K]) ≥ 5·5 mmol/L) over a one-year period during 2019. Multivariable logistic regression was performed to identify predictors of in-hospital mortality and multilinear regression was used to identify associations with the [K].

FINDINGS

We found an incidence rate of 3·7 cases per 100 patient-years. Nearly a third died during hospitalisation. Acute kidney injury (AKI) was common in patients who died (69·2% vs. 41·3%, P < 0·01). Age (odds ratio (OR) 1·02, 95% CI 1·01-1·03), [K] (OR 1·38, 95% CI 1·12-1·71), AKI (OR 3·13, 95% CI 2·19-4·47) and acute therapy (OR 1·93, 95% CI 1·40-2·66) were predictors of in-hospital death. AKI (r = 0·29, P < 0·01) and chronic kidney disease (r = 0·31, P < 0·01) were associated with the [K]. Fourteen percent of patients with hyperkalaemia were HIV positive with no difference in in-hospital death (P = 0·75).

INTERPRETATION

This is the largest study reporting on the epidemiology of hyperkalaemia in hospitalised adults from Africa. Hyperkalaemia in association with AKI was a strong predictor of in-hospital death. Late presentation to hospital may be a major factor contributing to poor outcomes.

FUNDING

Self-funded.

The frequency of acid-base disorders on admission to the intensive care and its association with in-hospital outcome, Cape Town, South Africa: a retrospective cohort study

INTRODUCTION

acid-base disorders are very common in critically ill patients and contribute significantly to morbidity and mortality. The aim of this study was to identify the types of acid-base disorders at the time of admission to the intensive care unit (ICU) and its associated ICU and in-hospital mortality.

METHODS

we conducted a retrospective cohort study of all adult patients that were admitted to the ICU and had an arterial blood gas sample at the time of admission from 1^st January 2019 to 31 December 2019. Using the traditional approach, acid-base disorders were categorised into six disorders. Variables predicting in-hospital death were identified using logistic regression.

RESULTS

a total of 375 patients were included. The median age for the entire cohort was 39 (IQR 30-52) years and 48.3% (n=181) were female. Mixed acid-base disorders were the most common at 48.8% (n=183), followed by no disorder at 24.8% (n=93), metabolic acidosis at 9.3% (n=35), metabolic alkalosis at 6.7% (n=25), respiratory acidosis 6.1% (n=23) and respiratory alkalosis at 4.3% (n=16). A total of 94 (25.0%) patients died. There were no differences in ICU (p = 0.35) or in-hospital death (p = 0.32) by acid-base disorder. Male sex (aOR: 5.8, 95% CI 1.55-21.42; p < 0.01), APACHE II score (aOR: 1.17, 95% CI 1.06-1.30; p < 0.01) and the corrected anion gap (aOR: 1.14, 95% CI 1.02-1.27; p = 0.02) were identified as predictors of in-hospital death using multivariable logistic regression.

CONCLUSION

there was no association between acid-base disorders at the time of ICU admission and ICU or in-hospital death. Therefore, in our setting, acid-base disorders at the time of ICU admission should not be used to predict the outcome of patients requiring intensive care.

Hypoglycaemia due to insulin therapy for the management of hyperkalaemia in hospitalised adults: A scoping review

Introduction

Hyperkalaemia is a very common electrolyte disorder encountered in hospitalised patients. Although hypoglycaemia is a frequent complication of insulin therapy, it is often under-appreciated. We conducted a scoping review of this important complication, and of other adverse effects, of the treatment of hyperkalaemia in hospitalised adults to map existing research on this topic and to identify any knowledge gaps.

Materials and methods

We followed the PRISMA-ScR guidelines. Studies were eligible for inclusion if they reported on any adverse effects in hospitalised patients ≥18-years-old, with hyperkalaemia receiving treatment that included insulin. All eligible research from 1980 to 12 October 2021 were included. We searched Medline (PubMed), Embase (Ovid), the Cochrane Library, CINHAL, Africa-Wide Information, Web of Science Core Collection, LILACS and Epistemonikos. The protocol was prospectively registered with the Open Science Framework (https://osf.io/x8cs9).

Results

Sixty-two articles were included. The prevalence of hypoglycaemia by any definition was 17.2% (95% CI 16.6–17.8%). The median timing of hypoglycaemia was 124 minutes after insulin administration (IQR 102–168 minutes). There were no differences in the prevalence of hypoglycaemia when comparing insulin dose (<10 units vs. ≥10 units), rate of insulin administration (continuous vs. bolus), type of insulin (regular vs. short-acting) or timing of insulin administration relative to dextrose. However, lower insulin doses were associated with a reduced prevalence of severe hypoglycaemia (3.5% vs. 5.9%, P = 0.02). There was no difference regarding prevalence of hypoglycaemia by dextrose dose (≤25 g vs. >25 g); however, prevalence was lower when dextrose was administered as a continuous infusion compared with bolus administration (3.3% vs. 19.5%, P = 0.02). The most common predictor of hypoglycaemia was the pre-treatment serum glucose concentration (n = 13 studies), which ranged from < 5.6–7.8 mmol/L.

Conclusion

This is the first comprehensive review of the adverse effects following insulin therapy for hyperkalaemia. Hypoglycaemia remains a common adverse effect in hospitalised adults. Future randomised trials should focus on identifying the optimal regimen of insulin therapy to mitigate the risk of hypoglycaemia.

The association between office blood pressure and fluid status using bioimpedance spectroscopy in stable continuous ambulatory peritoneal dialysis patients

Background

Hypertension is common in continuous ambulatory peritoneal dialysis (CAPD) patients. It remains to be determined the extent to which fluid overload contributes to uncontrolled blood pressure (BP) in this population. The aim was to determine the association between fluid status as measured using bioimpedance spectroscopy (BIS) and BP in CAPD patients.

Methods

A cross-sectional study was performed involving 50 stable CAPD patients at a single center in Cape Town, South Africa. All participants were known to have hypertension and were divided into two groups based on office BP measurements: an uncontrolled BP group (systolic BP ≥ 140 mmHg or diastolic BP ≥ 90 mmHg) and a controlled BP group. Fluid status was determined using BIS (Body Composition Monitor®, Fresenius Medical Care, Bad Homburg, Germany).

Results

There was a statistically significant difference in overhydration (OH) between the uncontrolled BP group and the controlled BP group (3.0 ± 2.3 L vs. 1.4 ± 1.6 L, respectively, P = 0.01). The uncontrolled BP group was older (37.7 ± 9.5 years vs. 32.0 ± 8.0 years, P = 0.04) and had a shorter dialysis vintage (15 [IQR, 7–22] months vs. 31 [IQR, 12–39] months, P = 0.02). Significant correlations were found between OH and the extracellular water (ECW) (r = 0.557, P < 0.01) and ECW to total body water (TBW) ratio (r = 0.474, P < 0.01). Mixed ancestry, presence of residual kidney function, ECW, and ECW to TBW ratio were identified as predictors of OH on multivariable linear regression.

Conclusions

We found that stable CAPD patients with uncontrolled BP had higher OH compared to patients whose BP was controlled.

Kidney outcomes of immune-complex associated mesangiocapillary glomerulonephritis in patients with and without HIV

Introduction: HIV-associated kidney diseases continue to be a major problem in South Africa. Objectives: We aimed to determine the kidney outcomes of immune-complex associated mesangiocapillary glomerulonephritis (MCGN) in patients with and without HIV. Patients and Methods: A retrospective cohort study was conducted on all adult patients with a kidney biopsy diagnosis of immune-complex associated MCGN from 1 January 2000 to 31 December 2016. We compared the proportion of HIV-positive and HIV-negative patients that reached the composite endpoint of either doubling of the serum creatinine or end-stage kidney disease. Cox proportional hazards models were employed to examine the association between the composite endpoint and predictor variables. Results: A total of 79 patients were included of which 20 (25.3%) were HIV-positive. Twentyfour patients (30.4%) reached the composite endpoint. The cumulative proportions reaching the composite endpoint at one and four years were 25.3% and 30.4% with no difference between HIVpositive and HIV-negative patients (45.0% versus 25.4%, respectively; P= 0.10). Multivariable Cox proportional hazards model identified estimated glomerular filtration rate at biopsy (hazard ratio [HR] = 0.92; 95% confidence interval [CI]: 0.84-1.00, P=0.04) and proteinuria at follow-up (HR = 1.60; 95% CI: 1.21-2.11, P<0.01) as predictors of the composite endpoint at one-year. On survival analysis, there was no difference in the composite endpoint for HIV status (P=0.09; log-rank). Conclusion: Immune-complex associated MCGN continues to be a common histopathological pattern of injury at our center. Due to late presentation, kidney outcomes remain poor, regardless of HIV status.

Knowledge of medical specialists on the emergency management of hyperkalaemia with a focus on insulin-based therapy

Introduction: Hyperkalaemia is a common electrolyte disorder in hospitalised patients and may cause life-threatening cardiac arrythmias and death. There is a lack of consensus regarding its optimal management, which may result in wide variations in practice and the guidance provided to junior staff. Methods: We conducted a survey on a Research Electronic Data Capture (REDCap) platform to evaluate the knowledge of medical specialists regarding the diagnosis and management of hyperkalaemia, with a focus on insulinbased therapy. A convenience sample of 70 specialists in nephrology, internal medicine, emergency medicine and critical-care medicine were invited to participate. Comparisons were also made between nephrologists and nonnephrologists. Results: A total of 51 medical specialists responded, of whom 47% were nephrologists. They were more likely to initiate therapy at a potassium concentration ([K]) of 6 mmol/L, whereas non-nephrologists tended to start at a lower concentration (P < 0.01). Half the respondents regarded blood gas machine measurements as providing an accurate measure of [K]. Non-nephrologists were more likely to perform an ECG before starting treatment (P = 0.02). All respondents regarded insulin and dextrose as the most effective and reliable means for shifting K. Only 22% monitored the serum glucose concentration beyond 2 hours following insulin-based therapy, and 22% thought that hypoglycaemia was an uncommon complication if dextrose also was administered. Conclusions: This is the first comprehensive survey to report on the knowledge of specialists regarding the emergency management of hyperkalaemia. There is a need to address knowledge gaps, particularly around the optimal and safe use of insulin-based therapies. Our findings and recommendations should be useful in informing the development of consensus guidelines and educational resources on hyperkalaemia.

How common is hyperkalaemia? A systematic review and meta-analysis of the prevalence and incidence of hyperkalaemia reported in observational studies

Background

The prevalence and incidence of hyperkalaemia, a potassium abnormality that can potentially have life-threatening consequences, are unclear.

Methods

The objective was to provide the most comprehensive overview of the epidemiology of hyperkalaemia to date within the general population, across different continents, in different healthcare settings and within pre-specified subgroups. Embase and MEDLINE were searched from database inception to 2 February 2021 using the Ovid SP platform. Relevant congress proceedings from 2018 to 2020 were also reviewed for inclusion. There was no language constraint applied. Observational studies from any time period and language reporting prevalence or incidence of hyperkalaemia within both adult and paediatric populations. Four investigators independently screened abstracts and assessed study quality of those meeting the pre-determined inclusion/exclusion criteria. Data extraction was conducted by the lead author with oversight from the senior author and data were pooled using a random-effects model. The measures assessed were the prevalence and incidence of hyperkalaemia. Prevalence was reported as a percentage, whilst incidence was reported as the rate per 100 person years.

Results

In total, 542 articles were included from an initial search of 14 112 articles. Across all adult studies, we report a prevalence of hyperkalaemia (by any definition/threshold) of 6.3% [95% confidence interval (CI): 5.8–6.8%], with an incidence of hyperkalaemia in the adult population of 2.8 (2.3–3.3) cases per 100 person years. Prevalence within the general population was 1.3% (1.0–1.8%), whilst incidence was 0.4 (0.2–0.8) cases per 100 person years. There was a variation by sex with a prevalence of 6.3% (4.9–8.0%) in males and 5.1% (4.0–6.6%) in females. Prevalence also varied according to the definition/threshold of hyperkalaemia used: >5 mmol/L—8.0% (7.2–8.9), ≥5.5 mmol/L—5.9% (3.5–10.0) and ≥6.0 mmol/L—1.0% (0.8–1.4); hyperkalaemia (by any definition/threshold) was highest amongst patients with end-stage kidney disease (21.5%; 18.3–25.3), kidney transplant patients (21.8%; 16.1–29.5) and patients with acute kidney injury (24.3%; 19.3–30.7).

Conclusions

This novel review provides a comprehensive and valuable resource on the prevalence and incidence of hyperkalaemia to better inform clinicians, healthcare providers and health policy makers on the burden of hyperkalaemia across different healthcare settings, patient populations and continents.

Urine ‘picket fence’ crystals in ethylene glycol poisoning

A 46-year-old woman intentionally ingested ethylene glycol and overdosed on paracetamol. She had clinical and laboratory features suggestive of ethylene glycol poisoning, and examination of the urine revealed calcium oxalate monohydrate, or ‘picket fence’, crystals. She responded well to therapy that included haemodialysis. Clinicians should be aware that these crystals appear late during the evolution of ethylene glycol poisoning and, along with other clinical and laboratory findings, should prompt the initiation of haemodialysis.

A method comparison study of a point-of-care blood gas analyser with a laboratory auto-analyser for the determination of potassium concentrations during hyperkalaemia in patients with kidney disease

Introduction

Hyperkalaemia is a common electrolyte disorder that may cause life-threatening cardiac arrythmias. We aimed to determine the agreement of potassium concentrations between GEM premier 3500 point-of-care blood gas analyser (POC-BGA) and Roche Cobas 6000 c501 auto-analyser in patients with hyperkalaemia.

Methods

A prospective, cross-sectional study of all consecutive adult patients referred to the Renal Unit with a serum potassium concentration ≥ 5.5 mmol/L was performed. A total of 59 paired venous blood samples were included in the final statistical analysis. Passing-Bablok regression and Bland Altman analysis were used to compare the two methods.

Results

The median laboratory auto-analyser potassium concentration was 6.1 (5.9-7.1) mmol/L as compared to the POC-BGA potassium concentration of 5.7 (5.5-6.8) mmol/L with a mean difference of - 0.43 mmol/L and 95% upper and lower limits of agreement of 0.35 mmol/L and - 1.21 mmol/L, respectively. Regression analysis revealed proportional systematic error. Test for linearity did not indicate significant deviation (P = 0.297).

Conclusion

Although regression analysis indicated proportional systematic error, on Bland Altman analysis, the mean difference appeared to remain relatively constant across the potassium range that was evaluated. Therefore, in patients presenting to the emergency department with a clinical suspicion of hyperkalaemia, POC-BGA potassium concentrations may be considered a surrogate for laboratory auto-analyser measurements once clinicians have been cautioned about this difference.

Outcomes of immunoglobulin-associated mesangiocapillary glomerulonephritis: A South African experience

AIM

Immunoglobulin-associated mesangiocapillary glomerulonephritis is currently the most common biopsy-confirmed glomerulonephritis in Cape Town, South Africa. We aimed to determine the outcome of patients with a biopsy-confirmed diagnosis of immunoglobulin-associated mesangiocapillary glomerulonephritis at our centre.

METHODS

A retrospective cohort study of adult patients was conducted from January 1, 2000 to December 31, 2016. The endpoint was a composite of doubling of creatinine and/or end-stage renal disease and/or death. Cox univariable and multivariable proportional hazards models were used to examine the association between the composite endpoint and predictor variables. Survival curves were made with the use of Kaplan-Meier estimates.

RESULTS

A total of 70 patients were included in the study and their median duration of follow-up was 30.4 months. Forty-eight (68.6%) patients reached the composite endpoint. The proportion reaching this endpoint at 1, 3 and 5 years were 37.5%, 64.6% and 81.3%, respectively. Cox multivariable proportional hazards model identified a serum creatinine concentration > 200 μmol/L at the time of biopsy, moderate to severe interstitial fibrosis, ≥50% crescents and cyclophosphamide therapy as predictors of the composite endpoint.

CONCLUSION

Immunoglobulin-associated mesangiocapillary glomerulonephritis remains a common glomerular pathological diagnosis in our setting and has poor outcomes. This may partially be explained by late presentation. Future research needs to focus on identifying the possible cause(s) of this common glomerular disease so that more targeted therapeutic approaches can be offered.

Central pontine myelinolysis: not just a low sodium issue

Osmotic demyelination syndrome is a rare complication following treatment of chronic hyponatraemia. We describe a case of a middle-aged man known with hypertension and hypothyroidism who presented with a reduced level of consciousness and a generalised convulsion. Laboratory results revealed severe hyponatraemia and hypokalaemia. Following rapid overcorrection of the serum sodium concentration, his level of consciousness remained unchanged, and he developed quadriplegia. Magnetic resonance imaging of the brain revealed central pontine myelinolysis (CPM). The patient died 3 weeks after hospitalisation. Other than rapid overcorrection of chronic hyponatraemia, this case also highlights the important role of potassium in the pathogenesis of CPM. Therefore, when severe chronic hyponatraemia is accompanied by hypokalaemia, the latter should be corrected first to further reduce the risk of CPM.

HIV-associated thrombotic thrombocytopaenic purpura: A retrospective cohort study during the anti-retroviral therapy era

BACKGROUND

HIV-associated thrombotic thrombocytopaenic purpura (TTP) is thought to represent the majority of current TTP diagnoses in South Africa (SA).

AIM

The primary aim was to describe the clinical features and compare the time to remission of TTP in those patients with and without HIV.

DESIGN

A retrospective cohort study conducted at Tygerberg Hospital in Cape Town, SA for the period January 1, 2010 to January 31, 2015.

METHODS

All adult patients requiring ≥5 units of plasma products for ≥1 day during hospitalization were screened for a diagnosis of TTP. Those with a reported clinical diagnosis and/or laboratory evidence of TTP were included in the final analysis.

RESULTS

A total of 52 cases were identified of which 78.8% were HIV-infected. Time to remission was 10 days in the HIV group vs 19 days in the HIV negative group, P = 0.07. Most of the patients were Black females. Fever was more common in those with HIV. Neurological features were common in both groups. The majority in the HIV group was managed exclusively with plasma infusion alone (90.2% vs 45.5%, P < 0.01). There were no differences in the time to remission regardless of treatments received. Anti-retroviral therapy initiation during hospitalization was a predictor for remission. Overall mortality rate was 44.2%.

CONCLUSION

There was no difference in the time to remission in patients with HIV-associated TTP as compared with HIV negative TTP. The high mortality was probably the result of less intensive plasma infusion and therapeutic plasma exchange regimens.

The many faces of atypical haemolytic-uraemic syndrome: a diagnostic challenge

Atypical haemolytic-uraemic syndrome (aHUS) is a rare cause of thrombotic microangiopathy (TMA). The typical form occurs most frequently in children following infection with Shiga-like toxin-producing bacteria, whereas in the atypical form genetic mutations affecting complement regulatory proteins involved in the alternative complement pathway may be identified. The clinical features of aHUS may mimic other causes of TMA such as thrombotic thrombocytopenic purpura and malignant hypertension. We present a case of a 67-year-old woman who presented with a TMA and discuss the diagnostic challenges that were confronted due to the many overlapping clinical and laboratory features of the different causes of this syndrome. Clinicians should be aware of the varied clinical manifestations of TMAs to ensure early diagnosis and initiation of appropriate treatment.

Hypodipsic-hypernatremia syndrome in an adult with polycythemia: a case report

Background

Hypernatremia is a very common electrolyte disorder and is frequently encountered in out-patient as well as in-hospital settings. We describe an adult who was found to have unexplained relative polycythemia and episodic hypernatremia. A diagnosis of idiopathic hypodipsic-hypernatremia syndrome was made and the patient was managed with a water-drinking schedule.

Case presentation

A 24-year-old South African-Indian man was found to have polycythemia in association with episodes of hypernatremia. Investigations indicated that he had relative polycythemia. He experienced no thirst at a time when his serum sodium concentration was found to be 151 mmol/L. Further testing indicated that his renal response to arginine vasopressin was intact and magnetic resonance imaging of his brain revealed no hypothalamic lesions. A diagnosis of idiopathic hypodipsic-hypernatremia syndrome was made and he was managed with a water-drinking schedule that corrected his hypernatremia.

Conclusion

Hypodipsia should always be considered when a patient without physical or cognitive disability presents with unexplained episodic hypernatremia or with relative polycythemia.

Awakening the sleeping kidney in a dialysis-dependent patient with fibromuscular dysplasia: A case report and review of literature

Renal artery stenosis is a common cause of secondary hypertension and chronic kidney disease. We present here a case of fibromuscular dysplasia that was treated with surgical revascularization, resulting in recovery of kidney function with eventual cessation of chronic dialysis. The case involves a 25-year-old female with coincidentally discovered hypertension, who underwent further investigations revealing a diagnosis of renal artery stenosis due to fibromuscular dysplasia. She subsequently developed two episodes of malignant hypertension, with flash pulmonary oedema and worsening renal failure that resulted in dialysis dependence. After evidence was obtained that the right kidney was still viable, a revascularization procedure was performed, improving blood pressure control and restoring kidney function, thereby allowing dialysis to be stopped. This case highlights the importance of evaluating patients with renal artery stenosis for revascularization before committing them to a life of chronic dialysis.

Unintentional diethylene glycol poisoning following the consumption of a shared alcoholic beverage

Diethylene glycol (DEG) is an uncommon cause of toxic alcohol poisoning. In the past, its ingestion in contaminated pharmaceutical products has resulted in mass outbreaks. We describe two isolated cases of unintentional DEG poisoning following the consumption of a shared alcoholic beverage and highlight the challenges that were confronted during the diagnostic work-up and management. Despite appropriate therapy, both cases had fatal outcomes, which emphasises the importance of early recognition of the condition and of instituting specific treatment.

Residual renal function in chronic dialysis is not associated with reduced erythropoietin-stimulating agent dose requirements: a cross-sectional study

BACKGROUND

Anaemia is a very common problem in patients with end-stage kidney disease (ESKD) and the use of erythropoietin-stimulating agents (ESA) has revolutionised its treatment. Residual renal function (RRF) is associated with a reduction in ESA resistance and mortality in chronic dialysis. The primary aim was to establish whether RRF has an association with ESA dose requirements in ESKD patients receiving chronic dialysis.

METHODS

A single center, cross-sectional study involving 100 chronic dialysis patients was conducted from December 2015 to May 2016. Participants were divided into two groups depending on presence of RRF, which was defined as a 24-h urine sample volume of ≥ 100 ml. Erythropoietin resistance index [ERI = total weekly ESA dose (IU)/weight (kg)/haemoglobin concentration (g/dL] was used as a measure of ESA dose requirements.

RESULTS

There was no difference in ERI between those with RRF as compared to those without (9.5 versus 11.0, respectively; P = 0.45). Also, ERI did not differ between those receiving haemodialysis as compared with peritoneal dialysis (10.8 versus 10.2, respectively; P = 0.84) or in those using renin-angiotensin system (RAS) blockers as compared with no RAS blocker use (11.6 versus 9.2, respectively; P = 0.10). Lower ERI was evident for those with cystic kidney disease as compared to those with other causes of ESKD (6.9 versus 16.5, respectively; P = 0.32) although this did not reach statistical significance. Higher ERI was found in those with evidence of systemic inflammation as compared to those without (16.5 versus 9.5, respectively; P = 0.003).

CONCLUSIONS

There was no association between RRF and ESA dose requirements, irrespective of dialysis modality, RAS blocker use, primary renal disease or hyperparathyroidism.

Intradialytic hypertension during chronic haemodialysis and subclinical fluid overload assessed by bioimpedance spectroscopy

BACKGROUND

Intradialytic hypertension (IDH) increases morbidity and mortality. The prevalence in South Africa is unknown. The pathogenesis is unclear, but it has been suggested that IDH may be due to subclinical fluid overload. The objective of this study was to determine the prevalence of IDH and to evaluate its association with fluid overload using bioimpedance spectroscopy (BIS).

METHODS

A cross-sectional study involving 190 chronic haemodialysis patients in the Western Cape province of South Africa was conducted between January 2013 and May 2014. IDH was defined as a >10 mmHg increase in systolic blood pressure in at least four of six prior consecutive haemodialysis sessions.

RESULTS

The prevalence of IDH was 28.4% (n = 54). There was a trend towards pre-dialysis overhydration in the IDH group when compared with controls {2.6 L [95% confidence interval (CI) 1.7-3.4] versus 1.8 L [95% CI 1.4-2.1], respectively; P = 0.06} as measured by BIS, but no difference in mean ultrafiltration (UF) volume (2.4 versus 2.6 L; P = 0.30). A trend towards greater use of antihypertensive drugs was noted in the IDH group [2.5 drugs (95% CI 2.15-2.87) versus 2.1 (95% CI 1.82-2.30); P = 0.05]. More participants in the IDH group received calcium channel blockers (54 versus 36; P = 0.03).

CONCLUSIONS

The prevalence of IDH in our treatment centres is much higher than previously reported. Subclinical fluid overload may be a major contributing factor to the mechanism of this condition. The use of BIS identifies patients who may benefit from additional UF.

Encapsulating peritoneal sclerosis presenting with haemorrhagic ascites after transfer from peritoneal dialysis to haemodialysis

A patient with end-stage kidney disease due to chronic glomerulonephritis was initiated on continuous ambulatoryperitoneal dialysis. After three years he was transferred to haemodialysis following recurrent episodes of peritonitis. After the commencement of haemodialysis the patient developed progressive abdominal distension; paracentesisrevealed bloody ascites. Radiographic imaging revealed features of small bowel obstruction with bowel loops matted tothe posterior abdominal wall. A diagnosis of encapsulating peritoneal sclerosis was made. Treatment with prednisonewas initiated but the patients condition steadily worsened and he demised a year later due to severe malnutrition andsepsis.

Bolus administration of intravenous glucose in the treatment of hyperkalemia: a randomized controlled trial

BACKGROUND

Hyperkalemia is a common medical emergency that may result in serious cardiac arrhythmias. Standard therapy with insulin plus glucose reliably lowers the serum potassium concentration ([K(+)]) but carries the risk of hypoglycemia. This study examined whether an intravenous glucose-only bolus lowers serum [K(+)] in stable, nondiabetic, hyperkalemic patients and compared this intervention with insulin-plus-glucose therapy.

METHODS

A randomized, crossover study was conducted in 10 chronic hemodialysis patients who were prone to hyperkalemia. Administration of 10 units of insulin with 100 ml of 50% glucose (50 g) was compared with the administration of 100 ml of 50% glucose only. Serum [K(+)] was measured up to 60 min. Patients were monitored for hypoglycemia and EKG changes.

RESULTS

Baseline serum [K(+)] was 6.01 ± 0.87 and 6.23 ± 1.20 mmol/l in the insulin and glucose-only groups, respectively (p = 0.45). At 60 min, the glucose-only group had a fall in [K(+)] of 0.50 ± 0.31 mmol/l (p < 0.001). In the insulin group, there was a fall of 0.83 ± 0.53 mmol/l at 60 min (p < 0.001) and a lower serum [K(+)] at that time compared to the glucose-only group (5.18 ± 0.76 vs. 5.73 ± 1.12 mmol/l, respectively; p = 0.01). In the glucose-only group, the glucose area under the curve (AUC) was greater and the insulin AUC was smaller. Two patients in the insulin group developed hypoglycemia.

CONCLUSION

Infusion of a glucose-only bolus caused a clinically significant decrease in serum [K(+)] without any episodes of hypoglycemia.