Acute kidney injury in an HIV patient with plasmablastic lymphoma - A double-edged sword.

HIV patients frequently develop acute kidney injury (AKI) because of sepsis and diarrhoeal disease. Here, we report a case of an HIV-positive man with partially treated sinonasal plasmablastic lymphoma (PBL) and unexplained AKI. A kidney biopsy revealed two pathological processes. Contribution: While urinary tract obstruction is the most common mechanism by which PBL causes AKI, maintaining a high level of suspicion for multiple pathological processes in cases involving light chain producing PBL.

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.

Incidence, microbiological aspects and associated risk factors of catheter-related bloodstream infections in adults on chronic haemodialysis at a tertiary hospital in Uganda.

Objectives: The high burden of infectious complications among patients receiving haemodialysis (HD) via central venous catheters increases morbidity and mortality. This study determined the incidence of catheter-related bloodstream infections (CRBSIs), microbiological profile of causative organisms, and associated predictors in patients on chronic HD. Methods: A prospective single-centre cohort study of 121 adult patients with end-stage kidney disease was conducted from October 2019 to March 2020. Antibiotic susceptibility was determined by the Kirby-Bauer disk diffusion method. Cox proportional hazards model was used to determine predictors of CRBSI. Results: The mean age was 50 (standard deviation 14.9) years and the median duration of follow-up was 69 (interquartile range 23-124) days. At least one CRBSI was recorded for 41% of patients, at a rate of 5.2 infections per 1000 patient-days. Causative organisms were predominantly Gram-negative bacteria (60.3%), and 36.5% of all isolates were multi-drug resistant. Anaemia [hazard ratio (HR) 5.44, P=0.019, 95% confidence interval (CI) 1.32-22.48] and previous bloodstream infection [HR 2.47, P=0.028, 95% CI 1.10-5.54] were predictors of CRBSI. Conclusion: The high incidence of CRBSI in patients on chronic HD with predominance of Gram-negative bacteria means that catheter care bundles should include Gram-negative coverage.

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 1st 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.

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.

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.

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.

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.

COVID-19 and the kidney: A South African state healthcare experience.

The first documented case of SARS-CoV-2 infection was confirmed in South Africa (SA) in March 2020. The Western Cape (WC) province was the initial epicenter. The pandemic peaked in July 2020 when 76,851 cases were documented and 2,323 deaths reported. COVID-19 can have multisystem involvement. Acute kidney injury (AKI) is well-documented and associated with increased mortality. We report our experience as the pandemic evolved in the WC province, focusing on those patients with a SARS-CoV-2 positive test presenting with AKI. We also reviewed our chronic dialysis cohort and renal transplant recipients who tested positive to assess incidence and outcomes. All patients presenting to nephrology services at the four main public hospitals were included. Information regarding demographics, co-morbidities, medical care, laboratory data, and outcomes were recorded. There were 86 patients referred with AKI, 48 required dialysis, and 47 died. There were 52 patients admitted to the intensive care unit with AKI (37 received dialysis, 1 of whom survived). In those presenting with AKI, diabetes, obesity, hypertension, and HIV were the most common comorbidities. Of the 295 patients receiving chronic dialysis within our services, 31 tested positive for SARS-CoV-2, and 6 died. Of the 45 kidney transplant recipients who tested positive, 9 died. Only 3 required dialysis. In conclusion, we report a high rate of AKI and poor prognosis in those requiring kidney replacement therapy, a better prognosis than anticipated was found in our chronic dialysis cohort, and high numbers of admissions were required for renal transplant recipients.

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.

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.

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.

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.