Pseudohypokalaemia and pseudohypoxaemia in a patient with acute myeloid leukaemia

Spurious laboratory results are frequently encountered in patients with haematological disorders and lead to unnecessary additional laboratory investigations and inappropriate treatment. An 80-year-old woman, known with acute myeloid leukaemia, was admitted with suspected sepsis. Laboratory tests revealed a leukocyte count of 358 x 109/L, serum potassium concentration of 2.6 mmol/L and partial pressure of arterial oxygen of 5.3 kPa. The patient did not display any clinical or electrocardiographic features of hypokalaemia and there were no signs of respiratory distress. A diagnosis of pseudohypokalaemia and pseudohypoxaemia was made and inappropriate therapeutic interventions were avoided. Pseudohypokalaemia and pseudohypoxaemia should always be a consideration in patients with hyperleukocytosis due to haematological malignancies, especially when there are no clinical features to support these findings. The inappropriate administration of potassium in such cases may cause serious cardiac arrythmias

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. &nbsp

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

Prevalence of chronic kidney disease among HIV-infected adults on antiretroviral therapy in northern Namibia: a cross-sectional study

Introduction: There is an epidemic of chronic kidney disease (CKD) in Africa and human immunodeficiency virus (HIV) infection is among the major drivers. However, the burden of CKD in HIV-infected patients in Africa varies widely by country and study, ranging from 0.5–59.3%. Published data on the prevalence of CKD in the Namibian HIV-infected population are scarce. In this study, we aimed to estimate the prevalence of CKD and associated factors in HIV-infected adults on antiretroviral therapy in northern Namibia. Methods: We conducted a cross-sectional study in the four regions of northern Namibia, using existing electronic records used in the management of HIV-infected patients. Variables captured included the two most recent serum creatinine measurements, date of birth, sex, date of initiating antiretroviral therapy, current antiretroviral treatment, and most recent HIV viral load results. We used standardised serum creatinine measurements to estimate the glomerular filtration rate (GFR) using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. CKD was defined as estimated GFR (eGFR) < 60 mL/min/1.73 m2 on two occasions at least three months apart. Factors associated with CKD were assessed using logistic regression. Results: We included 1 993 participants, of whom 1 362 (68%) were female and mean age was 44.5 ± 11.5 years.The proportion of participants who were virally suppressed was 97% (95% CI 96, 98%) and the median durationon antiretroviral therapy was 107 months (IQR 62–149). The prevalence of CKD was 1.4% (95% CI 1.0, 2.0%).CKD cases were 13 times more likely to be 45 years or older and 3.5 times more likely to be male than thosewithout CKD. Conclusions: Our findings suggest a low prevalence of CKD among the HIV-infected population in northernNamibia. Patients older than 45 years may need additional monitoring for kidney function using eGFR

Effect of diuretics on kidney stone-forming risk – an investigation using multiple timed urine collections

Introduction: Thiazide diuretics can lower urinary calcium excretion, helping to prevent recurrent calcium kidney stones. As dietary intake and urine chemistry varies throughout the day, a 24-h urine collection may not provide sufficient information to guide the optimal management in individual patients. Using multiple timed urine collections, we sought to identify times during the day when stone-forming risk is higher, allowing for therapy to be more accurately targeted. Methods: In a prospective study, healthy adult volunteers took a 4-week course of either hydrochlorothiazide (HCTZ) 25 mg/d or indapamide 2.5 mg/d. They were assessed at baseline, and at days 7, 14 and 28. At each time point, blood samples were taken for analysis and multiple timed urine samples were collected throughout the day, together with one overnight sample. Results: Diuretic treatment was well tolerated. Daily calcium and citrate excretion decreased, while ionized calcium and phosphate excretion were unchanged. Ionized calcium-divalent phosphate and ionized calcium-oxalate products were unchanged. In the timed urine samples, calcium excretion was decreased, particularly by indapamide, in the morning. Indapamide, but not HCTZ, decreased urinary citrate excretion, most obviously in overnight and early morning urines. No changes in ionized calcium were observed. Decreased divalent phosphate excretion was observed at several time points in the indapamide group. The ionized calcium-divalent phosphate product tended to decrease at most time points in both groups but no significant changes were observed in the ionized calcium-oxalate product. Conclusions: Indapamide 2.5 mg/d has a stronger protective effect against forming calcium kidney stones than HCTZ 25 mg/d. Most of the benefits appear to be achieved during the daytime and it may therefore be beneficial to prescribe medication twice daily or in the evening to maximize the protective effects of these agents. The benefits of indapamide treatment were attenuated by a reduction in urinary citrate excretion, an effect which has not been previously described

Bartter-like syndrome caused by kanamycin during therapy for multidrug-resistant Mycobacterium tuberculosis

Multidrug-resistant Mycobacterium tuberculosis infection (MDR-TB) is a highly prevalent communicable disease in South Africa and often occurs in those with HIV infection. We describe three HIV-infected patients with pulmonary MDR-TB who received treatment with a regimen that included kanamycin and subsequently developed a Bartter-like syndrome. The clinical presentation varied from asymptomatic to severely symptomatic electrolyte disturbances, with one fatal outcome. This report highlights the importance of the routine monitoring of electrolytes in MDR-TB patients receiving treatment that includes kanamycin

Patterns of biopsy-proven kidney disease amongst South African adults from 1995 to 2017

Introduction: Little data is available on biopsy-proven kidney disease in African countries. In this study, we have described the patterns of biopsy-proven kidney disease amongst South African adults encountered over a 23-year period and report whether these have changed over time. Methods: This retrospective study included all adults who underwent a native kidney biopsy at Tygerberg Hospital in Cape Town from January 1995 to December 2017. Only the first biopsy for each patient was included in the analysis. From patient records, we extracted demographic and clinical information and details of the kidney biopsies, including the indications and the final histopathological diagnosis. Results: During the study period, 2227 first native kidney biopsies were performed. The median age of the patients was 38.0 years (interquartile range 30.0–48.1 years), and 53.3% were female. The most common indication for biopsy was nephrotic syndrome (38.6%). Glomerulonephritis (GN) was the most common pattern of kidney disease, with similar numbers of cases of primary and secondary glomerular disease. Among the primary glomerular diseases, mesangiocapillary GN (34.5%) was the most common, followed by focal segmental glomerulosclerosis (22.3%) and membranous nephropathy (15.8%). Among the secondary glomerular diseases, lupus nephritis was the most common (39.1%), followed by human immunodeficiency virus-associated nephropathy (HIVAN, 22.1%), and diabetic nephropathy (14.4%). IgA nephropathy was uncommon, accounting for only 2.0% of all glomerular disease, as was hypertensive kidney disease, which was diagnosed in only 1.3% of all our biopsies. Conclusions: Over the last two decades, mesangiocapillary GN was the most common primary glomerular disease and lupus nephritis the most common secondary glomerular disease. There was a steady increase in the number of patients with HIVAN. Hypertensive nephropathy was an uncommon histological diagnosis, and IgA nephropathy remains rare

Trends in the nephrologist workforce in South Africa (2002–2017) and forecasting for 2030

Background: The growing global health burden of kidney disease is substantial and the nephrology workforce is critical to managing it. There are concerns that the nephrology workforce appears to be shrinking in many countries. This study analyses trends in South Africa for the period 2002–2017, describes current training capacity and uses this as a basis for forecasting the nephrology workforce for 2030. Methods: Data on registered nephrologists for the period 2002 to 2017 was obtained from the Health Professions Council of South Africa and the Colleges of Medicine of South Africa. Training capacity was assessed using data on government-funded posts for nephrologists and nephrology trainees, as well as training post numbers (the latter reflecting potential training capacity). Based on the trends, the gap in the supply of nephrologists was forecast for 2030 based on three targets: reducing the inequalities in provincial nephrologist densities, reducing the gap between public and private sector nephrologist densities, and international benchmarking using the Global Kidney Health Atlas and British Renal Society recommendations. Results: The number of nephrologists increased from 53 to 141 (paediatric nephrologists increased from 9 to 22) over the period 2002–2017. The density in 2017 was 2.5 nephrologists per million population (pmp). In 2002, the median age of nephrologists was 46 years (interquartile range (IQR) 39–56 years) and in 2017 the median age was 48 years (IQR 41–56 years). The number of female nephrologists increased from 4 to 3 and the number of Black nephrologists increased from 3 to 24. There have been no nephrologists practising in the North West and Mpumalanga provinces and only one each in Limpopo and the Northern Cape. The current rate of production of nephrologists is eight per year. At this rate, and considering estimates of nephrologists exiting the workforce, there will be 2.6 nephrologists pmp in 2030. There are 17 government-funded nephrology trainee posts while the potential number based on the prescribed trainer-trainee ratio is 72. To increase the nephrologist density of all provinces to at least the level of KwaZulu-Natal (2.8 pmp), which has a density closest to the country average, a projected 72 additional nephrologists (six per year) would be needed by 2030. Benchmarking against the 25th centile (5.1 pmp) of upper-middle income countries (UMICs) reported in the Global Kidney Health Atlas would require the training of an additional eight nephrologists per year. Conclusions South Africa has insufficient nephrologists, especially in the public sector and in certain provinces. A substantial increase in the production of new nephrologists is required. This requires an increase in funded training posts and posts for qualified nephrologists in the public sector. This study has estimated the numbers and distribution of nephrologists needed to address provincial inequalities and achieve realistic nephrologist density targets