Haemoglobin levels in the chronic dialysis population in the Nephrology Unit at Chris Hani Baragwanath Academic Hospital
Chronic kidney disease (CKD) is an increasingly important cause of morbidity and mortality worldwide and it is in developing countries, such as South Africa, that bears the greatest portion of the burden of CKD. Anaemia is a frequent complication of CKD that has significant implications in terms of progression of the disease, as well as on the quality of life. It is for that reason that we have reviewed the demographics and causes of CKD; as well the prevalence, contributors to and management of anaemia of the chronic dialysis population at Chris Hani Baragwanath Academic Hospital (CHBAH). Methods A retrospective review of the chronic dialysis population at CHBAH in January 2012 was conducted. Patients’ records, using both paper-based records and electronic records in the form of Bara Active Renal Tracking (BART) programme were analyzed. Data was captured electronically using the REDCap (Research Electronic Data Capture) tool and exported to Microsoft Excel and GraphPad InStat programmes to compile the statistics, figures and tables. Chi-square test was used for comparisons between groups with categorical variables and an unpaired t test was used to compare groups with normally distributed variables. To compare proportions between the two groups a Fishers exact test was performed. A P-value of < 0.05 was taken as significant. Results The chronic dialysis population consisted of a total of 140 patients in January 2012. Based on exclusion criteria, 4 patients were excluded. The mean age of the patients was 45 ± 13 years, with the peritoneal dialysis (PD) cohort being slightly older as compared to the haemodialysis (HD) cohort. A larger proportion of the cohort were male (56.6%) and 87% percent of the cohort were Black patients. The cause of CKD was unknown in the majority of the patients – 72% in the HD group and 56% in the PD group. The other causes noted were hypertension (17%), primary glomerulonephritis (5.9%), and diabetes mellitus (5.9%). None of the causes of CKD were associated with more severe rates or degrees of anaemia. Suboptimal haemoglobin levels were present in 40% of the patients, with higher rates and increased severity of anaemia noted among the patients on haemodialysis. Among the HD patients, those patients with an arteriovenous fistula or a permanent cuffed venous catheter had higher haemoglobin levels. Other factors associated with lower levels of haemoglobin included younger age of the patients, the presence of hyperparathyroidism, sepsis and inflammation (indicated by C - reactive protein and ferritin levels) and Hepatitis C seropositivity. Approximately 85 % of the patients were receiving erythropoiesis stimulating agents, with higher rates and doses noted in the HD group, as compared to the PD group (p˂0.001). Only 40% of the HD patients and 16% of the PD patients received intravenous iron as part of the regular prescription. Discussion Our findings that the mean age in the chronic dialysis population CHBAH is substantially lower than in developed countries is in keeping with the finding that that end stage renal disease (ESRD) patients on dialysis are younger in the developing world, where the delay in detection of renal disease and the failure to institute timely preventative measures results in a faster deterioration of renal function and the development of ESRD at a young age. A factor that may also affect the mean age of our study population are the selection criteria for patients to be enrolled on the chronic dialysis programme in the public sector in South Africa. The patients need to qualify for a renal transplant. In our population and in the developing world the cause in a large proportion of patients with ESRD remains unknown because of late presentation or referral of patients, inadequacy of medical care facilities and shrunken kidneys, as is represented by the more than 65% of patients in the study, for whom there was no attributable cause of ESRD stated. Suboptimal correction of anaemia is present in a significant portion of our chronic dialysis population with a variety of contributing factors. This complication is inadequately managed, both in terms of addressing contributing factors and the prescription of the correct treatment. Rates of erythropoietin use in our population were comparable to international studies; however hyporesponsiveness to ESA therapy in our population is a concern based on the suboptimal rates of usage of intravenous iron. Conclusion CKD is a major problem in South Africa, where a double burden of disease is present- diseases of lifestyle and infectious diseases. Renal replacement therapy is a scarce resource and complications such as anaemia need to be aggressively managed in patients on this therapy, so as to maximise the benefit and improve outcomes. In conclusion, there is much room for improvement in the management of this grave consequence of ESRD by more stringent application of the available recent international and local guidelines.
A Research Report submitted to the Faculty of Health Sciences, University of the Witwatersrand, in partial fulfillment of the requirements for the degree of Master of Medicine Johannesburg, 2015