A retrospective review of the profile and clinical course of patients requiring acute dialysis at Chris Hani Baragwanath Academic Hospital over a 2 year period
Acute kidney injury (AKI) is a condition with high rates of mortality and morbidity in the hospital setting. Various factors, such as social, political and ethical dilemmas are closely associated with scarce resources in the management of AKI in Africa. We therefore reviewed the demography, causes and outcomes of AKI at Chris Hani Baragwanath Academic Hospital (CHBAH). Methods A retrospective review of 324 patients with renal failure who were initiated on acute dialysis at the CHBAH over the periods of 1 July 2009 to 30 June 2011 was done. Results The mean age at presentation with AKI was 40±13 years. Males accounted for 57% whist 92% of the total cohort were Black. HIV positivity occurred in 26% of patients, whilst 4% and 2% of the cohort had Hepatitis B and C infection respectively. The leading causes for initiation of acute dialysis included decompensated chronic kidney disease (38.9%), acute tubular necrosis (ATN) (38.3%), HIV related kidney disease (13.6%), pregnancy-related kidney disease (7.4%), glomerulonephritis (7.4%) and malaria (5.7%). Acute tubular necrosis due to sepsis was the predominant cause of AKI in HIV positive patients. Decompensated chronic kidney disease was present in a large proportion of patients, suggesting that chronic co-morbid diseases such as hypertension and diabetes mellitus occurred in a large proportion of the general population. Medical referrals accounted for 78% of the patients presenting with AKI. Renal recovery occurred in patients presenting with a lower average pre-dialysis blood urea level of 34±19 mmol/l, compared to higher levels seen in patients with poorer outcomes (p <0.0001). Pregnancy- related kidney injury had the lowest average pre-dialysis blood urea levels of 20±6 mmol/l. The average pre-dialysis serum creatinine in patients with renal recovery was 804±467 μmol/l compared to those with poorer outcomes, that had average serum creatinine levels of greater than 1000 μmol/l at initiation of dialysis (p <0.0001). The overall renal recovery rate was 31%, with a mortality rate of 23%. Failure to regain renal function with subsequent chronic consequences occurred in 44.6% of patients, of which 23% were transferred to chronic renal replacement therapy and the remaining 21.6% of patients were transferred to Renal out patients department with cessation of acute dialysis. HIV positive patients had a greater renal recovery rate (36% vs 26%); however they had a higher mortality rate compared to their HIV negative counterparts (34% vs 19%); (p <0.0001). HIV positive patients with CD4 counts greater than 200 cells/μl had a 46% renal recovery rate compared to 30% in patients with CD4 counts less than 200 cells/μl (p=0.1894). Mortality with CD4 counts less than 200 cells/μl was 38% compared to 26% in patients with CD4 counts greater than 200 cells/μl (p=0.1894). Mortality rates were similar in HIV positive patients treated with antiretrovirals (ARVs) compared to those that were ARV-naive (p =0.5857). Pregnancy-related kidney injury and malaria both had high rates of renal recovery, 92% and 79% respectively. Discussion The mean age of presentation of AKI were consistent with other studies in developing countries but was substantially lower than in developed countries such as the United Kingdom and Spain. The underlying aetiology of AKI at CHBAH resembles that of other developing nations with ATN, malaria and pregnancy-induced kidney injury being amongst the leading causes. Acute tubular necrosis still remains a common cause of AKI in South Africa as previously documented by Seedat et al. Malignancy and obstructive uropathy occurs at a much lower frequency compared to developed nations. The leading cause in HIV positive patients is ATN secondary to sepsis. Mortality occurred in 23% of the cohort, with HIV positive patients having a much higher mortality of 34%, concurring with a Johannesburg-based study by Vachiat et al. Initiating dialysis at lower blood urea and serum creatinine levels in all patent groups had a much better outcome, including in HIV positive patients. Conclusion AKI remains a common presentation that frequently requires dialysis, a scarce resource in an already overburdened health system, with a high mortality rate. HIV positive patients had a higher mortality rate compared to HIV negative patients; however a higher renal recovery rate was observed in this group. CD4 count and ARV status had no statistical significant effect on outcomes, probably due to the small sample size.
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, 2014