Prevalence and outcome of acute kidney injury in the intensive care unit at Muhimbili national hospital, Dar es salaam, Tanzania.

Abstract

Acute kidney injury (AKI) is common among hospitalized patients worldwide and has a poor prognosis among intensive care unit (ICU) patients with mortality rates ranging from 10-90%. The reported incidence of AKI in the ICU ranges between 1-24%; this high incidence varies from region to region and is attributable to factors such as differences in definition of AKI, regional disparities and etiological regional differences. To date, there is a paucity of data on the burden and spectrum of AKI in the ICU in Tanzania and at Muhimbili National hospital (MNH). We therefore conducted this study to determine the prevalence and some outcome predictor variables of AKI in the ICU at MNH that could be easy distinguishable outcome factors of AKI to aid in future prompt intervention. Objective: The main objective of this study was to determine the prevalence and outcome of acute kidney injury in the intensive care unit at Muhimbili National Hospital. Methodology: This was a retrospective descriptive study of all patients admitted to the MNH-ICU from January 2009 through December 2012. Medical records of the patients admitted to the ICU during the study period were reviewed and those with AKI were identified. Standardized pre-tested data instrument tools were used to collect socio-demographic data, clinical and laboratory parameters which included; date of admission to the ICU, type of patient (surgical or medical patient), duration of ICU stay, modality of ICU treatment for AKI, need for mechanical ventilation and or inotropic support. For purposes of this study, serum creatinine and urine output based on the AKIN criteria was used to define AKI. Data entry was done using Epi Data (version 3.1) and statistical analyses performed using STATA (StataCorp. STATA 12.0, College Station, Texas 77845 USA). Continuous variables were summarized as means and standard deviations, categorical variables as frequencies and percentages. Bivariate analysis was used to test for the association between the outcome of AKI in ICU which was death or survival and each predictor variable. The study was approved by the MUHAS review Sub-committee of senate research and publication with clearance reference number MU/PGS/SAEC/Vol. IV/. Results: A total of seven hundred and sixty eight (768) patients were admitted to the MNH-ICU during the study period 2009-2012. Of these, two hundred and thirty three (233) patient files met the inclusion criteria and were accessible for review and included in the final analysis. Of these, 61.2% were male and the overall mean age was 45.7 years (SD 17.8). Patients with a medical diagnosis were 54% and the common underlying co-morbidities were; hypertension (33%), diabetes mellitus (15.5%), CKD (12%) and HIV (9%). The length of stay in the ICU for those with AKI was 2 days (IQR 2-6) while that for those with no AKI was 3 days (IQR 2-8), P=0.094. The prevalence of AKI in this study was 57.9% (135/233) with the different AKIN stages contributing: I-(19.2%), II-(28.1%) and III-(52.6%). Mortality among patients with AKI was 94.1% (127/135) while overall mortality of all study patients during the four year study period was 47.6% (301/632). Factors found significantly associated with AKI were underlying chronic kidney disease, (p=0.011) and needing vasopressor support in ICU (p=0.018). Needing mechanical ventilation was significantly associated with increased mortality among those with AKI (p=0.046). Among patients with AKI, 67.4 % had sepsis while 15.5% were recorded as having septic shock. Conclusion: The prevalence of AKI among ICU patients at MNH-ICU is high and is associated with a marked in-hospital mortality rate. Recommendation: All patients admitted to the ICU should be promptly screened for AKI at admission and through their ICU stay