Renal Resistive Index Findings among Patients Undergoing Renal Doppler Ultrasound at Muhimbili National Hospital

Abstract

Background: Renal sonography has been used for years in many clinical settings like the assessment of chronic renal allograft rejection, diagnosis and management of renal artery stenosis, assessment of risk progression in chronic kidney disease, differential diagnosis in acute and chronic obstructive renal diseases and as a predictor of renal and global outcome in the critically ill patient. Recent evidence shows that an increased renal resistive index reflects changes in intra-renal perfusion and presence of subclinical atherosclerosis. There is increased renal Doppler ultrasound at Muhimbili National Hospital and minimal research data on the subject contributed to this study been proposed. Purpose: To document renal resistive index findings among patients undergoing renal Doppler ultrasound at Muhimbili National Hospital from January 2018 to June 2019. Methods: Retrospective cross sectional hospital based study was conducted; data was collected from patients who have undergone renal ultrasound in ultrasound unit of Muhimbili National Hospital. The sample was selected by convenience consecutively from every eligible patient’s records for the study from the renal Doppler ultrasound records, during working hours. Data was collected by using a structured questionnaire. Socio-demographic patterns of patients, clinical indications for renal sonography and Doppler parameters and other renal sonographic findings was analyzed using SPSS version 23.0 to compute for descriptive statistics. P<0.05 was cut off value for statistical significance level. Results: Two to four percent of the native kidneys had raised renal resistive index while sixteen percent of transplanted kidneys had raised renal resistive index. The mean age of the patients who had renal Doppler ultrasound was 40.8years. Renal resistive index was statistically significantly associated with ESRD. Other sonographic factors such as renal size, hydronephrosis, CKD and CMD were significantly associated variably with native and allograft RRI. Conclusion: Majority of patients who had renal allograft had more raised renal resistive index compared to those with native kidneys. Recommendation: Renal Doppler study be done in patients suspected of renal disease particularly those with end stage renal disease contrary to other imaging modalities which use contrast. Further studies into this topic are suggested and strongly encouraged.