FREQUENCY OF INCREASE IN INTRA-RENAL RESISTIVE INDEX IN PATIENTS WITH ACUTE UNILATERAL URETERIC OBSTRUCTION DUE TO CALCULUS

Background: Urolithiasis is the commonest cause of acute urinary tract obstruction. Acute obstructive uropathies can lead to acute and chronic renal failure. This study was aimed to determine the frequency of increase in intra-renal resistive index (RI) in patients with acute unilateral ureteric obstruction due to calculus. Material Methods: This descriptive cross-sectional study was conducted at Radiology Department, PGMI, Hayatabad Medical Complex, Peshawar. Duration of the study was one year. Total sample size was 66, using 95% confidence level, 87.5% proportion of increase in RI in acute unilateral ureteric obstruction due to calculus and 8% margin of error under WHO software for sample size determination. Non-probability consecutive sampling technique was used. Results: In contralateral normal kidney 5(9%) patients had RI range from 0.50-0.55, 17(25%) had 0.56-0.60, 27(41%) had 0.61-0.65, 17(25%) had 0.66-0.70 while no patient had RI 0.7. Where as in affected kidney RI had increased as 1(1%) patient had RI range from 0.56-0.60, 3(4%) patients had 0.61-0.65, 5(9%) patients had 0.66- 0.70, 46(70%) patients had 0.71-0.75 and 11(16%) patients had RI range 0.76-0.80. Hence it was concluded that RI increases up to 100% in affected kidney as compared to contralateral normal kidney while in affected kidney RI increases more than 0.7 in 66(86%) patients. Conclusion: It is concluded that Doppler ultratrasound Resistive Index is a sensitive method in diagnosing early obstructed kidney, even before the appearance of hydronephrosis