Biomedical subjects

M el-Azab

Publications and source records attributed to M el-Azab.

7 recordsLinked to original sources

PubMed1997

Partial ureteral obstruction: effect of intravenous normal saline and furosemide upon the renal resistive index.

OBJECTIVE: To investigate the effect of intravenous normal saline fluid load, with and without furosemide, upon the renal resistive index (RI) of obstructed and nonobstructed kidneys. METHODS: Right partial ureteral obstruction was induced in 10 dogs. Grade 1 (mild) obstruction was performed in 5 dogs (group A), and grade 3 (severe) obstruction was carried out to the remaining 5 dogs (group B). Evaluation by Doppler ultrasonography was performed before induction of ureteral obstruction and by the end of the 8th week of obstruction. Every obstructed animal was subjected to bilateral renal Doppler ultrasonography 3 times in one setting: 1) before infusion of normal saline, 2) 30-60 minutes after intravenous infusion of normal saline (15 ml./kg.) given in a rate of 1 ml./kg./min. and 3) 10 minutes after admission of furosemide (1 mg./kg.). RESULTS: After induction of right partial ureteral obstruction, there was a significant increase of the RI of the right kidney and a significant decrease of the RI of the left kidney compared to baseline RI in both groups. Infusion of normal saline and administration of furosemide caused a further significant increase of the RI of the obstructed kidney and a further significant decrease of the RI in the nonobstructed kidney in both groups. CONCLUSION: In unilateral partial ureteral obstruction, addition of intravenous normal saline and furosemide cause the RI to increase in obstructed kidney and to decrease in nonobstructed kidney. Such a divergent response may be useful for the development of a pharmacologically challenged Doppler examination to diagnose better potentially obstructed kidneys.

Animals↗

PubMed1997

Partial ureteral obstruction: role of renal resistive index in stages of obstruction and release.

OBJECTIVES: To study the changes in renal resistive index (RI) and renal function before and after release of different grades of partial unilateral ureteral obstructions. METHODS: Ten dogs were subjected to right partial ureteral obstruction. Grade 1 (mild) obstruction was applied to 5 dogs (group A) and grade 3 (moderate and severe) obstruction was applied to the other 5 dogs (group B). Obstruction was maintained for 8 weeks, followed by release of obstruction. All dogs were subjected to excretory urography, technetium-99m mercaptoacetyltriglycine diuretic renography with calculation of half-time drainage (T1/2), and bilateral renal Doppler ultrasonography before the start of the experiment, after 8 weeks of obstruction, and every 2 weeks during the 8 weeks after release of obstruction. RESULTS: In both groups, after induction of right ureteral obstruction, there was a dramatic decrease of effective renal plasma flow (ERPF), increase of RI, and increase of T1/2 of the right kidney. Relief of obstruction was associated with normalization of T1/2, reversal of RI, and recovery of ERPF to near basal values. No correlation was found between ERPF at the end of the recovery period and the functional parameters (T1/2, RI, or ERPF) of the obstructed kidney before release of obstruction. CONCLUSIONS: (1) Unilateral partial ureteral obstruction produces an elevation of RI and T1/2 and a fall in ERPF of the corresponding kidney. (2) After relief of function is regained with associated reversal of RI. (3) Functional parameters (T1/2, RI, or ERPF) of the obstructed kidney do not predict the recovery of ERPF after release of obstruction. (4) Rapid reversal of a previously elevated RI is an early indicator of recoverability of renal function after relief of ureteral obstruction.

Animals↗

PubMed1996

Renal Doppler ultrasound in children with obstructive uropathy: effect of intravenous normal saline fluid load and furosemide.

PURPOSE: We studied the effect of hyperhydration with normal saline and furosemide on renal resistive index in children with obstructive uropathy. MATERIALS AND METHODS: 99mTechnetium-mercaptoacetyltriglycine diuretic renography and Doppler ultrasound were done in 27 children (54 renal units) with unilateral or bilateral hydronephrosis. Doppler studies were performed at baseline, and after infusion of normal saline and administration of furosemide. Half-time drainage, considered the gold standard for the diagnosis of renal obstruction, was compared to resistive index. RESULTS: There was a positive correlation between half-time and resistive index on both Doppler studies. With a resistive index of 0.70 as the critical value for predicting renal obstruction 82 versus 100% sensitivity (p < 0.006), 63 versus 94% specificity (p < 0.04) and 76 versus 98% overall accuracy (p < 0.0005) were obtained for Doppler studies at baseline and after induced diuresis, respectively. All children with false-positive results were younger than age 4 years. CONCLUSIONS: Doppler ultrasonography after hyperhydration with normal saline and furosemide is an accurate method for diagnosing renal obstruction in children. It is more sensitive, specific and accurate than baseline Doppler studies.

Child↗

PubMed1996

Renal Doppler ultrasound in children with normal upper urinary tracts: effect of fasting, hydration with normal saline, and furosemide administration.

OBJECTIVES: To study the age dependency of renal resistive index (RI) and to study the effect on the renal RI of fasting, intravenous infusion of normal saline, and administration of furosemide in children with normal upper urinary tracts. METHODS: The study included 28 nonobstructed renal units in 15 boys ranging in age from 3 to 11 years. Diuretic renography and Doppler ultrasonography were attempted in all children. Doppler ultrasonography was carried out under three different conditions: fasting state, 30 to 60 minutes after intravenous infusion of normal saline (15 mL/kg), and 10 minutes after administration of furosemide (1 mg/kg; maximum, 40 mg). RESULTS: There was an inverse correlation between age and RI of both renal units under the three conditions of Doppler studies. At fasting state mean RI was 0.70 +/- 0.04, whereas 15 of 28 renal units (54%) had an RI of 0.70 or higher. Intravenous infusion of normal saline significantly decreased the RI to 0.63 +/- 0.04 (P < 0.000001). Injection of furosemide caused a further significant decrease of RI from 0.63 +/- 0.04 to 0.60 +/- 0.04 (P < 0.002). CONCLUSIONS: The renal RI in healthy children is age dependent. In the fasting state, 54% of nonobstructed renal units in children have an RI of 0.70 or higher. Intravenous infusion of normal saline and administration of furosemide can independently cause a significant decrease of the RI in nonobstructed renal units in children.

Child↗

PubMed1996

Partial ureteric obstruction: a study of Doppler ultrasonography and diuretic renography in different grades and durations of obstruction.

OBJECTIVES: To study the changes in renal resistive index (RI) and renal function with time during different grades of partial unilateral ureteric obstruction, and to determine the correlation between the ultrasonographic and renographic findings. MATERIALS AND METHODS: Ten dogs underwent right partial ureteric obstruction: grade 1 (mild) obstruction was applied in five dogs (group A) and grade 3 (moderate and severe) obstruction in the other five (group B). All dogs were assessed using excretory urography, diuretic renography with the calculation of half-time drainage (T 1/2) and bilateral renal Doppler ultrasonography before the experiment began, after one week of obstruction, and every 2 weeks during 8 weeks of obstruction. RESULTS: In both groups, after the induction of right ureteric obstruction, there was a progressive decrease of effective renal plasma flow (ERPF) and a progressive increase of the RI of the right kidney at the end of the first and second weeks of obstruction, with an almost stable value thereafter. The decrease of ERPF and the increase of RI in the right kidney were correlated with the degree of obstruction. There was also a dramatic increase of T 1/2 of the right kidney that correlated with the degree of obstruction. Concomitantly, there was a significant compensatory increase of ERPF and a significant decrease of the RI of the left kidney in both groups. The compensatory increase in CRPF limited the loss in total ERPF in both groups. The contribution of obstructed kidney to the total ERPF was significantly reduced in both groups. At the end of the eighth week, taking all kidneys together, there was a statistically significant negative correlation between the ERPF and RI, and between ERPF and T 1/2 and a positive correlation between T 1/2 and RI. CONCLUSIONS: Unilateral partial ureteric obstruction increased the RI and T 1/2 and decreased the ERPF of the corresponding kidney, together with a decrease of RI and an increase in ERPF of the contralateral kidney. The more severe the obstruction, the greater the increase in RI and T 1/2 and the decrease in ERPF. After the obstruction stabilized, RI and T 1/2 were positively correlated.

Animals↗

PubMed1996

Doppler ultrasonography in evaluation of potential live kidney donors: a prospective study.

PURPOSE: We compared the accuracy of Doppler ultrasonography and intra-arterial digital subtraction angiography for preoperative visualization of the number of renal arteries in potential live kidney donors. MATERIALS AND METHODS: Intra-arterial digital subtraction angiography and Doppler ultrasonography were used to study the renal anatomy of 64 consecutive kidney donors. Doppler studies were performed without knowledge of the angiographic findings. All donors underwent nephrectomy, and the number of renal arteries at nephrectomy was compared with that predicted by intra-arterial digital subtraction angiography and Doppler ultrasonography. RESULTS: One renal artery was found in 53 harvested kidneys, 2 in 10 and 3 in only 1. Analysis of the data revealed sensitivity 96.2% and specificity 100% for intra-arterial digital subtraction angiography versus sensitivity 100% and specificity 60% for Doppler ultrasound. Overall accuracy was 96.8% for angiography versus 93.7% for Doppler ultrasound, compared to 96.2 and 100%, respectively, for single, and 100% and 60%, respectively, for double renal arteries (p < 0.03). Both tests were interpreted as showing double vessels in the case with triple renal arteries. CONCLUSIONS: Although Doppler ultrasonography is accurate in delineation of single renal arteries, its limited ability to identify multiple arteries should make one cautiously optimistic regarding its current use.

Adult↗

PubMed1995

Prostatic abscess in a child.

We report a metastatic prostatic abscess in a 12-year-old boy. Rectal examination revealed a tender, fluctuating prostatic mass, causing acute retention of urine. Prostatic imaging by computerized tomography and transrectal ultrasonography were important in the diagnosis and management.

Abscess↗