Correlation of the ERPF with the extraction fraction values of technetium-99m mercaptoacetyltriglycine.

OBJECTIVE: The objective of this study was to determine if a correlation exists between the effective renal plasma flow (ERPF) and the extraction fraction (EF) using 99mTc MAG3 in children. This EF has been previously described with 9mTc DTPA. However, the renal imaging agent of choice has become 9mTc MAG3. MATERIAL AND METHOD: The study was approved by The Children's Hospital of Philadelphia's institutional review board. Informed consent was also obtained A retrospective study of 29 children (16 males, 13 females) of ages 1 month to 19.5 years who underwent 99mTc MAG3 renal scintigraphy from September 2001 to December 2001 was analysed. EF values were calculated with and without attenuation correction in each kidney by determining the counts in a region of interest, correcting for background and comparing the counts with the injected dose. The EF was compared to the ERPF calculated using the Schlegel's method. The correlation between the EF and the ERPF corrected and non-corrected for soft tissue attenuation, were determined and were identified by using linear regression analysis. RESULTS: There was significant correlation between the ERPF and the EF with (r = 0.62, p < 0.05 on the left, r = 0.51, p = 0.005 on the right) than without attenuation correction (r = 0.54, p = 0.003 on the left, r = 0.42, p = 0.022 on the right). CONCLUSION: These results indicate a correlation of the ERPF calculated using the Schlegel's method with EF obtained from a 99mTc MAG3 renal scintigraphy. The EF may be the good alternative parameter for calculation of renal function, potentially more practical in pediatric patient and the ERPF for 99mTc MAG3 using the established software program based on Schlegel's formula.

Comparative experimental and clinical study between sevoflurane and isoflurane renal effects

Sevoflurane is a promising new nonflammable halogenated inhalational agent which produces anaesthesia of excellent quality. This study was performed to investigate experimental and clinical renal effects of sevoflurane versus isoflurane. The expermental part of study included 60 rats divided into 3 equal groups. Group I [control] was exposed to oxgen 4L/min for hours, group II [isoflurane] was exposed to 1.2% isoflueane for 2 hours, group III [sevoflurane] was exposed to 2% sevoflurane for 2 hours. Each group was further subdivided equally into two subgroups. Subgroup [A] in which animals were sacrified 24 hours after exposure, subgroup [B] in which animals were sacrified 7 days from the exposure. Animala blood samples were collected for blood urea nitrogen [BUN] and serum creatinine [Cr.] measurements, then the kidney was removed for histological and histochemical [succinic dehydrogenase enzyme activity] studies. The clinical part of this study was carried out on 40 ASAI and II of adult patients and were divided equally into two groups. Group I received 1.2 isoflurane for 2 hours and group II received sevoflurane 2% for 2 hours. Haemodynamics were assessed by measuring heart rate [HR] and mean arterial blood pressure [MBP], renal function tests [BUN and serum Cr.] was done preinduction, 2, 4,24 hours and 7 days postoperatively. Experimental study results founded that both isoflurane and sevoflurane had no effect on renal enzymes level all-through the study period. Histological examination of the kidney revealed mild congestion of central vein in sevoflurane group in contrast to isoflurane group which had severe congestion of central vein and cellular infiltration. On the other hand succinic dehydrogenase enzyme granules decreased slightly in sevoflurane but showed moderate activity in isoflurane group. The present clinical study showed that sevoflurane group had significantly lower [HR] than isoflurane group intra operatively. Also MBP was significantly lower in sevoflurane group from 5 minutes till 30 minutes intra operatively. No changes were recorded in renal enzymes all through the study period. Analysis of the data obtained from the experimental and clinical studies in this work demonstrated that sevoflurane had no harmful effect on the kidney with cardiovascular stability

The Effect of Angiotensin Converting Enzyme Inhibitor on Chronic Cyclosporine Nephropathyin Salt Depleted Rats

PURPOSE: Cyclosporine(CsA) is a potent immunosuppressant but the use of CsA is associated with various side effects, especially nephrotoxicity. In the kidney, salt depletion activates the renin-angiotensin-aldosteron(RAS) system and accentuates chronic CsA nephropathy. We postulate that angiotensin converting enzyme inhibitors(ACEI) can prevent chronic CsA nephropathy, since ACEI may inhibit this cascades. This study was aimed to assess the effect of ACEI on chronic cyclosporin nephropathy in salt depleted rats. METHODS: 36 Fischer-344 rats were divided into 6 groups. Group I received normal salt diet(NSD). Group II received a low salt diet(LSD). Group III received CsA with a NSD. Group IV received CsA with a LSD. Group V received NSD+CsA with ACEI. Group VI received LSD+CsA with ACEI. Rats were sacrificed after six weeks, and the glomerular filtration rate(GFR), serum sodium, potassium and whole blood cyclosporine levels were measured. Renal tissues were sampled for the observation of histological changes. RESULTS: No differences in blood CsA level and serum sodium were found between groups during the course of this experiment. Serum potassium in group VI was significantly increased compared with group IV and V(P<0.05). In groups treated with CsA only and in those where CsA was combined with ACEI, GFR was found to be significantly more decreased in LSD than NSD, and GFR in group V was significantly decreased in comparison with group III (P<0.05). Renal histologic lesions associated with CsA, which consisted of cortical interstitial fibrosis, tubular atrophy and hyalinization of arterioles, were more severe in the LSD group. But, no differences were observed between the groups treated with CsA and ACEI, and the groups treated with only CsA. CONCLUSION: Salt depletion associated with the activation of the RAS system accentuated chronic CsA nephrotoxicity, but, ACEI could not reduce the functional and morphological changes of salt depleted kidneys, in which nephropathy can be exacerbated in spite of the blocking of the angiotensin II pathway. Further studies are required to elucidate whether ACEI ameliorated the effect of salt-depleted CsA nephrotoxicity upon the effective renal blood flow.

Study of renal functional reserve in patients with severe chronic obstructive pulmonary disease by doppler ultrasound

This study was carried out on 15 patients with severe stable chronic obstructive pulmonary disease [COPD] and five normal controls. It aimed to assess the renal functional reserve in those subjects. The resistance index [RI] [pulsatility index], an index of renovascular resistance, was measured noninvasively by Doppler ultrasonography at baseline [fasting] and at intervals after a protein load of 250 g steak. The RI fall after the protein load in the normal subjects. The normocapnic patients had no significant change in RI after protein load; while in the hypercapnic ones, the RI tended to rise after protein load. In conclusion, renal blood flow was unchanged after protein load in patients with severe COPD suggesting that they had no renal functional reserve. This may be a factor in the development of edema seen in patients with severe COPD

Intrarenal doppler ultrasound versus diuretic renography and pressure flow study [Whitaker test] in obstructed kideny

Renal ultrasound examination and intrarenal arterial Doppler studies were performed on 30 patients with urographic evidence of renal obstruction. Renal Doppler ultrasound was compared with both drainage values [T [1/2]] and differential pressure obtained from diuretic renography and Whitaker test respectively, both pre- and post-operatively. Pre-operatively there was close correlation between resistive index [RI] and T [1/2] P<0.001 and also there was close correlation between RI and differential pressure P<0.05. Post-operatively out of the 30 kidneys, 8 still showing obstruction by RI and only one of them had shown obstruction by Whitaker test and 4 showed obstruction by diuretic renography giving us a sensitivity of 25%, specificity of 73.1% for the color Doppler as compared to Whitaker test and sensitivity and specificity of 45%, 81% respectively as compared to diuretic renography. Pre-operatively RI was 0.78 +/- 0.04 and post-operatively RI was 0.65 +/- 0.06 [P<0.001] which was significant Renal Doppler ultrasound correlates closely with both diuretic renography and Whitaker test pre-operatively, but not post-operatively after relief of obstruction, so it can not be used alone in evaluation of obstructive uropathy, but it can be used for follow up of dilated non obstructed system by diuretic renography i.e. non obstructed T [1/2] on a dilated system obviating the need for frequent isotope renography

Evaluación no invasiva del transporte de oxígeno renal en el paciente crítico / Non-invasive evaluation of the reanl oxygen transport in the critically ill patient

Introducción: las alteraciones en el flujo sanguíneo renal juegan un papel importante en la fisiopatología de la falla renal aguda (FRA) en el paciente crítico. Objetivo: evaluar mediante procedimientos no invasivos el transporte de oxígeno renal en el paciente crítico. Pacientes y métodos: se hicieron pruebas hemodinámicas renales (PHR) a 23 pacientes: 17 (grupo A, control) y seis (grupo B, con falla renal aguda, FRA): flujo plasmático efectivo (FPER), gasto renal (GR), disponibilidad de O2 (DO2r), consumo de O2 (VO2rc), fracción de filtración (FF) y diferencia arteriovenosa de O2 (D[av]O2r), pruebas de función renal (PFR). Resultados: el grupo A mostró: FPER 472 ñ 141 mL/min, GR 753 ñ 182 mL/min, RVR 143 ñ 29.7 U y 22.8 ñ 4.7 mmHg/mL, DO2r 113.5 ñ 3.1 mL/min, VO2rd 11.1 ñ4.5 mL/min, FF 21.9 ñ 9.3 por ciento, D(a - v)O2rc 1.42 ñ 0.03 mL/min (inferiores a los valores de referencia) y PFR normales, y el grupo B FPER 219 ñ 81 mL/min, VO2rc 0.13 ñ 0.06 mL/min, FF 0.81 ñ 0.32 por ciento y D(a - v)O2rc 0.04 ñ 0.02 mL/min (p<0.001). Conclusiones: este estudio demuestra que pueden ocurrir anormalidades del flujo sanguíneo renal aun con PFR normales

Diuresis transanestésica / Trans-anesthetic diuresis

A 25 pacientes adultos, en buenas condiciones generales se les practicó cirugía de la columna vertebral o histerectomía abdominal bajo anestesia general balanceada. Se constató disminución franca de la diuresis transoperatoria a pesar de la adecuada estabilidad cardiocirculatoria y persfusión de líquidos parenterales. Posiblemente el procedimiento anestésico quirúrgico, la posición prona y la comprensión intra-abdominal determinaron cambios en los mecanismos intrínsecos y extrínsicos que controlan el flujo sanguíneo renal y la velocidad de filtración glomerular siendo indispensable la vigilancia continua de la diuresis horaria y procurar protección renal en el periodo trans-anestésico

Study of renal arterial blood flow in different renal disorders using doppler ultrasonography

In thirty subjects with different renal disorders classified into three groups each group contains 10 subjects; nephritis group, renal colic group, and chronic renal failure group; and 10 subjects as healthy control group. Study of renal arterial blood flow and its relation to kidney functions in these renal disorders using Duplex-Doppler ultrasonography was done. The end diastolic flow [D] and the early peak systolic flow [S], the resistive index [RI], the pulsatility index [PI] and the D/S ratio were recorded. All the doppler indices were nearly the same as normal in the nephritis group. Resistive index values were significantly increased [P < 0.01] in the renal colic and chronic renal failure group, resistive index of 0.70 was considered the upper limit for normal kidneys. The D/S ratio was significantly decreased [P < 0.05] in renal colic and renal failure groups D/S ratio of 0.30 has considered the minimum value/or normal kidneys. Both chronic renal failure and renal colic increase the renal peripheral resistance but glomerulonephritis did not alter it, so all the doppler indices remain unchanged as long as the disease remain limited to the glomeruli. A significant correlation exists between blood urea and D/S ratio [r = 0.69], as well as between serum creatinine and D/S ratio [r = 0.75] in chronic renal failure group. In conclusion, there is an altered blood flow in renal obstruction and chronic renal failure. While no change in renal arterial blood flow in diseases limited to glomeruli. Duplex Doppler ultrasonography is a good non-invasive method for evaluation of renal functions from the pattern of renal arterial blood flow, however it can not differentiate between healthy subjects and glomerulonephritis or between renal obstruction and chronic renal failure