Evaluation of obstructive uropathy in children. 99mTc-DTPA renography studies under conditions of maximal diuresis

Renographic studies under standardised conditions of maximal diuresis provoked by hypotonic saline infusion and frusemide were used in 17 patients with dilatation of the upper urinary tract in order to distinguish between obstructed and non-obstructed urinary tracts. Of the six patients who were obstructed on clinical and X-ray evidence only three showed an obstructed pattern on the renographic curves after maximal diuresis. After operation these three patients showed improvement in both renographic curve and functional images of the renal parenchyma. A new method of identifying the parenchymal area is described.     

Predictive value of pressure flow studies for the functional outcome of reconstructive surgery for hydronephrosis

In 22 of 40 patients with unilateral hydronephrosis the pressure flow study was compared with the outcome of surgery. Seventeen of the 22 patients had impaired function before surgery as judged from the 2-min uptake on the renogram. The pressure flow study as a measure of pre-operative obstruction showed no relation to the functional outcome of surgery. Patients with obstructed pressure flow studies as well as those without signs of obstruction either remained stable or improved after surgery. It was concluded that pressure flow studies are of no value in predicting the outcome of surgery for hydronephrosis.     

99mTc DTPA diuretic renography in the evaluation of surgery in chronic schistosomal and non-schistosomal obstructive uropathy

The selection of patients with chronic obstructive uropathy for surgery is difficult because of problems in identifying true obstruction in a grossly dilated urinary tract. This is especially so in schistosomal (bilharzial) obstructive uropathy. A prospective study of 90 patients (68 with chronic schistosomal and 22 with non-bilharzial obstructive uropathy) was carried out. All patients underwent pre-operative and post-operative radionuclide 99mTc DTPA diuretic renography (RDR). The aims were to assess the value of RDR in the pre- and post-operative management of these patients and whether it could predict the outcome of surgery. Distinctive renogram patterns were identified in patients who required surgical management. These were found useful in monitoring the results and in predicting the outcome of surgery.     

Clinical outcome of fetal uropathy. I. Predictive value of prenatal echography positive for obstructive uropathy

Clinical followup was performed in 73 neonates with a prenatal echographic suspicion of uropathy. Of 42 patients with a prenatal suspicion of unilateral hydronephrosis only 15 had pathological obstruction and 2 had multicystic dysplastic kidneys. Among 10 infants with a prenatal suspicion of bilateral hydronephrosis only 1 had true bilateral obstruction and 2 had unilateral obstruction. In 2 patients hydroureteronephrosis seen on prenatal echography was due to massive bilateral vesicoureteral reflux. In this group there was also a multicystic dysplastic kidney and 1 patient with bilateral cystic dysplasia. There was a prenatal suspicion of cystic disease in 8 infants. Postnatally, diagnosis was multicystic dysplastic kidney in 2 patients and a simple renal cyst in 4. The remaining 2 neonates had obstructive uropathy. Finally, of 13 neonates with a prenatal suspicion of anatomical-echo-structural abnormalities a definitive abnormality could be established in only 8. The predictive value of prenatal echography positive for obstructive uropathy was 34.6%.     

Age factor in compensatory hypertrophy of the kidney evaluated by 99mTc-DTPA renography

Unilateral nephrectomy initiates a growth response in the contralateral kidney to compensate for the loss of a renal mass. The events which regulate this process are not very clear. We used a newly developed method, 99mTc-DTPA gamma-camera renography, to evaluate the individual kidney function for detection of the change of it. This method is simple, reliable and requires neither blood nor urine samples. Two groups of rabbits were used in the study. Those of 1.5-2 months of age were taken as the young aged group and those of 2 years of age as the old aged group. Kidney weight, glomerular filtration rate (GFR), and effective renal plasma flow (ERPF) were detected both before and 3 weeks after unilateral nephrectomy. After unilateral nephrectomy in both young and old age groups, the kidney weight increased by 119 and 38%, the GFR by 71 and 44%, and the ERPF by 116 and 35%. We conclude that nephrectomy at a young age where there is fast growth would cause the remaining kidney a compensatory hypertrophy which is much better than that in nephrectomy at an old age. The difference of glomerular filtration rate was less apparent than that of the kidney weight and renal plasma flow in both groups of rabbits.     

99mTc-DTPA肾动态显像在评价活体供肾者肾小球滤过率中的应用

目的 探讨99mTc-DTPA肾动态显像在评价活体肾移植供者肾小球滤过率(GFR)中的应用,并观察GFR水平与供者年龄和性别的相关性.方法 212名候选供者均接受肝肾超声波、肝炎病毒感染以及与受者的血型和组织配型等全面检查,如上述检查符合供肾的一般要求,则进一步行99mTc-DTPA肾动态显像检测候选供者的GFR,如GFR≥1.33 ml/s(1 ml/s=60 ml/min),则认为GFR正常;如1.17 ml/s≤GFR＜1.33 ml/s,则行内生肌酐清除率(CCr)检查,如CCr正常,则认为GFR正常,如CCr异常,则候选供者放弃供肾;如GFR＜1.17 ml/s,则候选供者放弃供肾.供者选取后,应用等级相关系数分析不同性别和不同年龄供者间的GFR水平的差异.结果 212名候选供者中,GFR≥1.33 ml/s者137名;1.17 ml/s≤GFR＜1.33 ml/s者55名,其中31名因CCr异常或其他安全性考虑而放弃供肾;GFR＜1.17 ml/s者20名.共有161名候选供者最终被选择为供者供肾,其中男性105名,女性56名,年龄(42.91±11.90)岁(20～62岁).供肾前,男性和女性供者双肾总的GFR分别为(1.51±0.22)ml/s和(1.45±0.18)ml/s,二者间差异无统计学意义(P＞0.05);不同年龄各组间GFR水平的差异均无统计学意义(P＞0.05),老年(＞55岁)和中青年(≤55岁)供者间GFR水平分别为(1.48±0.22)ml/s和(1.49±0.17)ml/s,二者间差异无统计学意义(P＞0.05).相关性分析显示,供者GFR与其年龄无明显相关性(r=-0.033,P=0.69),男性和女性供者的GFR水平与其年龄也无明显相关性(r=-0.053,P=0.571;r=-0.019,P=0.754).供肾后,所有供者短期内肾功能均恢复至正常水平,未发生肾功能异常和严重并发症.结论 99mTc-DTPA肾动态显像在评价活体肾移植供者GFR中具有较好准确性和可重复性;1.33 ml/s＞GFR≥1.17 ml/s者经严格筛选后可作为供者供肾,且预后良好;供者GFR水平与其年龄和性别间无明显相关性.     

Glomerular filtration rate estimated from the uptake phase of 99mTc-DTPA renography in chronic renal failure.

BACKGROUND: The purpose of the study was to compare the estimation of glomerular filtration rate (GFR) from 99mTc-DTPA renography with that estimated from the renal clearance of 51Cr-EDTA, creatinine and urea. METHODS: Fifty patients with reduced renal function (serum creatinine between 150 and 600 micromol/l) were enrolled in the study. GFR was estimated from the uptake phase of 99mTc-DTPA renography (GFR(DTPA)). The renal clearance of 51Cr-EDTA (GFR(EDTA)) was used as the reference method. Creatinine clearance (C(Cr)), urea clearance (C(Ur)) and the mean of urea and creatinine clearance (C(Cr+Ur)/2) were also calculated from urine collected during a period of 24 h. Limits of agreement were used for method comparison. RESULTS: The limit of agreement between GFR(DTPA) and GFR(EDTA) was 2 +/- 17 ml/min. The mean difference did not deviate significantly from zero. The other clearance techniques had larger limits of agreement and a mean difference significantly different from zero. Furthermore, C(Ur) and C(Cr+Ur)/2 had systematic deviations of the differences, indicating that C(Ur) and C(Cr+Ur)/2 are poor estimates of GFR. CONCLUSION: The limit of agreement between GFR(DTPA) and GFR(EDTA) are acceptable and, therefore, GFR estimated from 99mTc-DTPA renography is acceptable for clinical use in patients with reduced renal function. Furthermore, the method is simple and less time consuming compared with renal clearance techniques.     

Renal pelvis volume during diuresis in children with hydronephrosis: implications for diagnosing obstruction with diuretic renography

PURPOSE: We measured the volume of the renal pelvis during diuretic renography (DR) in children with normal and hydronephrotic kidneys to determine if changes in pelvic volume could affect the accuracy of DR in diagnosing obstruction. MATERIALS AND METHODS: We studied 18 patients 1 month to 10 years old with unilateral hydronephrosis ultimately proved to be either obstructive or nonobstructive. Simultaneous DR and ultrasound were performed with patients supine using the gamma camera. Ultrasound measurements of the renal pelvis in 3 dimensions, obtained before and at intervals after diuretic injection, were used to calculate renal pelvic volume. The contralateral normal kidneys were used as controls. RESULTS: Between 15 and 60 minutes after diuretic injection the renal pelvis enlarged to a maximum volume in all hydronephrotic and normal kidneys and then gradually decreased in size. Mean average increase in volume for hydronephrotic kidneys ranged from 46% in obstructed kidneys to 88% in nonobstructed kidneys. Volume expansion caused dilution of isotope within the renal pelvis, which resulted in prolongation of elimination half-time (T1/2) in 42% of nonobstructed hydronephrotic kidneys sufficient to register an obstructed washout pattern. However, there were no differences in the initial pelvic volume or the rate or extent of increases or decreases in pelvic volume that would permit nonobstructed hydronephrotic kidneys to be distinguished from obstructed ones. CONCLUSIONS: The renal pelvis enlarges during diuresis in children with hydronephrosis. This enlargement causes dilution of isotope within the renal pelvis during DR, which prolonged the isotope washout rate or T1/2 sufficiently to produce an obstructed washout pattern in more than 40% of hydronephrotic kidneys that were ultimately proved to be nonobstructed. This misdiagnosis of obstruction is particularly likely to occur in children younger than 2 years because pelvic volume expansion is so exaggerated. Consequently, T1/2 appears to be particularly vulnerable to inaccuracy in diagnosing obstruction in this age group, and, therefore, it should not be relied on as an operative determinant.     

The diagnosis of upper urinary tract obstruction in children: comparison of diuresis renography and pressure flow studies

We report the use of diuresis renography and pressure flow studies to diagnose urinary tract obstruction in 41 collecting systems of 33 children. If differential pressures between the renal pelvis and the bladder in excess of 22 cm. water at a flow rate of 10 ml. per minute is accepted as evidence of obstruction and below 15 cm. water is accepted as normal the interpretation of the renogram showing O'Reilly's pattern IIIa as evidence of stasis without obstruction was correct in 74 per cent of the cases. Likewise, the interpretation of O'Reilly's renogram pattern IIIb as showing partial obstruction was correct in only 40 per cent of the cases. Thus, we urge caution in the use of the diuresis renogram to diagnose or to rule out upper urinary tract obstruction.     

Long-term follow-up of renal function in patients after surgery for obstructive uropathy

In this prospective study, selected biochemical markers of glomerular and tubular function, proteinuria, and ultrasound findings in 62 pediatric patients who underwent surgery for obstructive uropathy were examined. Patients were younger than 12 months, normocreatininemic at the time of surgery, and examined at a mean age of 6.3 ± 0.9 years. Out of the markers tested, serum concentration of cystatin C was significantly higher in patients when compared with the control group (p < 0.001), and serum creatinine concentration was within reference interval in all patients. With respect to tubular function, 26% of patients had decreased concentration ability. Proteinuria was detected in 4.8% of patients. On ultrasound, 66.7% of kidneys after surgery had residual dilatation of the renal pelvis. The patients thrive well, and their somatic parameters do not differ from their peers. Half of the patients had one or more urinary tract infections from the date of surgery to the date of examination. Study results support the need for long-term nephrologic follow-up in patients after surgery for obstructive uropathy. The hypothesis that renal function in patients undergoing surgery aged younger than 3 or 6 months is better when compared with those aged 6 to 12 months has not been confirmed.     

Results of renal transplantation in children with obstructive uropathy due to malformations

180 renal transplants have been performed at our center in children less than 15 years old. Even if the distribution is equivalent (50/50%) between kidneys from living and cadaver donors, graft actuarial survival rate is 20% better at 5 years in the first group. 42 grafts have been implanted for end-stage renal failure due to chronic pyelonephritis (CNP). Among them, 17 were due to obstructive L.U.T. uropathies (posterior urethral valves): even if the results are identical in that subgroup compared to CPN group, there is an increased morbidity risk as 2 ureterovesical stenosis and 1 secondary vesico-ureteral reflux were observed (3/17 versus 4/163 in the remnant population).     

儿童早期预警评分在PICU病毒性脑炎患儿病情转归中的预测价值

目的研究儿童早期预警评分(PEWS)在儿科重症监护病房(PICU)病毒性脑炎患儿病情转归中的预测价值。方法对入住PICU的49例病毒性脑炎患儿的临床资料进行回顾性分析。以入住PICU时为观察起点,转出PICU或病死为观察终点。结果随着PEWS评分的增加,病毒性脑炎患儿的病死率相应升高,低危组与中危组、高危组的病死率比较,差异有统计学意义(P0.05);存活组PEWS评分较病死组低,差异有统计学意义(P0.01)。以病死作为预测指标,PEWS的ROC曲线下面积为0.944(95%CI 0.869~1.000,P0.01),最佳截断点为4分,此时Youden指数最大为0.844,灵敏度为100.0%,特异度为84.4%。结论PEWS对病毒性脑炎患儿病情转归有较高预测价值。     

99mTc-DTPA肾动态显像检测肾小球滤过率的临床应用评价

目的 以^99mTc-DTPA血浆清除率为标准，评价^99mTc-DTPA肾动态显像检查在检测肾小球滤过率(GFR)中的应用价值。方法 选择慢性肾脏病患者197例，年龄均>18岁，诊断均符合美国NKF-K/DOQI关于慢性肾脏病定义。排除肾功能急性恶化因素、水肿、肢体缺如、心功能不全。记录身高、体重。肘静脉“弹丸”式注射^99mTc-DTPA 111 MBq后即刻行肾动态图像采集120 帧，计算双肾GFR，即Gates法，同时于注射后2、4 h各抽血4 ml，分离血浆1 ml，测量其放射性计数，计算99mTc-DTPA的血浆清除率(双血浆法)，所测数值均用体表面积标准化。按双血浆法所测得的GFR值将患者分成3组:A组 77例，GFR < 30 ml·min^-1·(1.73 m²)^-1；B组 74例， 30 ml·min^-1·(1.73 m²)^-1≤GFR < 90 ml·min^-1·(1.73 m²)^-1；C组 46例，GFR≥90 ml·min^-1·(1.73 m²)^-1。分别行肾动态显像法与双血浆法所测值之间的相关分析。 结果 肾动态显像法及双血浆法所测3组GFR[单位:ml·min^-1·(1.73 m²)^-1]分别为:A组 (27.08±12.14) 比 (17.68±5.66)；B组 (63.18±23.59) 比 (51.95±16.81)； C组 (107.28±27.36) 比 (117.96±24.17)。2者间的相关系数分别为rA=0.286(P=0.012)；rB=0.804(P < 0.01)；rC=0.473(P < 0.01)。结论 99mTc-DTPA肾动态显像检查适用于轻、中度肾功能不全患者GFR的评估，但在重度肾功能不全患者中，其测量结果的准确性有待进一步提高。     

Predictive performance of eGFR equations in South Africans of African and Indian ancestry compared with 99mTc-DTPA imaging

Background

South African guidelines for early detection and management of chronic kidney disease (CKD) recommend using the Cockcroft?CGault (CG) or Modification of Diet in Renal Disease (MDRD) equations for calculating estimated glomerular filtration rate (eGFR) with the correction factor, 1.212, included for MDRD-eGFR in black patients. We compared eGFR against technetium-99m-diethylenetriaminepentaacetic acid (^99mTc-DTPA) imaging.

Methods

Using clinical records, we retrospectively recorded demographic, clinical, and laboratory data as well as ^99mTc-DTPA-measured GFR (mGFR) results obtained from routine visits. Data from 148 patients of African (n?=?91) and Indian (n?=?57) ancestry were analyzed.

Results

Median (IQR) mGFR was 38.5 (44) ml/min/1.73?m², with no statistical difference between African and Indian patients (P?=?0. 573). In African patients with stage 3 CKD, MDRD-eGFR (unadjusted for black ethnicity) overestimated mGFR by 5.3% [2.0 (16.0) ml/min/1.73?m²] compared to CG-eGFR and MDRD-eGFR (corrected for black ethnicity) that overestimated mGFR by 17.7% [6.0 (15.0) ml/min/1.73?m²] and 17.1% [6.0 (17.5) ml/min/1.73?m²], respectively. In stage 1?C2, CKD eGFR overestimated mGFR by 52.5, 38.0, and 19.3% for CG, MDRD (ethnicity-corrected), and MDRD (without correction), respectively. In Indian stage 3 CKD patients, MDRD-eGFR underestimated mGFR by 35.6% [?21.0 (6.5) ml/min/1.73?m²] and CG-eGFR by 4.4% [?2.0 (27.0) ml/min/1.73?m²], while in stage 1?C2 CKD, CG-eGFR and MDRD-eGFR overestimated mGFR by 13.8 and 6.3%, respectively.

Conclusion

MDRD-eGFR calculated without the African-American correction factor improved GFR prediction in African CKD patients and using the MDRD correction factor of 1.0 in Indian patients as in Caucasians may be inappropriate.     

Predictive value of perioperative cardiac troponin I for adverse outcome in coronary artery bypass surgery.

OBJECTIVES: Cardiac Troponin I (cTnI) is a well-known marker for myocardial damage in patients undergoing aorto-coronary bypass grafting (CABG) peaking 6-8 h after aortic declamping. The aim of this study was to evaluate cTnI release in the course of CABG procedures early, i.e. after the cessation of cardiopulmonary bypass (CPB) in order to recognize unstable cardiac function leading to hemodynamic deterioration and resulting in an adverse outcome (AO). AO is defined as the onset of myocardial infarction and/or death peri/postoperatively. METHODS: Five-hundred and forty consecutive patients who underwent CABG were evaluated for cTnI release immediately prior to the induction of anesthesia (IND) and after termination of CPB (END). Standard CPB with ante/retrograde cold blood cardioplegia was used. Patients with any of the following criteria were excluded: (1), CABG within 7 days of myocardial infarction; (2), emergency operation for both unstable angina and for coronary occlusion at angioplasty; (3), CABG with concomitant surgical cardiac procedures; (4), preoperative renal dysfunction requiring hemodialysis; (5), redos. Troponin I was measured with the Stratus CS fluorometric enzyme immunoassay analyzer (Dade-Behring) running on site in the operation room (OR), so values of cTnI could be obtained within 15 min. RESULTS: There were six deaths (1.1%) in the entire series, Q-wave myocardial infarction occurred in 19 patients (3.5%), AO was experienced by 21 patients (3.9%). The mean preoperative cTnI level was 0.04+/-0.17 ng/l (mean+/-standard deviation) for the entire group. The END cTnI level for the AO-group was 0.91+/-0.5 ng/l; for all other patients, this was 0.37+/-0.3 ng/l (P<0.001). Changes in intraoperative cTnI levels relative to time course showed a marked increase for the AO-group (0.0038+/-0.0035 ng/l*min) as compared with non-AO patients (0.0019+/-0.0015 ng/l*min; P=0.028). The receiver operating characteristic curve indicates a cTnI level at CPB-end of higher than 0.495 ng/l with an area under the curve of 0.83 as the optimal cut-off point for predicting AO with a sensitivity and specificity of 76.2%. Stepwise logistic regression analysis revealed END cTnI level (odds ratio, 17.24; P<0.001), CPB time (odds ratio, 1.03; P=0.001), female sex (odds ratio, 3.8; P=0.011) as significant independent predictors for AO. Age of over 70 years (P=0.8), Cleveland Clinic risk score (P=0.65), diabetes (P=0.26), elevated preoperative creatinine level (P=0.77), severe left ventricular dysfunction (P=0.51), the number of grafts performed (P=0.15), and change of intraoperative cTnI level relative to time course (P=0.94) did not reach statistical significance. CONCLUSIONS: cTnI release as determined at the end of CABG procedures represents a strong predictor of an AO after surgery. Analyzing blood samples for cTnI with an automated device on site in the OR provides for immediate results, so specific diagnostic and therapeutic interventions can be performed before hemodynamics deteriorate.     

Polysomnographic outcome of adenotonsillectomy for obstructive sleep apnea in children under 5 years old

OBJECTIVE: To determine success rates after adenotonsillectomy for obstructive sleep apnea (OSA); postoperative polysomnogram (PSG) results were compared with preoperative results in children younger than 5 years. METHODS: Thirty-four children with a preoperative respiratory disturbance index (RDI) greater than 5 in rapid eye movement (REM) sleep underwent both preoperative and postoperative PSG with at least five of seven parameters recorded. RESULTS: Preoperatively, mean total RDI was 15.5, mean REM RDI was 39.6, and 25 (74%) had severe OSA (REM RDI > 20). Postoperatively, mean total RDI improved to 3 (P < 0.001), mean REM RDI to 7.4 (P < 0.001), and 4 remained severe. Overall 22 (65%) showed REM RDI in the normal range (<5), including all with a preoperative REM RDI less than 30. CONCLUSION: On PSG criteria, most children with OSA significantly improved after adenotonsillectomy, but a number had persisting abnormalities. Postoperative PSG should be considered to identify unresolved OSA.