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Biomedical subjects

A Piepsz

Publications and source records attributed to A Piepsz.

At least 19 recordsLinked to original sources
PubMed2001

Attitude of Belgian pediatricians toward strategy in acute pyelonephritis.

To investigate the attitude of Belgian pediatricians toward the management and treatment of children with suspected acute pyelonephritis, a short letter was sent to all Belgian pediatricians (1,200). It contained a brief description of a clinical case strongly suggestive of acute pyelonephritis followed by a series of questions centered on complementary examinations to be performed, need of hospitalization and treatment. A total of 583 responses were received (49%). In the acute phase, 99% of pediatricians perform urine cultures, 87% blood examinations, and 76% renal ultrasound. Dimercaptosuccinate (DMSA) scintigraphy is performed during the acute phase by 37% and during follow-up by 32% of all pediatricians. A voiding cystogram is requested by 71%. Ambulatory treatment is considered by 30% of responders. Amoxicillin/clavulanic acid (44%) and trimethoprim/sulfonamide (22%) are the most frequently used oral antibiotics. Private pediatricians perform fewer examinations and more frequently consider ambulatory treatment of acute pyelonephritis, compared to pediatricians working in hospitals. Among Belgian pediatricians, attitudes toward the diagnosis and treatment of acute pyelonephritis are heterogeneous. This survey underlines the need for properly documented prospective studies for the evaluation of different treatment modalities in childhood acute pyelonephritis.

Acute Disease↗
PubMed2001

Role of Tc-99m DMSA scintigraphy in the diagnosis of culture negative pyelonephritis.

The aim of this work was to evaluate prospectively the proportion of children with a clinical and biological presentation of acute pyelonephritis, abnormal Tc-99m dimercaptosuccinic acid (DMSA) scintigraphy and negative or equivocal urine cultures. All patients aged 6 weeks to 15 years suspected of acute pyelonephritis (APN) were admitted to the Paediatric Department and underwent Tc-99m DMSA scintigraphy within 3 days after admission and at 6 months. Of 166 patients enrolled in the study, 15 (9%) had negative or equivocal urine culture despite clinical and scintigraphic evidence of APN. Of these 15 children, renal ultrasound was normal in 7 patients and vesicoureteric reflux was found in 9 patients. Control DMSA 6 months after acute episode showed the disappearance of cortical lesions in eight and partial improvement in four patients. In this prospective series, as many as 9% of patients with APN would have been missed on the basis of equivocal or negative urine cultures. It is suggested that Tc-99m DMSA scintigraphy should be performed in children with severe infection without clear aetiology, especially in those with abnormal urinalysis.

Adolescent↗
PubMed2001

Treatment of children with acute pyelonephritis: a prospective randomized study.

The aim of this study was to compare, in children with acute pyelonephritis, the efficacy of 7 days' (group A) and 3 days' (group B) intravenous antibiotics, both followed by an oral treatment. Children were randomized after 3 days of intravenous treatment. Technetium-99m dimercaptosuccinic acid (DMSA) scintigraphy was performed within the first days after admission and repeated 6 months later. Total or partial persistence of renal abnormalities on the 6-month DMSA scintigraphy was used as the endpoint of the study. Among the 92 children included in the study, 87 were followed for at least 6 months (43 in group A and 44 in group B) and were eligible for analysis. Late DMSA was abnormal in 9 kidneys of group A and 12 kidneys of group B, representing respectively 24% and 44% of kidneys with abnormalities on the initial DMSA (difference statistically not significant). When the patients were stratified according to the delay of treatment, the percentage of patients with sequelae in group A was comparable, whether the delay was less or more than 1 week. In group B, the percentage of patients with sequelae was significantly higher (P<0.01) when the delay was more than 1 week.

Acute Disease↗
PubMed2001

Influence of errors in sampling time and in activity measurement on the single sample clearance determination.

INTRODUCTION: Plasma clearance rate of 51Cr-EDTA estimated by using one blood sample is commonly used for the calculation of glomerular filtration rate. AIM: To estimate the error on single-sample clearance determination induced by errors in sampling time and activity measurement, and to compare it with the error observed on the clearance determination obtained using the slope-intercept method. METHODS: Forty-five adult patients were chosen from a data base of 51Cr-EDTA plasma clearance values determined by using two blood samples taken around 2 and 4 h. Patients were selected in such a way as to include clearances from 30 ml.min-1 to 155 ml.min-1, with steps of 3 ml.min-1. Based on the slope and the intercept of the slope with the y-axis, the plasma concentration at exactly 2 and 4 h was determined. Normally distributed random errors were then introduced in the sampling time (SD of 0, 1 and 2 min) as well as in the activity measurement (SD of 0, 1, 2 and 5%). Then, clearance was calculated using two single-sample methods (i.e. the algorithms of Groth and Tauxe), and the slope-intercept method, which requires two blood samples. For each setting, the simulation was repeated 200 times. The effects on clearance of a random error on the time sampling and/or the activity measurement were then evaluated. RESULTS: The error on single-sample clearance induced by a 2 min error in sampling time associated with a 5% error in activity measurement was negligible. For all clearance levels, the SD of the error on the calculated clearance was less than 3.8 ml.min-1. Whatever algorithm was chosen, the errors on the single-sample clearance were systematically lower than those observed with the slope-intercept method, for the whole clearance range. CONCLUSION: Errors in sampling time and in activity measurement induced only a very small error on the single-sample EDTA clearance, which is systematically lower compared to that observed on the slope-intercept method using two blood samples.

Adult↗
PubMed2001

Is deconvolution applicable to renography?

The feasibility of deconvolution depends on many factors, but the technique cannot provide accurate results if the maximal transit time (MaxTT) is longer than the duration of the acquisition. This study evaluated whether, on the basis of a 20 min renogram, it is possible to predict in which cases the MaxTT will exceed 20 min. Renograms of various shapes were simulated by convolution of a plasma disappearance curve and various created retention functions with a mean transit time (MTT) ranging from 3 to 23 min. The values of MaxTT were then derived from the created curves and compared to three parameters of transit measured on the renograms: the time to reach the maximum of the curve (Tmax), the output efficiency at 20 min (OE20), and the normalized residual activity at 20 min (NORA20). The proportion of retention functions (n=390) with MaxTT>20 min increased with increasing Tmax (e.g. 9% for 6< or =Tmax<10 min, and 34% for 11< or =Tmax<15 min), increasing NORA20 (e.g. 20% for 1.4< or =NORA20<3.0, and 84% for 3.0< or =NORA20<5.0) and decreasing OE20 (19% for 50% <OE20< or =75%, and 76% for 25% <OE20< or =50%). Use of Tmax, OE20 and NORA20 doesn't allow the differentiation of cases with a MaxTT longer or shorter than 20 min. Deconvolution can paradoxically only be used in cases of normal transit.

Humans↗
PubMed2001

Interobserver reproducibility in reporting on 99mTc-DMSA scintigraphy for detection of late renal sequelae.

UNLABELLED: This study was designed to evaluate the interobserver variability in reporting on 99mTc-dimercaptosuccinic acid (DMSA) scanning performed 6 mo after an acute episode of pyelonephritis for the detection of late renal sequelae. METHODS: Forty-six children were selected, who had early and late DMSA studies for evaluation of acute pyelonephritic lesions as well as sequelae. Three observers reported independently and separately on the early and late DMSA scans and, in a second step, on the late scan in the presence of the early scan. Interobserver reproducibility was evaluated for the early DMSA scan, the late DMSA scan alone, and the late DMSA scan with the early scan for comparison. RESULTS: Complete agreement between the three observers was reached in 75%, 78%, and 77% for the early DMSA scan, the late DMSA scan alone, and the late DMSA scan with the early scan for comparison, respectively. CONCLUSION: Interobserver reproducibility was high and was comparable for both early and late DMSA scintigraphy.

Acute Disease↗
PubMed2000

Atlas on acute pyelonephritis in children.

The authors describe various patterns of Tc-99m DMSA images that correspond to a diagnosis of acute pyelonephritis. Only those children with complete scintigraphic healing or considerable improvement after 6 months have been considered.

Acute Disease↗
PubMed2000

Simplified algorithms for the estimation of 99Tcm-MAG3 clearance.

The aim of this study was to evaluate two formulae allowing the determination of MAG3 clearance by means of a single blood sample, namely Bubeck's formula and Russell's formula. As a first step, a simulation study was performed with the two single-sample algorithms to predict MAG3 clearance as a function of plasma concentration, using various times for blood sampling and various body surface areas. As a second step, a validation study on 47 adult patients with varying renal function allowed a clinical comparison between the reference technique, namely the multiple blood sample technique, and the two simplified techniques. The simplified algorithms were calculated using the fitted value at 44 min. In the simulation study, whatever the time of blood sampling or the level of correction introduced for body surface area, the results obtained by means of Bubeck's algorithm diverged significantly from those of Russell's algorithm, for low clearance values as well as for high clearance values. The curve of the differences between the two methods had a typical boomerang shape. In the clinical study, the difference between Russell's algorithm and the reference method was generally within 20 ml.min-1, with no systematic bias; with Bubeck's algorithm there was a marked underestimation, both in the low and high clearance ranges. We suggest Russell's single-sample method is the method of choice.

Adult↗