The effect of diclofenac (voltarol) and pethidine on ureteric peristalsis and the isotope renogram

Radionuclides in nephrourology, part 1: Radiopharmaceuticals, quality control, and quantitative indices

Radionuclide renal scintigraphy provides important functional data to assist in the diagnosis and management of patients with a variety of suspected genitourinary tract problems, but the procedures are underutilized. Maximizing the utility of the available studies (as well as the perception of utility by referring physicians) requires a clear understanding of the clinical question, attention to quality control, acquisition of the essential elements necessary to produce an informed interpretation, and production of a report that presents a coherent impression that specifically addresses the clinical question and is supported by data contained in the report. To help achieve these goals, part 1 of this review covers information that should be provided to the patient before the scan, describes the advantages and limitations of the available radiopharmaceuticals, discusses quality control elements needed to optimize the study, summarizes approaches to the measurements of renal function, and focuses on recommended quantitative indices and their diagnostic applications. Although the primary focus is the adult patient, aspects of the review also apply to the pediatric population.

Effect of the NSAID diclofenac on 99mTc-MAG3 and 99mTc-DTPA renography

Renal function and disease are commonly evaluated by radionuclide studies. The choice of radiopharmaceutical agent for various studies is crucial for proper interpretation. (99m)Tc-mercaptoacetyltriglycine ((99m)Tc-MAG3) is excreted almost exclusively by the renal tubules, whereas (99m)Tc-diethylenetriamine pentaacetic acid ((99m)Tc-DTPA) is predominantly excreted by glomerular filtration. The present study compared the effect of the nonsteroidal antiinflammatory drug (NSAID) diclofenac, which is the most commonly used drug to relieve kidney pain, on the kinetic behavior of administered (99m)Tc-MAG3 and (99m)Tc-DTPA in experimental animals.

METHODS

Two groups of 12 New Zealand White rabbits ((99m)Tc-MAG3 and (99m)Tc-DTPA) were used for the renography. Each rabbit served as its own control. The animals were given 60 mL of saline intravenously 30 min before each renographic study. A baseline study (control) was done by injecting 48 MBq (1.3 mCi) of (99m)Tc-MAG3, and renography was performed. Two days later, a single intravenous dose of diclofenac (2 mg/kg) (treated animals) was given, and after 20 min, (99m)Tc-MAG3 renography was performed. This procedure was repeated for the (99m)Tc-DTPA group after administration of 96 MBq (2.6 mCi) of the tracer. Dynamic images (as 2-s frames for the first minute and 30-s frames for the next 30 min on a 64 × 64 matrix) were acquired using a γ-camera equipped with a low-energy high-resolution collimator interfaced with a computer. Regions of interest were drawn over the whole kidneys. Time-activity curves were generated from the region of interest. Time to peak activity (T(max)), time from peak to 50% activity (T(1/2)), and the uptake slope of each kidney were calculated from the renograms for control and treated rabbits.

RESULTS

Administration of diclofenac shifted the experimental renogram curves to the right, compared with the control curves, indicating that there was a delayed renal uptake of the 2 tracers and clearance of the radioactivity. The calculated average values of T(max) for control and treated rabbits using (99m)Tc-MAG3 were 1.8 ± 0.5 and 6.35 ± 0.4 min, respectively, whereas those of (99m)Tc-DTPA were 3.4 ± 0.4 and 18.2 ± 2 min, respectively. The T1/2 for control and treated rabbits for (99m)Tc-MAG3 were 3.2 ± 0.07 and 6.6 ± 0.07 min, respectively, whereas those for (99m)Tc-DTPA were 10.1 ± 1 and 35 ± 4 min, respectively. The differences were statistically significant (P < 0.05).

CONCLUSION

This study showed that diclofenac delayed both T(max) and T1/2. The NSAID-induced kinetic changes were considerably greater for (99m)Tc-DTPA than for (99m)Tc-MAG3. On the basis of these findings, it is suggested that (99m)Tc-MAG3 be used to perform renography for studies involving the use of NSAID administration to decrease any change that may occur due to the type of tracer and not to the condition of the kidney.

[Ureter drugs]

Many improvements have been made recently in the field of the ureteral smooth muscle pharmacology. After a brief summary on physiological basis, we review what is known about effects on ureter of different drugs class. In a second part, we review clinical applications for renal colic analgesia, calculi expulsive medical therapy, ESWL adjuvant treatment and preoperative treatment before retrograde access. There are now sufficient data on NSAID and alpha-blockers. beta-agonists, especially for beta3 selective ones, and topical drugs before retrograde access are interesting and should be further evaluated.

Pharmacological effect on pyeloureteric dynamics with a clinical perspective: a review of the literature

We searched to review experimental and clinical trials concerning the capabilities of impacting on the ureteric and pelvic activity by means of pharmacological stimulation. Ureteropyeloscopy may cause high renal pelvic pressure. The normal pressure is in the range of 5-15 mmHg whereas pressure of 410 mmHg has been measured during endoscopy. The threshold pressure for intrarenal reflux is about 35 mmHg. Studies in animals have revealed that high renal pelvic pressures may cause permanent damage to the renal parenchyma. Furthermore, it has been demonstrated that elevated pressures may entail an increased risk of several complications related to endourological procedures including bleeding, perforation and infection. In other words, means by which intrarenal pressure could be lowered during endourological procedures might be beneficial with respect to clinical outcomes. In vitro experiments support the existence of different receptors in the ureter and renal pelvis. The ureteric and pelvic responses to the corresponding neurotransmitters have been determined. It seems that alpha-adrenergic and cholinergic agents are stimulating whereas beta-adrenergic agents inhibit ureteric activity. The effect may depend on the mode of administration. Drugs exerting advantageous effects in the pyeloureter may cause undesirable systemic side effects when administered intravenously. In animal studies, renal pelvic pressure can be significantly lowered by topical administration of beta-adrenergic agonists without systemic side effects. In vivo human studies are necessary to clarify the exact dose-response relationship and the degree of urothelial absorption of a drug before clinical use may be adopted.

Evaluation of novel technique for studying ureteral function in vivo

BACKGROUND AND PURPOSE

Knowledge of the ureteral response to instrumentation is limited. Ureterodynamic parameters such as intraureteral pressure, conduction velocity, direction of peristalsis, and electromyography have been measured using a variety of methods; however, these techniques are impractical for routine clinical use. The aim of this study was to evaluate a new commercial ureteral pressure transducer catheter, which records peristaltic frequency, conduction velocity, and intraureteral pressure. This device was assessed in an animal model and in patients who had undergone ureteroscopy.

MATERIALS AND METHODS

An ambulatory urodynamic monitoring system was adapted to record the output from two pressure transducers mounted on a 4F ureteral catheter, which was inserted into the left ureters of six anesthetized pigs to record peristalsis. In six patients who had undergone ureteroscopy with or without stone removal, the recording catheter was inserted at the end of the procedure, and recovery of peristalsis was monitored for as long as 24 hours.

RESULTS

The un-instrumented pig ureter showed spontaneous peristalsis immediately on catheter insertion, whereas the instrumented human ureter displayed a variable response that appeared to be related to previous physical or pharmacologic effects.

CONCLUSIONS

Peristaltic frequency, pressure, and conduction velocity can be measured with the ureteral catheter described in both the experimental and clinical settings. Within the first 24 hours after ureteroscopy, peristaltic recovery is variable. Such information may enable both elucidation of the underlying mechanisms and improvement in the treatment of a variety of upper urinary-tract disorders.

Cólico renal: Revisión de la literatura y evidencia científica

In recent years diagnosis and treatment of acute renal colic have changed thanks to the introduction of new radiological procedures that allow with high reliability to establish obstructive cause and a better treatment. In the other hand, there are multiple clinical studies that show the most effective treatments for acute crisis. The aim of this revision is to update the diagnostic and therapeutic aspects of renal colic which were modified recently, and allowed to break some classic concepts without scientific evidence.

Ureteric jet in the anaesthetised child

We have already suggested that there is an active bimodal sphincteric mechanism in the human vesicoureteral junction (VUJ). This mechanism is affected by immaturity, hormonal effects and surgical ablation. This study set out to investigate the effects of anaesthesia on this mechanism. A total of 16 children undergoing surgery were recruited. They were well hydrated. The ureteric jets before and after anaesthesia were recorded using the colour and pulse wave Doppler. Of the total, 14 children showed mature (complex pattern) and two showed immature (monophasic pattern) waveforms before surgery. After anaesthesia, all showed the monophasic waveform (p=0.01). Thus, the sphincteric action of VUJ as manifest by the complexity of the ureteric jet was modified by anaesthesia by loss of the complex pattern. This supports the hypothesis that the complex pattern is a neural modulation of the simpler myogenic mechanism that produces the monophasic jet.

Effects of carprofen on renal function and results of serum biochemical and hematologic analyses in anesthetized dogs that had low blood pressure during anesthesia

OBJECTIVE

To investigate effects of IV administered carprofen on indices of renal function and results of serum biochemical and hematologic analyses in dogs anesthetized with acepromazine-thiopentone-isoflurane that had low blood pressure during anesthesia.

ANIMALS

6 healthy Beagles.

PROCEDURE

A randomized crossover study was conducted, using the following treatments: saline (0.9% NaCl solution)-saline, saline-carprofen, and carprofen-saline. Saline (0.08 ml/kg) and carprofen (4 mg/kg) were administered IV. The first treatment was administered 30 minutes before induction of anesthesia and immediately before administration of acepromazine (0.1 mg/kg, IM). Anesthesia was induced with thiopentone (25 mg/ml, IV) and maintained with inspired isoflurane (2% in oxygen). The second treatment was administered 30 minutes after onset of inhalation anesthesia. Blood gases, circulation, and ventilation were monitored. Renal function was assessed by glomerular filtration rate (GFR), using scintigraphy, serum biochemical analyses, and urinalysis. Hematologic analysis was performed. Statistical analysis was conducted, using ANOVA or Friedman ANOVA.

RESULTS

Values did not differ significantly among the 3 treatments. For all treatments, sedation and anesthesia caused changes in results of serum biochemical and hematologic analyses, a decrease in mean arterial blood pressure to 65 mm Hg, an increase of 115 pmol/L in angiotensin II concentration, and an increase of 100 seconds in time required to reach maximum activity counts during scintigraphy.

CONCLUSIONS AND CLINICAL RELEVANCE

Carprofen administered IV before or during anesthesia did not cause detectable significant adverse effects on renal function or results of serum biochemical and hematologic analyses in healthy Beagles with low blood pressure during anesthesia.

Application of mathematical methods in dynamic nuclear medicine studies

Dynamic nuclear medicine studies can generate large quantities of data, and their analysis consists essentially of a reduction of these data to a small number of relevant parameters which will assist in clinical decision making. This review examines some of the mathematical techniques that have been used in the process of data reduction and attempts to explain the principles behind their application. It particularly identifies the techniques that have stood the test of time and demonstrated their usefulness, many of which are now available as standard tools on nuclear medicine processing computers. These include curve processing tools such as smoothing, fitting and factor analysis, as well as tools based on empirical models, such as the Patlak/Rutland plot and deconvolution. Compartmental models and vascular models are also examined and the review finishes with a summary of some functional images and condensed images. It is concluded that an appreciation of the principles and limitations of these mathematical tools is valuable for their correct usage and interpretation of the results produced.