PubMed Health⌕ Search

Biomedical subjects

J J Pahira

Publications and source records attributed to J J Pahira.

At least 19 recordsLinked to original sources
PubMed2001

Nonvisualization of intravenous methylene blue in patients with clinically normal renal function.

Urologists use intravenous dyes in diagnosing genitourinary fistulas and in investigating ureteral patency. Methylene blue and indigo carmine are the most common dyes used today. Generally, patients with clinically normal renal function demonstrate dye in their urine after several minutes. We report on 2 patients in whom methylene blue was not visualized after intravenous injection. A review of urologic and pharmacologic published reports led to a possible explanation for this phenomenon. Methylene blue can metabolize into leukomethylene blue, which is colorless in urine. Indigo carmine, however, is not readily metabolized but is rather freely filterable by the kidneys. Therefore, it is important to appreciate that nonvisualization of methylene blue may be a metabolism effect and not an anatomic one.

Female↗
PubMed1998

A telemedicine consultative service for the evaluation of patients with urolithiasis.

OBJECTIVES: A 6-month pilot teleconsultative project linking Georgetown University Medical Center (GUMC) in Washington, DC, and City Hospital in Martinsburg, West Virginia, 90 miles away, was designed to assess the effectiveness of telemedicine on the clinical decision-making process for patients with urolithiasis. METHODS: The telemedicine system designed and tested for this project was based on a PC-based platform. Videoconferencing and review of the patient's imaging studies were performed over an Integrated Service Digital Network (ISDN) with 3 Basic Rate (BRI) ISDN lines providing a 336-kilobytes/s bandwidth through an Inverse Multiplexor (IMUX). Treatment options were recorded for the clinical trial group and a simulated study group by the consulting urologist after the initial telephone consultation, after the telemedicine consultation, and after examination of those patients transferred to GUMC. RESULTS: A total of 32 telemedicine consultations were performed: 14 in the clinical trial group and 18 in the simulated study group. The recommendation of the consulting urologist at the tertiary center was altered in 12 patients (37.5%) after the telemedicine consultation compared with the recommended treatment after the initial telephone consultation. CONCLUSIONS: In the evaluation of patients with urolithiasis, this telemedicine application enhanced the clinical decision-making process by allowing for improved quality of care through immediate access and effective transfer of information between the referring urologist, the patient, and the stone center specialist.

Adult↗
PubMed1997

Requirements for urology and renal dialysis PC-based telemedicine applications: comparative analysis.

The Imaging Science and Information Systems (ISIS) Center of the Department of Radiology at Georgetown University Medical Center (GUMC) has been developing technical requirements for different telemedicine applications. This paper details the process through which those technical requirements are determined and shows how they may differ substantially, depending on the clinical need. This information is presented in light of two telemedicine applications being undertaken at GUMC: a urology application for the management of patients with surgical stone disease and a nephrology application for monitoring of renal dialysis patients.

Humans↗
PubMed1995

A modification of standard percutaneous nephrolithotripsy technique for the morbidly obese patient.

OBJECTIVES: Urolithiasis in the morbidly obese patient presents several unique challenges to the urologist, and its treatment often requires creativity and innovation. We present a new modification of standard percutaneous nephrolithotripsy (PNL) technique, which is very helpful in overcoming some of the problems that are encountered when performing PNL in this group of patients. METHODS: We present 5 patients in whom this new technique has been used. Each had either failed prior extracorporeal shock-wave lithotripsy (ESWL) therapy or their size and abdominal girth precluded use of ESWL technology. All 5 patients underwent PNL. The radiographically measured skin-to-stone distances (determined by computed tomography or ultrasonography or both) exceeded the lengths of the standard percutaneous access sheaths and the 26 F rigid nephroscope. Thus larger and longer Amplatz access sheaths and a 30 F gynecologic laparoscope were used to reach the stones. Standard ultrasonic lithotripsy was then performed, and extralong bronchoscopic grasping forceps were used to remove stone fragments. RESULTS: All 5 patients were rendered stone-free using this technique. There was no significant perioperative morbidity. CONCLUSIONS: For this very challenging group of patients, the use of larger and longer access sheaths and the gynecologic laparoscope have been very effective additions to the urologists' armamentarium in the treatment of urolithiasis.

Adult↗
PubMed1995

Technical tip: use of open-ended guidewire to facilitate laser lithotripsy during flexible ureteroscopy.

You have just passed your flexible ureteroscope to the level of the upper-ureteral calculus. The stone is in view, but as you advance the laser fiber, it fails to exit the ureteroscope. All measures to advance the fiber prove futile. Sound familiar? We have found this to be an all too common and frustrating situation with the use of the flexible ureteroscope during laser lithotripsy. Our review of the literature reveals that this subject has not been adequately addressed. We have been successful with the aid of an open-ended 0.035-inch guidewire that admits the 320-microns laser fiber.

Cost-Benefit Analysis↗
PubMed1993

The effects of a soft tissue mimicking medium and increased power settings on the location and magnitude of lithotripter peak positive pressure.

In vitro experiments showed that a tissue mimicking medium alters the peak positive pressure (p+), focal zone properties and frequency content of shockwaves compared with their behavior in water. The reduction in (p+) ranged from 5% at 10 kV. to 19% at 18.1 kV., when measured at the geometric focus with the tissue mimicking medium present. As power settings were increased, the relative gain in pressure was damped by attenuation. A 2 mm. shift in the acoustic focus was seen both axially and laterally with the tissue mimicking medium. While the former is probably not significant, the latter may be clinically significant given the narrow lateral beam width at the acoustic focus. These attenuation experiments suggest that clinical targeting through tissue may not be as precise or result in as high peak pressures as the clinician expects. Especially at high power settings, the depth of tissue traversed should be minimized to limit attenuation effects.

Biophysical Phenomena↗
PubMed1990

Primary hyperparathyroidism in patients with renal stones.

There has been an observed decline in the incidence of renal stones in patients with primary hyperparathyroidism. Some believe that this is related to earlier surgical intervention. Two studies from the 1950s examined the reverse questions to determine the prevalence of primary hyperparathyroidism in patients with renal stones. This report examined 1,500 consecutive patients treated by lithotripsy seen at the Georgetown University Medical Center and found, using the historical criterion for diagnosis of hyperparathyroidism (a serum calcium level of 10.5 milligrams per deciliter or greater) that the prevalence had decreased significantly from 8.0 per cent to our level of 3.02 per cent. Neither age nor sex contributed significantly to this decrease, and there were significantly more calcium stones than in the previous studies. Using an elevated calcium level with an elevated chloride to phosphate ratio as criteria for a diagnosis of probable primary hyperparathyroidism, a true prevalence of 1.65 per cent (+/- 0.6 per cent) was found. We believe that there has been a significant decrease in the frequency of primary hyperparathyroidism in the general population of patients with renal stones.

Calcium↗
PubMed1989

Rhabdomyolysis: need for high index of suspicion.

Rhabdomyolysis, both traumatic and nontraumatic, may be defined as a triad of skeletal muscle injury, pigmented urine, and acute renal failure. Nontraumatic rhabdomyolysis may be more of a subtle diagnosis and requires a high index of suspicion. Pertinent findings in the history as well as clinical evidence of muscle injury with a marked elevation of creatinine kinase will suggest the diagnosis. A disproportionate elevation of serum creatinine to blood urea nitrogen may also occur. Treatment consists of adequate hydration to help prevent oliguric or anuric renal failure without additional calcium or bicarbonate supplementation in most cases. Radiologic studies involving intravenous contrast media as well as urologic instrumentation should be avoided in the acute setting. With early diagnosis and prompt treatment the prognosis for recovery is excellent.

Acute Kidney Injury↗
PubMed1988

Ureteral stricture: experience with 31 cases.

We reviewed the records of 31 patients treated during the last 5 years for ureteral stricture disease. The causes of stricture formation included ureteroenteral anastomoses (23 per cent), open ureterolithotomy (19 per cent), ureteroscopy (19 per cent), other urological procedures (16 per cent), general surgical and gynecological procedures (13 per cent) and miscellaneous causes (7 per cent). Of the patients 24 were managed initially with antegrade or retrograde balloon dilation or stenting and favorable outcomes were achieved in 12 (50 per cent), with a mean followup of 13 months. Of the 12 patients who failed endourological management 6 subsequently underwent open repair with a 100 per cent success rate. The remaining 7 patients underwent an open operation as the initial management and successful results were achieved in 6. The over-all rate of successful management of ureteral stricture disease using endoscopic and open surgical techniques was 77 per cent. A total of 7 patients (23 per cent) failed attempts at intervention: 5 showed evidence of decreasing renal function and 2 required nephrectomy.

Adolescent↗
PubMed1987

New approaches in the treatment of renal calculi.

Indications for intervention in patients with renal stone disease include persistent pain or bleeding, obstruction, infection and the presence of stones that are too large to pass spontaneously. Extracorporeal shock wave lithotripsy has revolutionized the surgical treatment of kidney stones. Contraindications include anticoagulation, bleeding diathesis, sepsis and renal malignancy. Stones in the renal pelvis and upper ureter are treated with shock wave lithotripsy; those in the lower ureter are best approached with the ureteroscope.

Endoscopy↗
PubMed1987

Management of the patient with cystinuria.

Cystinuria is a complex hereditary disorder characterized by excessive urinary excretion of cystine. For the homozygote patient who excretes more than 400 mg per day, recurrent urinary calculus formation can necessitate repeat surgical manipulation with its associated morbidity. This review details the long-term medical management program for the patient with cystinuria and recurrent calculus formation.

Adult↗
PubMed1985

New self-developing film for intraoperative renal stone localization.

The use of intraoperative radiography for localization of small renal calculi has been a valuable adjunct to surgery. Unfortunately, because of the considerable time required for mobilization of the kidney, the development of x-ray films and the not infrequent need for repeat exposures, considerable time can be added to the operation. We have found that the use of Polaroid film can give high-quality intraoperative radiographs. The main advantage of Polaroid film over the standard Kodak kidney film is that the film is developed in the operative suite and, in most cases, requires less than one minute.

Humans↗
PubMed1985

Acute focal bacterial nephritis: a systematic approach to diagnosis and treatment.

Acute focal bacterial nephritis, synonymous with acute lobar nephronia or focal nonliquefactive pyelonephritis, represents a localized area of renal inflammation. Clinically, acute focal bacterial nephritis presents as acute pyelonephritis but is distinguishable by the presence of a focal mass on excretory urography. The further distinction between acute focal bacterial nephritis and other renal masses is aided by the appropriate use of renal sonography and computerized tomography. The clinical and imaging manifestations in 9 patients with acute focal bacterial nephritis are described. Our experience coupled with a review of the literature suggests that a systematic approach to the diagnosis and management of acute focal bacterial nephritis allows for the most efficacious use of the noninvasive imaging modalities.

Acute Disease↗
PubMed1985

Extracorporeal shockwave lithotripsy: role of the radiologist.

Extracorporeal shockwave lithotripsy (ESWL) is a new noninvasive treatment modality for urinary calculi. ESWL may be applied to the majority of patients requiring stone removal and is expected to replace, to a large degree, percutaneous stone removal (PSR), now practiced jointly by interventional radiologists and endourologists in most institutions. In a number of cases, ESWL and PSR will be complementary procedures. Technically, ESWL can be considered a radiologic procedure; thus far, radiologists are not participating in its use. In the authors' opinion, ESWL should be a combined urologic radiologic procedure analogous to PSR; this will allow the most rational and effective treatment.

Humans↗