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Biomedical subjects

R C Pfister

Publications and source records attributed to R C Pfister.

At least 55 records · Page 3Linked to original sources
PubMed1983

Contrast-medium-induced electrocardiographic abnormalities: comparison of bolus and infusion of methylglucamine iodamide and methylglucamine/sodium diatrizoate.

A double-blind study comparing electrocardiographic (ECG) abnormalities induced by methyglucamine iodamide and methylglucamine/sodium diatrizoate was conducted in 189 patients. The media were each administered by both bolus and infusion. Iodamide caused fewer ECG changes both by injection and infusion. This contrast medium also resulted in fewer ECG changes in the patient groups with known prior ECG abnormalities, cardiovascular disease, arrhythmias, ischemia, or renal impairment and in those over 50 years of age. Digitalis did not increase the frequency of ECG abnormalities with either medium. With diatrizoate, the lower bolus dose produced as many major ECG changes in the presence of preexisting ECG abnormalities (arrhythmias, ischemia) or prior cardiovascular disease as the three-times-larger infusion dose more slowly administered; conversely, the opposite was found when renal insufficiency or older age existed. The conclusion is that iodamide media caused fewer ECG abnormalities and may be less hazardous.

Arrhythmias, Cardiac↗
PubMed1983

Pyonephrosis: imaging and intervention.

A series of 70 pyonephrotic kidneys drained by percutaneous nephrostomy tube was examined to evaluate the contribution of radiologic imaging to the diagnosis of pyonephrosis and to assess the diagnostic and therapeutic role of drainage by percutaneous nephrostomy catheter. The diagnosis of pyonephrosis is suspected when the clinical symptoms of fever and flank pain are combined with the radiologic evidence of obstruction to the urinary tract. Sonography gives a prompt diagnosis of hydronephrosis, and needle puncture of the kidney yields pus and establishes the presence of pyonephrosis. A percutaneous nephrostomy catheter is then inserted and serves for initial drainage of infected urine and for evaluation of residual kidney function before definitive surgery. The nephrostomy catheter is used for diagnostic nephrostograms, ureteral perfusions, therapeutic dissolution of stones, and indefinite drainage of the kidney. In 10 azotemic patients, the blood urea nitrogen and serum creatinine values returned to normal levels after antibiotic therapy and nephrostomy drainage of infection. Long-term evaluation of residual renal function by means of an excretory urogram or a renogram was available in another 26 patients and 25 of them showed function of the previously pyonephrotic kidney.

Adolescent↗
PubMed1983

Percutaneous transtracheal ventilation: experimental and practical aspects.

Percutaneous transtracheal ventilation can be a lifesaving procedure when endotracheal intubation is not possible, but an understanding of the technique and necessary instruments is essential. This study, performed on adult sheep, defined the limited circumstances under which a 15-gauge needle, connected to oxygen at 50 pounds per square inch (psi), can provide an emergency transtracheal airway. There are situations, such as complete airway obstruction, when this combination is contraindicated. In addition, transtracheal ventilation might have to be performed using simpler equipment, such as a self-inflating resuscitation bag (AMBU-type) or with no equipment other than the transtracheal airway. A 3.0-mm I.D. cannula provided an adequate transtracheal airway under all circumstances examined. A 3.5-mm cannula is commercially available and physicians who deal with airway problems should be familiar with its use.

Airway Obstruction↗
PubMed1983

Complications of pediatric percutaneous renal procedures: incidence and observations.

Successful definitive (complete) percutaneous renal procedures in the pediatric age group were performed in 97 per cent of antegrade pyelograms, in 94 per cent of ureteral perfusions (Whitaker test), in 98 per cent of nephrostomies, and 100 per cent of both retroperitoneal fluid drainages and renal aspiration biopsies. Significant complications, or those necessitating specific treatment or prolonged hospitalization, were 1.1 per cent. 0.7 per cent, 15.2 per cent, 0 per cent, and 0 per cent, respectively, for the above procedures. Not surprisingly, certain operators are more adept than others at successfully performing procedures and at avoiding some but not all complications (see Tables 2 and 3). Proper training, experience, and adherence to basic principles are important. However, there were no deaths, no kidneys lost, and no transfusions or operations required as a result of any complication from the pediatric percutaneous renal procedures; correction of any existing blood coagulation disorder is necessary prior to their performance to avoid potentially fatal hemorrhage.

Biopsy, Needle↗
PubMed1982

Yield of screening urography in young women with urinary tract infection.

In order to determine the diagnostic yield and therapeutic outcome of screening urography in young women with urinary tract infection, 1000 urographic examinations were reviewed. Of these 96.4% were normal; 1.4% revealed abnormalities that subsequently required therapy. Each treated abnormality was expensive to diagnose; protocols other than universal urography could have made most of these diagnoses. The incidence of treated abnormalities may be no greater in this group than in the general population. Universal screening urography in these patients cannot be definitely recommended.

Adolescent↗
PubMed1982

Renal cysts: curios and caveats.

Interesting, unusual, and confusing renal cysts from a group of 200 cysts punctured percutaneously during the past decade are presented. Some cases illustrate pressure phenomena in cysts adjacent to each other or causing calyceal obstruction. Also reported are cyst wall findings, unusual cyst configurations, infection in pre-existing cysts, examples of cysts simulating renal cell carcinoma, and renal cell carcinoma presenting as cysts. In unusual cases, percutaneous needle puncture remains the procedure of choice for establishing the diagnosis of benign simple cyst versus malignancy or infection, or for determining the relationship of a cyst with the collecting system or with other cysts. Cyst puncture may also result in iatrogenic changes.

Adenocarcinoma↗
PubMed1982

Ultrasonic inaccuracies in diagnosing renal obstruction.

Renal ultrasound is an excellent screening examination for suspected urinary tract obstruction. Its usefulness is based on the ability to detect hydronephrosis. However, it must be recognized that a significant number of conditions exist which can mimic or produce dilatation of the collecting system without urinary tract obstruction. Similarly, obstruction without hydronephrosis, although infrequent, exists. Situations causing either false positive or false negative renal sonograms are discussed. Renal sonography suggesting hydronephrosis should be followed with additional diagnostic studies to confirm or exclude obstruction. Similar persistence should be used when obstruction is strongly suggested clinically, and ultrasound fails to demonstrate hydronephrosis.

Adult↗
PubMed1982

Impressions on floor of female bladder: "the female prostate".

The "female prostate" denotes an impression on the base of the female bladder resembling the enlarged male prostate radiographically. Though the finding is widely recognized, confusion exists as to its significance. The differential diagnosis is moderately extensive, and includes retroverted uterus, anterior vaginal tumors, urethral and bladder floor tumors, benign and malignant bony pelvic lesions, urethral diverticulum, and postsurgical changes. Several cases are presented illustrating the previously mentioned causations. An impression on the floor of the female bladder should not be routinely dismissed as inconsequential without thorough evaluation.

Adult↗
PubMed1982

Role of abdominal computed tomography in evaluating left upper quadrant masses.

The etiology of abdominal masses in the left upper quadrant may be confusing because of the anatomic relationships of the organs involved. In three representative cases presented, computed tomography (CT) clearly defined masses as being nonurologic in origin, although conventional radiologic diagnostic techniques originally yielded results that suggested a renal or adrenal origin. In two other cases, masses thought to originate from the spleen or retroperitoneum were shown by CT to be renal tumors. In a sixth case, a large mass thought to be of renal origin but not evaluated by CT was found at surgery to be a pancreatic cyst. Abdominal CT is more sensitive than other imaging modalities in clarifying organ relationships and the origin of masses in the left upper quadrant.

Abdominal Neoplasms↗
PubMed1982

Pseudohydronephrosis on noncontrast computed tomography.

Noncontrast renal computed tomography (CT) has been advocated for the evaluation of the poorly functioning or nonvisualized kidney. However, some conditions can mimic hydronephrosis on such scans, leading to a false positive diagnosis of renal obstruction; two entities include peripelvic cysts and subcapsular hematoma. Illustrative cases are presented. Close attention to attenuation values and basic renal anatomic configurations will usually elucidate the true nature of equivocal findings. However, when hydronephrosis is still suspected on noncontrast renal CT, postcontrast images should be obtained or the finding further evaluated with other radiographic modalities.

Adult↗
PubMed1982

Renal subcapsular rim sign: new etiologies and pathogenesis.

Two prior reports have described a cortical rim sign associated with renal infarction from acute renal artery obstruction. This paper adds four additional cases of a thin outer (subcapsular) cortical nephrogram due to renal vein thrombosis (two cases), acute tubular necrosis (one case), and renal artery embolization (one case). An acute vascular compromise from differing etiologic mechanisms appears to be the common denominator of the rim nephrogram. The nephrogram probably represents an intact subcapsular renal cortex (2-4 mm thick) perfused by the perirenal capsular collateral circulation. To date, the rim nephrogram has been visible only on high dose nephrotomography. Its smooth inner margin is sufficiently distinct to differentiate it from the shell nephrogram of severe hydronephrosis.

Adult↗
PubMed1982

Peripelvic cysts: an impostor of sonographic hydronephrosis.

Static and real-time ultrasound examinations have proved clinically useful in the evaluation of renal obstruction. False-negative findings are rare. False-positive findings have been reported as being due to slightly dilated, nonobstructed urinary systems causing the ultrasonographic appearance of mild (grade I) hydronephrosis. The authors describe the ultrasonographic appearance of 16 false-positive cases that had suggested moderate (grade II) to severe (grade III) hydronephrosis in collecting systems subsequently shown to be completely unobstructed. This appearance was caused by peripelvic cysts. These cases emphasize the screening role of ultrasound and the need to employ additional diagnostic modalities to verify the presence of hydronephrosis and renal obstruction.

Cysts↗
PubMed1982

Cystosonography in the detection of bladder tumors: a prospective and retrospective study.

To determine the sensitivity of real-time abdominal ultrasound as a screening test to detect bladder tumors, a prospective study of 100 patients with painless hematuria was undertaken. Each patient was examined by excretory urography, bladder ultrasound, and cystoscopy. Results of the ultrasound and intravenous urography examinations were compared with cystoscopy results. Of 14 bladder lesions noted, ultrasound detected seven prospectively whereas intravenous urography detected 12. With awareness of the ultrasonographic appearance of bladder tumors, 12 lesions could be detected retrospectively. A fully distended bladder is necessary to avoid simulation of a neoplasm and false-positive ultrasound findings. Awareness of the cystosonographic appearance of bladder tumors may allow detection of asymptomatic tumors during routine pelvic ultrasound examinations.

Carcinoma, Transitional Cell↗
PubMed1981

Percutaneous catheterization of the kidney and perinephric space: trocar technique.

Percutaneous nephrostomy can be accomplished by using a trocar-cannula assembly without resorting to serial dilations of the tube tract or utilizing stiff catheters. After puncture the trocar is removed and a catheter inserted through the cannula; then the cannula is removed. A large number of these procedures have been performed and have been found to be simple and quite safe. The method is able to provide nephrostomy drainage in virtually any case of ureteral obstruction or leak, and can be used to drain perinephric fluid collections as well. Antegrade pyelography precedes trocar puncture; puncture is most easily guided by fluoroscopy. The technique is described in detail; indications, applications, complications, and contraindications are outlined.

Humans↗