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C Fonseca

Publications and source records attributed to C Fonseca.

27 records · Page 2Linked to original sources

Differential diagnosis of jaundice by 99mTc-IDA hepatobiliary imaging.

The utility of 99mTc-IDA imaging in the differential diagnosis of jaundice was assessed. Although overall accuracy was 84%, this method is still inferior to the reported efficiency of ultrasonography and CT in making the correct diagnosis. Radionuclide imaging is a good alternative when these other modalities are not available and it functions well in an adjuvant capacity. The diagnostic limitations of 99mTc-dimethyl IDA imaging in cases of moderate to severe jaundice are largely overcome by the use of 99mTc-p-butyl IDA.

Aged

99mTc-IDA imaging in the differential diagnosis of acute cholecystitis and acute pancreatitis.

99mTc-IDA (99mTc-dimethyl-acetanilide-iminodiacetic acid) hepato-biliary imaging was evaluated for its efficacy in distinguishing acute cholecystitis from acute pancreatitis. In a retrospective review, gallbladders were demonstrated by 99mTc-IDA in 13 of 15 patients (87%) with acute pancreatitis. This is significantly higher than reports on the frequency of gallbladder filling with oral and intravenous cholangiography in the presence of acute cholecystitis.

Acetanilides

99mTc-IDA hepatobiliary imaging following upper abdominal surgery.

Bile flow patterns were studied with serial 99mTc-IDA images in 19 patients with cholecysto- and choledochointestinal anastomoses, gastroenteric bypasses, and combinations of the two. Complications such as anastomotic, afferent, and efferent loop obstruction and bile leakage were readily detected even in the presence of jaundice. This noninvasive technique warrants further investigation to determine its indications and weaknesses.

Abdomen

Assessment of the utility of gallbladder imaging with 99mTc-IDA.

Cholescintigraphy was performed in 113 patients of whom 38 had normal gallbladders, 37 had acute cholecystitis and 38 had chronic cholecystitis. The radiopharmaceuticals used in the study were either 99mTc-dimethyl acetanilide iminodiacetic acid or 99mTc-paraisopropyl acetanilide iminodiacetic acid, both of which performed equally well. All patients with non-visualized gallbladders had cholecystitis, but visualization did not exclude disease. The rapidity of obtaining the results (within one hour), the complete absence of untoward reactions to the radiopharmaceuticals, the much lower frequency of subtle or indeterminate results, the ability to render useful information in the presence of moderate jaundice and the lack of interference from overlying intestinal contents establishes these radionuclide agents as superior to both radiographic oral and intravenous cholangiography in the investigation of the acute abdomen.

Acetanilides

Antiphospholipid syndrome in patients with cyanotic congenital heart disease.

Patients with cyanotic congenital heart disease exhibit an increased incidence of thrombotic episodes and are frequently thrombocytopenic. We studied the sera of 15 patients with this type of heart malformation, searching for anticardiolipin antibodies. 3/15 had positive results. The three of them were adult females; two had thrombotic episodes and a false positive VDRL. Thus, cyanotic congenital heart disease may be another disease entity associated with the antiphospholipid syndrome.

Adult

[Individualized monitoring of the therapy with gentamycin using pharmacokinetic methods. Which method to choose?].

Gentamicin has an excellent cost/efficacy ratio for gram negative infections treatment. Its use is often limited in clinical practice by its narrow safety margins and a high incidence of toxicity. Gentamicin related nephrotoxicity is a major adverse effect, mostly in patients with other concomitant potential risk factors. As many other Authors we have found in our Internal Medicine Service during 1992 a gentamicin related nephrotoxicity incidence of 22.5%. Various empiric methods and nomograms have shown a significant incidence of error in predicting individualized gentamicin dosage regimens. Pharmacokinetics methods have demonstrated much better results regarding efficacy and toxicity. The aim of this prospective study carried out during 1993-1994 was to individualize by pharmacokinetics methods dosage regimens of gentamicin in patients with one or more concomitant risk factors of nephrotoxicity. The purpose of pharmacokinetics dosage regimens has been to achieve trough serum concentrations of gentamicin in therapeutics range-0.5 to 2 micrograms/ml-on the first 24 to 48 hours of treatment, and the maintenance in this range during all the treatment, avoiding both toxic and under therapeutic levels. The incidence of gentamicin related nephrotoxicity has been evaluated in this population. Twenty patients were studied: 18 males and 2 females aged 59.6 years (19 to 85). All had one or more potential risk factors for nephrotoxicity-65 years or more: 13, previous renal failure: 6, other nephrotoxic drugs: 10, diuretics: 4, dehydration: 5, congestive heart failure: 5, diabetes: 3, hypertension: 3. For the first 10 patients gentamicin dosage regimens have been determined by Sawchuk-Zaske pharmacokinetics method and for the subsequent 10 patients by Bayesian method. The two subpopulations had no significant differences regarding mean age, sex and potential risk factors for nephrotoxicity. Results of Sawchuk-Zaske method: 53 trough gentamicin serum concentration were obtained; 86.8% were within the therapeutic range, 7.5% were toxic and 5.7% were under therapeutic. Results of Bayesian method: 44 determinations of gentamicin through concentrations were obtained; 86.3% within therapeutic range, 2.4% were toxic and 11.3% were under therapeutic. A great variability in pharmacokinetic patient's profile has been found and explains the great variability of individualized dosage regimens of gentamicin (30 to 320 mg/day). No patients had gentamicin related nephrotoxicity. Both pharmacokinetics methods lead to a efficient and save employment of gentamicin in patients with previous renal failure and other potential risk factors for nephrotoxicity.

Adult