False-Positive Result of a Captopril-Enhanced Radionuclide Renogram in a Child Secondary to Dehydration

• Published in: Clinical nuclear medicine 1999-01, Vol.24 (1), p.6-8
• Main Authors: LEVEY, CHRISTOPHER S, SCHRAML, FRANK V, ABREU, SUE H, SILVERMAN, EUGENE D
• Format: Article
• Language: English
• Subjects: Anesthesia, General; Angiotensin-Converting Enzyme Inhibitors; Antihypertensive Agents; Biological and medical sciences; Blood Pressure - physiology; Captopril; Child, Preschool; Dehydration - complications; Dehydration - physiopathology; Diagnosis, Differential; Enalapril; False Positive Reactions; Fluid Therapy; Glomerular Filtration Rate - physiology; Humans; Hypertension, Renovascular - diagnostic imaging; Hypnotics and Sedatives - administration & dosage; Hypotension - etiology; Investigative techniques, diagnostic techniques (general aspects); Kidney - diagnostic imaging; Male; Medical sciences; Radionuclide Imaging; Radionuclide investigations; Radiopharmaceuticals; Technetium Tc 99m Mertiatide; Urinary system
• ISSN: 0363-9762; 1536-0229
• DOI: 10.1097/00003072-199901000-00002

PURPOSE:Renovascular hypertension is an unusual cause of elevated mean arterial pressure in children. When suspected, angiotensin-converting enzyme inhibitor-enhanced renal scintigraphy is usually one of the initial studies done to evaluate patients. The accuracy of this test depends not only on patient selection but also on technical factors involved in performing the study. We report a case of a false-positive angiotensin-converting enzyme inhibitor-enhanced radionuclide renogram in a 5-year-old boy with hypertension. METHODS:Angiotensin-converting enzyme inhibitor-enhanced renal scintigraphy was performed and the result was interpreted as positive for bilateral renovascular disease. A review of the anesthesia record from the study revealed that the patient was hypotensive. A repeated study with adequate hydration and blood pressure stability was then done. RESULTS:The result of the second examination was interpreted as normal, without evidence of abnormal renovascular physiology. CONCLUSIONS:The cause of the initial false-positive result was determined to be dehydration with secondary hypotension. Dehydration, with secondary hypotension, can cause a diminished glomerular filtration rate and mimic bilateral renovascular physiology on angiotensin-converting enzyme inhibitor-enhanced renal scans.