Veterinary Medicine - July 2008 - (Page 384)

Hematuria PEER-REVIEWED Figure 6—Coagulopathy: Diagnostic procedures and potential outcomes If you suspect a coagulopathy, perform a coagulation proﬁle consisting of a prothrombin time, partial thromboplastin time, platelet estimate or count, and ﬁbrin degradation products measurement. procedures. Advanced imaging such as computed tomography or magnetic resonance imaging may be indicated when the results of traditional imaging methods are inconclusive. Cystourethroscopy Cystourethroscopy is becoming more popular for diagnosing hematuria-related disorders. Although equipment availability, the patient’s size, and the need for sedation or anesthesia can be limiting factors, lower urinary tract endoscopy allows localization of the source of hematuria, direct visualization of lesions, the opportunity to biopsy lesions with less chance of seeding neoplastic cells, and therapeutic options such as lithotripsy. Endoscopy provides an excellent method of establishing one or both kidneys as the source of hematuria by enabling visualization of blood-tinged urine owing from the ureteral openings into the bladder (Figure 8). Rigid endoscopy allows visualization of the bladder and urethra in patients weighing > 6.6 lb (3 kg) and < 44 lb (20 kg), including female dogs and cats and male cats that have undergone perineal urethrostomy. Flexible endoscopes allow examination of the lower urinary tract in most dogs and cats regardless of size or sex.6,7 If the results are abnormal, pursue diagnostic procedures appropriate for coagulopathies. Also, rule out concurrent urogenital disorders by using the unknown source algorithm (Figure 7). If the results are normal, go to the unknown source algorithm (Figure 7). to assess kidney function and structure as well as other organs that might be affected by these parasites. Blood pressure measurement Routine screening for systemic hypertension by performing blood pressure measurements is advisable if you suspect upper urinary tract disorders or in cases in which localizing the source of hematuria cannot be reasonably accomplished through historical and physical examination ndings. Coagulation proﬁle Coagulopathy-related hematuria is more likely to be caused by a primary hemostatic defect involving platelets rather than secondary hemostatic clotting factor defects. Consequently, consider evaluating von Willebrand’s factor activity and platelet function if the initial coagulation pro le (Figure 6) is unremarkable or inconclusive. When a coagulopathy is identi ed, it is advisable to nd the location of bleeding from the urogenital tract and to rule out any concurrent urogenital disease that might be exacerbating the patient’s bleeding tendencies. Diagnostic imaging Diagnostic imaging plays an important role in tracking down the site and cause of hematuria. Abdominal radiography and ultrasonography are usually indicated in cases of hematuria. Imaging is indicated early in the diagnostic process in patients with a recent history of trauma or physical examination ndings such as abdominal masses or abnormalities associated with a kidney, the bladder, the uterus, or the prostate. Use imaging to thoroughly examine the urogenital tract for irregularities, including masses, abnormalities in the shape and size of structures, and uroliths or bladder sediment. Although blind aspirates and biopsies of suspicious areas of the urogenital tract can be performed, ultrasonography provides a potentially safer, more accurate method of obtaining samples for cytologic or histologic examination or culture. In patients with lower urinary tract signs, a retrograde contrast study may be indicated to identify urethral abnormalities, further evaluate bladder masses, and recognize radiolucent calculi. Patients with evidence of upper urinary tract disease or hematuria that has yet to be localized may be candidates for an excretory urogram to identify functional or subtler structural abnormalities. To avoid introducing bacteria or other contaminants, collect samples from the urogenital tract for bacterial culture or other analysis before performing contrast Abdominal exploratory If less-invasive diagnostic tests have not revealed the source of the hematuria, abdominal exploratory surgery may be indicated. An exploratory not only allows gross examination and biopsy of the urogenital system, the ureters can be catheterized individually to determine whether blood is present in the urine produced by one or both kidneys. Before performing biopsies or exploratory surgery in patients with hematuria, perform a coagulation pro le to establish that excessive bleeding is unlikely to occur. An activated clotting time could be used as a screening test, but it is not as sensitive of an indicator of bleeding potential as are the prothrombin time, partial thromboplastin time, and platelet count included in a standard coagulation pro le. 384 July 2008 VETERINARY MEDICINE

Table of Contents Feed for the Digital Edition of Veterinary Medicine - July 2008

Veterinary Medicine - July 2008 Contents Leading Off Practical Matters Idea Exchange Clarification Dental Corner The Diagnostic Approach to Hematuria Guidelines for Evaluating Hypercalcemic Cats CE Form Advertiser Index Marketplace/Classifieds Mind Over Miller

Veterinary Medicine - July 2008

For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.