Today's Veterinary Practice

JUL-AUG 2011

Today's Veterinary Practice provides comprehensive information to keep every small animal practitioner up to date on companion animal medicine and surgery as well as practice building and management.

Issue link: http://todaysveterinarypractice.epubxp.com/i/38074

Contents of this Issue

Navigation

Page 76 of 83

JOURNAL CLUB | UROLOGY Retrospective Study to Characterize Postobstructive Diuresis in Cats with Urethral Obstruction Francis BJ, Wells RJ, Rao S, Hackett TB. Journal of Feline Medicine and Surgery 2010; 12(8):606-608. This study reviewed records from 32 male cats admitted to the Colorado State University Veterinary Medical Teaching Hospital for urethral obstruction. An indwelling urethral catheter connected to a closed sterile collection system was maintained in all cats. The volume of urine collected was measured every 6 hours and diuresis was defined as urine production > 2 mL/kg/H. Postobstructive diuresis developed during the first 6 hours of urine collection in 46% of cats, and continued to increase through the first 30 hours. The likelihood of diuresis was greatest during the 18- to 24-hour time period, with 87% to 95% of cats exhibiting increased urine production. The occurrence of postobstructive diuresis was more likely in cats with venous pH < 7.35 at the time of admission. This study suggested that urine production should be monitored following resolution of urethral obstruction because many cats will develop postobstructive diuresis. By measuring urine production, replacement fluid requirements can be adjusted to meet the actual needs of the individual patient. Key Considerations r *O UIJT TUVEZ EJVSFTJT XBT EFGJOFE BT VSJOF production > 2 mL/kg/H. r %JVSFTJT XBT NPTU MJLFMZ UP IPVST postobstruction, with 87% to 95% of cats exhibiting increased urine production. r 1PTUPCTUSVDUJWF EJVSFTJT XBT NPSF MJLFMZ XIFO venous pH was < 7.35 at time of admission. r $BUT TIPVME CF NPOJUPSFE GPS QPTUPCTUSVDUJWF diuresis in order to meet the patient’s actual replacement fluid requirements. —Gregory Grauer, DVM, MS, Diplomate ACVIM (Small Animal Internal Medicine), Kansas State University HEMATOLOGY Influence of Transfusion Technique on Survival of Autologous Red Blood Cells in the Dog McDevitt RI, Ruaux CG, Baltzer WI. Journal of Veterinary Emergency and Critical Care 2011; Epub ahead of print. This study evaluated the effects of 3 different transfusion techniques on survival of autolo- gous canine red blood cells (RBCs). The data suggested that RBCs delivered via volumetric peristaltic fluid pumps (through a 170–260 mcm built-in filter) and syringe pumps (through an 18 mcm microaggregate hemonate filter) were less likely to survive and be detected 24 hours following transfusion than those delivered by gravity flow. That being said, the circulating half-life of cells (assessed to 49 days) surviving 24 hours after delivery by volumetric pump was not significantly different compared to those delivered by gravity flow. The exact reason for these differences is not known since the investigators did not detect an effect of transfusion technique on in vitro RBC integrity or osmotic fragility. It was hypothesized that shearing stresses, which resulted from blood being forced through the microaggregate filter, may have resulted in damaged RBCs that were moved by the reticu- loendothelial system after transfusion. Similarly, the pumping mechanism used by the volumetric pump may have caused minor damage to some RBCs, which were then cleared from circulation following transfusion. It did appear that cells that survived 24 hours had a normal Key Considerations r 5IJT TUVEZ FWBMVBUFE UIF FGGFDU PG EJGGFSFOU transfusion techniques—volumetric peristaltic fluid pumps, syringe pumps, and gravity flow— on autologous canine RBCs. r 3#$T EFMJWFSFE CZ HSBWJUZ GMPX XFSF NPTU MJLFMZ to be detected 24 hours following transfusion. r 3FHBSEMFTT PG BENJOJTUSBUJPO UFDIOJRVF DFMMT that were detected in circulation 24 hours after delivery had a normal lifespan. r " QPUFOUJBM SFBTPO GPS MBDL PG DFMM TVSWJWBM XBT damage to cells during the transfusion process. lifespan. The main limitations of this study were (1) the relatively small sample size (9 dogs) and (2) the substantial processing of RBCs prior to transfusion to allow detection (which may have reduced lifespan). The authors concluded that while their find- ings were compelling, they should be very carefully considered before changes in transfusion practice are made. —Claire Sharp, BSc, BVMS (Hons), CMAVA, MS, Diplomate ACVECC, Tufts University July/August 2011 Today’s Veterinary Practice 75 Commentaries on Veterinary & Medical Literature

Articles in this issue

Archives of this issue

view archives of Today's Veterinary Practice - JUL-AUG 2011