Fluid balance, glomerular filtration rate, and urine output in dogs anesthetized for an orthopedic surgical procedure.
OBJECTIVE
To determine fluid retention, glomerular filtration rate, and urine output in dogs anesthetized for a surgical orthopedic procedure.


METHODS
23 dogs treated with a tibial plateau leveling osteotomy.


METHODS
12 dogs were used as a control group. Cardiac output was measured in 5 dogs, and 6 dogs received carprofen for at least 14 days. Dogs received oxymorphone, atropine, propofol, and isoflurane for anesthesia (duration, 4 hours). Urine and blood samples were obtained for analysis every 30 minutes. Lactated Ringer's solution was administered at 10 mL/kg/h. Urine output was measured and glomerular filtration rate was estimated. Fluid retention was measured by use of body weight, fluid balance, and bioimpedance spectroscopy.


RESULTS
No difference was found among control, cardiac output, or carprofen groups, so data were combined. Median urine output and glomerular filtration rate were 0.46 mL/kg/h and 1.84 mL/kg/min. Dogs retained a large amount of fluids during anesthesia, as indicated by increased body weight, positive fluid balance, increased total body water volume, and increased extracellular fluid volume. The PCV, total protein concentration, and esophageal temperature decreased in a linear manner.


CONCLUSIONS
Dogs anesthetized for a tibial plateau leveling osteotomy retained a large amount of fluids, had low urinary output, and had decreased PCV, total protein concentration, and esophageal temperature. Evaluation of urine output alone in anesthetized dogs may not be an adequate indicator of fluid balance.
Boscan
Pedro
P
Department of Surgical & Radiological Sciences, School of Veterinary Medicine, University of California-Davis, Davis, CA 95616, USA. pboscan@colostate.edu
Pypendop
Bruno H
BH
Siao
Kristine T
KT
Francey
Thierry
T
Dowers
Kristy
K
Cowgill
Larry
L
Ilkiw
Jan E
JE
D000758:Anesthesia / Q000379:methods / Q000662:veterinary*; D000818:Animals; D016118:Anterior Cruciate Ligament / Q000601:surgery*; D001831:Body Temperature; D002302:Cardiac Output; D004231:Diuresis / Q000502:physiology*; D004283:Dog Diseases / Q000503:physiopathology / Q000601:surgery; D004285:Dogs / Q000502:physiology*; D005260:Female; D005919:Glomerular Filtration Rate / Q000502:physiology*; D007530:Isoflurane / Q000627:therapeutic use; D008297:Male; D016343:Monitoring, Intraoperative / Q000662:veterinary; D019637:Orthopedic Procedures / Q000662:veterinary*; D010111:Oxymorphone / Q000627:therapeutic use; D016119:Posterior Cruciate Ligament / Q000601:surgery*; D015742:Propofol / Q000627:therapeutic use; D012422:Rupture, Spontaneous / Q000601:surgery / Q000662:veterinary
D010111:Oxymorphone; D007530:Isoflurane; D015742:Propofol