Evaluation of a lithium dilution cardiac output technique as a method for measurement of cardiac output in anesthetized cats.
OBJECTIVE
To evaluate the use of a lithium dilution cardiac output (LiDCO) technique for measurement of CO and determine the agreement between LiDCO and thermodilution CO (TDCO) values in anesthetized cats.


METHODS
6 mature cats.


METHODS
Cardiac output in isoflurane-anesthetized cats was measured via each technique. To induce different rates of CO in each cat, anesthesia was maintained at > 1.5X end-tidal minimum alveolar concentration (MAC) of isoflurane and at 1.3X end-tidal isoflurane MAC with or without administration of dobutamine (1 to 3 microg/kg/min, i.v.). At least 2 comparisons between LiDCO and TDCO values were made at each CO rate. The TDCO indicator was 1.5 mL of 5% dextrose at room temperature; with the LiDCO technique, each cat received 0.005 mmol of lithium/kg (concentration, 0.015 mmol/mL). Serum lithium concentrations were measured prior to the first and following the last CO determination.


RESULTS
35 of 47 recorded comparisons were analyzed; via linear regression analysis (LiDCO vs TDCO values), the coefficient of determination was 0.91. The mean bias (TDCO-LiDCO) was -4 mL/kg/min (limits of agreement, -35.8 to + 27.2 mL/kg/min). The concordance coefficient was 0.94. After the last CO determination, serum lithium concentration was < 0.1 mmol/L in each cat.


CONCLUSIONS
Results indicated a strong relationship and good agreement between LiDCO and TDCO values; the LiDCO method appears to be a practical, relatively noninvasive method for measurement of CO in anesthetized cats.
Beaulieu
Kim E
KE
Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, ON N1G 2W1, Canada.
Kerr
Carolyn L
CL
McDonell
Wayne N
WN
D000758:Anesthesia / Q000662:veterinary; D000818:Animals; D002302:Cardiac Output / Q000502:physiology*; D002415:Cats / Q000502:physiology*; D004280:Dobutamine / Q000008:administration & dosage; D006334:Heart Function Tests / Q000379:methods / Q000662:veterinary*; D007201:Indicator Dilution Techniques / Q000662:veterinary*; D007530:Isoflurane / Q000008:administration & dosage; D016014:Linear Models; D018021:Lithium Chloride / Q000008:administration & dosage* / Q000097:blood; D013815:Thermodilution / Q000662:veterinary*
D004280:Dobutamine; D007530:Isoflurane; D018021:Lithium Chloride