The effect of four anesthetic protocols on splenic size in dogs.
OBJECTIVE
To characterize the effects of four anesthetic protocols on the size of the spleen during surgery in dogs.


METHODS
Prospective experimental trial.


METHODS
Twenty-four beagle dogs, 1.1 +/- 0.3 years of age and weighing 10.9 +/- 2.7 kg.


METHODS
Dogs were allocated to receive one of four anesthetic protocols: 1 - pre-medication with acepromazine and butorphanol, induction with thiopental; 2 - pre-medication with acepromazine and butorphanol, induction with propofol; 3 - pre-medication with medetomidine and butorphanol, induction with propofol; and 4 - pre-medication with medetomidine and butorphanol, induction with ketamine and diazepam. Anesthesia was then maintained with halothane. At laparotomy, the spleen length, width, and height were measured, these were measured again just prior to closure of the abdomen. Splenic area and volume were calculated. Hematocrit and total serum protein (TSP) were measured before and after induction and during laparotomy.


RESULTS
Splenic volume was greatest after protocol 4 (161.2 +/- 40.2 cm(3); p < 0.05) and was least after protocol 2. The differences in volume were because of differences in length, width, and height between groups. There was no significant change in area, length, or width over the study period. Hematocrit decreased significantly in all dogs but at different times. The decrease occurred after pre-medication if acepromazine was administered, at induction following protocol 3 and during surgery following protocol 4.


CONCLUSIONS
If splenic volume is to be minimized during surgery, then acepromazine and propofol should be used in the anesthetic protocol. The administration of medetomidine, diazepam, and ketamine will produce a greater splenic volume. Lack of correlation between hematocrit and spleen size following the anesthetic protocols studied suggests sequestration of red blood cells in nonsplenic sites.
Wilson
Deborah V
DV
Department of Large Animal Clinical Sciences, Michigan State University, East Lansing, MI 48824, USA. wilsondv@cvm.msu.edu
Evans
A Thomas
AT
Carpenter
Rachael A
RA
Mullineaux
David R
DR
D000075:Acepromazine / Q000008:administration & dosage / Q000494:pharmacology; D000768:Anesthesia, General / Q000662:veterinary*; D018686:Anesthetics, Intravenous / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D001798:Blood Proteins / Q000187:drug effects; D002077:Butorphanol / Q000008:administration & dosage / Q000494:pharmacology; D003975:Diazepam / Q000008:administration & dosage / Q000494:pharmacology; D004285:Dogs / Q000502:physiology*; D004338:Drug Combinations; D006400:Hematocrit / Q000662:veterinary; D007649:Ketamine / Q000008:administration & dosage / Q000494:pharmacology; D020926:Medetomidine / Q000008:administration & dosage / Q000494:pharmacology; D011229:Preanesthetic Medication / Q000662:veterinary; D015742:Propofol / Q000008:administration & dosage / Q000494:pharmacology; D011446:Prospective Studies; D013154:Spleen / Q000187:drug effects*; D013874:Thiopental / Q000008:administration & dosage / Q000494:pharmacology
D018686:Anesthetics, Intravenous; D001798:Blood Proteins; D004338:Drug Combinations; D000075:Acepromazine; D007649:Ketamine; D013874:Thiopental; D020926:Medetomidine; D003975:Diazepam; D002077:Butorphanol; D015742:Propofol