Effects of anesthetic drugs on canine splenic volume determined via computed tomography

Abstract

Administration of acepromazine, thiopental, and propofol resulted in splenomegaly. Dexmedetomidine did not alter splenic volume. Hydromorphone slightly decreased splenic volume. Propofol should not be used when splenomegaly is not desirable, whereas hydromorphone and dexmedetomidine may be used when it is best to avoid splenic enlargement.

Hemodynamic influence of acepromazine or dexmedetomidine premedication in isoflurane-anesthetized dogs

“…Acepromazine administered at 0.044 mg/kg (0.02 mg/lb), IM, decreased PCV by 22%. 14 More recently, Baldo et al 15 reported a reduction of PCV in dogs after acepromazine (0.03 mg/kg [0.014 mg/lb]) and propofol (5.0 mg/kg) administration IV. Steffey et al 28 reported a 15% to 30% reduction, and Merin et al 29 reported a 13% reduction of PCV in dogs that received halothane.…”

“…Similarly, isoflurane anesthesia has been shown to cause a dose-dependent decrease in CO and SV followed by systemic hypotension and tachycardia. 12,13 Combined administration of acepromazine, propofol, and isoflurane in dogs decreases PCV 14,15 and therefore oxygen-carrying capacity owing to sequestration of erythrocytes in the spleen as well as in the liver, skeletal muscle, and skin. 14 The effect of dexmedetomidine on PCV and oxygen-carrying capacity in propofol-and isoflurane-anesthetized dogs is unclear, and to our knowledge, research comparing the effects of acepromazine and dexmedetomidine premedication on oxygen-carrying capacity in isoflurane-anesthetized dogs has not been performed.…”

Anesthesia for Endoscopy

“…27 In a more recent study, acepromazine, propofol, and thiopental treatments caused the greatest increase in splenic volume, whereas hydromorphone and dexmedetomidine used in combination as premedicants did not cause a significant change in splenic volume. 28 Taken together, these studies suggest that, for premedication, combinations of acepromazine plus butorphanol, or hydromorphone plus dexmedetomidine followed by induction with propofol are more likely to have little effect on splenic volume. Other concerns may favor some drugs more than others.…”

“…Selecting drugs that cause minimal or no splenic enlargement is important and several studies have addressed this issue. [26][27][28] In one study, significant splenic enlargement was seen after administering acepromazine or thiopental, but not after administering propofol. 26 Another study found that a combination of acepromazine and butorphanol followed by induction with propofol had minimal effect on splenic volume, whereas medetomidine and butorphanol as premedicants followed by ketamine and diazepam for induction were associated with a significant increase in splenic volume.…”

“…Thiopental for induction is not appropriate, because it causes significant splenic engorgement. 26,28 Alpha-2 agonists, such as dexmedetomidine, can be used for endoscopic anesthesia and might help attenuate cardiovascular effects associated with pneumoperitoneum. 29 However, doses typically used for premedication induce significant hemodynamic changes that may not be desirable in patients with cardiac diseases.…”