Cardiopulmonary effects of administration of a combination solution of xylazine, guaifenesin, and ketamine or inhaled isoflurane in mechanically ventilated calves.
OBJECTIVE
To compare the cardiopulmonary effects of administration of a solution of xylazine, guaifenesin, and ketamine (XGK) or inhaled isoflurane in mechanically ventilated calves undergoing surgery.


METHODS
13 male calves 2 to 26 days of age. Procedures-In calves in the XGK group, anesthesia was induced (0.5 mL/kg) and maintained (2.5 mL/kg/h) with a combination solution of xylazine (0.1 mg/mL), guaifenesin (50 mg/mL), and ketamine (1.0 mg/mL). For calves in the isoflurane group, anesthesia was induced and maintained with isoflurane in oxygen. The rates of XGK infusion and isoflurane administration were adjusted to achieve suitable anesthetic depth. All calves received 100% oxygen and were mechanically ventilated to maintain end-tidal carbon dioxide concentrations from 35 to 40 mm Hg and underwent laparoscopic bladder surgery through an abdominal approach. Cardiopulmonary variables were measured before induction and at intervals up to 90 minutes after anesthetic induction.


RESULTS
The quality of induction was excellent in all calves. The XGK requirements were 0.57 +/- 0.18 mL/kg and 2.70 +/- 0.40 mL/kg/h to induce and maintain anesthesia, respectively. Heart rate was significantly lower than baseline throughout the anesthetic period in the XGK group. Systolic arterial blood pressure was significantly higher in the XGK group, compared with the isoflurane group, from 5 to 90 minutes. Cardiac index was lower than baseline in both groups. Differences between groups in cardiac index and arterial blood gas values were not significant.


CONCLUSIONS
Administration of XGK resulted in excellent anesthetic induction and maintenance with cardiopulmonary alterations similar to those associated with isoflurane in mechanically ventilated calves.
Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada.
Carolyn L
CL
Kerr
Claire
C
Windeyer
Ludovic P
LP
Bouré
Kuldip K
KK
Mirakhur
Wayne
W
McDonell
D000769:Anesthesia, Inhalation / Q000662:veterinary; D000771:Anesthesia, Intravenous / Q000662:veterinary; D000777:Anesthetics / Q000008:administration & dosage / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002417:Cattle / Q000502:physiology*; D004359:Drug Therapy, Combination; D006140:Guaifenesin / Q000008:administration & dosage* / Q000494:pharmacology; D006339:Heart Rate / Q000187:drug effects; D007530:Isoflurane / Q000008:administration & dosage* / Q000494:pharmacology; D007649:Ketamine / Q000008:administration & dosage* / Q000494:pharmacology; D008297:Male; D012121:Respiration, Artificial / Q000662:veterinary*; D013997:Time Factors; D014991:Xylazine / Q000008:administration & dosage* / Q000494:pharmacology
D000777:Anesthetics; D014991:Xylazine; D006140:Guaifenesin; D007649:Ketamine; D007530:Isoflurane