TY - JOUR
T1 - The influence of butorphanol dose on characteristics of xylazine-butorphanol-propofol anesthesia in horses at altitude
AU - Garcia Lascurain, Alma A.
AU - Sumano Lopez, Hector
AU - Steffey, Eugene
AU - Santillán Doherty, Patricio
AU - Hernandez, Enrique Núñez
PY - 2006/1/1
Y1 - 2006/1/1
N2 - Objective: To characterize behavioral and physiological responses to short-term, unsupplemented intravenous (IV) anesthesia in healthy horses at high altitude (2240 m), and to test the hypothesis that the dose of butorphanol modifies the response of the horse to propofol anesthesia following xylazine pre-medication. Study design: Randomized prospective butorphanol dose cross-over experimental design. Animals: Eight healthy horses, 13 ± 6 (mean ± SD) years of age, and weighing 523 ± 26 kg. Methods: Each horse was anesthetized three times with at least 3 weeks between each anesthesia. After collecting pre-drug data, xylazine (0.5 mg kg-1) was given IV. Five minutes later butorphanol was given IV according to a randomized order of three doses: 0.025, 0.05 and 0.075 mg kg-1. Five minutes later, anesthesia was induced with propofol, 2 mg kg-1 IV. Data on heart rate (HR) and respiratory rate (fr), mean arterial blood pressure, PaO2, PaCO2 and pHa were collected before, during and for 60 minutes following anesthesia, and quality of induction and recovery was scored. Results: The pre-drug values for the three butorphanol groups did not differ. The combined pre-drug values from the 24 studies were HR, 33 ± 7 beats minute-1; fr, 11 ± 3 breaths minute-1; PaO2, 67 ± 7 mmHg; PaCO2, 36 ± 4 mmHg; and pHa, 7.42 ± 0.04. Five minutes after anesthetic induction PaO 2 decreased and PaCO2 increased 14.5 ± 7.7 and 5.1 ± 4.9 mmHg, respectively, but returned to pre-drug levels within 15 minutes of anesthetic recovery. There were no significant butorphanol dose-related differences in physiological results, anesthetic induction and recovery quality scores or recovery time. Conclusions and clinical relevance: Dose of butorphanol did not markedly influence study results. Notably, low PaO2 values related to geographic location of study and general anesthesia indicates a narrow margin of error for hypoxemia-related complications in anesthetized horses breathing unsupplemented air at high altitude.
AB - Objective: To characterize behavioral and physiological responses to short-term, unsupplemented intravenous (IV) anesthesia in healthy horses at high altitude (2240 m), and to test the hypothesis that the dose of butorphanol modifies the response of the horse to propofol anesthesia following xylazine pre-medication. Study design: Randomized prospective butorphanol dose cross-over experimental design. Animals: Eight healthy horses, 13 ± 6 (mean ± SD) years of age, and weighing 523 ± 26 kg. Methods: Each horse was anesthetized three times with at least 3 weeks between each anesthesia. After collecting pre-drug data, xylazine (0.5 mg kg-1) was given IV. Five minutes later butorphanol was given IV according to a randomized order of three doses: 0.025, 0.05 and 0.075 mg kg-1. Five minutes later, anesthesia was induced with propofol, 2 mg kg-1 IV. Data on heart rate (HR) and respiratory rate (fr), mean arterial blood pressure, PaO2, PaCO2 and pHa were collected before, during and for 60 minutes following anesthesia, and quality of induction and recovery was scored. Results: The pre-drug values for the three butorphanol groups did not differ. The combined pre-drug values from the 24 studies were HR, 33 ± 7 beats minute-1; fr, 11 ± 3 breaths minute-1; PaO2, 67 ± 7 mmHg; PaCO2, 36 ± 4 mmHg; and pHa, 7.42 ± 0.04. Five minutes after anesthetic induction PaO 2 decreased and PaCO2 increased 14.5 ± 7.7 and 5.1 ± 4.9 mmHg, respectively, but returned to pre-drug levels within 15 minutes of anesthetic recovery. There were no significant butorphanol dose-related differences in physiological results, anesthetic induction and recovery quality scores or recovery time. Conclusions and clinical relevance: Dose of butorphanol did not markedly influence study results. Notably, low PaO2 values related to geographic location of study and general anesthesia indicates a narrow margin of error for hypoxemia-related complications in anesthetized horses breathing unsupplemented air at high altitude.
KW - Altitude
KW - Anesthesia
KW - Butorphanol
KW - Horse
KW - Propofol
KW - Xylazine
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U2 - 10.1111/j.1467-2995.2005.00237.x
DO - 10.1111/j.1467-2995.2005.00237.x
M3 - Article
C2 - 16476000
AN - SCOPUS:33644903205
VL - 33
SP - 104
EP - 110
JO - Veterinary Anaesthesia and Analgesia
JF - Veterinary Anaesthesia and Analgesia
SN - 1467-2987
IS - 2
ER -