Total intravenous anesthesia with propofol and S(+)-ketamine in rabbits.
OBJECTIVE
To evaluate total intravenous anesthesia with propofol alone or in combination with S(+)-ketamine in rabbits undergoing surgery.


METHODS
Prospective, randomized, blinded trial.


METHODS
Nine 6-month-old New Zealand white rabbits, weighing 2.5-3 kg.


METHODS
Animals received acepromazine (0.1 mg kg(-1)) and buprenorphine (20 microg kg(-1)) IM, and anesthesia was induced with propofol (2 mg kg(-1)) and S(+)-ketamine (1 mg kg(-1)) IV. Rabbits received two of three treatments: propofol (0.8 mg kg(-1) minute(-1)) (control treatment, P), propofol (0.8 mg kg(-1) minute(-1)) + S(+)-ketamine (100 microg kg(-1) minute(-1)) (PK100) or propofol (0.8 mg kg(-1) minute(-1)) + S(+)-ketamine (200 microg kg(-1) minute(-1)) (PK200). All animals received 100% O(2) during anesthesia. Heart rate, mean arterial pressure, hemoglobin oxygen saturation and respiratory rate were measured every 5 minutes for 60 minutes. Blood-gas parameters were measured at zero time and 60 minutes. Additional propofol injections, if necessary, and recovery time were recorded.


RESULTS
An increase in heart rate was observed in P and PK200 up to 10 minutes after induction of anesthesia. Blood pressure decreased from baseline values during the first 10 minutes in P and PK200, and during the first 15 minutes and between 45 and 55 minutes in PK100. A reduction in respiratory rate was observed after 5 minutes in all treatments. Respiratory acidosis was observed in all treatments. Six (2.8) [median (interquartile range)] further propofol injections were necessary in P, which differed statistically from PK100 [1 (0.2)] and PK200 [2 (0.6)]. Recovery time was shorter in P compared with PK100 and PK200, being [7.5 minutes (4.11)], [17.5 minutes (10.30)], and [12 minutes (10.30)], respectively.


CONCLUSIONS
S(+)-ketamine potentiates propofol-induced anesthesia in rabbits, providing better maintenance of heart rate. All of these techniques were accompanied by clinically significant respiratory depression.
Cruz
Fernando Sf
FS
Pharmacology Graduate Program, Universidade Federal de Santa Maria, Santa Maria, Rio Grande do Sul, Brazil.
Carregaro
Adriano B
AB
Raiser
Alceu G
AG
Zimmerman
Marina
M
Lukarsewski
Rafael
R
Steffen
Renata Pb
RP
D000700:Analgesics; D000771:Anesthesia, Intravenous / Q000379:methods / Q000662:veterinary*; D018686:Anesthetics, Intravenous; D000818:Animals; D001784:Blood Gas Analysis / Q000662:veterinary; D001794:Blood Pressure / Q000187:drug effects; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D007649:Ketamine; D008297:Male; D015742:Propofol; D011817:Rabbits; D056152:Respiratory Rate / Q000187:drug effects
D000700:Analgesics; D018686:Anesthetics, Intravenous; D007649:Ketamine; D015742:Propofol