title: Prolonged (12 hours) intravenous anesthesia in the rat.
abstract: A method is described for prolonging anesthesia in the rat for periods of up to 12 h, with subsequent recovery. Ketamine and xylazine in a ratio of 30 to 1 were infused intravenously by use of an adjustable syringe pump at rates of 40 to 50 microliters/min (1,000 to 1,250 micrograms/kg of body weight/min for ketamine and 32 to 40 micrograms/ kg/min for xylazine), and the rate of infusion was adjusted to maintain a stable depth of anesthesia. Primary assessment of the depth of anesthesia was provided by observation of the respiratory rate, which was maintained between 80 and 100 breaths/min. Rectal temperature was maintained between 35 and 36 degrees C. Blood pressure, pulse, and blood pH and bicarbonate concentration were stable during the 12-h period. The PCO2 increased slightly to 53 mm Hg; PO2 decreased gradually to 59 mm Hg at the last measurement. Plasma glucose concentration decreased progressively; supplemental glucose was given to maintain plasma concentration > 5 mM. After anesthetic administration was discontinued, the animals recovered promptly.
authors.affiliation: Madrona Research Institute, Lopez, Washington 98261, USA.
authors.forename: D P
authors.initials: DP
authors.lastname: Simpson
mesh_terms: D000762:Anesthesia Recovery Period; D000771:Anesthesia, Intravenous / Q000379:methods*; D000778:Anesthetics, Dissociative / Q000008:administration & dosage*; D000818:Animals; D001784:Blood Gas Analysis; D001786:Blood Glucose / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D007649:Ketamine / Q000008:administration & dosage*; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D012119:Respiration / Q000187:drug effects; D014554:Urination / Q000187:drug effects; D014991:Xylazine / Q000008:administration & dosage*
chemical_list: D000778:Anesthetics, Dissociative; D001786:Blood Glucose; D014991:Xylazine; D007649:Ketamine