Electroanesthesia in the cat: standardization of electric current parameters and anesthetic criteria.
This study was an attempt to apply to electroanesthesia (EA) the accepted criteria for surgical anesthesia brought about by chemical agents, namely, analgesia, muscle relaxation and the abolition of such reflexes as the corneal, pinnal and light reflexes. In the cat, with extracranial, bilateral, temporally placed electrodes, anesthesia was best achieved by a sine wave of 3,500 to 4,500 Hz with a low-frequency component of 100 Hz (15% of the applied current). The appropriate current intensity differed for each cat, ranging from 45 to 55 mA, peak to peak. Special attention was paid to smooth and rapid induction of the anesthetic state. Pupil diameter (greater than or equal to 12 mm) was used as an indication of the establishment of EA. Application of the current at lower frequencies (100 to 2,500 Hz) produced analgesia only, whereas higher current intensities at the same frequencies caused respiratory paralysis and muscular rigidity. Stimulation through electrodes placed at various locations in the brain stem resulted in analgesia only.
D000698:Analgesia; D000818:Animals; D002415:Cats; D004580:Electronarcosis / Q000379:methods / Q000592:standards*; D005260:Female; D008297:Male; D009126:Muscle Relaxation; D011680:Pupil; D012018:Reflex; D013477:Superior Colliculi / Q000502:physiology