Culp, L.P., Skarda, R.T. and Muir, W.W. Comparisons of the effects of acupuncture, electroacupuncture, and transcutaneous cranial electrical stimulation on the minimum alveolar concentration of isoflurane in dogs. Am J Vet Res. 66(8):1364-70, 2005.
This study at the College of Veterinary Medicine, Ohio State University, Columbus, compared the effects of acupuncture (AP), electroacupuncture (EA), and CES with highfrequency intermittent currents on the minimum alveolar concentration (MAC) of isoflurane and associated cardiovascular variables in dogs. 8 healthy adult female Beagles were anesthetized with isoflurane on 4 occasions, allowing a minimum of 10 days between experiments. Isoflurane MAC values were determined for each dog without treatment (controls) and after treatment with AP and EA (AP points included LI 4, LU 7, GV 20, GV 14, San Tai and Baihui) and CES. Isoflurane MAC values were determined by use of noxious electrical buccal stimulation. Heart rate, mean arterial blood pressure (MAP), arterial blood oxygen saturation (SpO2) measured by use of pulse oximetry, esophageal body temperature, inspired and expired end-tidal isoflurane concentrations, end-tidal carbon dioxide concentration, and bispectral index (BIS) were monitored. Blood samples were collected for determination of plasma cortisol concentration. Mean +/- SD baseline MAC of isoflurane was 1.19 +/- 0.1%. Acupuncture did not significantly change MAC of isoflurane. Treatments with EA and CES significantly lowered the MAC of isoflurane by 10.1% and 13.4%, respectively. The SpO2, heart rate, MAP, BIS, esophageal body temperature, and plasma cortisol concentration were not significantly different after AP, EA, CES, and control treatments at any time interval. The authors concluded that the use of EA and CES decreased MAC of isoflurane in dogs without inducing adverse hemodynamic effects. However, the reduction in isoflurane MAC by EA and CES treatments was not considered clinically relevant.