EFFECTS OF CL 1848C, A NEW DISSOCIATIVE ANESTHETIC, ON THE CANINE CARDIOVASCULAR AND RESPIRATORY SYSTEMS

¹ Departments of Physiology and Anesthesiology, The University of Texas Medical Branch, and The Division of Anesthesiology, Shriners Burns Institute, Galveston, Texas

Three doses of CL 1848C [(+)-2-(2-ethyl-2-phenyl-1,3 dioxolan-4-yl) piperidine HCl], a new dissociative anesthetic agent, were administered to awake unanesthetized dogs in order to determine their effects on the cardiovascular and respiratory systems. The doses of drug utilized were 2.5, 5 and 10 mg/kg i.v. The number of animals which received each dose was 12, 21 and 12, respectively. These dosages produced an anesthetic state that varied from 23 to 78 minutes. The low dose produced an elevation of mean arterial pressure, heart rate, cardiac output, the maximum dp/dt of the left ventricle, minute volume and respiratory rate. The left ventricular end diastolic preesure, pH, pCO₂, and pO₂ were essentially unchanged. As the dose of drug was increased, this cardiovascular and respiratory stimulation became less pronounced. The elevations in mean arterial pressure and cardiac output which were observed with the 10-mg/kg dose were small. With this dose the left ventricular end diastolic pressure and pCO₂, were elevated and the pH was reduced, whereas the maximum dp/dt of the left ventricle, the minute volume and the respiratory rate were essentially unchanged. The heart rate was elevated to the same extent with all three doses. It is concluded that in low dosages CL 1848C is a cardiorespiratory stimulant, but at high dosages this stimulation is vitiated by a depressive action.