EFFECT OF PREANESTHETIC MEDICATION ON EASE OF ENDOSCOPIC INTUBATION OF THE DUODENUM IN ANESTHETIZED DOGS

The effects of preanesthetic medication on ease of duodenal endoscopic intubation in dogs was evaluated. One of 12 combinations of preanesth etic medications (using atropine, glycopyrrolate, morphine, meperidine , acepromazine, and 0.9% NaCl solution) was administered IM to each of 12 dogs in a trial. Twelve endoscopic trials were performed so that e ach dog received each treatment combination once. Anesthesia was induc ed with thiamylal administered IV and maintained with halothane vapori zed in oxygen. Electrocardiographic recordings, indirect blood pressur e measurements, end-tidal carbon dioxide partial pressures, and haloth ane concentrations were monitored during the anesthetic period. The ea se with which the fiberoptic endoscope was passed into the proximal po rtion of the duodenum was qualitatively scored on the basis of time an d maneuvering effort. None of the preanesthetic combinations made intu bation of the duodenum significantly easier than that with 0.9% NaCl s olution (control). Only the combination of morphine and atropine induc ed gastropyloric conditions that resulted in significantly higher (mor e difficult) endoscopic scores than those after preanesthetic medicati on with 0.9% NaCl solution.