Effect of butorphanol tartrate on shock-related discomfort during internalatrial defibrillation

Background-In patients with atrial fibrillation, intracardiac atrial defibr illation causes discomfort. An easily applicable, short-acting analgesic an d anxiolytic drug would increase acceptability of this new treatment mode. Methods and Results-In a double-blind, placebo-controlled manner, the effec t of intranasal butorphanol, an opioid, was evaluated in 47 patients with t he use of a step-up internal atrial defibrillation protocol (stage I). On r equest, additional butorphanol was administered and the step-up protocol co ntinued (stage II). Thereafter, if necessary, patients were intravenously s edated (stage III). After each shock, the McGill Pain Questionnaire was use d to obtain a sensory (S), affective (A), evaluative (E), and total (T) pai n rating index (PRI) and a visual analogue scale analyzing pain (VAS-P) and fear (VAS-F). For every patient, the slope of each pain or fear parameter against the shock number was calculated and individual slopes were averaged for the placebo and butorphanol group. All patients were cardioverted at a mean threshold of 4.4+/-3.3 J. Comparing both patient groups for stage II, the mean slopes for PRI-T (P=0.0099), PRI-S (P=0.019), and PRI-E (P=0.015) became significantly lower in the butorphanol group than in the placebo gr oup. Comparing patients who received the same shock intensity ending stage I and going to stage II, in those patients randomized to placebo the mean V AS-P (P=0.023), PRI-T (P=0.029), PRT-S (P=0.030), and PRI-E (P=0.023) becam e significantly lower after butorphanol administration. Conclusions-During a step-up internal atrial defibrillation protocol, intra nasal butorphanol decreased or stabilized the value of several pain variabl es and did not affect fear. Of the 3 qualitative components of pain, only t he affective component was not influenced by butorphanol. The PRI evaluated pain more accurately than the VAS.