Infiltration of epinephrine in tonsillectomy: a randomized, prospective, double-blind study. A variety of hemostatic agents and techniques have been used in an attempt to reduce intraoperative blood loss and postoperative bleeding in tonsillectomy. The efficacy of most of these substances and techniques has been judged primarily on clinical impressions. Because of the paucity of prospective studies, a randomized, prospective, double-blind study, using the patients as their own controls, was conducted. Ninety-two patients were injected before tonsillectomy in a random, double-blind fashion with normal saline solution in one tonsil and 1:100,000 epinephrine in the other. The blood loss, time of dissection, and postoperative bleeding were recorded separately for each tonsil. Cardiac manifestations were also monitored. The tonsils injected with epinephrine had a statistically significant reduction in blood loss and dissection time when compared with those injected with normal saline. Subjectively, dissection was easier on the epinephrine-injected side. There was no difference in the incidence of postoperative hemorrhage. Cardiac manifestations of epinephrine were minimal and transient. This study demonstrates that epinephrine is useful in reducing hemorrhage during tonsillectomy and can be used safely with the appropriate inhalation anesthetics. 