The purpose of this prospective, randomized, double-blind study was to compare the pain of injection, heart rate increase, and postinjection pain of the intraligamentary injection of 4% articaine with 1:100,000 epinephrine and 2% lidocaine with 1:100,000 epinephrine administered with a computer-controlled local anesthetic delivery system. Using a crossover design, intraligamentary injections of 1.4 mL of 4% articaine with 1:100,000 epinephrine and 1.4 mL of 2% lidocaine with 1:100,000 epinephrine were randomly administered on the mesial and distal aspects of the mandibular first molar with a computer-controlled local anesthetic delivery system in a double-blind manner at 2 separate appointments to 51 subjects. The results demonstrated the incidence of moderate pain was 14%-27% with needle insertion, with 0%-4% reporting severe pain. For solution deposition, moderate pain was reported 8%-18% of the time, with no reports of severe pain. There were no significant differences between the articaine and lidocaine solutions. Regarding heart rate changes, neither anesthetic solution resulted in a significant increase in heart rate over baseline readings. On day 1 postinjection, there was a 31% incidence of moderate/severe pain with the articaine solution and 20% incidence of moderate/severe pain with the lidocaine solution. The moderate/severe pain ratings decreased over the next 2 days. There were no significant differences between the articaine and lidocaine solutions. We concluded that the intraligamentary injection of 4% articaine with 1:100,000 epinephrine was similar to 2% lidocaine with 1:100,000 epinephrine for injection pain and postinjection pain in the mandibular first molar when administered with a computer-controlled local anesthetic delivery system. For both anesthetic solutions, heart rate did not significantly increase with the intraligamentary injection using the computer-controlled local anesthetic system.
A healthy but slightly pale 24-year-old female patient with a history of "turning blue" following dental procedures performed under local anesthesia claimed allergies to sulfa drugs, aspirin, Benadryl, and "all caines." The patient also acknowledged mild cyanosis after extreme exertion, Native American ancestry, and a 1996 diagnosis of methemoglobinemia following administration of a sulfa drug. Previous medical and dental records were reviewed. Restoration of several teeth and extraction of 2 third-molar teeth were completed under general anesthesia. Anesthesia was induced with propofol, nasotracheal intubation was accomplished with succinylcholine, and anesthesia was maintained with desflurane in oxygen supplemented by meperidine without local anesthesia. Vital signs, including pulse oximetry, remained stable, and the patient was dismissed after a 2-hour recovery/observation period. The patient experienced no postoperative complications. This case report provides a review of literature and clinical guidelines for management of methemoglobinemia-susceptible patients.