下顎埋伏智歯抜去術の術後疼痛制御におけるレボブピバカインの有用性に関する研究

抄録

This study examined the usefulness of levobupivacaine for inducing conduction anesthesia of the mandibular foramen for pain management after operation. The subjects were 30 patients who underwent extraction of an impacted mandibular wisdom tooth (G. B. Winter's impaction classification: Class II, Position B). All subjects were ASA Class I patients and provided informed consent. Tooth extraction was performed after infiltration anesthesia with 3.0 ml of a 2% lidocaine hydrochloride solution containing 1/80000 adrenalin. Oral surgeons with more than five years of clinical experience performed all procedures and the surgical stress was approximately equal. Patients then received 2 ml of 0.25% levobupivacaine solution (Group I, 10 subjects), 0.25% bupivacaine solution (Group II, 10 subjects), or 2% lidocaine hydrochloride solution containing 1/80,000 adrenalin (Group III, 10 subjects) for conduction anesthesia of the mandibular foramen. Each group was assessed for postoperative pain levels, Visual Analogue Scale (VAS) scores, time of onset of unbearable postoperative pain, time of the first administration of an analgesic drug (60 mg loxoprofen sodium), and frequency of analgesic administration to manage unbearable postoperative pain. Postoperative pain levels were scored by patients immediately after surgery and at 30, 60, 90, 120, 180, 240, 300, and 360 min after surgery using VAS scores ranging from “no pain” (left) to “worst imaginable pain” (right). Sufficient instruction for scoring pain levels was given to patients before surgery. VAS scores were determined by measuring from the left of the line to the vertical bar marked by patients. Significant increases in the VAS scores were observed postoperatively at 120 min and 90 min in Group I and Group III, respectively, but were not observed in Group II within the measuring time. The onset of unbearable pain occurred significantly later in Group I and Group II (191 ± 71 min and 170 ± 89 min after surgery, respectively) than in Group III (88 ± 46 min after surgery). The time of the first analgesic administration was 253 ± 90 min, 196 ± 68 min, and 125 ± 55 min after surgery in Group I, Group II, and Group III, respectively, and the differences between Group I and Group III were significant. Our results showed that the duration of the effect of levobupivacaine is not significantly different from that of bupivacaine. However, taking into account central nervous system toxicity and cardio toxicity, levobupivacaine is an appropriate drug for conduction anesthesia in postoperative pain management of the mandibular foramen.