Effects of Lidocaine on the Dose-Response Curve of Cisatracurium / 대한마취과학회지

BACKGROUND: Lidocaine is useful as a local anesthetic and antiarrhythmic agent perioperatively. It may augment a neuromuscular block from both nondepolarizing and depolarizing muscle relaxants. Cisatracurium is a new muscle relaxant as an isomer of atracurium. We investigated the interaction of cisatracurium and lidocaine on the dose-response curve in vitro. METHODS: Institutional approvement was obtained. Forty male Sprague-Dawley rats (150 - 200 gm) were divided into four groups (control, lidocaine 0.01, 0.1, or 1ng/ml). The animals were anesthetized with 40 mg/kg pentobarbital. The hemidiaphragm with the phrenic nerve was dissected and mounted within 5 minutes in a bath containing 100 ml Kreb's solution at 32degreesC. The phrenic nerve was stimulated at supramaximal intensity by a Grass(R) S88 stimulator through an SIU5 isolation unit. A twitch height was measured by a precalibrated Grass FT88 force displacement transducer and recorded with a Grass 79 polygraph. After stabilization of the twitch response, cisatracurium was added to the solution to obtain an initial concentration of 50ng/ml with saline 1 ml or lidocaine 0.01, 0.1 or 1ng/ml. When a stable 3 - 5 twitch inhibition was obtained after the first dose, additional cisatracurium was added to the Kreb's solution in increments of 25ng/ml to more than a 90% neuromuscular block. The data was analyzed by repeated measures of ANOVA. RESULTS: There was a significant decrease in the effective dose of cisatracurium needed to depress the twitch response in lidocaine 0.1ng/ml and 1ng/ml groups compared with the control group and with the lidocaine 0.01ng/ml group. CONCLUSIONS: We concluded that lidocaine will increase the sensitivity to cisatracurium in the hemidiaphragm preparation of rats.

Effects of Lidocaine on the Neuromuscular Block of Cisatracurium and Rocuronium / 대한마취과학회지

BACKGROUND: Lidocaine is a useful local anesthetic and antiarrhythmic agent perioperatively. It may augment a neuromuscular block from both nondepolarizing and depolarizing muscle relaxants. Cisatracurium of benzylisoquinoline derivatives and rocuronium of aminosteroid derivatives are new nondepolarizing muscle ralaxants. We investigated interactions of cisatracurium or rocuronium with lidocaine in vitro. METHODS: Institutional approvement was obtained. Eighty male Sprague Dawley rats (150 - 200 g) were divided into 8 groups (control, lidocaine 1, 10 and 100microgram of both cisatracurium and rocuronium groups). The animals were anesthetized with phentobarbital 40 mg/kg I.P.. The hemidiaphragm with the phrenic nerve was dissected and mounted within 5 minutes in a bath containing 100 ml Kreb's solution at room temperature. The phrenic nerve was stimulated at supramaximal intensity by a Grass S88 stimulator through an SIU5 isolation unit. A twitch height was measured by a precalibrated Grass FT88 force displacement transducer and recorded with a Grass 79 polygraph. After stabilization of the twitch response, cisatracurium (50microgram), and rocuronium (100microgram) were added to the Kreb's solutions. After 10 minutes, we measured twitch height, and saline 1 ml or lidocaine 1, 10 or 100microgram was added to the Kreb's solution. After 10 minutes, we again measured twitch responses. The data was analyzed by repeated measures of ANOVA. RESULTS: There were significant depressions in the twitch response of cisatracurium in lidocaine 10microgram and 100microgram groups compared with the control group and lidocaine 1microgram group. In addition, the lidocaine 100microgram group was significantly depressed compared with the lidocaine 10microgram group. There were no significant depressions of the twitch response of rocuronium in lidocaine 1microgram, 10microgram, and 100microgram groups compared with the control group. CONCLUSIONS: We concluded that lidocaine will increase the sensitivity to cisatracurium in the hemdiaphragm preparation of rats. Lidocaine will be able to cause recurarization. There was not a statistically significant change in the rocuronium group but it was clinically significant.