Changes in Middle Cerebral Artery Blood Flow Velocity after the Intravenous Injection of Lidocaine by Transcranial Doppler / 대한마취과학회지

BACKGROUND: Lidocaine is used for suppressing circulatory responses to endotracheal intubation. In this study the investigated changes of middle cerebral artery blood flow velocity (Vmca) before and after intravenous lidocaine injection by transcranial doppler. METHODS: Fifteen healthy volunteers received a bolus dose of intravenous lidocaine 1.5 mg/kg. Vmca's were measured on the temple using a bidirectional 2-MHz transcranial doppler probe before and after lidocaine injection. Vmca's were recorded continually every 10 sec for 10 minutes after lidocaine injection. RESULTS: Mean Vmca was 67.6 +/- 7.6 cm/sec before lidocaine injection. Maximal Vmca's (70.7 +/- 7.5 cm/sec, P<0.05) occurred 35 +/- 16 sec after lidocaine injection, and then the Vmca decreased gradually. Minimal Vmca's (56.6 +/- 7.4 cm/sec, P<0.05) were measured at 164 +/- 40 sec after lidocaine injection. CONCLUSIONS: We suggest that lidocaine generally causes the decreases in Vmca, excepting the temporarily increase in Vmca about 35 sec after a single bolus administration of intravenous lidocaine.

Comparison of Cerebral Blood Flow Velocities by Transcranial Doppler during Anesthetic Induction: Rocuronium and Succinylcholine / 대한마취과학회지

BACKGROUND: In intravenous administration of a depolarizing neuromuscular blocker, succinylcholine is reported to produce activation of the electroencephalogram and increase cerebral blood flow and intracranial pressure. In this point, rocuronium was recently introduced as a non-depolarizing relaxant, and recommended as a safe alternative to succinylcholine. The purpose of this study was to evaluate the effects of rocuronium and succinylcholine on cerebral blood flow velocities during anesthetic induction. METHODS: Forty patients were randomly assigned into two groups. Group 1 was administrated rocuronium 0.6 mg/kg and group 2 was administrated succinylcholine 1 mg/kg for tracheal intubation after each group had intravenous administration of thiopental 5 mg/kg. The author observed changes of mean arterial pressure, arterial carbon dioxide tension, and middle cerebral arterial blood flow velocities at 5 times: before induction (control), 30 sec after thiopental administration, 30 sec, 60 sec and 90 sec after muscle relaxant administration. RESULTS: Mean arterial pressure decreased more at 30 sec after thiopental administration compared with the control (P<0.05). Middle cerebral arterial blood flow velocities were reduced at 30 sec after thiopental administration and 60 sec after rocuronium administration compared with the control (P<0.05). Middle cerebral arterial blood flow velocities were reduced at 30, 60, 90 sec after rocuronium administration compared with succinylcholine administration (P<0.05). CONCLUSIONS: We conclude that rocuronium has little effects on increasing cerebral blood flow. These result suggest that rocuronium have a less effect on increase in cerebral blood flow during neurosurgical anesthesia.