Uncommon Clinical Presentation of Inadvertent Subdural Local Anesthetic Injection While Attempting Thoracic Epidural Anesthesia: A case report / 대한마취과학회지

Subdural catheterization and the injection of local anesthetics are rare complications of epidural anesthesia. Those complications reported have similar characteristics of the late onset of analgesia, extensive sensory blockade, moderate hypotension and the rapid recovery from anesthesia. We encountered an unusual presentation of subdural catheterization with a subsequent injection of local anesthesia that was identified radiographically and manifested as a non-detectable neural blockade. We discus the possible mechanisms for this complication.

The Effect of Distraction Induced by ReliefBand(R) on the Pain Threshold and Temporal Summation Threshold / 대한마취과학회지

BACKGROUND: Pain is recognized as a cognitive phenomenon, which involves the processing of information. Given that human information processing is largely restricted to a number of simultaneous tasks, many interventions and techniques have been used to modify pain perception by distracting the cognitive processing of pain. This study tested the hypothesis that the pain threshold to electrical stimuli is increased as a result of distraction using a ReliefBand(R). METHODS: Twenty volunteers were enrolled in this study. After attaching surface electrode to the medial plantar nerve territory of left foot, electrical stimuli were delivered to obtain baseline pain threshold and temporal summation threshold. After 15 minutes, while distracting with ReliefBand(R), the same parameters were obtained. RESULTS: Pain threshold and temporal summation threshold before distraction were 7.9+/-2.2 mA and 7.0+/-2.1 mA respectively. During distraction pain threshold and temporal summation threshold were increased to 9.0+/-2.4 mA and 7.8+/-2.2 mA respectively. CONCLUSIONS: Pain and temporal summation threshold to electrical stimuli were increased during distraction with ReliefBand(R). Although we applied a technique with weak distracting ability, this distracted the processing of pain perception significantly. Further research about various distraction technique will be required.

Lidocaine and Verapamil Enhances Neuromuscular Block Induced by Rocuronium / 대한마취과학회지

BACKGROUND: Lidocaine or verapamil are used as an antiarrhythmic agent or agent blunting the cardiovascular changes induced by intubation or extubation during anesthesia. After recovery from general anesthesia with muscle relaxants, most patients remained in a residual paralytic state, hence it might develop easily recurarization by factors that affect neuromuscular transmission. Lidocaine and verapamil are well known as agents to potentiate the neuromuscular block. We investigated the effects of lidocaine or verapamil on neuromuscular transmission in vitro. METHODS: Square wave, 0.2 ms duration at a frequency of 0.1 Hz supramaximal or train of four stimuli was applied and the twitch height response was recorded mechanomyographically on rat phrenic nerve hemidiaphragm preparations. Dose responses of rocuronium, lidocaine, verapamil, rocuronium pretreated with lidocaine or verapamil, lidocaine pretreated with rocuronium, and verapamil pretreated with rocuronium were observed by cumulative method, and effective doses (Lag dose, ED50 and ED95) between a pretreated and nonpretreated agent were compared statistically. TOF ratios were observed at 80, 70, 40 and 30% of the control twitch height value during the observation of dose responses. RESULTS: Lag dose, ED50 and ED95 of rocuronium were reduced significantly after pretreatment of lidocaine, verapamil or their mixture, and the dose response of lidocaine, verapamil or their mixture were also reduced significantly by rocuronium pretreatment. TOF ratios at the point of each twitch height decreased significantly after pretreatment. CONCLUSIONS: Lidocaine or verapamil itself did not affect the neuromuscular transmission but might have potentiated the neuromuscular blocking effect induced by rocuronium. However, in excessive doses, these agents produced neuromuscular blockade. Consequently, in the residual neuromuscular block induced by rocuronium, lidocaine or verapamil may enhance recurarization.