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Neuromuscular blocking agents (NMBAs) might diminish the electromyography signal of the vocalis muscles during intraoperative neuromonitoring of the recurrent laryngeal nerve. The aim of this study was to compare differential sensitivity of different muscles to succinylcholine in a swine model, and to realize the influence of NMBAs on neuromonitoring. Six male Duroc-Landrace piglets were anesthetized with thiamylal and underwent tracheal intubation without the use of an NMBA. The left recurrent laryngeal nerve, the spinal accessory nerve, the right phrenic nerve and the brachial plexus were stimulated. Evoked potentials (electromyography signal) of four muscle groups were elicited from needle electrodes before and after intravenous succinylcholine bolus (1.0 mg/kg). Recorded muscles included the vocalis muscles, trapezius muscle, diaphragm and triceps brachii muscles. The onset time and 80% recovery of control response were recorded and analyzed. The testing was repeated after 30 minutes. The onset time of neuromuscular blocking for the vocalis muscles, trapezius muscle, diaphragm and triceps brachii muscle was 36.3 ± 6.3 seconds, 38.8 ± 14.9 seconds, 52.5 ± 9.7 seconds and 45.0 ± 8.2 seconds during the first test; and 49.3 ± 10.8 seconds, 40.0 ± 12.2 seconds, 47.5 ± 11.9 seconds and 41.3 ± 10.1 seconds during the second test. The 80% recovery of the control response for each muscle was 18.3 ± 2.7 minutes, 16.5±6.9 minutes, 8.1±2.5 minutes and 14.8±2.9 minutes during the first test; and 21.5±3.8 minutes, 12.5 ± 4.3 minutes, 10.5 ± 3.1 minutes and 16.4 ± 4.2 minutes during the second test. The sensitivity of the muscles to succinylcholine, ranked in order, was: the vocalis muscles, the triceps brachii muscle, the trapezius muscle and the diaphragm. We demonstrated a useful and reliable animal model to investigate the effects of NMBAs on intraoperative neuromonitoring. Extrapolation of these data to humans should be done with caution., (Copyright © 2010 Elsevier. Published by Elsevier B.V. All rights reserved.)

Two important issues after a complete right forearm amputation are replantation and ongoing pain management. There are no reports of successful forearm replantation as a consequence of a crocodile bite. Here, we discuss our pain management in a case of complete forearm amputation after a bite from a saltwater crocodile (Crocodylus porosus), which necessitated six further operations to achieve successful replantation. Continuous infraclavicular brachial plexus block was effective for acute pain control in this case. We strongly recommend performing the block with an indwelling catheter under ultrasound guidance for higher accuracy and safety.

Femoral nerve block (FNB) is by far the most useful lower extremity regional anesthetic technique for the anesthesiologist, and high-resolution ultrasonography is a useful tool with which to guide the performance of FNB. However, the relationships between the femoral nerve and the femoral artery in different lower extremity positions have rarely been discussed. The purpose of this study was to evaluate the relative positions of the femoral nerve and artery at different lateral rotational angles of the lower extremities using ultrasonographic imaging. We enrolled 41 healthy volunteers in this study. Two-dimensional ultrasonographic images of the femoral nerve were obtained using an ultrasound unit, in the inguinal crease, for four positions of the bilateral lower extremities: 0 degrees , 15 degrees , 30 degrees and 45 degrees lateral rotation of each extremity. The following assessments were made in each position: minimal skin-to-nerve distance (SN) and deviation of nerve-to-landmark (femoral artery pulsation) horizontal distance (NF). A trend towards lateral rotation of both lower extremities was identified. The Pearson correlation values between rotational degree to SN and rotational degree to NF were -0.216 and 0.430, with p values of 0.001 and less than 0.001, respectively. Body mass index had a good correlation ( r = 0.76-0.78) with SN. The results of our ultrasound study revealed that the more lateral the rotation of both lower extremities, the closer the femoral nerve was to the skin and the farther away it was from the femoral artery. In order to increase the success rate and decrease the rate of complications, a suggested lateral 45 rotation of both lower extremities is strongly recommended when performing FNB using the peripheral nerve stimulator technique or the field block technique. In any situation, individual ultrasound guidance is recommended for FNB whenever possible.

The aim of this study was to evaluate the efficiency of lightwand-guided endotracheal intubation (LWEI) performed using either the right (dominant) or left (nondominant) hand. Two hundred and forty patients aged 21-64 years, with a Mallampati airway classification grade of I-II and undergoing endotracheal intubation under general anesthesia, were enrolled in this randomized and controlled study. Induction of anesthesia was initiated by intravenous administration of fentanyl (2 microg/kg) and thiopentone (5 mg/kg), and tracheal intubation was facilitated by intravenous atracurium (0.5 mg/kg). In the direct-vision laryngoscope group (group D; n = 80), the intubator held the laryngoscope in the left hand and inserted the endotracheal tube (ETT) into the glottic opening with the right hand. In the group in which LWEI was performed with the right hand (group R; n = 80), the intubator lifted the patients' jaws with the left hand and inserted the ETT-LW unit into the glottic openings with the right hand. On the contrary, in the group in which LWEI was performed with the left hand (group L; n = 80), the intubator lifted the jaws with the right hand and inserted the ETT-LW unit with the left hand. Data including total intubation time, the number of intubation attempts, hemodynamic changes during intubation, and side effects following intubation, were collected. Regardless of whether lightwand manipulation was performed with the left hand (group L; 11.4 +/- 9.3 s) or the right-hand (group R; 12.4 +/- 9.2 s), less time was consumed in the LWEI groups than in the laryngoscope group (group D; 17.9 +/- 9.9 s) (p < 0.001). All three groups obtained success rates greater than 95% on their first intubation attempts. The changes in mean arterial blood pressure and heart rate were similar among the three groups. A higher incidence of intubation-related oral injury and ventricular premature contractions (VPC) was found in group D compared with groups L and R (oral injury: group D 8.5%, group L 1.3%, group R 0%, p = 0.005; VPC: group D 16.3%, group L 5%, group R 7.5%, p = 0.04). We concluded that LWEI performed by either dominant or nondominant hands resulted in similar efficiency, and could be a suitable alternative to traditional laryngoscopy. It is both feasible and logical for an experienced anesthesiologist to use the nondominant hand to perform LWEI.