Standardization of the Nerve Localization Technique in Percutaneous Peripheral Nerve Blockade

OBJECTIVE: We compared a few variables such as the type of needle, the direction of bevel, and the effect of stimulation duration in percutaneous peripheral nerve blockade. We also studied the real distribution of injected drug through nerve biopsy. METHOD: The sciatic nerve-tibialis posterior muscle preparation of rabbit was chosen as a model. Experimental rabbits were divided into 3 groups: Group 1 (16 legs), use of insulated needle and 100 microsecond stimulation duration; Group 2 (9 legs), use of insulated needle and 240 microsecond stimul ation duration; Group 3 (6 legs), use of uninsulated needle and 100 microsecond stimulation duration. The mixed solution, 0.1 cc, of 5% phenol and indian ink was injected in 10 legs and the muscles were obtained to observe the spreads of injected solution after 2 weeks. RESULTS: The minimal stimulation currents of group 1, 2, 3 were 0.49 mA, 0.37 mA, 2.07 mA, respectively. The distance between needle and sciatic nerve sheath of group 1, 2, 3 were 0.09 mm, 0.11 mm, 0.20 mm in width, and 1.84 mm, 3.33 mm, 4.50 mm in depth, respectively. The current required to stimulate the nerve increased rapidly as the tip of the insulated needle passed the nerve, and the direction of bevel had no effect on the minimal stimulation current. Injected indian ink was located alongside the perineurium. CONCLUSION: In three methods, the most exact method was the use of insulated needle and 100s stimulation duration. The needle tip was located 1.84 mm past the nerve.

The Characteristics of Nerve Stimulators in Peripheral Nerve Block

OBJECTIVE: To find the characteristics of the nerve stimulator for the peripheral nerve blockade. METHOD: We studied four different nerve stimulators currently available in the clinical setting. The output characteristics(wave shape, voltage and duration of the stimulus impulse) were measured for each stimulator using an oscilloscope. Target current from 0 mA to 5 mA and load resistances from 200 ohm to 10 kohm were selected to model the normal ranges of operating current and tissue impedance when performing peripheral nerve block technique. RESULTS: There was a marked variation in performance of nerve stimulators depending on the target current value and resistances. Measured pulse width was not identical to the target pulse width in three nerve stimulators. Measured voltage with a fixed resistance was smaller in two nerve stimulators than the target voltage which was supposed to be produce in target current value of same resistance. One nerve stimulator showed the differences of calculated current value according to the used resistances. CONCLUSION: For the successful nerve block, it is important for the operator to be aware of the design and functional limitations of the nerve stimulator being used in clinical practice.

Intrathecal Baclofen for Spasticity: Changes in Clinical Feature and Gait

OBJECTIVE: To know the effect of intrathecal baclofen on increased muscle tone, spasm and ambulation. METHODS: Six patients with a severe chronic spasticity were evaluated with 10~75 microgram of intrathecal baclofen infusion. Two patient were infused more than two times (25 microgram, 50 microgram, 75 microgram). After each bolus infusion, an assesment was done for the patient's Ashworth score, spasm score, reflex score, peak eccentric torque by Cybex 6000 system , H/M ratio, subjective feeling of walking and the gait analysis. RESULTS: Spasticity decreased from the mean prebolus Ashworth score of 3.4 to mean postbolus Ashworth score of 1.4 and the pre- and postbolus mean reflex score were 3.9 and 1.6 respectively for a minimum of 4 hours. All patients showed that spasms disappeared, and the peak eccentric torque and H/M ratios also decreased. For the bipedal locomotion, all patients improved in their gait speed, step length, and maximal knee flexion angle, but only two patients improved in their subjective ambulatory functions. These two patients could control the spastic limbs voluntarily and walk independently at the prebolus stage. Four patients had more difficulty in gait because of the subjective weakness of extensor muscles of the lower extremities. CONCLUSION: Intrathecal baclofen decreased the spasticity, and spasm effectively in patients who had failed the conservative treatment with medication and physical therapy.

Complex Physical Therapy for Lymphedema

Complex Physical Therapy (CPT) is one of the variable conservative methods of lymphedema and recently used in many countries with great success. The main concept of CPT is to improve central lymph flow by opening non-functioning lymphatic pathway and by stimulating collateral lymphatic channels to drain the swollen area into adjacent areas where lymph flow is normal. CPT consists of 4 main parts; 1. meticulous skin care, 2. manual lymph drainage, 3. multilayered non-stretching compression bandages and compression garments, 4. special exercise. We tried to assess the immediate and maintenance effects of CPT in patients with lymphedema. CPT was used on 25 patients (male 5, female 20) with 10 upper and 15 lower extremity edemas for 2weeks such as 5 days per week, 1.5 hours per day at out-patient clinic. Immediately, the reduction of edema volume was 25.5+/-13.8% at the upper extremity and 27.5+/-15.5% at lower extremity in 2 weeks after treatment. All these were well maintained following 3 months without any significant variation. In comparison between proximal and distal parts, there was no significant difference except the immediate post-treatment result of the lower extremity. But the maintenance of volume reduction of distal part was better than proximal part through 3 months after treatment. We also found the reduction of skin subcutaneous thickness according to the volume reduction. In conclusion, CPT is a effective treatment method for patients with lymphedema but follow up study will be needed for identifying long term maintenance effect.