Objective: evaluation of the differences in the level of temperature, sensory and motor blockade during the various techniques of spinal anesthesia. Materials and Methods. Prospectively the randomized study included 70 patients. In the group with conventional spinal anesthesia (n=35) 15mg of bupivacaine injected quickly. In the group with unilateral spinal anesthesia (n=35) 7.5mg of bupivacaine administered slowly, at a rate of 1 ml per minute. We studied the level of temperature and time, sensory and motor blockade. The data are statistically processed. Results. Reduced thermal sensitivity recorded in an average of 48 seconds as a unilateral spinal anesthesia group and the control group. Subarachnoid administration of 7.5 mg of hyperbaric bupivacaine resulted in the development of a complete motor blockade underlying lower extremity in only 16 patients (45.7%). Conclusion. Using lower dosages of bupivacaine for unilateral spinal anesthesia lowers the threshold concentration of the local anesthetic in the subarachnoid space, resulting in slower motor neuron blockade and it is not total in more than 50% of cases.
Lakhin R.E., Panov V.A., Schegolev A.V., Kuligin A.V. Evaluation of latent period of temperature sensitivity in traditional and unilateral spinal anesthesia // Saratov Journal of Medical Scientific Research, Vol. 11, Issue 3, 2015, pp. 263-267

Objective: to evaluate the nature of unilateral spinal anesthesia using various modes of administration of low doses of hyperbaric bupivacaine. Materials and Methods. Prospectively, the randomized study included 56 patients undergoing knee arthroscopy. In the control group bupivacaine of 5mg was administered simultaneously, in the main group — fractionally by 2.5 mg. The development of thermal and pain blocks from different sides was investigated. The data were statistically processed. Results. In the control group, the positioning of the patient usually began after the entire dose of anesthetic had been administered. In the case of temperature paresthesia in the area of the sacral segments of the full anesthesia throughout underlying limb was not always achieved. In 6 cases of block was not sufficient. In the main group patient positioning was performed after the administration of 2.5 mg of anesthetic and evaluate temperature paresthesia and in 2 cases the total dose was increased to 7.5 mg. The successful development of sensory block at fractional administration was significantly higher than in the single-step introduction. Conclusion. Temperature paresthesia occurs within the first minute and is an early predictor of developing spinal anesthesia. The area of arising paresthesia shows preferential distribution of the anesthetic. In the application of low dose local anesthetic the desired upper level of anesthesia via the patient positioning and dose adjustment may be achieved.
Lakhin R.E., Schegolev A.V., Panov V.A., Kuligin A.V. Low dose spinal anesthesia for knee arthroscopy // Saratov Journal of Medical Scientific Research, Vol. 11, Issue 2, 2015, pp. 126-128