Optimization of Hyperbaric Anesthetic Dosage for Unilateral Spinal Anesthesia in Orthopedic and Trauma Operations

Abstract

Topicality. Using generally accepted methods of calculating doses of local anesthetic during spinal anesthesia, the efficiency and safety of anesthesia are not always sufficient.
 The aim of our study was to determine the optimal dose of local anesthetic according to the height of the patient gradation method for unilateral and bilateral spinal anesthesia during orthopedic and traumatological operations on the lower extremities. Determine the advantages and disadvantages of both methods of analgesia.
 Materials and methods: Our study is based on an examination of 52 patients of I-II degrees of surgical risk according to ASA, divided into two groups. The first group (control) included 25 patients who underwent bilateral spinal anesthesia, the second group included 27 patients who underwent unilateral spinal anesthesia during orthopedic and traumatological operations on the lower extremities. Spinal anesthesia was performed with a hyperbaric solution of 0.5% bupivacaine, with the anesthetic dosing algorithm developed by us.
 Results: When evaluating the effectiveness of the performed spinal anesthesia, the duration of sensory and motor blocks and the level of development of sensory blockade by dermatomes in both study groups were determined. In the 1st group, the sensory block was 252.2±74.32 min., the motor block was 198.2±59 min. In the II group, the sensory block was 189.25±34.27 min., the motor block was 154.07±28.59 min. When determining the frequency of cardiovascular complications, dynamics of indicators in mean arterial pressure (MAP) and heart rate (HR) were determined before surgery, after 5 min., 30 min., 1 h., 2 h., 3 h., 5 h., 7 h., 9 h. It was found that the decrease in MAP and heart rate prevailed in the first group during the study. The volume of crystalloid infusion in the first research group was 2042±663.9 ml, and in the second group – 1666.66±635.49 ml. Laboratory diagnostic methods were used in order to determine dynamics of indicators in the basic metabolism and hormonal background during the occurrence of pain syndrome in patients and the effect of the dose of local anesthetic on the speed and level of changes in these parameters. For this purpose, changes in blood glucose, lactate and blood cortisol were determined before surgery, 3 hours, 6 hours and 9 hours of anesthesia course.
 Conclusions: 1. Gradational dosing of local anesthetic for unilateral and bilateral spinal anesthesia according to height ensures the necessary effectiveness of analgesia. 2. Reducing the dose of anesthetic during unilateral spinal anesthesia increases the safety of anesthesia and causes less side effects. 3. The duration and level of sensory blockade of unilateral spinal anesthesia is significantly reduced when using a reduced dose of local anesthetic in comparison with bilateral.