Effect Analysis of Epidural Anesthesia with 0.4% Ropivacaine in Transforaminal Endoscopic Surgery

BACKGROUND: Epidural anesthesia used in percutaneous endoscopic lumber discectomy (PELD) has the risk of complete neurotactile block. Patients cannot timely respond to the operator when the nerve is touched by mistake, so the potential risk of nerve injury cannot be avoided. According to pharmacodynamics, with the decrease of local anesthetic concentration, the nerve tactile gradually recovered; however, the analgesic effect also gradually weakened. Therefore, it is necessary to explore an appropriate concentration of local anesthetics that can keep the patients' nerve touch without pain. By comparing the advantages and disadvantages of 0.4% ropivacaine epidural anesthesia, local anesthesia and intravenous anesthesia on intraoperative circulation fluctuation, the incidence of salvage analgesia and the incidence of nerve non-touch, the feasibility of using low concentration epidural anesthesia in PELD to obtain enough analgesia and avoid the risk of nerve injury was confirmed. METHODS: 153 cases of intervertebral foramen surgery from October 2017 to January 2020 were selected and divided into local anesthesia group (LA group), 0.4% ropivacaine epidural anesthesia group (EA group), and intravenous anesthesia group (IVA group) according to different anesthesia methods. The changes of blood pressure and heart rate, the incidence of rescue analgesia and nerve root non-touch were compared among the three groups. RESULTS: The difference of map peak value among the three groups was statistically significant (P < 0.001); pairwise comparison showed that the map peak value of the LA group was higher than that of the EA group (P < 0.001) and IVA group (P < 0.001), but there was no statistical significance between the EA group and IVA group. The difference of HR peak value among the three groups was statistically significant; pairwise comparison showed that the HR peak value of the LA group was higher than that of the EA group (P < 0.001) and IVA group (P < 0.001), but there was no statistical significance between the EA group and IVA group. There was significant difference in the incidence of intraoperative hypertension among the three groups (P < 0.05); pairwise comparison showed that the incidence of intraoperative hypertension in the EA group was lower than that in the LA group (P < 0.05), while there was no significant difference between the IVA group, EA group, and LA group. There was significant difference in the incidence of rescue analgesia among the three groups (P < 0.01); pairwise comparison showed that the incidence of rescue analgesia in the EA group was lower than that in the LA group (P < 0.05) and IVA group (P < 0.05), but there was no significant difference between the LA group and IVA group. Due to the different analgesic mechanisms of the three anesthesia methods, local anesthesia and intravenous anesthesia do not cause the loss of nerve tactile, while the incidence of nerve tactile in 0.4% ropivacaine epidural anesthesia is only 2.4%, which is still satisfactory. CONCLUSION: Epidural anesthesia with 0.4% ropivacaine is a better anesthesia method for PELD. It not only has a low incidence of non-tactile nerve, but also has perfect analgesia and more stable intraoperative circulation.