To reduce perioperative complications caused by anesthesia procedures and relieve the incidence of side effects related to anesthesia drugs, opioid-reduced combined with non-intubation and nerve block anesthesia techniques have gradually been promoted and have achieved good results in thoracic surgeries in recent years [12, 13]. In the present study, we combined multiple methods to monitor opioid-reduced anesthesia in patients with palmar hyperhidrosis who underwent thoracoscopic sympathectomy.
Dezocine, an opioid κ receptor partial agonist with weak inhibitory effects on cardiovascular function and low incidence of drowsiness, nausea, vomiting, etc. has been widely applied for the treatment of acute pain for years [14]. The trauma of sympathectomy was minimal, and the pain caused by this surgery was mild; thus, the application of dezocine could meet the requirements of intraoperative analgesia. DEX, a selective α2-adrenal receptor agonist that could activate corresponding receptors in the brain and spinal dorsal horn producing sedative and analgesic effects, has been widely used in perioperative adjuvant analgesic treatment [15]. In this study, patients in Group W received an infusion of DEX before anesthesia to reduce the excitability of the sympathetic nervous system, and there were no cases of tachycardia during the operation. Furthermore, to implement the ERAS concept, all patients in this study were orally administered carbohydrate-containing beverages 2 h before surgery. As a result, the perioperative blood volume was sufficient, and there was no significant difference in the incidence of bradycardia and hypotension between groups. The HR, MAP, and incidence of adverse reactions were similar between groups, suggesting that the use of DEX in this surgery was safe. Flurbiprofen, a classic NSAID with strong anti-inflammatory and analgesic effects, plays an important role in the development of multimodal analgesia during surgery [16]. We used this medication in both groups, and the postoperative pain experienced by the patients was low. This result confirmed the rationality of the above drug combinations.
Analgesia and sedation are important indicators during anesthesia, and PI and BIS are reliable indicators of intraoperative analgesia and sedation [17, 18]. The VAS score is a common tool for evaluating pain intensity; typically, a VAS score of less than 4 signifies slight pain [19, 20]. We combined the PI and BIS to guide the dose of sedatives and analgesics during surgery, and various VAS scores were used to assess postoperative pain. An intercostal nerve block is a common regional block method that can effectively alleviate pain caused by the incision and thoracic drainage tube, reduce the dosage of analgesic drugs, and promote rapid postoperative recovery of patients during thoracic surgery [21]. To improve the intraoperative analgesic effect, we combined intercostal nerve block in patients in Group W. The results showed that the VAS, PI, and BIS values were similar between the groups and were maintained at clinically appropriate levels, suggesting that analgesia via the combination of multiple analgesics and nerve block was effective.
In this study, the incidence of perioperative complications was important in assessing the effect of the opioid-reduced anesthesia strategy. The results showed that patients in the two groups did not show significant differences in opioid-related adverse reactions. This indicates that the use of opioid-reduced anesthesia during thoracoscopic sympathectomy is safe and feasible.
During spontaneous breathing, preserving general anesthesia, hypoxemia, and hypercapnia are the major challenges faced by anesthesiologists [22]. In this study, patients in both groups were treated with laryngeal mask intubation to relieve upper respiratory tract obstruction after repeated preliminary tests to avoid hypoxia caused by upper respiratory obstruction. Auxiliary ventilation was administered when necessary. In addition, during single-lung ventilation, oxygen was supplied to all patients through the inhalation end of the threaded tube to ensure oxygen supply. The exhalation end of the threaded tube was detached from the anesthesia machine, which aided in the emission of carbon dioxide while performing lung collapse on the surgical side. Before surgery was completed, manual breathing was used to fully inflate the lungs to avoid postoperative atelectasis. In Group W, some patients experienced insufficient tidal volume and elevated transient carbon dioxide levels during surgery. In this situation, excessive ventilation was performed via manually assisted breathing after the completion of sympathectomy to keep PETCO2 near normal levels as much as possible before the end of surgery. Blood gas analysis showed that the partial pressures of oxygen and carbon dioxide were at a healthy level when the patients exited the operating room. These results are consistent with those of Li et al. [23], who reported that short-term mild hypercapnia during thoracic surgery did not affect patient prognosis. In addition, none of the patients experienced complications, such as hypoxemia, heart failure, or delayed awakening during the perioperative period, and the dosage of propofol was similar between the groups; therefore, the postoperative recovery time was not extended. Finally, all patients were either very satisfied or satisfied with the anesthesia. These results confirm that implementing an anesthetic strategy without muscle relaxation during thoracoscopic sympathectomy is safe. However, the anesthesia scheme in Group W was relatively complex and did not reduce the incidence of perioperative complications. Therefore, the use of opioid-reduced anesthesia in this surgery has no clinical advantages.
This study had some limitations. First, to improve patient comfort, all patients underwent peripheral venous puncture and catheterization, and blood gas analysis samples were obtained from the venous indwelling needle during the perioperative period. For subjects who had apparent anxiety before anesthesia, oxygen inhalation began immediately after the patient’s admission, which might have an impact on the blood gas index results of patients. Second, this was a single-center, single-blind trial, and funds supported by our institution had a 2-year cycle; after completing the preliminary preparation, subjects were recruited within 10 months. A multicenter, large sample, and longer research are necessary to enhance the reliability and finality of this study.
In summary, during minimally invasive surgery, such as thoracoscopic sympathectomy, the strategy of opioid-reduced anesthesia was safe and effective; however, this method did not show clinical advantages.