Effect of Right-stellate Ganglion Block in Preventing Postoperative Nausea and Vomiting in Gynecological Laparoscopic Patients

Postoperative nausea and vomiting is one of the most common postoperative complications second only to postoperative pain. Studies have reported that without any antiemetic prevention treatment, the overall incidence of PONV in surgical operations is up to 20-30%, and the incidence of PONV in high-risk patients such as gynecologic laparoscopy is higher. The pathogenesis of postoperative nausea and vomiting is very complex, including central, peripheral receptors and multiple nerve pathways. When peripheral receptors are stimulated, the signal passes through the afferent nerve to the vomiting center, causing nausea and vomiting. The emetic chemical receptors are rich in many receptors, which can directly feel various toxins, metabolites or drugs in the blood and cerebrospinal fluid, project signals to the nerve center and then spread to the cerebral cortex, causing nausea and vertigo, or transmit signals along the vagus nerve, glossopharyngeal nerve, spinal nerve, etc. to the digestive tract, diaphragm and abdominal wall muscles, resulting in the opening of the sphincter in the upper esophagus and strong contraction of the diaphragm. Abdominal muscles contract, so that the stomach pressure increases, stomach contents through the digestive tract is expelled from the body, vomiting.

There are many factors affecting postoperative nausea and vomiting in gynecological laparoscopic surgery, including patient factors, anesthetic factors and surgical factors. Firstly, gender as an independent risk factor for postoperative nausea and vomiting is widely recognized by researchers, and a large number of studies have confirmed that the incidence of postoperative nausea and vomiting is higher in females, and the possible mechanism is caused by different hormone levels. Secondly, some studies believe that the type of surgery is also a risk factor for postoperative nausea and vomiting, but there is some controversy. In general, laparoscopic surgery patients have a higher incidence of postoperative nausea and vomiting. Finally, the mode of anesthesia and anesthesia-related drugs are also one of the risk factors affecting PONV. Compared with other anesthesia methods, the incidence of PONV was increased under general anesthesia, and the combination of intravenous anesthesia and intraoperative opioid application also increased the incidence of postoperative nausea and vomiting.

Stellate ganglion block has been proved to be widely used in clinic and can play a positive role in multiple organs and systems of the whole body. In clinical work, stellate ganglion block is more widely used in the treatment of various pain, autonomic nerve disorders and other diseases. However, there are few clinical studies on whether stellate ganglion block can be used as an effective and feasible means to prevent postoperative nausea and vomiting and the related mechanisms to prevent the possible occurrence of nausea and vomiting. Therefore, this study will explore the preventive effect of stellate ganglion block on postoperative nausea and vomiting in gynecological laparoscopic patients, and hope to explore its possible mechanism, so as to provide more effective and feasible methods for clinical prevention of postoperative nausea and vomiting and improve patients' medical comfort and satisfaction.

Inclusion criteria

• Age ≥18 years and ≤ 70 years
• American Society of Anesthesiologists(ASA) physical status classification I-Ill.
• Voluntary participation and ability to understand and sign the informed consent form
• Patients undergoing gynecological laparoscopic surgery elective general anesthesia

Exclusion criteria

• Patients with obesity(BMI>30kg/m2)
• Contraindicated to stellate ganglion block
• Patients who cannot cooperate with the study for any reason,or whom the investigator deems unsuitable for inclusion in this trial.