Effects Of Ultrasound-guided Transversus Abdominis Plane(TAP) Block During Gynecological Laparoscopic Surgery

Objective: Laparoscopic is used more widely gynecological surgery,although its postoperative trauma is small,there are still some patients feel pain,and the application of painkillers will increase the risk of postoperative nausea and vomiting.Transversus abdominis plane?TAP?block may relieve the pain with interceping innervation of abdominal incision.Dexmedetomidine has good effects of sedative and analgesic,and topical application can prolong the effect of local anesthetics.This study discusses the efficacy of dexmedetomidine mixed with ropivacaine for ultrasound-guided transversus abdominis plane?TAP?block combined with general anesthesia in the patients undergoing gynecological laparoscopic surgery.Methods:Sixty patients?ASA classification I or II?,aged 20⁶0 y,with a body index of 18²4 kg/m²,scheduled for gynecological laparoscopic surgery under general anesthesia,were randomly divided into 3 groups?n=20?: control group?Group C?,ropivacaine group?Group R?,and dexmedetomidine combined with ropivacaine group?Group DR?.Exclusion criteria were a history of heart or respiratory disease,kidney or liver failure,coagulation disorders,morbid obesity,local infection at the site of block,mental disorder,allergy to the study drug and long-term use of painkillers or adrenergic receptor agonists or antagonists.Peripheral venous access was obtained after the patient had entered the operating room.Standard monitoring included continuous electrocardiography?ECG?,noninvasive blood pressure?BP?pulse oximetry?SpO₂?and capnography(P_ETCO₂).Before the induction of anesthesia,10 ml/kg lactated Ringer's solution was infused rapidly.During the surgery,6% hydroxyethyl starch 130/0.4 was infused at a rate of 6 ml/kg/h based on the amount of bleeding and urine output.Narcotrend monitoring was used in patients at the same time.According to the equipment specifications,Clean the skin of the electrode portion of the forehead with othe grinding paste,using Narcotrend special electrode and single channel to make the electrode resistance less than 4 k?.Induction of anesthesia was performed as follows: General anesthesia was induced with midazolam 0.05 mg/kg,fentanyl 4 ?g/kg,propofol 2 mg/kg and vecuronium 0.08⁰.12 mg/kg.A laryngeal mask airway?LMA?was inserted when loss of eyelash reflex was confirmed.The Aestiva/5 anesthesia machine?Datex-hmeda company,USA?was used for mechanical ventilation,with the following settings: tidal volume,8¹0ml/kg;ventilation frequency,12 times per minute;inspiratory-to-expiratory ratio,1:2;FiO₂,100%;and oxygen flow,2 L/min.A single-injection ultrasound-guided left-sided unilateral TAP block was performed in Group R and Group DR.In Group R,patients received a TAP block with 20 ml of 0.375% ropivacaine and in Group DR,patients received a TAP block with 20 ml of 0.375% ropivacaine and 1 ?g/kg dexmedetomidine after induction.Anesthesia was maintained with remifentanil using micro pump injection at a speed of 0.2 ?g/kg/min.Vecuronium was used to maintain muscle relaxation through intermittent intravenous boluses.The rate of the propofol pump was adjusted based on Narcotrend monitoring to maintain the Narcotrend index?NTI?at 37⁴6?D2?,intraoperative BP and HR fluctuation less than the basic value of 20%,urine output of more than 1 ml/kg/h,and P_ETCO₂ of 35-45 mm Hg with mechanical ventilation.After completion of the operation,anesthetics were stopped.Only group I received disposable intravenous analgesia pumps?non electric-drive?with the following analgesia pump formula: sufentanil 100 ug+ butorphanol 4 mg+ granisetron 3 mg,dissolved in normal saline and diluted to 100 ml,analgesia pump parameters for 3ml/h infusion.After the patients had recovered from anesthesia and were spontaneously breathing,the LMAs were removed.Patients were sent to the ward while vital signs were stable.The operative time,propofol dosage,time to emergence,time to spontaneous breathing,extubation time,Steward awakening score,VAS score without support at 2,4,8,12,24 h after the operation,nausea and vomiting and respiratory depression were recorded.Results:The intra-operative dosage of propofol was significantly lower in Group C than those in Group A?P<0.01?,the time of operation?awakening ?spontaneous breathing and extubation were lower in Group C than those in Group A?P<0.05?,while the scores of Steward among three groups have no significantly difference.The score of VAS at2,4,8h after operation were significantly lower in Group B?C than those in Group A?P<0.05?P<0.01?,while the score of VAS at12,24 h after operation among three groups have no significantly difference.The cases of nausea and vomiting were also fewer in Group B?C than those in Group A?P<0.05?.There were no respiratory depression in three groups.The patients in the three groups did not use additional analgesics for 24 hours after the operation.Conclusions: 1.The ultrasound-guided TAP block combined with dexmedetomidine adjunct may reduce the dosage of general anesthetics during surgery and improve the quality of anesthesia recovery;2.The ultrasound-guided TAP block combined with dexmedetomidine adjunct can be used in gynecological laparoscopic surgery and may reduce postoperative pain and the incidence of nausea and vomiting.