Hemodynamics Studies During Perioperative Period Of Spontaneous Breathing Intravenous Anesthesia In Video-assisted Thoracic Surgery

Background and Purpose Thoracic anesthesia management is always difficult and complicated in anesthesia management,including double lumen tube intubation,pulmonary separation,single lung ventilation and other specialized anesthesia techniques.single lung With the advantages of clearer vision,less trauma,and faster recovery,the VATS has been increasingly used in various types of chest surgeries and significantly shortened the operation time.However,the traditional anesthesia for VATS is the general anesthesia with double-lumen endotracheal intubation,which has a greater impact on the patients.Patients recover slowly and have more complications postoperatively.Since Pompeo et al.(2004)from Italy reported that the use of thoracic epidural block for VATS Pulmonary Mass Wedge Resection with non-tracheal intubation anesthesia was successful,international scholars have gradually reported that thoracic surgeries such as thoracic sympathectomy,lung metastasis,pulmonary nodule resection,bulla resection,pleural lung biopsy,mediastinal tumor resection and lobectomy could be finished under similar anesthesia.Unlike the traditional anesthesia with tracheal intubation under mechanical ventilation,the pressure in the thoracic cavity of new anesthesia method with voluntary respiratory is maintained negative.To some extents,medial concussion can happen which may have influence on hemodynamics because of the negative pressure of contralateral chest cavity and spontaneous breathing during the surgeries..We intent to observe the changes of hemodynamic parameters during peri-anaesthesia in patients undergoing spontaneous thoracoscopic surgery to explore the trend of hemodynamics and its impact on patients under this new anesthesia.MethodsForty cases of VATS were enrolled.Patients were eligible with an ASA physical status I-II grade,age 18-65 years old,BMI?25,normal or mild impairment pulmonary function(FEV1/FVC%?70%).None of included patients had cardiac function of III or had serious cardiac,pulmonary,liver,kidney and neurologic diseases.The patient was monitored by electrocardiogram(ECG),heart rate(HR),respiratory rate(RR),noninvasive blood pressure(NIBP),pulse oxygen saturation(SPO2)and bispectral index(BIS).Intravenous anesthesia was induced with dexmedetomidate,sufentanil,propofol.When BIS reduced to 60,Right internal jugular vein catheter would be inserted and central venous pressure(CVP)would be measured continuously.,measuring central venous pressure(CVP)continuously.The radial artery puncture catheter would be also inserted and the hemodynamic parameters including measuring mean arterial blood pressure(MAP),cardiac output(CO),Cardiac index(CI),Stroke Volume(SV),Stroke volume index(SVI),Stroke volume variation(SVV)would be recorded.Anesthesia Was mantained with propofol,remifentanil and dexmedetomidate.The surgeon performed local anaesthesia with 1% lidocaine at the incision before incision.After entering the thoracic cavity,intercostal nerve block was performed with a mixture of 1% lidocaine and 0.375% ropivacaine in the intercostal space of 2,3,4,5,6,7 and 8.Lateral mediastinal vagus nerve block was performed with 1% lidocaine and 0.375% ropivacaine.After the closure of the pleural cavity at the end of the surgery,the pumping of the intravenous anesthetic Would be stopped and a face mask assisted expansion retraction of lung tissue.The self-control method was used to compare the time points.The statistical method was analyzed by one-way ANOVA.P<0.05 was considered statistically significant.The following are the points of observation and recording of each hemodynamic parameter:1.T0 Basic value period: After the patient enters the operating room to establish the various tests,before induction of anesthesia.2.T1 Before thoracotomy after induction of anesthesia: After induction of anesthesia is completed,the position of the surgery is set to wait before opening the chest;3.T2 15 minutes after thoracotomy: Fifteen minutes after the opening of the chest cavity,the iatrogenic pneumothorax is established and the lateral lung collapsed.The patient is in a single-lung spontaneous breathing state.4.T3 30 minutes after thoracotomy: The patient continued single lung spontaneous breathing for 30 minutes.5.T4 60 minutes after thoracotomy: The patient continued single lung spontaneous breathing for 60 minutes.6.T5 The chest closed: The operation is completed,the thoracic cavity is closed and the closed state is restored,and the lung of operational side reexpansion is resumed,the patient recovers spontaneous breathing of both lungs.7.T6 15 minutes after chest closure: 15 minutes after the thoracic closure of the surgical side,the patient's operative lung was completely reexpanded,and spontaneous breathing of both lungs continued.8.T7 30 minutes after closing the chest: 30 minutes after the operation,the patient basically recovered to awake.Results and ConclusionReferring BIS,there was no significant difference at each time point between T1,T2,T3,T4,T5,P>0.05.T1 was statistically significant compared with the baseline value T0.T6 and T7 are statistically higher compare with T1(P<0.05).In terms of HR,there was no statistically significant difference between T1 and baseline T0 before thoracotomy after induction of anesthesia.There was no significant difference between T1,T2,T3,T4,and T5 at each time point,P>0.05.However,postoperative HR T6,T7 and T0,T1 were statistically significant,P<0.05.Referring MAP there was no statistically significant difference between T1 and baseline T0 after induction of MAP anesthesia.There was no statistically significant difference between T1,T3,T4,and T5 at each time point,P>0.05.However,the comparison between T1 before thoracoscopic chest opening and T2 after thoracotomy,and between postoperative T7 and T1 were statistically significant P<0.05.In terms of SPO2 there was no statistically significant difference between T1 and baseline T0 after induction of SPO2 anesthesia.There was no significant difference between T1,T4,and T5 at each time point,and there was no significant difference between T0,T1,T6,and T7,P>0.05.However,after thoracotomy,T2 and T3 were statistically significant compared with T1 and there was a statistically significant difference between T5 and T2 after thoracolumbar closure,P<0.05.Referring RR,there was no significant difference at each time point between T1,T3,T4,T5,and there was no statistically significant difference between T1 before thoracotomy and T6,T7 after chest closure.P>0.05.After anesthesia,T1 was statistically significant compared with baseline T0.T3 after thoracotomy was also statistically significant compared with T1 before thoracotomy P<0.05.In terms of CVP thoracotomy T2,T3,T4,chest close T5 and after chest close T6,T7 were increased compared with T1 before thoracotomy,P<0.05.This study preliminarily showed no significant changes of hemodynamic parameters perioperatively in the patients underwent VATS under total venous anesthesia for spontaneous breathing.