Application Of Asphyxiation Technique In Thoracoscopic Segmentectomy

Objectives:To study the effect of asphyxiation technology on the intersegment plane display rate of thoracoscopic segment resection,and explore the effect of asphyxiation technology under different oxygen flow through tracheal catheter on the balance of oxygen supply and demand and the intracellular oxygen environment by further monitoring the oxygen metabolism indexes and serum hypoxia induction factor 1αbefore,during and after surgery,so as to confirm the most favorable mode of asphyxiation.In order to provide a strong basis for the application and method of asphyxiation in thoracoscopic segmental resection.Methods:The study was a prospective,randomized,double-blind controlled study,a total of81 patients,aged 22-65 years old,weighing 38-75kg,body mass index（BMI）16.89-27.05kg/m²,were selected from the same group of surgeons in the Third Affiliated Hospital of Kunming Medical University during December 2021 to December 2022 to undergo thoracoscopic segmentectomy.Rating is I-II by the american society of anesthesiologists（ASA）and I by the new york heart disease assocation（NYHA）.There were no serious cardiovascular and cerebrovascular diseases or severe hepatic and renal insufficiency before operation.The results of preoperative lung function and arterial blood gas analysis showed no obvious abnormalities.81 patients with random number table method points:proportion of random divided into one-lung mechanical ventilation group（Control group）,the double lumen endotracheal tube ventilation side for seats on a joint line 3L/min suffocation oxygen group（T₁）,the double lumen endotracheal tube ventilation side for seats on a joint line 7 L/min suffocation oxygen group（T₂）.All patients were forbidden to drink for>4 h and fasted for>8 h.Heart Rate（HR）,mean arterial pressure（MAP）and pulse oxygen saturation（Sp O₂）were monitored after entering the house.Right internal jugular vein puncture catheterization under local anesthesia,healthy radial artery puncture catheterization and connection with Flo Trac/Vigileo system were performed to perform stroke volume variability（SVV）and cardiac output（cardiac output）.CO),cardiac index（CI）,stroke volume（SV）and other indicators were monitored.In order to ensure the principle of blindness,Flo Trac/Vigileo was connected to block the screen,and the above monitoring indicators could only be recorded by the anesthesia nurse periodically.All patients in the three groups were given the same anesthetic drugs and methods.After anesthesia induction,double-lumen bronchial intubation was performed on the healthy side.After intubation and change of body position,fibrobronchoscope was used for localization.After anesthesia,mechanical ventilation parameters were set as follows:Fi O₂=1.0,volume control mode was adopted,tidal volume was 6～8m L/kg and suction/breathing ratio was1:1.5.During one-lung ventilation,the tidal volume was 4～6 m L/kg,and the respiration rate was adjusted by end-tial CO₂ gas tension(P_ETCO₂).All patients in the three groups were treated with target-oriented fluid therapy as the fluid management strategy.That is,based on Flo Trac/Vigileo system monitoring,fluid management was carried out with the target SVV value of 8～10%and CI>2.5L/min·m^-2 as the guidance,and intraoperative blood pressure fluctuation was maintained within±20%,maintain BIS at 40～60.The indicators observed and recorded were:ventilation（T₀）,Two-lung ventilation for 15min（T₁）,one-lung Ventilation 15min（T₂）,immediately after pure oxygen double lung reexpansion（T₃）,intersegment plane display immediately（T₄）,15min after trachea extubation（T₅）,vital signs of patients at each time point:Sp O₂,HR,MAP;Cardiac output measurement indexes:CO,CI,SV;Arterial blood gas analysis index:potential of hydrogen（p H）,hemoglobin（Hb）,oxygenation index（PO₂/Fi O₂）,arterial partial pressure（Pa CO₂）,alvelor arterial oxygen partial pressure（A-a O₂）,lactic acid value（Lac）,oxyhemoglobin（O₂Hb）,and deoxyhemoglobin（h Hb）;central venous oxygen saturation（Scv O₂）and central venous oxygen content（Cv O₂）were the indicators of central venous oxygen saturation（Scv O₂）.Oxygen supply（DO₂）,Oxygen consumption（VO₂）and Oxygen extraction ratio（O₂ER）were calculated.Time of emergence of ideal intersegmental plane,single lung ventilation time,operation time,postoperative recovery time,extubation time;Intraoperative infusion volume,urine volume,blood loss,times of use of vasoactive drugs during intersegment plane waiting,and whether arrhythmia occurred during intersegment plane waiting;Serum Hypoxia inducible factor 1（HIF-1α）level before surgery,at the end of surgery and 24h after surgery;Pathological diagnosis results of rapid intraoperative freezing,postoperative hospitalization days,postoperative complications（subcutaneous emphysema,pneumothorax,mediastinal emphysema,atelectasis,pulmonary infection）,incidence of cerebrovascular complications 3 months after surgery.Results:A total of 81 patients who were scheduled to undergo thoracoscopic segmotomy participated in this study and were randomly divided into group C,group T1 and group T2 by using a random number table method at 1:1:1,among which 6 patients were excluded（3 patients due to incomplete clinical data and 3 patients with intraoperative changes in surgical methods）.A total of 75 patients were enrolled in the study,25 in each group.1.Results of preoperative general dataThere were no significant differences in age,sex composition ratio,height,weight,BMI,ASA grading,smoking history ratio,nodule size,nodule location,lung function indexes and other general data among the three groups（P>0.05）.2.Results of intraoperative general dataThere were no significant differences among the three groups in anesthesia time,operation time,single lung ventilation time,blood loss,infusion volume,urine volume,times of use of vasoactive drugs during intersegment plane waiting,proportion of arrhythmia cases during intersegment plane waiting,proportion of intraoperative rapid freezing pathological diagnosis（P>0.05）.3.Results of intraoperative ideal intersegmental plane display timeThe time of intersegment plane display in T₁ and T₂groups was shorter than that in C group,and the difference was statistically significant（P<0.05）.The comparison of intersegment plane display time between T₁group and T₂group had no significant difference（P>0.05）.4.Intraoperative oxygen metabolism indexesExcept T₄,there were no significant differences in DO₂,VO₂,O₂ER,Scv O₂ and Lac at other time points among the three groups（P>0.05）.At T₄,there was no significant difference in DO₂ and Lac among three groups（P>0.05）.VO₂ and O₂ER in groups T₁ and T₂ were lower than those in group C,and the difference was statistically significant（P<0.05）.Scv O₂ in groups T₁ and T₂ was higher than that in group C,and the difference was statistically significant（P<0.05）.There were no significant pairwise differences in VO₂,O₂ER and Scv O₂ at T₄ between T₁ and T₂groups（P>0.05）.5.Results of other intraoperative indicatorsThere was no significant difference in hemodynamic indexes（HR,MAP,SVV,CO,SV,CI）at T₀,T₁,T₂,T₃,T₄,T₅ among the three groups（P>0.05）.There was no significant difference in arterial blood gas analysis indexes（Hb and Ca O₂）between groups（P>0.05）.There was no significant difference in PO₂/Fi O₂,PCO₂,A-a O₂,O₂Hb and h Hb among the three groups except T₄time point（P>0.05）.At T₄,p H,PO₂/Fi O₂,A-a O₂ and O₂Hb in groups T₁ and T₂ were lower than those in group C,and the difference was statistically significant（P<0.05）.PCO₂ and h Hb in group T₁ and T₂were higher than those in group C,and the difference was statistically significant（P<0.05）.PCO₂in group T₁ was higher than that in group T₂,and the difference was statistically significant（P<0.05）.Pairwise comparison of other indicators（p H,PO₂/Fi O₂,A-a O₂,O₂Hb,h Hb）between group T₁ and group T₂ showed no statistically significant difference（P>0.05）.There was no statistical significance in The Times of vasoactive drug use and the component ratio of arrhythmia cases during the intersegment plane waiting period among the three groups（P>0.05）.6.Results of serum hypoxia inducible factor 1αThere was no significant difference in serum hypoxia inducible factor 1αlevels among three groups before,immediately after and 24h after surgery（P>0.05）.The serum HIF-1αlevel in three groups immediately after surgery and 24h after surgery was higher than that before surgery,the difference was statistically significant（P<0.05）.Serum HIF-1αlevel at 24h after surgery was slightly lower than that immediately after surgery,but the difference was not statistically significant（P>0.05）.7.Results of postoperative indicatorsThere were no significant differences in postoperative recovery time,extubation time,postoperative hospital stay,postoperative subcutaneous emphysema,pneumothorax,mediastinal emphysema,atelectasis,pulmonary infection,and the incidence of cardiovascular complications 3 months after surgery among the three groups（P>0.05）Conclusions:1.In thoracoscopic segmental resection,both conventional single-lung mechanical ventilation and asphyxiation can clearly display the plane between lung segments in the modified dilatation wilt method,providing necessary conditions for surgeons to accurately remove lung segments.2.Compared with conventional single-lung mechanical ventilation,asphyxiation technique can effectively accelerate the rate of intersegment plane display and ensure adequate oxygen supply during the operation.It has no obvious influence on the balance of oxygen supply and demand and the intracellular oxygen environment,and has good safety at the level of cells,tissues and organs.3.Compared with 7L/min oxygen flow,there was no statistical significance in the safety and effectiveness of 3L/min oxygen flow asphyxiation technique,but the intraoperative arterial blood carbon dioxide partial pressure was higher,suggesting that low flow asphyxiation may affect the removal of carbon dioxide and increase the accumulation risk.