The Influence Of Artificial CO₂ Room On Human Physiological Functions In Brest-approach Endoscopic Neck Surgery

Objective:To study the influence of carbon dioxide room with pressure of 5mmHg on human internal environment and circulatary,respiratory functions during Breast-approach endoscopic neck surgery,meanwhile investigate the possible mechanism and reasonable monitoring,managing measures,thus evaluate the feasibility and safety of this new technology.Methods:40 patients who were diagnosed by type B ultrasonography as mono- or bi-lateral thyroid node and prepared to be treated through operation are included in this study.20 of them were distributed randomly to experiment group,receiving endoscopic surgery.Another 20 as control group,receiving traditional open surgery.Their were 4 monitoring point in each group(T₁,T₂,T₃,T₄),in experiment group they are:after anesthesia is stable but before insufflation,10min after insufflation,30min after insufflation,60min after insufflation,in control group they are:after anesthesia is stable but before operation,15min after operation,35min after operation,65min after operation.The follwoing index were observed and recorded:heart rate(HR),blood pressure(systolic pressure/diastolic pressure, SBP/DBP),peak pressure of the airway(Ppeak),terminal expiratory CO₂ pressure(PetCO₂), arterial blood was obtained from radial artery to measure the blood gas values:Aterial blood CO₂ pressure(PaCO₂),PH,[HCO₃^-],base excess(BE),concerntration of lactic(Lac) and O₂ pressure(PaO₂),saturation of O₂(SaO₂),caculate the elimination amount of CO₂ at each point(VCO₂),compare the inner- and inter-group differences.Measure the skin flap area of experiment group(S),analyse the relation between change of VCO₂ and S.Results:All patients underwent operations successfully,no complications during or after operation were observed.(1)experiment group:â‘ Blood gas:There is significant statistical difference between values of PaCO₂,PH before insufflation and 10min after insufflation,P＜0.05,no significant statistical differences exist refer to BE,[HCO₃^-],Lac,P＞0.05,There is significant statistical difference between values of PaCO2,PH,[HCO₃^-] 10min after insufflation and 30min after insufflation,P＜0.05,no significant statistical differences exist refer to BE,Lac,P＞0.05,There is significant statistical difference between values of PaCO₂,PH,[HCO₃^-]30min after insufflation and 60min after insufflation,P＜0.05,no significant statistical differences exist refer to BE,Lac,P＞0.05,There is significant statistical difference between values of PaCO₂,PH,[HCO₃^-]before insufflation and 30min after insufflation,P＜0.05,no significant statistical differences exist refer to BE,Lac,P＞0.05,There is significant statistical difference between values of PaCO₂,PH,[HCO₃^-]before insufflation and 60min after insufflation,P＜0.05,no significant statistical differences exist refer to BE,Lac,P＞0.05;â‘¡Circulatory functions:There is significant statistical difference between values of HR before insufflation and 10min after insufflation,P＜0.05,no significant statistical differences exist refer to SBP,DBP,P＞0.05,There is no significant statistical difference between HR,SBP,DBP before insufflation and 30min after insufflation,P＞0.05,There is no significant statistical difference between them before insufflation and 60min after insufflation,P＞0.05;â‘¢Respiratory functions:There is significant statistical difference between values of PetCO₂,VCO₂ before insufflation and 10min after insufflation,P＜0.05,There is no significant statistical difference between values of Ppeak,VD before insufflation and 10min after insufflation,P＞0.05,There is significant statistical difference between values of PetCO₂,VCO₂ before insufflation and 30min after insufflation,P＜0.05,There is no significant statistical difference between values of Ppeak,VD before insufflation and 30min after insufflation,P＞0.05,There is significant statistical difference between values of PetCO₂,VCO₂ before insufflation and 60min after insufflation,P＜0.05,There is no significant statistical difference between values of Ppeak,VD before insufflation and 60min after insufflation,P＞0.05,There is significant statistical difference between values of PetCO₂,VCO₂ 10min after insufflation and 30min after insufflation,P＜0.05,There is no significant statistical difference between values of Ppeak,VD 10min after insufflation and 30min after insufflation,P＞0.05,There is significant statistical difference between values of PetCO₂,VCO₂ 30min after insufflation and 60min after insufflation,P＜0.05,There is no significant statistical difference between values of Ppeak,VD 30min after insufflation and 60min after insufflation,P＞0.05;(2)Control group:â‘ Blood gas:There is no significant statistical difference between values of PaCO₂,PH,[HCO₃^-],BE,Lac among any point during operation,P＞0.05;â‘¡Circulatory functions:There is no significant statistical difference between values of HR,SBP,DBP among any point during operation,P＞0.05;â‘¢Respiratory functions:There is no significant statistical difference between values of Ppeak,PetCO₂,VD,VCO₂ among any point during operation,P＞0.05;(3)Comparison between two groups:â‘ Blood gas:There is significant statistical difference between changes of PaCO₂,PH,[HCO₃^-]when comparing two groups at the according time points after insufflation vs before insufflation, P＜0.05,There is no significant statistical difference between changes of BE,Lac,PaO₂,SaO₂ when comparing two groups at the according time points after insufflation vs before insufflation,P＞0.05;â‘¡Circulatory functions:There is significant statistical difference between changes of HR when comparing two groups 10min after insufflation(15min after operation) vs before insufflation(before operation),P＜0.05,There is no significant statistical difference between changes of SBP,DBP when comparing two groups 100min after insufflation(15min after operation) vs before insufflation(before operation),P＞0.05,There is no significant statistical difference between changes of HR,SBP,DBP when comparing two groups 30min after insufflation(35min after operation) and 60min after insufflation(65min after operation) vs before insufflation(before operation),P＞0.05â‘¢Respiratory functions:There is significant statistical difference between changes of PetCO₂,VCO₂ when comparing two groups at the according time points after insufflation vs before insufflation,P＜0.05,There is no significant statistical difference between changes of Ppeak,VD when comparing two groups at the according time points after insufflation vs before insufflation,P＞0.05;(4)Relations between VCO₂ and S:The correlation betweenâ–³VCO₂ of T₃,T₄ vs T₁ and S is linear,P＜0.05,correlation coefficient is 0.776 and 0.834 respectively.Conclusion:The main effects occurred to human physiology after establishment of carbon dioxide room during breast-apporach endoscopic neck surgery were elevation of PaCO₂,[HCO₃^-],and decrease of pH,but they were still within normal ranges,no significant changes happened to circulatory and respiratory function;the absorption of CO₂ increased as the area of skin flap increased.In general,the safety and feasibility of carbon dioxide as mediator for establishing surgical room are high enough.we should pay attention(1) Closely monitor during operation,adjust ventilation volume according to PetCO₂ or PaCO₂;(2)Control the pressure of gas room,with good cooperation,5mmHg is enough to obtain a satisfactory manipulating room;(3)Minimizing the skin flap,and searching correct segregation plane,can decrease absorption of CO₂.