Influence Of The Occurrence Of Intrinsic Positive End-expiratory Pressure In Children Intubated With Different Types Of Tracheal Catheter

Objective:Intrinsic positive end-expiratory pressure(PEEPi)is defined as an elevation in the end-expiratory lung volume which exceed predicted functional residual capacity due to the expiratory airflow obstruction or the insufficiency of the effective expiratory time.Low level of PEEPi can reduce the degree of atelectasis,and it is beneficial to respiratory function,but high level of PEEPi can cause barotrauma,hemodynamic compromise,hypotension and other adverse events.There are no reports on whether PEEPi forms in pediatric surgeries under general anesthesia.The aim of this study was to observe the incidence of PEEPi and related respiratory mechanical parameters in children applied with different types of tracheal catheter under general anesthesia,and analyzed the correlation between the respiratory mechanical parameters and PEEPi in order to provide reference for clinical work.Methods:Ninty-five patients scheduled to undergo endoscopic hypothermic plasma adenoidectomy(tonsillectomy)were sequentially involved in thestudy.According to the actual type of tracheal catheter,the children were divided into theoretical type group,half size smaller group and one size smaller group based on the formula “ID=4+(1/4)×age”.In children over 2year-old,we chose the type of tracheal catheter according to the traditional formula “ID=4+(1/4)×age” for the first time.At the same time,if not matchable,we pepared the half size smaller one and one size smaller one for another choice.After the intubation,the patient was connected to the ventilator.Volume-controlled ventilation was set as follows: tidal volume(VT),8 to 10 m L/kg ideal body weight;the inspiratory/expiratory ratio(I:E),1:2;respiratory rate to maintain end-tidal partial pressure of carbon dioxide(PETCO2)between 30 and 40 mm Hg;inspiratory pause,10%;No PEEPe was applied.Attention should be paid to keeping the respiratory duct unobstructed.When completing the induction of anesthesia(T1)and 10 minutes after anesthesia induction(T2),PEEPi,Crs,Ppeak and Pplat were measured and recorded.Comparing the occurrence of PEEPi among groups.PEEPi was measured with the end-expiratory occlusion method just before the next inhalation and recorded.All statistical analyses were performed using SPSS version19.0.The non-normal distribution data were presented as P50(P25,P75).Inter-group comparisons were conducted with ?2test and the rank sum.The correlation analysis was carried out by Spearman correlation.The value of P<0.05 was considered to be statistically significant.Results:There were no significant differences in age,sex,BMI,time of induction,time of surgery,VT,respiractory rate,Ppeak,and Crs between the three groups(P>0.05).There was significant difference in Pplateau among the three groups(P<0.05).There was no significant difference in PEEPi between the half size smaller group and the theoretical type group(P>0.05).There was significant difference in PEEPi between the one size smaller group and the theoretical type group(P <0.05).There was significant difference in PEEPi between the one size smaller group and half size smaller group(P < 0.05).There is correlation between Pplateau and PEEPi(r=0.737,P<0.05).Conclusions:Endotracheal intubation with one size smaller tracheal catheter promotes the occurrence of PEEPi.Pplateau is related to PEEPi,which has some clinical significance.