最低安全压力下不同形状气囊气管导管封闭效果的体外研究

In vitro study on the sealing effect of different shapes of cuff tracheal tubes under the lowest safe pressure

目的比较最低安全压力下不同测压方法评估柱形气囊和锥形气囊导管封闭气道的有效性,以指导临床应用。方法选择2021年12月至2022年1月广西医科大学附属肿瘤医院重症监护病房(ICU)收治的24例气管插管患者,对其气囊上的滞留物进行体外渗漏实验。取20 mL注射器,分离针头及活塞后用胶水封闭,并将注射器乳头充分填满,制成气管模型。分别将柱形气囊导管和锥形气囊导管置入模拟气管,校正气囊压力为20 cmH2O(1 cmH2O≈0.098 kPa)后开始实验。对患者气囊上滞留物进行黏稠度分级(Ⅰ度为水样,Ⅱ度为黏稠样,Ⅲ度为凝胶样),抽取相同黏稠度滞留物注入到模拟气管内的导管气囊上,采用自身对照方法,先分别对柱形气囊和锥形气囊采用改进测压法进行间断测压实验(间断测压组),再进行持续测压实验(持续测压组)。记录不同形状气囊导管充气4、6、8 h 3种黏稠度滞留物渗漏量及气囊压力检测值。结果24例气管插管患者通气过程中共抽取180份滞留物样本,不同测压方法两组各90份,两组内不同黏稠度滞留物样本各30份。间断测压组充气4 h时柱形气囊上Ⅰ度、Ⅱ度黏稠度滞留物即全部发生渗漏,Ⅲ度黏稠度滞留物也有3份样本渗漏;而锥形气囊上Ⅰ度黏稠度滞留物有28份样本渗漏,Ⅱ度黏稠度滞留物仅有2份样本渗漏,Ⅲ度黏稠度滞留物则无渗漏。充气6 h时不同形状气囊上3种黏稠度滞留物均发生渗漏,且渗漏量随充气时间延长而逐渐增加。持续测压组充气4 h时柱形气囊上Ⅰ度黏稠度滞留物均发生渗漏,Ⅱ度黏稠度滞留物有29份样本渗漏,Ⅲ度黏稠度滞留物无渗漏;而锥形气囊上Ⅰ度黏稠度滞留物有26份样本渗漏,Ⅱ度、Ⅲ度黏稠度滞留物均无渗漏。充气6 h时锥形气囊上Ⅲ度黏稠度滞留物仍无渗漏。随充气时间延长,两组不同形状气囊上滞留物渗漏情况均逐渐加重,充气8 h时全部样本均发生渗漏,但持续测压组不同形状气囊上滞留物渗漏量均较间断测压组明显减少〔Ⅲ度黏稠度滞留物(mL):柱形气囊为1.00(0.00,1.25)比2.00(1.00,2.00),锥形气囊为1.00(0.00,1.00)比2.00(2.00,2.00),均P<0.01〕。持续测压组充气各时间点不同形状气囊导管气囊压力检测值均在设定范围内(20~21 cmH2O)。间断测压组气囊压力在充气4 h时即明显低于初始压力(cmH_(2)O:柱形气囊为18.3±0.6比20.0±0.0,锥形气囊为18.4±0.6比20.0±0.0,均P<0.01),且随充气时间延长而逐渐下降;但不同形状气囊导管各时间点气囊压力检测值差异均无统计学意义。结论持续测压设备可维持锥形气囊导管在最低安全压力时有较好的封闭效果;采用改进测压法进行间断测压和(或)选用柱形气囊导管时,应将目标压力设定为25~30 cmH_(2)O,并定时调整气囊压力。

Objective To compare the effectiveness of cylindrical-shaped and conical-shaped cuff catheters for airway closure using different pressure measurement methods at the lowest safe pressure and to guide the clinical application.Methods Twenty-four patients with endotracheal intubation admitted to the intensive care unit(ICU)of Guangxi Medical University Cancer Hospital from December 2021 to January 2022 were enrolled.Leakage test in vitro was performed on the secretion on the patients'cuff.The needle and plunger from 20 mL syringe was separated,the syringe was sealed with adhesive,and the syringe nozzle was filled thoroughly to create a tracheal model.Consecutively,both cylindrical-shaped and conical-shaped cuff catheters were inserted into the simulated trachea,and the cuff pressure was calibrated to 20 cmH2O(1 cmH2O≈0.098 kPa)before commencing the experiment.The viscosity of the secretion on the patients'cuff was classified(grade Ⅰ was watery subglottic secretion,grade Ⅱ was thick subglottic secretion,grade Ⅲ was gel-like subglottic secretion),and the same viscosity secretion was injected into the catheter cuff.Utilizing a self-control approach,intermittent pressure measurement was initially conducted on both the cylindrical-shaped and conical-shaped cuff by improved pressure measurement method(intermittent pressure measurement group),followed by continuous pressure measurement experiment(continuous pressure measurement group).The leakage volume of the three viscosity subglottic secretions and the values of cuff pressure measurement of different shaped cuff catheters at 4,6,8 hours of inflation were recorded.Results A total of 180 retention samples were extracted from 24 patients with tracheal intubation during ventilation,with 90 samples in each of the two groups using different pressure measurement methods,and 30 samples of retention materials with different viscosities in each group.In the intermittent pressure measurement group,at 4 hours of inflation,all samples of secretion with grade Ⅰ and grade Ⅱ on cylindrical-shaped cuff leaked,while 3 samples of secretion with grade Ⅲ also leaked.For conical-shaped cuff,28 samples of secretion with gradeⅠleaked,only 2 samples of secretion with grade Ⅱ leaked,and there was no leak for secretion with grade Ⅲ.At 6 hours of inflation,all samples of the three viscosity secretions on different shaped cuffs leaked.The leakage was gradually increased with the prolongation of inflation time.In the continuous pressure measurement group,at 4 hours of inflation,all samples of secretion with gradeⅠon cylindrical-shaped cuff leaked,while 29 samples of secretion with grade Ⅱ leaked,and there was no leak for secretion with grade Ⅲ.For the conical-shaped cuff,26 samples of secretion with gradeⅠleaked,and there was no leak for secretion with grade Ⅱ and grade Ⅲ.At 6 hours of inflation,the conical-shaped cuff still had no leak for secretion with grade Ⅲ.As the inflation time prolonged,the leakage of subglottic secretion on different shaped cuffs in both groups was gradually increased.At 8 hours of inflation,all samples experienced leakage,but the leakage of subglottic secretion on different shaped cuffs in the continuous pressure measurement group was significantly reduced as compared with the intermittent pressure measurement group[leakage for secretion with grade Ⅲ(mL):1.00(0.00,1.25)vs.2.00(1.00,2.00)on the cylindrical-shaped cuff,1.00(0.00,1.00)vs.2.00(2.00,2.00)on the conical-shaped cuff,both P<0.01].The values of pressure measurement of cuffs with different shapes at different time points of inflation in the continuous pressure measurement group were within the set range(20-21 cmH_(2)O).The cuff pressure at 4 hours of inflation in the intermittent pressure measurement group was significantly lower than the initial value(cmH_(2)O:18.3±0.6 vs.20.0±0.0 in the cylindrical-shaped cuff,18.4±0.6 vs.20.0±0.0 in the conical-shaped cuff,both P<0.01),and the cuff pressure in both shaped cuffs showed a significant decrease tendency as inflation time prolonged.However,there was no statistically significant difference in values of pressure measurement between the different shaped cuff catheters.Conclusions Continuous pressure monitoring devices can maintain the effective sealing of conical-shaped cuff catheters at the lowest safe pressure.When using an improved pressure measurement method for intermittent pressure measurement and/or using a cylindrical cuff catheter,the target pressure should be set at 25-30 cmH2O,and the cuff pressure should be adjusted regularly.