两种复合型呼吸过滤器在通气模型中的滤菌效应

Bacteriological Filtration Efficiency of Two Compound Membrane Breathing Filters in Mechanical Model

目的探讨两种复合型呼吸过滤器(breathing filer,BF)DAR 352/5805(D组)和Vital signs 5708 HE-PA(V组)的滤菌效果。方法用测试液对BF行液体渗透性测试。建立模拟通气环路,对两组BF依次进行3种方法(Ⅰ、Ⅱ、Ⅲ)的测试,通气3 h后,在模拟肺侧、呼吸环路侧、Y型接头内侧采样并孵育24 h。结果随着测试液的加入,V组测试液不断渗入到亲水性滤过膜部分,加入5 ml时可观察到少量蓄积,加入12 ml时,出现测试液明显蓄积且有少量测试液渗入到其疏水膜部分,但测试液未从膜对侧渗出;D组一直表现为测试液不断渗入到亲水性滤过膜中,无测试液渗入到疏水膜中或从滤过膜对侧渗出。模拟机械通气后,V组和D组在采样点模拟肺侧细菌培养均为阳性。在采样点呼吸环路侧和Y型接头内侧,方法Ⅰ中,两组细菌培养均为阴性;方法Ⅱ和Ⅲ中,V组细菌培养均为阳性,D组细菌培养均为阴性,两组比较差异有统计学意义(P<0.05)。结论复合型BF具有明显的滤菌效果;但当滤过膜有液体蓄积时,DAR 352/5805呼吸过滤器的滤菌效应优于Vital signs 5708 HEPA呼吸过滤器。

Objective To compare the efficiency of two compound membrane Breathing Filters（BFs） namely DAR 352/5805（group D） and Vital signs 5708 HEPA（group V） on bacteriological filtration.Methods Liquid permeability test was conducted on BF.The two groups of BFs were tested by three methods（Ⅰ,Ⅱ,Ⅲ） after establishing simulated ventilation hoop.After three hours ventilation,samples were taken from simulated lung,ventilation hoop and inner side of Y joint and then the samples were cultivated for 24 hours.Results With the addition of liquid,the liquid in group V continuously infiltrated into hydrophilic membrane and when the liquid reached 5 ml,a little accumulation was seen.When the liquid reached 12ml,obvious accumulation was seen and a small amount of liquid infiltrated into hydrophobic membrane,but no liquid infiltrated into the opposite side of the membrane.The liquid in group D continuously infiltrated into hydrophilic membrane and no liquid infiltrated into hydrophobic membrane or the opposite side of the membrane.After simulated ventilation,samples of cultivated bacteria from simulated lung were positive both in group V and group D.While samples from ventilation hoop and Y joint by method Ⅰ were both positive in the two groups.While these samples by methods Ⅱ and Ⅲ were positive in group V and were negative in group D.The differences between the two groups were statistically significant（P〈0.05）.Conclusion The compound membrane breathing filters have good efficiency on bacteriological filtration.However,when the liquid infiltrates into the hydrophobic membrane,the bacteriological filtration of DAR is better than that of Vital signs.