改装EcoScreen冷凝器收集机械通气患者呼出气冷凝液的研究

Application of Modified EcoScreen Condenser in Ventilated Patients for Collecting Exhaled Breath Condensate

目的探讨设计改装EcoScreen冷凝器收集机械通气患者呼出气冷凝液(EBC)的可行性。方法①体外模拟肺测试:改装EcoScreen冷凝器与模拟肺连接,在干燥呼吸机管道不连接湿化器、连接不加温湿化器、连接加温湿化器三种不同连接状态下机械通气60min,观察气道压和潮气量(VT)的变化,并测量收集冷凝液量。②人体测试:10例患者在干燥呼吸机管道不连接湿化器状态下进行机械通气20min,观察气道压、VT、呼吸频率及心率、血压、SpO2的变化。并测量收集冷凝液量。结果①体外模拟肺测试发现,干燥呼吸机管道不连接湿化器机械通气60min可收集冷凝液2.2mL,期间气道压、VT无明显增高,冷凝器收集管腔无阻塞;连接不加温湿化器,机械通气中VT下降伴气道压升高,50min时被迫中止测试,发现冷凝器收集管腔被冷凝物质明显堵塞,收集冷凝液5mL;连接加温湿化器机械通气60min,收集冷凝液10.5mL,期间气道压轻度升高,VT轻度下降。②人体测试显示,干燥呼吸机管道不连接湿化器,直接与呼吸机相连,机械通气20min可收集冷凝液2mL,收集过程中气道压、VT、呼吸频率及心率、血压和SpO2无显著变化。结论改装EcoScreen冷凝器可用于收集机械通气患者的EBC。为获得检测所需的足量EBC标本,并防止EBC被稀释和气道阻塞,建议脱离湿化器,收集时间20min,同时加强呼吸机和临床监护。

Objective To investigate the feasibility of collecting exhaled breath condensate （EBC） from artificially ventilated patients with modified EcoScreen condenser.Methods ①In vitro test with lung simulator：the modified EcoScreen condenser was connected to lung simulator and mechanically ventilated for 60 min through three different types of connected tube as follows：dry ventilator pipe disconnected to humidifier,connected to the unheated humidifier,and connected to heated humidifier.Meanwhile,the changes of the peak pressure of inspiration （PI） and tidal volume （VT） were observed.The volume of condensate was measured at last.②In vivo test from artificially ventilated patients：10 patients were artificially ventilated and their EBCs were collected with the modified EcoScreen condenser through dry pipe disconnected to humidifier for 20 min.The changes of PI,VT,respiratory frequency（f）,heart rate（HR）,mean arterial blood pressure （MAP）,and blood oxygen saturation （SpO2） were observed.Results ①In vitro test with lung simulator：At the end of the ventilating through the dry pipe disconnected to humidifier for 60 min,2.2 mL condensate was collected.Neither the change of PI or VT nor the obstruction of the collecting tube by iced condensate were observed.The ventilating through dry pipe connected to unheated humidifier had to stop at 50 min as the obstruction of the collecting tube caused by ice.5 mL condensate was collected.It was observed that VT decreased and PI increased.After ventilation through dry pipe connected to heated humidifier for 60 min,10.5 mL condensate was collected while PI slightly increased and VT decreased.②In vivo test from artificially ventilated patients：After ventilation through dry pipe disconnected to humidifier for 20 min,2 mL EBC was collected without significance changes in PI,VT,f,HR,MAP,and SpO2.Conclusions The modified EcoScreen condenser can be favourably applied to artificially ventilated patients for collecting EBC.It is recommended to perform for 20 min through the pipe disconnected to humidifier to obtain sufficient EBC without condensate dilution and airway obstruction.It is warranted more attention to the clinical and mechanical monitoring in this procedure.