Construction and uses of a concentric catheter for gas sampling in lung airways.
Construction and uses of a concentric catheter for gas sampling in lung airways.
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用于肺气道气体采样的同心导管的构造和使用。
DOI：
10.1152/jappl.1993.74.6.3063
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发表时间：
1993
期刊：
影响因子：
--
通讯作者：
Drazen,JM
中科院分区：
文献类型：
--
作者：
Gavriely,N;Solway,J;Elad,D;Shabtai-Musih,Y;Gaver3rd,DP;Grotberg,JB;Drazen,JM
用同心聚乙烯管构建了一种用于呼吸道内气体浓度采样的导管。内管(内径0.58 mm，外径0.91 mm)连接到气体分析仪，而外管(内径1.20 mm，外径1.75 mm)不断用空气或校准气体冲洗，除非在采样期间。进样和进样死区分别为0.35和0.28毫升。在4毫升/分钟采样速率下的延迟为4+/-0.2 S。当连接质谱仪时，对气体成分突然变化的0-90%阶跃响应为0.24 S。该导管被用来评估示踪气体在直长管内振荡流动(1-20赫兹)中的分散情况。在通过外管注入少量示踪气体后，通过导管测量的局部浓度，与通过管壁插入针头的直接测量和理论预测相比，是有利的。该导管还被用来测量在自主呼吸、常规机械通气、高频通气、高频振动通风和恒流通风过程中犬呼吸道内气体浓度。由纤维支气管镜放置，用团注法测量局部准稳态二氧化碳浓度和局部弥散度。分泌物堵塞导管的发生随着流经外管而大大减少。通过外管传输校准气体便于在不移除导管的情况下就地重新校准气体分析仪。该导管的使用提高了测量肺内气体浓度的效率和准确性。
A catheter for intra-airway sampling of gas concentrations was constructed from concentric polyethylene tubes. The internal tube (0.58 mm ID, 0.91 mm OD) was connected to a gas analyzer while the external tube (1.20 mm ID, 1.75 mm OD) was constantly flushed by air or a calibration gas, except during sampling. Injection and sampling dead spaces were 0.35 and 0.28 ml, respectively. Delay at 4-ml/min sampling rate was 4.0 +/- 0.2 s. The 0–90% step response to a sudden change in gas composition was 0.24 s when connected to a mass spectrometer. This catheter was used to assess tracer gas dispersion during oscillatory flow (1–20 Hz) in a straight long tube. Local concentrations measured through the catheter, after a small bolus of tracer gas was injected through the external tube, compared favorably with direct measurements through needles inserted via the tube wall and with theoretical predictions. The catheter was also used to measure intra-airway gas concentrations in dog airways during spontaneous breathing, conventional mechanical ventilation, high-frequency ventilation, high-frequency vibration ventilation, and constant-flow ventilation. It ws placed by a fiber-optic bronchoscope and used to measure local quasi-steady concentrations of CO2 and local dispersion with the bolus method. The occurrence of catheter clogging with secretions was substantially reduced with flow through the external tube. Transmitting a calibration gas through the external tube facilitated in situ recalibration of the gas analyzer without removing the catheter. The use of this catheter improved the efficiency and accuracy of measurements of gas concentrations inside lung airways.