野战麻醉机中气动控制呼吸机的耗氧量

Oxygen consumption of a pneumatically controlled ventilator in a field anesthesia machine.

作者信息

Szpisjak Dale F, Javernick Elizabeth N, Kyle Richard R, Austin Paul N

机构信息

Department of Anesthesiology, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814, USA.

出版信息

Anesth Analg. 2008 Dec;107(6):1907-11. doi: 10.1213/ane.0b013e31818a04da.

DOI:10.1213/ane.0b013e31818a04da

PMID:19020137

Abstract

BACKGROUND

Field anesthesia machines (FAM) have been developed for remote locations where reliable supplies of compressed medical gases or electricity may be absent. In place of electricity, pneumatically controlled ventilators use compressed gas to power timing circuitry and actuate valves. We sought to determine the total O(2) consumption and ventilator gas consumption (drive gas [DG] plus pneumatic control [PC] gas) of a FAM's pneumatically controlled ventilator in mechanical models of high (HC) and low (LC) total thoracic compliance.

METHODS

The amount of total O(2) consumed by the Magellan-2200 (Oceanic Medical Products, Atchison, KS) FAM with pneumatically controlled ventilator was calculated using the ideal gas law and the measured mass of O(2) consumed from E cylinders. DG to the bellows canister assembly was measured with the Wright Respirometer Mk 8 (Ferraris Respiratory Europe, Hertford, UK). PC gas consumption was calculated by subtracting DG and fresh gas flow (FGF) from the total O(2) consumed from the E cylinder. The delivered tidal volume (V(T)) was measured with a pneumotach (Hans Rudolph, KS City, MO). Three different V(T) were tested (500, 750, and 1000 mL) with two lung models (HC and LC) using the Vent Aid Training Test Lung (MI Instruments, Grand Rapids, MI). Respiratory variables included an I:E of 1:2, FGF of 1 L/min, and respiratory rate of 10 breaths/min.

RESULTS

Total O(2) consumption was directly proportional to V(T) and inversely proportional to compliance. The smallest total O(2) consumption rate (including FGF) was 9.3 +/- 0.4 L/min in the HC-500 model and the largest was 15.9 +/- 0.5 L/min in the LC-1000 model (P < 0.001). The mean PC circuitry consumption was 3.9 +/- 0.24 L/min or 390 mL +/- 24 mL/breath.

CONCLUSIONS

To prepare for loss of central DG supply, patient safety will be improved by estimating cylinder duration for low total thoracic compliance. Using data from the smaller compliance and greatest V(T) model (LC-1000), a full O(2) E cylinder would be depleted in <42 min, whereas a full H cylinder would last approximately 433 min.

摘要

背景

野外麻醉机（FAM）是为那些可能缺乏可靠压缩医用气体供应或电力供应的偏远地区而开发的。气动控制呼吸机不用电，而是使用压缩气体来驱动定时电路并启动阀门。我们试图确定在高（HC）和低（LC）全胸顺应性的机械模型中，FAM的气动控制呼吸机的总氧气消耗量和呼吸机气体消耗量（驱动气体[DG]加气动控制[PC]气体）。

方法

使用理想气体定律和从E型气瓶消耗的氧气的测量质量，计算配备气动控制呼吸机的麦哲伦-2200（海洋医疗产品公司，堪萨斯州阿奇森）FAM的总氧气消耗量。使用赖特呼吸计Mk 8（法拉利呼吸欧洲公司，英国赫特福德）测量通向波纹管罐组件的DG。通过从E型气瓶消耗的总氧气量中减去DG和新鲜气体流量（FGF）来计算PC气体消耗量。使用呼吸流速仪（汉斯·鲁道夫公司，密苏里州堪萨斯城）测量呼出潮气量（V(T)）。使用通气辅助训练测试肺（MI仪器公司，密歇根州大急流城），在两种肺模型（HC和LC）上测试三种不同的V(T)（500、750和1000 mL）。呼吸变量包括吸呼比1:2、FGF 1 L/min和呼吸频率10次/分钟。

结果

总氧气消耗量与V(T)成正比，与顺应性成反比。最小的总氧气消耗率（包括FGF）在HC - 500模型中为9.3±0.4 L/min，最大的在LC - 1000模型中为15.9±0.5 L/min（P < 0.001）。PC电路的平均消耗量为3.9±0.24 L/min或390 mL±24 mL/次呼吸。