Gilmour I J, Boyle M J, Rozenberg A, Palahniuk R J
Department of Anesthesiology, University of Minnesota Medical School, Minneapolis.
Anesth Analg. 1994 Jul;79(1):160-4. doi: 10.1213/00000539-199407000-00030.
We performed this study to determine the effect of heated wire circuits on humidity delivered by several humidifiers commonly used during anesthesia. Humidifier bases from three manufacturers with several humidifying chambers for each base were tested using both heated and unheated circuits. Delivered humidity and circuit temperature were measured at the distal end of the circuit. Each chamber was tested under both continuous flow (CF) and intermittent flow (IF) conditions. IF was provided by a Servo 900 B ventilator. Adjustments of flow and volume were made for pediatric chambers. At 90 L/m CF, humidifier performance was unsatisfactory with both heated and unheated circuits. At 15 and 45 L/m CF, both distal circuit temperature (DCT) and humidity were within acceptable limits; unheated circuits delivered more humidity than heated circuits (P < 0.05). Relative humidity was lower at 45 L/m CF than at 15 L/m (P < 0.05). During IF while all chambers provided satisfactory humidity, humidity was greater when unheated circuits were used. We conclude that when heated circuits are used, humidifying systems may fail to deliver 100% humidity to patients.
我们进行这项研究以确定加热丝回路对麻醉期间常用的几种加湿器所输送湿度的影响。对来自三个制造商的加湿器底座进行测试，每个底座有多个加湿腔，分别使用加热回路和未加热回路。在回路远端测量输送的湿度和回路温度。每个腔在持续气流（CF）和间歇气流（IF）条件下进行测试。IF由Servo 900 B呼吸机提供。对儿科腔进行了流量和容量调整。在90 L/m CF时，加热回路和未加热回路的加湿器性能均不令人满意。在15和45 L/m CF时，远端回路温度（DCT）和湿度均在可接受范围内；未加热回路输送的湿度比加热回路更多（P < 0.05）。45 L/m CF时的相对湿度低于15 L/m时（P < 0.05）。在IF期间，虽然所有腔都能提供令人满意的湿度，但使用未加热回路时湿度更大。我们得出结论，当使用加热回路时，加湿系统可能无法向患者输送100%的湿度。
