Martin C, Papazian L, Perrin G, Saux P, Gouin F
Department of Anesthesia and Intensive Care, Sainte-Marguerite Hospital, Marseilles School of Medicine, France.
Crit Care Med. 1994 Nov;22(11):1871-6.
To compare the temperature and humidification output of one heated humidifier system (Bennett Cascade 2 Humidifier) and two heat and moisture exchangers (Pall Ultipor, BB 50, and Humid-Vent Filter) in intensive care unit (ICU) patients submitted to a minute ventilation of > 10 L/min.
Prospective, controlled, randomized, unblinded study.
ICU of a university hospital.
Eleven sedated and paralyzed patients who required controlled mechanical ventilation with a minute ventilation of > 10 L/min for > 3 days.
After a randomized selection process, the patients were ventilated for 24-hr periods with the humidifier and one of the heat and moisture exchangers. Both heat and moisture exchangers were first tested for 45 mins; then, the heat and moisture exchanger that demonstrated the best performance in terms of temperature and water preservation was tested for 24 hrs.
During the inspiration phase for each patient, the following measurements were performed: mean and minimum values of temperature, relative and absolute humidity of inspired gases. During the 45-min test period, the Humid-Vent Filter had a better temperature and humidification output than the Pall Ultipor Filter and thus was tested for 24 hrs. The Bennett Cascade 2 Humidifier and the Humid-Vent Filter had a better thermic capacity than the Pall Ultipor Filter (p < .001). No difference was ever observed between the Bennett Cascade 2 Humidifier and the Humid-Vent Filter regarding relative humidity. The Pall Ultipor Filter had a lower temperature and humidification output when compared with the other two systems (p < .007). Concerning absolute humidity of inspired gases, the Pall Ultipor Filter achieved a lower performance than any other tested systems (p < .02). A small but significant decrease in temperature and absolute humidity, but not in relative humidity, was seen after 24 hrs of use with the Humid-Vent Filter. However, with this heat and moisture exchanger, all patients had an absolute humidity of > 28 mg H2O/L and a relative humidity of > 93% after 24 hrs of use.
In patients with a minute ventilation of > 10 L/min (> 10.5 to 16.0 L/min), the Humid-Vent Filter had a temperature and humidification output close to the reference system (the Bennett Cascade 2 Humidifier). The Pall Ultipor Filter had a significantly lower temperature and humidification output in these patients.
比较一种加热湿化器系统（贝内特Cascade 2湿化器）和两种热湿交换器（颇尔Ultipor、BB 50和湿化通风过滤器）在分钟通气量>10L/min的重症监护病房（ICU）患者中的温度和湿化输出。
前瞻性、对照、随机、非盲研究。
大学医院的ICU。
11例接受镇静和肌松治疗、需要控制机械通气且分钟通气量>10L/min超过3天的患者。
经过随机选择过程后，患者分别使用湿化器和其中一种热湿交换器进行24小时通气。两种热湿交换器均先测试45分钟；然后，选择在温度和水分保持方面表现最佳的热湿交换器进行24小时测试。
在每位患者的吸气阶段，进行以下测量：温度的平均值和最小值、吸入气体的相对湿度和绝对湿度。在45分钟的测试期内，湿化通风过滤器的温度和湿化输出优于颇尔Ultipor过滤器，因此对其进行了24小时测试。贝内特Cascade 2湿化器和湿化通风过滤器的热容量优于颇尔Ultipor过滤器（p<0.001）。贝内特Cascade 2湿化器和湿化通风过滤器在相对湿度方面未观察到差异。与其他两个系统相比，颇尔Ultipor过滤器的温度和湿化输出较低（p<0.007）。关于吸入气体的绝对湿度，颇尔Ultipor过滤器的性能低于任何其他测试系统（p<0.02）。使用湿化通风过滤器24小时后，温度和绝对湿度有小幅但显著的下降，但相对湿度未下降。然而，使用这种热湿交换器时，所有患者在使用24小时后绝对湿度>28mg H2O/L，相对湿度>93%。
在分钟通气量>10L/min（10.5至16.0L/min）的患者中，湿化通风过滤器的温度和湿化输出接近参考系统（贝内特Cascade 2湿化器）。在这些患者中，颇尔Ultipor过滤器的温度和湿化输出明显较低。
