Thomachot L, Viviand X, Arnaud S, Vialet R, Albanese J, Martin C
Department of Anesthesia and Intensive Care, Hôpital Nord, Marseilles University Hospital System, Marseilles School of Medicine, France.
Acta Anaesthesiol Scand. 1998 Aug;42(7):841-4. doi: 10.1111/j.1399-6576.1998.tb05331.x.
Ventilation with endotracheal intubation bypasses the upper airway and the normal heat and moisture exchanging process of inspired gases. A continuous loss of moisture and heat occurs and predisposes patients to serious airway damage. We therefore prospectively studied one heated humidifier system, one cold humidifier system and one heat and moisture exchanger in spontaneously breathing, tracheostomized intensive care unit patients to determine the ability to preserve patients' heat and water.
Following a randomized order, 10 patients were spontaneously ventilated for 24-h periods with the Nam 35 humidifier (Europe Medical, France, a cold water humidifier), the heat and moisture exchange Trach-Vent (Gibeck, Sweden), and the Aerodyne humidifier (Kendall USA). In each patient, during the inspiration phase, the following measurements were performed: mean values of temperature and relative humidity of inspired gases. The absolute humidity was calculated. Values were obtained in each patients after 40 min and 24 h.
The Trach-Vent filter and the Aerodyne humidifier had better humidification and thermic capacities than the Nam 35 humidifier (P < 0.001). With the Nam 35 humidifier, no patient had temperature of inspired gas > 29 degrees C. Concerning absolute humidity of inspired gases, the Nam 35 humidifier achieved a lower performance than the other two tested systems (P < 0.001).
In spontaneously breathing, tracheostomized intensive care unit patients, the Trach-Vent heat and moisture exchanger and the Aerodyne heated system achieved satisfactorily preservation of heat and humidity of inspired gases.
气管插管通气绕过了上呼吸道以及吸入气体正常的热湿交换过程。水分和热量持续流失，使患者易发生严重气道损伤。因此，我们前瞻性地研究了一种加热加湿器系统、一种冷加湿器系统和一种热湿交换器，用于自主呼吸的气管切开重症监护病房患者，以确定它们保持患者热量和水分的能力。
按照随机顺序，10例患者分别使用Nam 35加湿器（欧洲医疗公司，法国，一种冷水加湿器）、热湿交换器Trach-Vent（瑞典吉贝克公司）和Aerodyne加湿器（美国肯德尔公司）进行24小时自主通气。在每位患者的吸气阶段，进行以下测量：吸入气体的温度和相对湿度平均值，并计算绝对湿度。在每位患者通气40分钟和24小时后获取相关数值。
Trach-Vent过滤器和Aerodyne加湿器的加湿和热容量优于Nam 35加湿器（P < 0.001）。使用Nam 35加湿器时，没有患者的吸入气体温度超过29摄氏度。关于吸入气体的绝对湿度，Nam 35加湿器的性能低于其他两个测试系统（P < 0.001）。
在自主呼吸的气管切开重症监护病房患者中，Trach-Vent热湿交换器和Aerodyne加热系统能令人满意地保持吸入气体的热量和湿度。
