Natalini G, Bardini P, Latronico N, Candiani A
Dept of Anesthesiology and Intensive Care, University of Brescia, Italy.
Monaldi Arch Chest Dis. 1994 Dec;49(6):561-4.
The upper airways warm and saturate inspired air with water vapour. In intubated or tracheotomized patients, this function is replaced either by hot water humidifiers or by heat and moisture exchangers (HMEs). The aim of this study was to quantify the modifications of ventilatory mechanics and patients' work when two different HMEs were added to spontaneously breathing patients. We studied nine consecutive patients with no previous history of chronic obstructive lung disease. All patients had been weaned from mechanical ventilation. They were breathing through devices supplying positive end-expiratory pressure and/or O2 enrichment. Two different HMEs were used: Icor Mediflux 1 and Icor Mediflux 2. These HMEs have identical chemical composition and configuration, but the Mediflux 1 is larger than the Mediflux 2. The humidification of the inspired gases was obtained alternatively by an active humidifier and the two HMEs. Data regarding ventilatory pattern and respiratory mechanics were collected by pulmonary monitor CP100 (Bicore). Tidal volume, work of breathing and pressure-time product were greater with Mediflux 1 than with Mediflux 2 or active humidifier. There were no significant differences in respiratory rate, intrinsic positive end-expiratory pressure (PEEPi), rapid shallow breathing index, arterial CO2 and O2 partial pressure. The larger HME (Mediflux 1) increased patient's effort, with no evidence of patient discomfort. However, the smaller HME (Mediflux 2) did not add a detectable load and provided adequate humidification. In conclusion, the smaller HME appears to be preferable for the management of spontaneously breathing patients.
上呼吸道可使吸入的空气升温并使其充满水蒸气。对于插管或气管切开的患者，这一功能可由热水加湿器或热湿交换器（HME）替代。本研究的目的是量化在自主呼吸患者中添加两种不同的HME时通气力学和患者做功的改变。我们研究了9例既往无慢性阻塞性肺疾病病史的连续患者。所有患者均已撤机。他们通过提供呼气末正压和/或氧气富集的装置进行呼吸。使用了两种不同的HME：Icor Mediflux 1和Icor Mediflux 2。这些HME具有相同的化学成分和结构，但Mediflux 1比Mediflux 2更大。吸入气体的加湿交替通过主动加湿器和两种HME来实现。通过肺监测仪CP100（Bicore）收集通气模式和呼吸力学的数据。Mediflux 1组的潮气量、呼吸功和压力-时间乘积高于Mediflux 2组或主动加湿器组。呼吸频率、内源性呼气末正压（PEEPi）、快速浅呼吸指数、动脉血二氧化碳和氧分压无显著差异。较大的HME（Mediflux 1）增加了患者的做功，但无患者不适的证据。然而，较小的HME（Mediflux 2）未增加可检测到的负荷并提供了足够的加湿。总之，较小的HME似乎更适合用于自主呼吸患者的管理。
