de Oliveira Sergius A R, Lucio Lorena M C, Modolo Norma S P, Hayashi Yoko, Braz Mariana G, de Carvalho Lídia R, Braz Leandro G, Braz José Reinaldo C
Department of Anesthesiology, Botucatu Medical School, UNESP-Univ Estadual Paulista, Botucatu, Sao Paulo State, Brazil.
Department of Biostatistics, Institute of Biosciences, UNESP-Univ Estadual Paulista, Botucatu, Sao Paulo State, Brazil.
PLoS One. 2017 Jan 27;12(1):e0170723. doi: 10.1371/journal.pone.0170723. eCollection 2017.
During anesthesia, as compared with intensive care, the time of the tracheal intubation is much shorter. An inhaled gas minimum humidity of 20 mgH2O.L-1 is recommended to reduce the deleterious effects of dry gas on the airways during anesthesia with tracheal intubation. The Fabius GS Premium® anesthesia workstation (Dräger Medical, Lübeck, Germany) has a built-in hotplate to heat gases in the breathing circuit. A heat and moisture exchanger (HME) is used to further heat and humidify the inhaled gas. The humidity of the gases in the breathing circuit is influenced by the ambient temperature. We compared the humidity of the inhaled gases from a low-flow Fabius anesthesia workstation with or without thermal insulation (TI) of the breathing circuit and with or without an HME.
We conducted a prospective randomized trial in 41 adult female patients who underwent elective abdominal surgery. The patients were allocated into four groups according to the devices used to ventilate their lungs using a Dräger Fabius anesthesia workstation with a low gas flow (1 L.min-1): control, with TI, with an HME or with TI and an HME (TIHME). The mean temperature and humidity of the inhaled gases were measured during 2-h after connecting the patients to the breathing circuit.
The mean inhaled gas temperature and absolute humidity were higher in the HME (29.2±1.3°C; 28.1±2.3 mgH2O·L-1) and TIHME (30.1±1.2°C; 29.4±2.0 mgH2O·L-1) groups compared with the control (27.5±1.0°C; 25.0±1.8 mgH2O·L-1) and TI (27.2±1.1°C; 24.9±1.8 mgH2O·L-1) groups (P = 0.003 and P<0.001, respectively).
The low-flow Fabius GS Premium breathing circuit provides the minimum humidity level of inhaled gases to avoid damage to the tracheobronchial epithelia during anesthesia. TI of the breathing circuit does not increase the humidity of the inhaled gases, whereas inserting an HME increases the moisture of the inhaled gases closer to physiological values.
与重症监护相比，麻醉期间气管插管的时间要短得多。建议吸入气体的最低湿度为20mgH₂O·L⁻¹，以减少气管插管麻醉期间干燥气体对气道的有害影响。费比乌斯GS高级版®麻醉工作站（德国吕贝克德尔格医疗公司）内置加热板，用于加热呼吸回路中的气体。热湿交换器（HME）用于进一步加热和湿化吸入气体。呼吸回路中气体的湿度受环境温度影响。我们比较了低流量费比乌斯麻醉工作站在呼吸回路有无隔热（TI）以及有无HME情况下吸入气体的湿度。
我们对41例接受择期腹部手术的成年女性患者进行了一项前瞻性随机试验。根据使用德尔格费比乌斯麻醉工作站以低气体流量（1L·min⁻¹）为患者肺部通气所使用的设备，将患者分为四组：对照组、有TI组、有HME组或有TI和HME组（TI - HME组）。在将患者连接到呼吸回路后的2小时内，测量吸入气体的平均温度和湿度。
与对照组（27.5±1.0°C；25.0±1.8mgH₂O·L⁻¹）和TI组（27.2±1.1°C；24.9±1.8mgH₂O·L⁻¹）相比，HME组（29.2±1.3°C；28.1±2.3mgH₂O·L⁻¹）和TI - HME组（30.1±1.2°C；29.4±2.0mgH₂O·L⁻¹）的吸入气体平均温度和绝对湿度更高（P分别为0.003和P<0.001）。
低流量费比乌斯GS高级版呼吸回路可提供吸入气体的最低湿度水平，以避免麻醉期间气管支气管上皮受到损伤。呼吸回路的TI不会增加吸入气体的湿度，而插入HME可使吸入气体的湿度更接近生理值。
