Department of Anaesthesiology, Intensive Care Medicine and Pain Therapy, University Hospital Frankfurt, Goethe University, Frankfurt, Germany.
Department of Anaesthesiology, Intensive Care Medicine and Pain Therapy, Sana Clinic Offenbach, Offenbach am Main, Germany.
Anaesthesiol Intensive Ther. 2020;52(2):119-125. doi: 10.5114/ait.2020.93416.
The i-gel mask is a second-generation, single-use supraglottic airway device which does not have an inflatable cuff. The cuff consists of a thermoplastic elastomer and its mechanism of sealing still remains unclear. Various theories such as temperature-dependent changes in hardness and volume expansion as well as fluid absorption have been discussed. The aim of the present study is to investigate changes in volume, weight and density caused by temperature changes.
Three i-gel masks (sizes 3, 4 and 5) were heated in a water bath from 10°C to 50°C in 5°C steps. The changes in weight, volume, and density were measured at each temperature step. In a second study, the identical parameters of masks (n = 5 of sizes 3, 4 and 5) used in patients were investigated. Results of volume and density between benchtop and patient measurements were examined for correlation.
All masks investigated, regardless of the size, showed a significant linear temperature-dependent volume expansion (sizes 3, 4 and 5: P < 0.001), a weight increase (sizes 3: P = 0.018; 4: P = 0.027; and 5: P = 0.006) and a linear decrease in density (sizes 3, 4 and 5: P < 0.001). There was a very strong correlation between the results of benchtop and patient measurements (volume: P < 0.001; density: P < 0.001).
We observed significant changes in all three properties investigated. Thus, a temperature-dependent volume expansion and weight increasement was observed, which can be considered as a further explanation for improved sealing after insertion.
i-gel 面罩是第二代一次性使用的声门上气道装置，它没有可充气的袖套。袖套由热塑性弹性体制成，其密封机制仍不清楚。已经讨论了各种理论，例如硬度和体积膨胀随温度的变化以及流体吸收等。本研究的目的是研究由于温度变化引起的体积，重量和密度的变化。
将三个 i-gel 面罩（尺寸 3、4 和 5）在水浴中从 10°C 加热至 50°C，每 5°C 一步。在每个温度步骤下测量重量，体积和密度的变化。在第二项研究中，研究了在患者中使用的相同尺寸（n = 5 个尺寸 3、4 和 5）的面罩的相同参数。检查了台面上和患者测量的体积和密度结果之间的相关性。
在所研究的所有面罩中，无论尺寸如何，都显示出明显的线性温度依赖性体积膨胀（尺寸 3、4 和 5：P <0.001），重量增加（尺寸 3：P = 0.018；4：P = 0.027；和 5：P = 0.006）以及密度线性下降（尺寸 3、4 和 5：P <0.001）。台面上和患者测量结果之间存在很强的相关性（体积：P <0.001；密度：P <0.001）。
我们观察到所有三个研究特性都发生了重大变化。因此，观察到了依赖于温度的体积膨胀和重量增加，这可以被认为是插入后密封性能改善的进一步解释。
