Xhauflaire-Uhoda Emmanuelle, Paquet Philippe, Piérard Gérald E
Department of Dermatopathology, University Hospital of Liège, Liège, Belgium.
Dermatology. 2008;216(1):37-9. doi: 10.1159/000109356.
Cooled hydrogel pads are used to prevent overheating effects of laser therapy. They do not induce cold injuries to the skin, but their more subtle physiological effects have not been thoroughly studied.
To describe the changes in transepidermal water loss and electrometric properties of the skin surface following application of cooled hydrogel pads. Measurements were performed on normal forearm skin of 27 healthy volunteers and on freshly excised skin from abdominoplasty.
LaserAid hydrogel pads cooled to 4 degrees C were placed for 15 min on the forearm skin. Measurements of transepidermal water loss (TEWL) and electrometric properties (Corneometer, Nova DPM 900) were performed before application and after removal of the cooled pads.
A consistent increase in corneometer units, dermal phase meter (DPM) values and TEWL were recorded at removal of the cooled hydrogel pads. Both the in vivo and in vitro assessments brought similar information.
The similar changes disclosed in vitro and in vivo suggest that a common physical process is operating in these conditions. The observed phenomenon is opposite to the predicted events given by the Arrhenius law probably because of the combination of cooling and occlusion by the pads. A dew point effect (air temperature at which relative humidity is maximal) is likely involved in the moisture content of the stratum corneum. Thus, the biological impact of using cooling hydrogel pads during laser therapy is different from the effect of a cryogenic spray cooling procedure. The better preservation of the water balance in the stratum corneum by the cooled hydrogel pads could have a beneficial esthetic effect on laser treated areas.
冷却水凝胶垫用于预防激光治疗的过热效应。它们不会对皮肤造成冷损伤，但其更细微的生理效应尚未得到充分研究。
描述应用冷却水凝胶垫后经表皮水分流失和皮肤表面电性能的变化。对27名健康志愿者的正常前臂皮肤以及腹壁成形术切除的新鲜皮肤进行了测量。
将冷却至4摄氏度的LaserAid水凝胶垫置于前臂皮肤上15分钟。在应用冷却垫之前和移除之后，对经表皮水分流失（TEWL）和电性能（角质层测量仪，Nova DPM 900）进行测量。
在移除冷却水凝胶垫时，记录到角质层测量仪单位、真皮相位测量仪（DPM）值和TEWL一致增加。体内和体外评估都得出了类似的信息。
体内和体外揭示的类似变化表明，在这些条件下存在一个共同的物理过程。观察到的现象与阿仑尼乌斯定律预测的情况相反，可能是因为垫子的冷却和封闭作用相结合。露点效应（相对湿度最大时的气温）可能与角质层的水分含量有关。因此，在激光治疗期间使用冷却水凝胶垫的生物学影响与低温喷雾冷却程序的影响不同。冷却水凝胶垫对角质层水分平衡的更好保持可能对激光治疗区域产生有益的美学效果。
