Due to aging characteristics such as dry, loose and inelastic skin, and decreased skin tolerance, the elderly are more vulnerable to injuries caused by pressure. An appropriate decompression mattress is the key to preventing pressure injury.

To compare the decompression effects of two types of mattresses by analyzing the pressures and temperatures of sacrococcygeal skin in bedridden elderly patients in the supine position.

By convenience sampling, 45 bedridden elderly patients who were admitted to Cadre Internal Medicine Ward, General Hospital of Eastern Theater Command from January 2021 to March 2022 were selected as the participants (all of them were male since most of the patients in the ward were male) . They were assigned to group A (n=23, use of gel mattress, repositioned every two hours for seven days) or group B (n=22, use of air mattress, repositioned every two hours for seven days) according to their willingness. The maximal sacrococcygeal pressure and skin temperature were measured at three fixed defined time points every day during supine position〔at the beginning (baseline) , and at one and two hours in the position〕. Maximal sacrococcygeal pressure was measured using a continuous bedside pressure mapping system, and the skin temperature in the same location was measured using a hand-held thermometer. The linear mixed-effects model was used to analyse the changes in sacrococcygeal pressure and skin temperature of the elderly bedridden patients and compare the decompression effects of the two mattresses.

There were no pressure injuries in both groups during the intervention. The interaction effect between group and day was not statistically significant on the changes in sacrococcygeal pressure (F_group*day=0.07, P_group*day=0.999) , while the interaction effect between group and time on them was statistically significant (F_group*time =6.45, P_group*time=0.012) . Therefore, the mixed-effects model analysis was conducted again after removing the interaction between the group and day. The results indicated that the sacrococcygeal pressures in the gel mattress group were lower than those in the air mattress group after one and two hours after the supine position (P<0.05) . For the changes in skin temperature, the interaction effect between group and day was not statistically significant (F_group*day=0.12, P_group*day=0.994) , while the interaction effect between group and time was statistically significant (F_group*time =16.90, P_group*time<0.001) . Therefore, the mixed-effects model analysis for temperature was conducted again after removing the interaction between the group and day. The results demonstrated that the sacrococcygeal pressure changes in the gel mattress group were lower than those in the air mattress group after one and two hours in the supine position (P<0.05) .

Both the sacrococcygeal pressures and skin temperatures of bedridden hospitalized elderly male patients were increased after using the gel mattress or air mattress for one or two hours in supine position. The pressure and skin temperature increments were less from the gel mattress than from the air mattress, indicating that gel mattress was superior to air mattress in mitigating sacrococcygeal pressure and skin temperature.

老年人因皮肤干燥、松弛缺乏弹性、耐受性下降等衰老特征，更容易受到压力影响而发生压力性损伤，适宜的减压床垫是预防压力性损伤的关键。

监测老年卧床患者平卧于凝胶床垫和充气床垫期间骶尾部压力与皮肤温度变化，比较两种床垫的减压效果。

采用方便抽样的方法，选取2021年1月—2022年3月入住东部战区总医院干部内科病房的45例老年卧床患者为研究对象（因干部内科病房患者多为男性，本次纳入者均为老年男性）。根据患者意愿将45例患者分为A组23例和B组22例，A组使用凝胶床垫结合2h翻身1次的方案；B组使用充气床垫结合2 h翻身1次的方案，两组均连续使用7 d。每日固定3个时间点监测患者平卧位期间骶尾部最大压力值和局部皮肤温度，3个时间点分别为平卧位的开始及1、2 h后的时间点。使用床边压力图监测系统，测量骶尾部最大压力值，同时使用手提式测温仪测量局部皮肤温度。采用线性混合效应模型分析比较两种床垫对老年卧床患者骶尾部压力及皮肤温度变化，以判断其减压效果。

研究期间两组均无压力性损伤发生。对于骶尾部压力变化值，床垫组别与天数的交互作用项无统计学意义（F_{组别*天数}=0.07，P_{组别*天数}=0.999），床垫组别与时间的交互作用项有统计学意义（F_{组别*时间}=6.45，P_{组别*时间}=0.012）。因此，去除床垫组别与天数的交互作用项重新进行混合模型分析，结果显示，平卧位后1 h和2 h，凝胶床垫组骶尾部压力变化值均低于充气床垫组（P<0.05）。对于骶尾部皮肤温度变化值，床垫组别与天数的交互作用项无统计学意义（F_{组别*天数}=0.12，P_{组别*天数}=0.994），床垫组别与时间的交互作用项有统计学意义（F_{组别*时间}=16.90，P_{组别*时间}<0.001）。因此，去除床垫组别与天数的交互作用项重新进行混合模型分析，结果显示，平卧位后1 h和2 h，凝胶床垫组骶尾部皮肤温度变化值均低于充气床垫组（P<0.05）。

住院老年卧床男性患者使用两种减压床垫平卧1、2 h后的骶尾部压力、皮肤温度均有所增高，凝胶床垫的增量均小于充气床垫，反映凝胶床垫在控制骶尾部压力和皮肤温度的效果上优于充气床垫。