目的:观察不同血容量状态下颅高压的急性呼吸窘迫综合征(ARDS)猪模型，增加呼气末正压(PEEP)后，其血流动力学状态、颅内压(ICP)及脑氧分压(PtiOn 2)的变化。n 方法:选取雄性14～16月龄巴马小型猪12头，随机数字表法随机分成低血容量组和正常血容量组。建立ARDS和颅高压模型。自5 cmHn 2O(1 cmHn 2O＝0.098 kPa)水平逐步增加PEEP 5 cmHn 2O，直至25 cmHn 2O。采用重复测量的方差分析，并应用Sidak法进行多重比较和n P值的校正。n 结果:随着PEEP逐渐增加，正常血容量组ICP逐渐升高，而低血容量组ICP逐渐下降；当PEEP在5、10、15 cmHn 2O时，两组间ICP值分别为(25.83±1.47) mmHg(1 mmHg＝0.133 kPa)比(27.00±1.63) mmHg、(27.33±1.75) mmHg比(27.67±2.21) mmHg、(28.83±1.72) mmHg比(27.5±2.06) mmHg，差异均无统计学意义(n t＝0.793、0.227、0.906，n P值均>0.05)；当PEEP在20、25 cmHn 2O时，两组间ICP值分别为(31.33±2.07) mmHg比(26.5±3.35) mmHg、(31.67±2.94) mmHg比(25.83±3.67) mmHg，差异均有统计学意义(n t＝3.284、3.964，n P值均<0.01)。随着PEEP逐渐增加，两组PtiOn 2均逐渐下降，其中低血容量组下降更明显；在各PEEP水平时，两组间PtiOn 2值分别为(19.83±2.64) mmHg比(14.33±3.50) mmHg、(18.67±2.50) mmHg比(12.33±3.88) mmHg、(17.67±3.88) mmHg比(10.67±3.88) mmHg、(15.33±2.34) mmHg比(9.17±3.54) mmHg、(13.67±3.61) mmHg比(6.67±2.73) mmHg，差异均有统计学意义(t＝2.333、3.319、3.668、3.231、3.668，n P值均0.05). When PEEP were 20 cmHn 2O and 25 cmHn 2O, the ICP of the two groups were (31.33±2.07) mmHg vs. (26.50±3.35) mmHg and (31.67±2.94) mmHg vs. (25.83±3.67) mmHg, respectively, showing statistical differences (n t=3.284, 3.964, n P<0.01). As PEEP gradually increased, PtiOn 2 in both groups decreased gradually, with the hypovolemia group decreasing more significantly. At each PEEP level, the PtiOn 2 between the two groups were (19.83±2.64) mmHg vs. (14.33±3.50) mmHg, (18.67±2.50) mmHg vs. (12.33±3.88) mmHg, (17.67±3.88) mmHg vs. (10.67±3.88) mmHg, (15.33±2.34) mmHg vs. (9.17±3.54) mmHg, (13.67±3.61) mmHg vs. (6.67±2.73) mmHg, all with statistical difference (n t=2.333, 3.319, 3.668, 3.231, 3.668, all n P<0.05).n Conclusion:The effects of PEEP on hemodynamics, intracranial pressure, and brain metabolism are affected by different volume states. In the state of hypovolemia, as PEEP gradually increases, its cardiac output, blood pressure and PtiOn 2 decreased more significantly.n