Abstract: Objective To observe the changes of matrix metalloproteinase 2(MMP-2) and matrix metalloproteinase 9(MMP-9) in severe meconium-injured young rabbits treated by PAV. Methods Thirty 20~30 days rabbits were randomly divided into four groups:implement proportional assist ventilation after poured into the meconium(PAV group),implement synchronized intermittent mandatory ventilation after meconium instillation(SIMV group),no ventilation after meconium instillation(MAS group) and the saline irrigation with no ventilation group(control group).The rabbits were sacrificed after 8 hours,lungs and trachea were excised.Levels of MMP-2 and MMP-9 in lung homogenate and bronchoalveolar lavage fluid(BALF) were measured by enzyme-link immunosorbent assay(ELISA). Results 1) There were statistically significant differences among the lung tissue MMP-2(F=72.575,P=0.000) and MMP-9 levels of all groups.Between the lung tissue MMP-2,MMP-9 (F=48.374,P=0.000) levels of every group,the differences were significant(all P<0.05).The value of SIMV group was highest,the value of control group was lowest.2) There were statistically significant differences among the BALF MMP-2(F=116.779,P=0.000) and MMP-9(F=59.095,P=0.000)levels of all groups.Between the BALF MMP-2 and MMP-9 levels of every group,all the differences were significant(all of the P<0.05).The value of SIMV group was hightest,the value of control group was lowest.3) There were statistically significant differences in PIP at 2 h(F=46.095,P=0.000)、4 h(F=50.757,P=0.000)、6 h(F=56.127,P=0.000) and 8 h(F=73.684,P=0.000) after ventilation between PAV group and SIMV group,the value of SIMV group was higher than PAV. Conclusions In case to maintain normal oxygen saturation and blood gas,the values of MMP-2,MMP-9 and PIP in SIMV model were higher than PAV model.It suggest that when the MAS surported with mechanical ventilation,the priority is given to PAV model.

Key words: matrix metalloproteinase, proportional assist ventilation, meconium aspiration syndrome, lung injury

摘要： 目的 观察比例辅助通气(proportional assist ventilation,PAV)对胎粪吸入新生兔肺组织中基质金属蛋白酶2(MMP-2)、基质金属蛋白酶9(MMP-9)含量的影响。方法 将30只日龄20~30 d的幼兔随机分为灌入胎粪后实施比例辅助通气组(PAV组),灌入胎粪后实施同步间歇指令通气组(SIMV组),并与胎粪吸入不予通气组及灌生理盐水组进行对照,各组分别于8 h后处死,ELISA法检测肺组织匀浆及肺泡灌洗液中MMP-2、MMP-9的水平。结果 不同组之间肺组织匀浆中MMP-2(F=72.575,P=0.000)和MMP-9数值(F=48.374,P=0.000)的差异有统计学意义;各组之间肺组织匀浆中MMP-2和MMP-9数值差异均有统计学意义(P<0.05),以SIMV组最高,生理盐水对照组最低;不同组之间肺泡灌洗液中MMP-2(F=116.779,P=0.000)和MMP-9数值(F=59.095,P=0.000)的差异有统计学意义(F=48.734,P=0.000);各组之间肺泡灌洗液中MMP-9数值差异均有统计学意义(P<0.05),以SIMV组最高,生理盐水对照组最低。PAV组和SIMV组在通气后2 h(F=46.095,P=0.000)、4 h(F=50.757,P=0.000)、6 h(F=56.127,P=0.000)和8 h(F=73.684,P=0.000)的气道峰压(PIP)数值差异均有统计学意义,PAV组显著低于SIMV组。 结论 在维持正常经皮氧饱和度和血气情况下,PAV模式下肺组织匀浆及肺泡灌洗液中MMP-2,MMP-9含量及PIP较SIMV模式下低,所致肺损伤程度较SIMV模式小,提示当机械通气治疗MAS时,优先考虑使用PAV模式。

关键词: 胎粪吸入综合征, 机械性肺损伤, 基质金属蛋白酶, 比例辅助通气