解剖和生理死腔变化在高频双向喷射通气中的意义

SIGNIFICE OF CHANGING ANATOMICALAND PHYSIOLOGICAL DEADSPACES DURING HIGH FREQUENCY TWO-WAY JET VENTILATION

本实验对９只蒸汽吸入伤犬在高频喷射通气（ＨＦＪＶ）或高频双向喷射通气（ＨＦＴＪＶ）条件下解剖死腔（Ｖ＿（ａｎａｔ））和生理死腔（Ｖ＿（ｐｈｙｓ）的变化进行了观察。结果：①ＨＦＪＶ和ＨＦＴＪＶ的ＣＯ＿２排出量（Ｖｃｏ＿２）（４．９０±０．６５，６．３２±１．３０ｍｌ·ｍｉｎ￣１·ｋｇ￣１）的差异非常显著（Ｐ＜０．０１），②ＨＦＴＪＶ的ＶＶ＿（ａｎａｔ）（７６．６６±１９ｍｌ）和Ｖ＿（ｐｈｙｓ）（８０．８７±２０ｍｌ）比ＨＦＪＶ（分别为８８．１７±２２ｍｌ和９０．６９±２２ｍｌ）的均显著减少（Ｐ＜０．０５）。③ＨＦＪＶ和ＨＦＴＪＶ的功能残气量（ＦＲＣ）（４３３±５６，４４４±５６ｍｌ无显著差异。因此，ＨＦＴＪＶ确有加速ＣＯ＿２排除的效能，其作用应归因于Ｖ＿（ａｎａｔ），和Ｖ＿（ｐｈｙｓ）的减少，它可能成为解决Ⅱ型呼吸衰竭ＣＯ＿２排除障碍的一种有效途径。

Changes of anatomical(V_(anat))and physiological(V_(phys))deadspaces were observed in nineadult dogs with vapour inhalation injury during high frequency jet ventilation(HFJV)and thenhigh frequency two-way jet ventilation (HFTJV)with 20 min apart.The main results were as fol-lows:①There was very significant difference in carbon dioxide elimination (Vco_2) betweenHFTJV and HFJV(6.32 ± 1.30 and 4.90 ± 0.65ml· min￣(-1)· kg￣(-1),p<0.01);②V_(anat)(76.66 ±19ml)and V_(pnys)(80.87± 20ml)in HFTJV were significantly lower than those in HFJV(88.17± 22and 90.69 ± 22ml,respectively,P<0.05);③There was no significant difference in FRC betweenHFTJV and HFJV(444 ± 56 and 433 ± 56m1,P>0.05).It is considered that H FTJV has impor-tant effect on CO_2 elimination.the mechanism of which is attributed to the decreasein V_(anat)and V_(phys).The HFTJV may become an effective way to solve the obstruction of CO_2elimination which happens in patients with the type Ⅱ respiratory failure.