不同通气方式对实验性Ⅱ型呼吸衰竭犬通气效果的比较

Comparison of various ventilatory modes in type Ⅱ respiratory fail-ure experimental model in canine

目的：评价不同通气方式的通气效果并探讨通气作用原理．方法：通过蒸汽吸入致伤，复制了９只犬Ⅱ型呼吸衰竭模型．结果：①当限定ＣＭＶ峰值气道压≤１２ｃｍＨ２Ｏ时，有ＣＯ２潴留，不能满足通气要求；②ＨＦＪＶ＋ＰＥＥＰ与单纯ＨＦＪＶ相比较，Ｖｃｏ２（２．９１±１．０９对４．９０±０．６５ｍｌ／（ｍｉｎ·ｋｇ）显著减少（Ｐ＜０．０１），Ｐａｃｏ２（１０．２８±１．３６对７．０５±１．３７ｋＰａ）大幅度增加（Ｐ＜０．０１），Ｐａｏ２（７．２３±２．２７对９．３３±２．１８ｋＰａ）显著降低（Ｐ＜０．０１），可能与ＶＴ和ＶＡ的减少有关；③ＨＦＴＪＶ与ＨＦＪＶ相比较，Ｖｃｏ２（６．３２±１．３０ｍｌ／（ｍｉｎ·ｋｇ）增加，Ｐａｃｏ２（５．９９±０．９０ｋＰａ）减少均达到非常显著水平（Ｐ＜０．０１），Ｐａｏ２维持稳定．结论：ＨＦＴＪＶ确有增强ＣＯ２的排除效能，其作用应归因于解剖和生理死腔量的减少，其可能成为解决Ⅱ型呼吸衰竭ＣＯ２排除障碍的有效途径．

Objective: The aims of the study were to evaluate the effect of various ventilatory modes and their mechanism. Methods : Respiratory failure experimental model induced by vapour inhalation was established indogs. Results:(1) Conventional mechanical ventilation(CMV) could not satisfy the ventilatory demand when peak airway pressure was limited to≤12 cmH2O;(2)CO2 elimilation[2.91±1.09 ml/(min·kg)]and oxygen pressure in arterial blood(7.23± 2.27 kPa)in HFJV+PEEP were significantly lower than those(4.90±0.65 and 9.33±2.18)in HFJV(P<0.01).CO2 pressure in arterial blood(Paco2)showed a marked increase from 7.05±1.37 in HFJV to 10.28±1.36 kPa in HFJV+PEEP(P<0.01),which mav result from the decrease of tidal volume(VT)and alveolar ventilatory volume(VA);(3)Compared with those in HFJV, Vco2 increased significantly from 4.90±0.64 to 6.32±1.30 ml(min·kg)and Paco2 decreased remarkably from 7.05±11.37 to 5.99±0.99 kPa in HFTJV. Conclusions:HFTJV can improve CO2 elimination as a re- sult of the decrease of VD and VD. Therefore,HFTJV might be an effective way for CO2 elimilation in pa-tients with type Ⅱ respiratory failure。.