Santos R L, Santos M A, Sakae R S, Saldiva P H, Zin W A
Instituto de Biofisica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Brazil.
J Appl Physiol (1985). 1992 May;72(5):1985-90. doi: 10.1152/jappl.1992.72.5.1985.
In six sedated, anesthetized, paralyzed, and mechanically ventilated guinea pigs, total respiratory system (RT,rs), lung, and chest wall resistances and respiratory system (Est,rs), lung, and chest wall (Est,w) elastances were determined before and after longitudinal laparotomy. Furthermore the resistances were also split into their initial and difference components, with the former reflecting the Newtonian resistances and the latter representing the viscoelastic/inhomogeneous pressure dissipations in the system. For such purpose the end-inflation occlusion during constant inspiratory flow method was used. During laparotomy, a statistically significant increase in respiratory system difference resistance (from 0.086 to 0.101 cmH2O.ml-1.s) significantly augmented RT,rs (from 0.157 to 0.167 cmH2O.ml-1.s). The former was entirely secondary to a significant increase in chest wall difference resistance (0.019 to 0.034 cmH2O.ml-1.s), which naturally raised chest wall total resistance (from 0.030 to 0.047 cmH2O.ml-1.s). Est,rs and Est,w also increased (14.7 and 13.1%, respectively) after abdominal incision. It can be concluded that the midline xiphipubic laparotomy accompanied by the bilateral ventrodorsal infracostal incision increases RT,rs as a consequence of augmented chest wall difference resistance and Est,rs as a result of higher Est,w.
在六只接受镇静、麻醉、麻痹并进行机械通气的豚鼠身上，在纵向剖腹手术前后测定了总呼吸系统（RT,rs）、肺和胸壁的阻力以及呼吸系统（Est,rs）、肺和胸壁（Est,w）的弹性。此外，阻力还被分为初始分量和差值分量，前者反映牛顿阻力，后者代表系统中的粘弹性/非均匀压力耗散。为此采用了恒流吸气末阻断法。在剖腹手术期间，呼吸系统差值阻力有统计学意义的增加（从0.086增至0.101 cmH2O·ml-1·s），显著增加了RT,rs（从0.157增至0.167 cmH2O·ml-1·s）。前者完全继发于胸壁差值阻力的显著增加（从0.019增至0.034 cmH2O·ml-1·s），这自然增加了胸壁总阻力（从0.030增至0.047 cmH2O·ml-1·s）。腹部切开后Est,rs和Est,w也增加了（分别为14.7%和13.1%）。可以得出结论，中线剑突耻骨上剖腹术伴双侧腹背肋下切口会因胸壁差值阻力增加而使RT,rs增加，因Est,w升高而使Est,rs增加。
