包扎、肋骨牵引和内固定治疗对连枷胸犬呼吸功能的影响

Curative effect of pressure dressing on chest wall,traction and internal fixation on pulmonary function in dogs with flail chest

目的观察连枷胸犬胸壁加压包扎、肋骨牵引和手术内固定的治疗效果。方法实验用Beagle犬24只,随机分为A组(对照组)、B组(包扎治疗组)、C组(牵引治疗组)和D组(手术固定组),每组6只,建立大面积(15 cm2/kg)浮动胸壁动物摸型。用MPA动物肺功能记录仪、血气分析、胸腔置管等观察犬呼吸频率(RR)、潮气量(Vt)、每分钟静息通气量(VE)、肺顺应性(CL)、气道阻力(Raw)、动脉血氧分压(PaO2)、动脉血二氧化碳分压(PaCO2)、动脉血氧饱和度(SaO2)、剩余碱(BE)及胸膜腔内压(IPP)等变化,比较胸壁加压包扎、肋骨牵引固定和手术内固定的治疗效果。结果浮动胸壁模型完成后,均出现反常呼吸,胸膜腔内压负压绝对值减小(P<0.01),RR、Raw明显升高(P<0.01),V、tVE、PaO2、CL下降(P<0.05),PaCO2、SaO2显著下降(P<0.01),BE无统计学意义(P>0.1)。与A比较,B组IPP、Raw、RR显著升高(P<0.01),Vt、VE显著减少(P<0.01),PaO2、PaCO2、SaO2、BE、CL均无统计学意义(P>0.1);C组Vt、Raw显著升高(P<0.01),IPP、PaO2、PaCO2、SaO2、BE、CL、VE、RR均无统计学意义(P>0.05);D组VE升高(P<0.05),PaO2、PaCO2、SaO2、CL、Vt显著升高(P<0.01),IPP负压值加大(P<0.05),RR显著减少(P<0.01),BE、Raw无统计学意义(P>0.1)。结论大面积浮动胸壁的病理改变以胸腔容积减少为基础,胸壁加压包扎无治疗效果,甚至加重低氧。肋骨巾钳悬吊牵引固定虽可增加潮气量,但对连枷胸缺氧内环境的改善效果不佳。手术切开复位内固定是改善大面积浮动胸壁呼吸功能障碍的有效方法。

Objective To study curative effect of pressure dressing on chest wall ,traction and internal fixation on pulmonary function in dogs with flail chest. Methods A total of 24 Beagle dogs were set up as great floating tho- racic wall models（ 15cm^2/kg）, then divided into internal fixation group, rib skeletal traction group, pressure dressing group and control group randomly,with 6 dogs in each group. The change of respiratory rate（RR） ,tidal volume（ Vt）, minute ventilation （ VE ）, lung compliance （ CL ）, airway resistance （ Raw ）, partial pressure of oxygen in artery （ PaCO2 ）, partial pressure of carbon dioxide in artery （ PaCO2 ）, arterial oxygen saturation （ SaO2 ）, base excess （ BE）, intrapleural pressure（IPP） were observed and recorded by MPA pulmonary function recorder and blood gas analysis. At last the therapeutic effect was compared among 4 groups. Results Paradoxical respiration occurred;intrapleural pressure decreased （ P 〈 0. 01 ） ; RR, Raw increased obviously （ P 〈 0.01 ） ; Vt, VE, PaO2, CL decreased while PaCO2, and SaO2 ,decreased obviously（ P 〈0.05 ） ;BE didn＇t show statistical significanee（P 〉 0.1 ）. Compared with the control group, IPP, Raw, RR increased obviously（ P 〈 0.01 ） while Vt, VE decreased obviously（ P 〈 0. 01 ） in the pressure dressing group. Vt, Raw increased obviously （ P 〈 0.01 ） while IPP, PaO2, PaCO2, SaO2, BE, CL, VE, RR had no meaningful change in the traction group. PaO2, PaCO2, SaO2, CL, Vt increased obviously （ P 〈 0. 01 ） while RR decreased obviously in the internal fixation group（P 〈 0.01 ） . Conclusion The decrease of thoracic cavity volume is the fundamental change of the great floating chest wall. The pressure dressing on chest wall does not have the therapeutic efficacy,on the contrary,it intensifies hypoxia. The rib skeletal traction can increase tidal volume,but it brings no benefit to retrieve hypoxia. The internal fixation is the best way to improve the reduced pulmonary dysfunction caused by great floating thoracic wall.