不同肺复张吸痰法对急性呼吸窘迫综合征犬呼吸力学的影响

Influence of Sputum Suction with Various Recruitment Maneuver Techniques on Respiratory Mechanics of Dogs with ARDS

目的探讨不同肺复张方式的吸痰干预对急性呼吸窘迫综合征(acute respiratory distress syndrome,ARDS)犬呼吸力学的影响。方法 8只健康杂种犬(23.69±7.35)kg,经静脉注射油酸制成ARDS模型。每只犬按随机顺序分别采用以下3种方法进行气管内吸痰:(1)无肺复张吸痰法,吸痰过程不实施肺复张干预;(2)持续充气肺复张吸痰法,吸痰后把呼气末正压(PEEP)从10 cm H2O(1 cmH2O=0.098 kPa)直接调高至30 cmH2O,VT减至50 mL,通气60 s后,PEEP回调至10 cm H2O,VT回调至10 mL/kg;(3)延伸式叹气肺复张吸痰法,吸痰后把PEEP从10 cmH2O增至15 cm H2O,2次呼吸后VT从10 mL/kg降至8 mL/kg,通气30 s。以此类推,每通气30 s后,PEEP增加5 cmH2O,2次呼吸后VT减少2 mL/kg,最后PEEP增至30 cm H2O,VT减至50 mL,通气60 s后,PEEP回调至10 cmH2O,VT回调至10 mL/kg。于吸痰前后记录呼吸力学的数据。结果对ARDS犬实施不同肺复张方式的吸痰法,在吸痰前1 min和吸痰后30 min,各吸痰法的呼吸力学参数水平差异无统计学意义;在吸痰后1 min和5 min,延伸式叹气肺复张吸痰法的气道峰压和平台压最低,肺静态顺应性最高,无肺复张吸痰法的气道峰压和平台压则最高,肺静态顺应性最低,3种吸痰方法的呼吸力学参数水平差异有统计学意义。结论无肺复张吸痰法可使ARDS犬气道峰压和平台压增高,肺静态顺应性降低;肺复张吸痰法则可改善ARDS犬的通气,延伸式叹气肺复张吸痰法效果优于持续充气肺复张吸痰法,但持续时间均不足30 min。

Objective To discuss the influence of sputum suction with various recruitment maneuver techniques on respiratory mechanics of dogs with ARDS.Methods 8 oleic acid induced canine ARDS models [（23.69±7.35）kg] were randomly conducted endotracheal sputum suctions with the following three methods respectively：（1） Sputum suction without recruitment maneuver.（2） Sputum suction with sustain inflation.After suction,PEEP increased from 10 cmH2O to 30 cm H2O directly and VT decreased to 50 mL.60 seconds ventilation later,PEEP was changed back to 10 cm H2O and VT to 10 mL/kg.（3） Sputum suction with extended sigh.After suction,PEET increased from 10 cm H2O to 15 cm H2O and VT decreased from 10 mL/kg to 8 mL/kg for 30 seconds ventilation.The increase of PPET and the decrease of VT were conducted correspondingly every 30 seconds until PEET finally reached 30 cm H2O and VT down to 50 mL.PPEP was changed back to 10 cm H2O and VT to 10 mL/kg after 60 seconds ventilation.Data of respiratory mechanics were kept before and after each suction.Results Parameter difference of respiratory mechanics was without any statistical significance 1 minute before and 30 minutes after suction.P（peak） and p（plat） reached the lowest while Cs the highest 1 minute and 5 minutes after suction in the third method.P（peak） and p（plat） in the first method reached the highest while Cs the lowest.Conclusion P（plat） and p（plat） increase while Cs decrease in sputum suction without recruitment maneuver.Sputum suction with recruitment maneuver could improve the ventilation of dogs with ARDS.The effect of sputum suction with extended sigh is better than that of sputum suction with sustain inflation with a duration of less than 30 minutes.