机械通气患者呼吸附加功影响因素的临床研究

Imposed work of breathing in mechanically ventilated patients

目的 评价呼吸机、气管导管等器械阻力导致的附加功 (WOBimp)对患者呼吸功 (WOBp)的影响。方法 通过Ventrak 15 5 0呼吸监测仪 ,测定 18例患者不同机械通气条件下WOBp和WOBimp的变化。结果 持续气道正压 (CPAP) 5cmH2 O时 ,WOBp为 (10 14± 3 46 )J/min ,分别比压力支持通气 (PSV) 5cmH2 O和T管高 48 5 % (P <0 0 5 )和 2 3 7% (P >0 0 5 ) ,但比CPAP 0cmH2 O低 7 2 % (P >0 0 5 )。CPAP 5、 0cmH2 O和T管时 ,WOBimp占WOBp的比例分别为 5 8%、 5 1%和 42 %。CPAP 5cmH2 O时 ,WOBimp为 (0 78± 0 2 4)J/L ,分别比PSV 5cmH2 O〔(0 34± 0 13)J/L〕和T管〔(0 5 3± 0 14)J/L〕高 48 5 % (P <0 0 5 )和 2 3 7%(P <0 0 5 )。结论 呼吸机及气管导管导致的WOBimp使WOBp明显增加 。

Objective To evaluate the effect of imposed work of breathing (WOBimp) caused by apparatus (endotracheal tube,ventilator tube and valve) on the patients work of breathing (WOBp).Methods Eighteen patients with mechanical ventilation were observed.WOBp and WOBimp were measured by Ventrak 1550 pulmonary monitor.Results While breathing at pressure support(PSV) 5 cm H 2O,T-piece and continuous positive airway pressure(CPAP) 0 cm H 2O,the WOBp were 48 5%(P<0 05) and 23 7%(P>0 05) less,and 7 2%(P>0 05) greater than the WOBp at CPAP 5 cm H 2O respectively.The WOBimp contributed to 58%,51% and 42% of the WOBp at CPAP 5,0 cm H 2O,and T-piece.WOBimp at CPAP 5 cm H 2O〔(0 78±0 24)J/L〕 was 48 5% and 23 7% greater than WOBimp at PSV 5 cm H 2O〔(0 34±0 13)J/L,P<0 05〕 and T-piece〔(0 53±0 14)J/L,P<0 05〕 respectively.Conclusion WOBimp caused by apparatus could markedly increase WOBp,and the endotracheal tube is the major cause of WOBimp. [