全麻肌松恢复期不同机械通气模式的研究

目的 :观察全麻患者在肌松恢复期用间歇正压通气 (IPPV)、同步间歇指令通气 (SIMV)、双水平压力正压通气 (Bi PAP)对自主呼吸恢复的影响。方法 :30例手术患者随机均分 3组。术中初始通气方式均为 IPPV,给最后一次肌松剂后将后两组的通气模式分别调整为 SIMV和 Bi PAP。不同时间点记录气道峰压 (Ppeak)、每分通气量 (MV)、呼气末二氧化碳分压 (PEt CO2 )和血气 ,观察给最后一次肌松剂至自主呼吸恢复的时间(L R S)。结果 :1给予最后一次肌松剂后和 T1 出现时 Bi PAP组的 Ppeak均明显低于 IPPV和 SIMV组(P均 <0 .0 1) ,TR=0 .75时 IPPV组的 Ppeak均明显低于 SIMV和 Bi PAP组 (P均 <0 .0 1) ;2 T1 恢复时Bi PAP组的 MV高于 IPPV组 (P<0 .0 5 ) ,T4 恢复、TR=0 .2 5、TR=0 .75时 SIMV和 Bi PAP组的 MV均明显高于 IPPV组 (P均 <0 .0 1) ;3TR=0 .2 5、TR=0 .75时 SIMV和 Bi PAP组的 PEt CO2 均低于 IPPV组 (P均 <0 .0 5 ) ;4拔管前 SIMV和 Bi PAP组的动脉二氧化碳分压 (Pa CO2 )均低于 IPPV组 (P均 <0 .0 5 ) ;5 SIMV组和Bi PAP组的 L R S均短于 IPPV组 (P均 <0 .0 5 )。结论 :SIMV和 Bi PAP具有不对抗患者自主呼吸、L R S短、Ppeak变化小、MV高、PEt CO2 低等优点 ,更适于全麻恢复期使用。 Bi PAP还具有 Ppeak

A study of mechanical ventilation pattern in different recovery stages of muscle relaxant after general anesthesia

OBJECTIVE: To observe the effects of intermittent positive pressure ventilation (IPPV), synchronized intermittent mandatory ventilation (SIMV), and biphasic intermittent positive airway pressure (BiPAP) on the recovery time of automatic breathing in patients in different stages of recovery of general anesthesia with muscle relaxant. METHODS: Thirty patients were randomly divided into three groups. The initial ventilation pattern was IPPV for all patients. After the last dose of muscle relaxant, the pattern of ventilation of group II and group III was adjusted to SIMV and BiPAP, respectively. The airway peak pressure(Ppeak), minute ventilation(MV), expiration carbon dioxide(P(Et)CO(2)), blood gases, and the interval between the last dose of muscle relaxant and automatic breathing(LR-S) was observed. RESULTS: (1) When T(1) appeared, Ppeak of the BiPAP group was lower than that of the IPPV group and SIMV (all P<0.01). When T(R)=0.75, Ppeak of IPPV group was lower compared with the SIMV and BiPAP groups (all P<0.01). (2) When T(1) re-appeared, the MV of BiPAP was higher than that of the IPPV group (P<0.05), but was not different from that of the SIMV group (P>0.05). When T(4) appeared, T(R)=0.25, T(R)=0.75, MV of SIMV group and BiPAP group was higher than that of IPPV group (all P<0.01). (3) When T(R)=0.25, T(R)=0.75, the P(Et)CO(2) of the SIMV group and BiPAP group was lower than that of IPPV group (all P<0.05). (4) Partial pressure of carbon dioxide in artery (PaCO(2)) of the SIMV and BiPAP group was lower than that of the IPPV group (all P<0.05). (5) The LR-S before extubation was shorter in SIMV and BiPAP group than that in IPPV group (P<0.05). CONCLUSION: SIMV and BiPAP have the advantages as follows: no confrontation between mechanical ventilation and autonomous breathing, quick recovery of autonomous breathing, little change in airway pressure, high MV and low P(Et)CO(2). So SIMV and BiPAP are more suitable for recovery from anesthesia. In addition, BiPAP can lower the airway's peak pressure and decrease the probability of barotrauma therefore it is more suitable for those patients with high airway pressure.