Gao Lu-bo, Song Zhen-guo, Li Jin-cheng
Department of Anesthesiology, Cancer Hospital of Tianjin Medical University, Tianjin 300060, China.
Zhongguo Wei Zhong Bing Ji Jiu Yi Xue. 2003 Jul;15(7):438-40.
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.
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.
(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).
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.
观察间歇正压通气（IPPV）、同步间歇指令通气（SIMV）和双水平气道正压通气（BiPAP）对使用肌肉松弛剂的全身麻醉不同恢复阶段患者自主呼吸恢复时间的影响。
30例患者随机分为三组。所有患者初始通气模式均为IPPV。在最后一剂肌肉松弛剂使用后，将Ⅱ组和Ⅲ组的通气模式分别调整为SIMV和BiPAP。观察气道峰压（Ppeak）、分钟通气量（MV）、呼气末二氧化碳分压（P(Et)CO₂）、血气以及最后一剂肌肉松弛剂至自主呼吸出现的间隔时间（LR-S）。
（1）当出现T(1)时，BiPAP组的Ppeak低于IPPV组和SIMV组（均P<0.01）。当T(R)=0.75时，IPPV组的Ppeak低于SIMV组和BiPAP组（均P<0.01）。（2）当再次出现T(1)时，BiPAP组的MV高于IPPV组（P<0.05），但与SIMV组无差异（P>0.05）。当出现T(4)、T(R)=0.25、T(R)=0.75时，SIMV组和BiPAP组的MV高于IPPV组（均P<0.01）。（3）当T(R)=0.25、T(R)=0.75时，SIMV组和BiPAP组的P(Et)CO₂低于IPPV组（均P<0.05）。（4）SIMV组和BiPAP组的动脉血二氧化碳分压（PaCO₂）低于IPPV组（均P<0.05）。（5）拔管前SIMV组和BiPAP组的LR-S短于IPPV组（P<0.05）。
SIMV和BiPAP具有以下优点：机械通气与自主呼吸无对抗，自主呼吸恢复快，气道压力变化小，MV高且P(Et)CO₂低。因此，SIMV和BiPAP更适合于麻醉恢复。此外，BiPAP可降低气道峰压，减少气压伤发生概率，因此更适合气道压力高的患者。
