对辅助/控制呼吸、同步间歇指令通气模式的再认识

Comments on the assist/control-mode ventilation and synchronized intermittent mandatory ventilation

目的 探讨辅助 控制呼吸 (AMV CMV ,A C)、同步间歇指令通气 (SIMV)的通气规律。方法 启动New portE2 0 0呼吸机。选A C ,通气频率 (f1 )依次为 6、10、12次 min。操作者分别于AMV和CMV的吸气时间 (Ti)内、第 3、60·f- 11 秒对螺纹管的“Y”接口吸气 (均达触发负压 )分为A、B、C组 ,不吸气者为D组。每组在AMV和CMV后分别测试 15次。选SIMV ,f1 依次为 4、5、6次 min。操作者在同步时间间期 (STP)后 2 5 %的结束前吸气等于触发负压为E组 ;在后 2 5 %不呼吸为F组 ;在前 75 % ,其吸气负压分别等于、大于触发负压而在后 2 5 %结束前又小于此水平分为G、H组。每组测试 3 0次。结果 A C :A组不触发AMV ,B、C组均触发AMV ,A、B、D组的CMV均出现在AMV或CMV后第 60·f- 11 秒时。SIMV :在STP后 2 5 %的结束前E、H组触发机械通气而G组不触发 ;在结束时F、G组开始机械通气。结论 在患者自主呼吸均触发呼吸机产生AMV时 ,A C的通气模式不仅为AMV ,还可为AMV +CMV。SIMV :机械通气可不由患者吸气触发 。

Objective To investigate the ventilatory regularity of assist/control-mode ventilation (AMV/CMV or A/C) and synchronized intermittent mandatory ventilation (SIMV). Methods After the Newport E200 Ventilator was turned on, the mode selector was set to A/C and the ventilatory frequencies (f 1) were 6, 10 and 12 breaths per minute (bpm). The operator inspired at the full time, the third second and the 60·f -1 1 second of AMV's and CMV's inspiratory time to meet the trigger level (-1 cm H 2O). According to the time the operator inspired, the tests were designated as groups A, B and C, while in group D, the operator didn't inspire. The test was repeated 15 times after AMV and CMV respectively in each group. In SIMV mode, f 1 were 4, 5 and 6 bpm. The operator inspired by the end of the late 25% window of the synchronized timing period (STP) in group E to meet the trigger level; and held breath during the late 25% window in group F. When the operater's inspiratory negative pressure was equal to or below the trigger level line during the early 75% window and went above the line before the end of the late 25% window, the tests were designated as groups G and H respectively. The tests were repeated 30 times in each group. Results In A/C mode, AMV appeared in groups B and C, but not in group A. All CMV initiated at the 60·f -1 1 second after AMV or CMV in groups A, B and D. In SIMV mode, the operater's inspiratory effort caused mandatory ventilation in groups E and H before the end of the 25% window, and the ventilator initiated mandatory ventilation at the end of the 25% window in groups F and G. Conclusion When each spontaneous inspiratory effort causes AMV, the mode of A/C ventilation may be AMV and AMV+CMV as well. As for the SIMV mode, the mandatory ventilation may not be initiated by the patient's inspiratory effort, and nonsynchronized mandatory ventilation may appear sometimes.