1. The concept and the purpose
This place handles according to the mode because A/C is not a mode name purely but is the term that a frequently-used is recently done. The way of putting an active-ventilation is the same as CMV(Contineous Mandatory Ventilation) but CMV(Contineous Mandatory Ventilation) is a historic term and it generally often means the mode to be done by the volume ventilation. In other words, if expressing CMV(Contineous Mandatory Ventilation) modernistically, it is expressed with A/C(VC). On the other hand, because A/C means the ventilation mode to give all triggers an active-ventilation, it doesn't ask the kind of the active-ventilation. Generally, it writes and it expresses the kind of the active-ventilations such as A/C(VC), A/C(PC), A/C(PRVC). When specified only with A/C, at the resuscitator for the adult, it often means A/C(VC). However, in the infant business, it often means A/C(PC).
Of the concept to become SIMV and a pair however, there is A/C. Way, CMV(Contineous Mandatory Ventilation) is the concept to become IMV and a pair. A/C and SIMV are the concept to have expressed a difference to the way of putting an active-ventilation. When usual, it seemed an active-ventilation by the volume ventilation automatically *of* SIMV, too, but there are SIMV(PC) and SIMV(PRVC), and so on, recently and SIMV however, it is the mainstream that writes the kind of the active-ventilation. However, when specified only with SIMV like the expression in A/C, there are many SIMV(VC) in the adult business and in the infant business, it often means SIMV(PC).
2. The component
1) The trigger window (Figure ; Timer diagram : Excerpting from the mode explanation of the Bennett840 user's manual)
It synchronizes with the trigger if there is a trigger in the time which was decided from the time which the active-ventilation in the last time began in (the trigger window time) and it sends active-ventilation (PIM). A timer is again reset when beginning an active-ventilation. It is the time when trigger window time was ended and an active-ventilation is sent if there is not a trigger (VIM). Way, in trigger window time (Tb set), it is a setting air changes per hour in 60 seconds.
2) The refractory period, the compulsion expiration time
When mis-detecting a trigger by the noise and in case of respiratory center's being unstable, voluntary is caused by the stimulation of the active-ventilation and there has sometimes been it in the trigger again while not summoning expiration sufficiently. Now, the intake time becomes by nearly twice and a synchronism with patient breathing is compromised. In A/C(VC), the air quantity of ventilation is nearly twice as harmful, becoming. To prevent such a condition, after trigger detection, in the constant time, there is a prepared resuscitator, too, in the period which doesn't react to the trigger. This time is called a refractory period, compulsion expiration time.
3. The control method
There are a mechanical method, a new Mattick method, an electronic circuit method, a microprocessor method. At present, the microprocessor method is mainstream.
4. The advantage and the fault
There is little degree of freedom of the patient in A/C and in the conventional opinion of it one-sided It thought that SIMV was evaluated when it was the ventilation mode that there is an adaptability which it is possible to make an active-ventilation and a spontaneous-respiration fit in with freely and that the latter could be made the 1st choice to the patient of any clinical condition. In a sense, at present, it is possible to say that it is the SIMV prime, too. However, at all, there is a fault which different ventilation is disorderedly for the patient given to and in two kinds, at it, it isn't possible to deny the point which is a quite unnatural ventilation mode by SIMV. Generally, that it seems that there is little ONE'S turn of A/C tends but the ventilation mode to use VCV for the active-ventilation is a classic now. There is not inevitability to use unnatural SIMV forcibly because the degree of freedom of the patient is high in the active-ventilation in the new generation which added boiling Flow Termination control such as PRVC and the PC, AutoFLow and the flexibility of the active-ventilation is high on it. The spontaneous-respiration of the patient can be supported, that A/C which used an active-ventilation in the new generation is rather smarter.