PCV(Pressure Control Ventilation),A/C(Pressure)
1. The concept and the purpose (Figure ; Corrugation of PCV)
PCV, too, was loaded into -900 C of Servo like PSV, beginning. PCV was contrived in the demand flow method to support a newborn baby and is the starting point. It is the intermediate mode of sCMV and PSV. The beginning and the ending of intake are similar to the former, during intake, it is pressurized at the constant pressure and it is similar to PSV. Adult however, there is little merger of pressure fault (Baro-trauma), as the useful ventilation law which improves oxygenation ability, it is beating at the recent resuscitator and it is equipped with it.
2. The component
PCV is composed of the beginning (begun in A/C) of (1) intake, control (the same as PSV) during (2) intake, the ending (ending in Time cycle) of (3) intake.
3. The control method
1) The controlling mechanism
The model which used an electronically controlled method by the servo valve is mainstream. In the past, the equipment which applied a new Mattick control system by the of CV -5000 and so on demand valve has been sold, too.
2) The operating principle
It is available in Servo-i, Servo-300, New-Port e500, Vela, Avea, Evita “™. PCV with the type which is different from this can realize BIPAP and PLV(Pressure Limitation Ventilation) of Drager Evita by applying them. There are Time cycle, Pressure relief(VIP Bird,Bear-5 etc.) which relieves a continuous flow with the pressure missing valve as the ventilation law that the inspiratory-pressure pattern of the PCV similarity is gotten and Pressure Relief Ventilation(New-Port E-100,E-150) which relieves an active-ventilation in the pressure. But, because there is much gas consumption, these are used for the master by the newborn baby.
a) The beginning of intake
It is the method which is the same as A/C. The beginning of intake synchronizes with the spontaneous-respiration if the spontaneous-respiration is above the setting breathing rate and below the setting breathing rate, it is begun in Time cycle based on the setting breathing rate.
b) The method of the start-up of intake
The pressure index method (Servo-900¤Servo-300¤Bear-1000¤Benette 7200ae¤Evita(BIPAP)) which adjusts an intake gas flow rate to this at a breath for the set-pressure and until it becomes a set-pressure, the flow rate index method (New Port E-200¤Infant Star) to supply at the intake flow rate (of the active-ventilation) is marketed. Recently, start-up speed regulator ability (slope control, rise time control) is prepared (to the model (the pressure index method) of Servo-300, Bear-1000, Evita 2, the 4th prize Evita). It is realized at making standard pressure rise with the passage of time in this case but exceptionally, Bear-1000 is controlling the time constant of the servo loop.
c) The control during intake
An inspiratory-phase is adjusted with the servo valve for a set-pressure to be maintained. The pressure (=100cmH that free intake is possible in the inspiratory-phase but that an exhalation-valve is released at the time of the abnormal fluid pressure in PCV2Because it is closed at ) as much as the O, free expiration isn't permitted. However, because it is closed by the inspiratory-pressure in PCV by the BIPAP mechanism, even if it is under the pressurization, free intake and the expiration are possible.
d) The ending of intake
PCV ends in Time cycle.
4. The advantage and the fault
The danger reduces because the barotrauma by the extraordinary rise of the maximum airway pressure is easy to merge in active-ventilation (Volume Control Ventilation) but the same air quantity of ventilation is supplied at the lower peak pressure in PCV. Therefore, IRV by PCV is evaluative as the safe ventilation law which has the oxygenation ability improvement effect which is equal to PEEP, too. On the other hand, because PCV doesn't avoid a fault, that the air quantity of ventilation is responsible, because it is an ironhand type ventilation law, the check of the air quantity of ventilation by the graphic monitor is indispensable.