Pressure Control

[JacksonDagger]

• Clinician sets: Inspiratory Pressure, inspiratory time, RR, PEEP, FiO2, and Trigger sensitivity. (Insp Pressure set by manually adding weight)

• Constant inspiratory pressure over the set inspiratory time. All breaths are either Mandatory or Assisted Breaths (Set Inspiratory Time). If the patient breathes above the set RR, all breaths are Assisted. If the patient triggers at a rate below the set RR, the ventilator will begin to give Mandatory Breaths. “Trigger Windows” are temporally arranged based on the set minimum RR (evenly spaced such that they occur at a frequency equal to the respiratory rate). If the patient initiates a trigger during a window, an Assisted Breath is given, and if they do not, a Mandatory Breath is given. The next trigger window will start at a set time after the last breath (dictated by the set RR).

• Refractory time reduces double triggering or breath stacking by making it impossible to trigger right after a breath was given. Refractory time = 0.5x inspiratory time.
  Example of code for set minimum RR of 10 (breath every 6s) and Inspiratory time of 2 seconds:

    1. - Open insp. Valve
    2. - Start 6 sec inspiratory time countdown (ICD)
    3. - Give inspiration for 2 seconds
    4. - Close insp valve
    5. - Start 1 second refractory count down (RCD). 
    6. - Once RCD=0, 
    7. - if volume/pressure trigger happens OR if ICD = 0, loop to beginning