Mechanical Ventilation Flashcards
Four primary variables of mechanical ventilation
Trigger
Control/target
Limit
Cycling
How is tidal volume adjusted during time cycled ventilation
I time, flow, set PIP
Where should high pressure alarm be set
5-10 above peak airway pressure
Where should the low pressure alarm be set
5-10 below peak airway pressure
Where should the minimum exhaled tidal volume be set
10-20% below set tidal volume
What can cause low pressure alarm
Leak
Disconnect
Insufficient flow
What causes a minimum exhaled tidal volume alarm
Disconnect
Low Vt
Phase one MV
Initiate ventilation
Initiate ventilation settings
Phase 2 MV
Monitor
Changes to settings
Identify/correct problems
Phase 3 MV
Readiness for weaning
Implement weaning
Monitor during weaning
Newborn basic ABG values
7.25-7.35
45-55
50-70
Infant basic ABG values
7.34-7.46
30-45
85-100
Acceptable VD/Vt
<60%
Acceptable A-a 21%
10-15
Acceptable A-a 100%
66-300
Acceptable percent shunt
<20%
Initial PIP for infants/children
20-25 / 20-30 or PIP from manual ventilation
Initial VC infants/chilfren
4-6 ml/kg / 6-10 ml/kg
Corrected tidal volume equation
Set Vt - compressible gas volume
Compressible gas volume equation
(PIP-PEEP) x Tubing compliance factor
Tubing compliance factor equation
= volume delivered / (PIP-PEEP)
How to determine tidal volume from flow and I-time
Vt = flow (mL/sec) x I-time (sec)
How to convert L/min to mL/sec
L/min x 16.7
How to convert mL/sec to L/min
ML/sec x 0.06
How to calculate I-time
Total cycle time (60 / set rate) divided by I + E
How to calculate I:E
1) TCT = 60 / rr
2) Expiratory time = TCT - I time
3) I:E= TE / TI
Dynamic compliance formula
Vte / PIP - PEEP
Static compliance formula
Vte / Plat - PEEP
Normal Static for FT infants >8hrs old
50-55