1. Sue Pilbeam & Gopal Allada, M.D.
Mechanical Ventilation Mode and Initial Settings a research-based approach
RET 2264C #2
Dr. J.B. Elsberry
Prof. Jean Newberry
Special Thanks to:
Sue Pilbeam & Gopal Allada, M.D.

2. Today’s Focus: Review of Basic Indications for mechanical ventilation:
Type I and II Respiratory Failure
and/or Protect the A/W
Ventilator Modes- the basics
Initiating Orders
Management of the ventilated patient
Review of Original Goal(s)

3. Who needs M.V.?

4. Who else needs M.V. ? Possible Goals: Improve Myocardial oxygenation
Reduce intracranial pressure through controlled hyperventilation
Stabilize the chest wall
Protect airway 2o Neurologic impairment or airway obstruction

5. ABG Indications for Mechanical Ventilation ?
PaO2? __________________
PaCO2?__________________
pH? ____________________

7. RF 2: Hypoxemia There are five reasons for hypoxemia:
PIO2 is too low (i.e. high altitude, O2 supply problems)
Global alveolar hypoventilation
(yes it can also happen on a Ventilator!)
Right-to-left shunts
V/Q mismatch
Incomplete diffusion

8. Definitions Reviewed (again)
PIP: maximum pressure measured by the ventilator during inspiration (aka Pressure Limit).
Pplateau static pressure (no flow) measured during inflation hold [essential for measurements of static CL ]
PEEP: pressure present in the airways at the end of expiration during Mechanical Ventilation.
CPAP: amount of pressure applied to the airway during all phases of the respiratory cycle (Spontaneous Ventilation).
PS: amount of pressure applied to the airway during spontaneous inspiration by the patient.
I-time: amount of time delegated to inspiration. I:E –(TCT/I + E )
Target VT: Tidal Volume delivered during a mechanical breath

9. Ventilator Orders/ Initial Set-up Protocols
Ventilator Mode (let’s apply the Top Ten) f
Set VT or Pressure Control (PIP & TI)
FIO2 +/- PEEP
Other: inspiratory flow rate (V), flow pattern, I:E, inspiratory hold, patient trigger mode/sensitivity

10. M.V. -- How much Support?
M.V. Modes Classified into one of following categories:
those that provide full ventilatory support (machine is responsible for entire minute ventilation)
those that provide partial support (pt. is responsible for some or all of the minute ventilation)
Spontaneous Ventilation (pt is weaned from all pressurized ventilatory adjuncts.)

11. Operational Assumptions for Analysis of Each Mode of Ventilation
Compare the Traditional names for Mode
Use the Chatburn Classification (8 types)
What are the Physician’s or Protocol orders
What limits are imposed on the breath sequence
Advantages
Disadvantages

12. Choosing Ventilator Mode
“Control” modes: VC-CMV & PC-CMV
Volume control (ie Assist / Control): VC (AC)
Pressure control: PC
PRVC or Autoflow
Mixed PC or VC
Synchronized Intermittent Mandatory Ventilation (SIMV) with support (controlled and spontaneous)
“Spontaneous” Modes
Pressure Support (PS)
APRV, BiVent or BiLevel
CPAP
T-Piece

13. Old Mode Limits Vol A/C VC-CMV Vol SIMV VC-IMV Press A/C Press SIMV
Chatburn Mode
Settings
Limits
Advantages
Dis-advantages
Vol A/C
VC-CMV
f, VT, FIO2,Peep
Flow, PIP, Vol
Easy to understand
Pt. sedation barotrauma
Vol SIMV
VC-IMV
Press A/C
f, TI, PIP FIO2,Peep
Safer, more natural
VT varies with CL & Raw
Press SIMV
PSV
Flow
Press SIMV + PS

14. Now, describe the pt…Size does matter
Set inspiratory percentage to achieve an I/E ratio of greater than or equal to 1:1.5
(Ideally; 1:2 or better)
BSA = body surface area
IBW = ideal body weight.
* In patients with neuromuscular disorders or cerebral disorders, a VT of as high as 15 mL/kg may be required.

15. BSA vs. IBW for Volume Target
Minute Ventilation VE
Men VE = 4 x BSA
Women VE = 3.5 x BSA
IBW in kg. x #ml protocol for VT

16. Determining Ideal Body Weight:
Women IBW (lbs) = (H – 60)
Men IBW (lbs) = (H – 60)
to convert to kg, divide by 2.2.

17. Initial Tidal Volume Settings for VC-CMV & VC-IMV Modes
Normal pulmonary mechanics:
VT = ml/kg—f = 8-12/min
Restrictive lung disease:
VT = 4-8 ml/kg—f = 15-25/min
Obstructive lung disease:
VT = 8-10 ml/kg—f = 8-12/min
---Hess and Kacmarek (2002)

18. Question Mode characteristics
What parameters do I have to set or get orders for?
What initiates the breath?
What terminates a breath (i.e. how will the ventilator cycle)?
What are the flow characteristics?
What are the pressure characteristics?
What are the determinants of VT?
What are the Limits?

19. Volume control (VC) Orders: RR, VT, (VI:E), FIO2 +/- PEEP
Initiate: Patient (pressure vs. flow triggered) or controlled; breaths beyond set rate to get FULL set VT Termination: VT (and V)- volume-cycled
Flow: constant ( L/min); can be variable on some vents
Pressure: Increases as lungs distend until inspiration terminates; varies with load
VT or VE: Fixed

20. Flow Patterns

21. Volume Control (top line)

22. Suggested Initial Ventilator Settings for COPD (Sethi, 2000; Hess, 2002; Saura, 2002)
Parameter Recommendation
Mode Assist/control (pressure-target, PC-CMV, preferred over volume-target, VC-CMV
VT 8 to 10 mL/kg (targeted to keep Pplateau as low as possible < 30 cm H2O)
f 8 to 10 breaths/min
TI to 1.2 sec
Flow >60 L/min (up to 100 L/min)
Flow pattern - descending ramp
PEEP < 5 cm H2O or < 85 % of auto-PEEP measured (initially)
FIO2 < 0.5 (if possible)

23. Pressure Control (PC)
Orders: f, Pinsp level above PEEP, TI , FIO2 +/- PEEP
Initiate: Patient or controlled; breaths beyond set f get full set PIP/I time (unless SIMV)
Termination: Set pressure at the I time
Flow: decelerating rate; can vary with patient demand
Pressure: constant
Volume, I time; varies with lung compliance
(CL = V/P)

24. Required Setting Selection and Variables during Pressure Ventilation
Mode Name Trigger Cycle
PSV Patient Flow
PC-CMV Time/patient Time
NAVA Time/Flow
APRV or Bilevel PAP Servo-controlled pressure ventilation:
Time/patient Flow
PAug Patient Volume/Flow
PRVC Time/patient Time
VS patient Flow

25. Pressure Support (PS) Orders: Pinsp above PEEP, FIO2 +/- PEEP
Initiate: Patient
Termination: Flow is 25% of max (flow cycled)
Flow: decelerating rate; patient can increase
Pressure: constant
Volume: varies with pressure, effort, and compliance

26. Names for PRVC on Different Ventilators
Hamilton Galileo Adaptive pressure ventilation
Viasys Avea PRVC
Dräger E-4 Autoflow
Newport E500 Volume targeted pressure control
Servo 300 and Servoi PRVC

27. Names for VS on Different Ventilators
Ventilator Name VS Name
Servo 300 and Servoi Volume Support
Newport E-500 Volume target pressure support (VTPS)

28. Pressure Control (top) Pressure Support (bottom)

29. CPAP (via ETT) Orders: FIO2 and “EEP” (baseline) level
Initiate: patient
Termination: patient
Flow: patient
Pressure: oscillates around the CPAP
Volume: varies with pressure, effort and compliance
Patient breathing spontaneously at a higher end expiratory pressure

30. CPAP (bottom line)

31. T-piece (T-tube) Orders: FIO2 Initiate: Patient Termination: Patient
Flow: Patient
Pressure: negative with inspiration
Volume: varies with effort and compliance
Spontaneous breathing through an ETT
Remember Raw

32. SIMV(VC or PC)/PS
Orders: f, VT (VI:E) or Pinsp, FIO2 +/- PEEP; add PS (for breaths beyond set rate)
Initiate: Patient or controlled (synchronized)
Termination:
Controlled breath (VC or PC)
PS breath (beyond set f): Flow is ~25% of peak flow (flow-cycled)
Flow:
PS breath: Decelerating rate; varies with demand

33. SIMV(VC or PC)/PS Pressure: VT: Controlled breath (VC or PC)
PS breath: constant at whatever you set
VT:
PS breath: patient effort; lung compliance
Try to match spontaneous VT with controlled VT

34. SIMV/T-piece (middle line)

35. Basic Modes: A Quick Reference
Orders
(FIO2, PEEP)
Initiate
(trigger)
Terminate (cycled)
Flow
Pressure VT VC
VT, RR, V(flow)
(P)atient
(C)ontrolled
constant
(usually)
rising
fixed PC
Pinsp, RR
I time
P, C
decelerating
varies with compliance
SIMV
PC or VC; PS, CPAP
P, C (synch with patient)
VT or
Constant
or decelerating
Rising or constant
Fixed or variable
PS/bilevel
Pinsp P
25% of peak flow
compliance, effort
CPAP
“PEEP”
Patient determines
around PEEP
T-tube
FIO2
around atm

36. Managing the ventilated patient
Initial orders
Reading the vent board (yes, you’re supposed to do that in clinic when you are assessing the pt.)
Lung mechanics VE, NIF, RSBI, Raw and CL
Ventilator adjustments for O2 and CO2
Revisit Goal(s) (stay awake)

37. Remember, what were the goals in the first place…

38. After Lunch Modes Jeopardy and Vent Set-ups