This document discusses ventilator settings and parameters. It covers: 1. Modes of ventilation like IMV, SIMV, AC/SIPPV, PSV and their characteristics. 2. Parameters that determine gas exchange like FiO2, PEEP, PIP, flow rate, I:E ratio and how they affect oxygenation and ventilation. 3. Other settings like trigger sensitivity, tidal volume, alarms and graphics that help optimize the ventilator for the patient's needs. The goal is to maintain gas exchange with minimum lung injury or other adverse effects by properly adjusting these various settings.

1. 3. VENTILATORY
SETTING
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2. June 1, 2016 2

3. Ventilator parameters
1. Selection of the mode
2. FiO2
3. Inspiratory flow rate or Slope
4. Ti (Some ventilators may also have Te, or I : E ratio.)
5. Frequency ( Rate)
6. PEEP
7. PIP
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4. Ventilator parameters
8. Trigger
sensitivity
9. Termination
sensitivity of PSV
10. Variable
inspiratory and
variable
expiratory flow
11. TV & MV in
volume targeted
ventilation
12. Ventilator
alarm settings
13. Graphics
monitoring
settings
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5. 1. Which mode?
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IMV
A/C SIPPV
SIMV
CPAP
PS
SIMV&
PS
CMVVG
BIPAP ASV
PCV
VCV

6. Different ventilatory modes
and their characteristics
Weaning byPIP
Inspiratory
time
Ventilator
respiration
rate
Assistance
of each
breath
Inspiratory
trigger
Ventilatory
mode
RR&
PIP
FixedFixedFixedNoNoIMV
RR&
PIP
FixedFixedFixedNoYesSIMV
PIPFixedFixedVariable
YesYesAC/
SIPPV
PIPFixedVariableVariable
YesYesPSV

7. 2. Fraction of Inspired Oxygen
The simplest and most direct
mean to improve oxygenation
Adjust FiO2 to maintain adequate
oxygenation
Can be adjusted as low as 21% and
as high as 100%
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8. FIO2
 Oxygen is a drug used to:
Relieving hypoxemia
pulmonary vasodilator in cases of PPHTN
 Inadequate O2 administration will resultant to:
Hypoxemia and hypoxia
May result in severe neurologic injury
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9. FIO2
 Excessive O2 administration has been
implicated as:
ROP
BPD
 Try to maintain:
PaO2 (60-80 mmHg)
Saturation (PT 90-95% & FT >
95%)
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10. Anatomy of Pressure waveform
Hera NICU
2016
Ti
Te
Pressure
Begin
inspiration
Cycle to expiration
Time
Flow determines rate
of rise and reaching
peak pressure
Pressure limited =
“PIP”
PEEP
∆p
MAP
Inflating pressure
Distending pressure

11. 3. Flow Rate
Volume of gas passed / time unit (liter/minute)
Minimum flow of at least 3 times the baby’s minute
ventilation is usually required but in practice the operating
range can be much higher
Flow rate of 6-10 liter/minute are usually sufficient
Flow rate is an important determinant of the ability of the
ventilator to deliver desired levels of PIP, waveform, I : E
ratios, and in some cases, respiratory rate.
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12. June 1, 2016 Hera NICU 12

13. Slope (80 to 150 ms is
recommended)
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14. Wave forms
SINE WAVE SQUARE WAVE
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PIPPIPPIP PIP
20
30
10
1 second 1 second 1 second 1 second

15. June 1, 2016 15
Wave forms
SQAURE WAVESINE WAVE
Adverse effectsAdvantagesAdverse effectsAdvantages
1. With high
flow, the
ventilation
may be
applying
higher pressure
to normal
airways and
alveoli
2. Impede venous
return if longer
Ti is used or I :
E ratio is
reversed
1. Higher MAP
for equivalent
PIP
2. Longer time at
PIP may open
atelectatic areas of
lung and improve
distribution of
ventilation
1. Lower mean
airway pressure
1. Smoother
increase of
pressure
2. More like
normal respiratory
pattern

16. 4. Inspiratory time
 Usually adjusted between 0.30- 0.50 seconds
 Depends on the pulmonary mechanics:
Compliance
Resistance
Time constant
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17. Total Cycle Time
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18. Inspiratory time
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19. Inspiratory / Expiratory Time Ratio
I:E ratio should not
be less than 1:1.2
It should not be
reversed
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20. If inspiratory time is too short
Incomplete inspiration
Tidal volume Mean airway pressure
Hypercapnia Hypoxia
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21. If expiratory time is too short
Incomplete expiration
Gas trapping
Complianc Tidal volume Mean airway pressure
Tidal volume Cardiac output
Hypercapnia Hyperoxemia
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22. Ti & Te
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23. I / E Ratio
PROLONGED EXPIRATORY
(> 1:3)
NORMAL (1:2-1:3)INVERSE (>1 : 1)
Adverse
Effects
AdvantagesAdverse
Effects
AdvantagesAdverse
Effects
Advantages
1. Low Ti may
decrease
tidal volume
2. May have
to use higher
flow rates,
which may
not be
optimal for
distribution
of ventilation
3. May
ventilate
more dead
space
1. Useful
during
weaning,
when
oxygenatio
n is less of
a problem
2. May be
more
useful in
diseases
such as
MAS,
when air
trapping is
a part of
the disease
process
1. Insufficient
emptying at
highest rates
1. Mimics
natural
breathing
pattern
2. May give
best ratio
at higher
rates
1.May have
insufficient
emptying time
and air
trapping may
result
2. May impede
venous return
to the heart
3.↑Pulmonary
vascular
resistance and
worsens
diseases such
as PPHN and
CHD
4. Worsens
PAL
1. ↑ MAP
2. ↑ Pao2 in
RDS
3. May
enhance
alveolar
recruitment
when
atelectasis
is present
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24. June 1, 2016 24

25.  Determine minute ventilation ( RR x VT),
thus CO2 elimination
 Depend on:
The infant gestational age
The underling disease and resulting
pulmonary mechanics
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5. Respiratory Rate

26. Respiratory Rate
Rate PaCO2
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27. Ventilatory Rate
RAPID (≤ 60 breaths /min)MEDIUM (40-60 breaths/miSLOW (≤40 breaths/min)
Adverse
Effects
AdvantagesAdverse
Effects
AdvantagesAdverse
Effects
Advantages
1. May exceed
time constant
and produce
air trapping
2. May cause
inadvertent
PEEP
3. May result
in change in
compliance
(frequency
dependence of
compliance)
4.Inadequate
Vt and minute
ventilation if
only dead
space is
ventilated
1. Higher
PO2 (may be
the result of
air trapping
2.May allow
↑ PIP and Vt
3.Hyperventi
lation may
be useful in
PPHN
4. May
reduce
atelectasis
(air
trapping)
1. May not
provide
adequate
ventilation in
some cases
2. ↑ PIP may
still be
needed to
maintain
minute
ventilation
1. Mimic
normal
ventilatory
rate
2. Will
effectively
treat most
neonatal
lung diseases
3. Usually
does not
exceed time
constant of
lung, so air
trapping is
unlikely
1. Must
increase
PIP to
maintain
minute
ventilation
2. ↑ PIP may
cause
barotrauma
3. Patient
may require
paralysis
1.↑ Pao2
with
increased
MAP
2. Useful in
weaning
3. Used with
square wave
ventilation
4. Needed
when I : E
ratio is
inverted
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28. 6. Positive End Expiratory Pressure
The positive pressure applied at the end of
expiration to prevent lung collapse and maintain
stability of the alveoli (FRC)
Optimum PEEP is the level below which the lung
volume is not maintained and above which the
lung volume become over-distended
Can be as low as low as 4 cm H2o& as high as 8
cm H2o, PEEP less than 5 cm in diseased lung is
exception.
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29. Optimum PEEP
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30. PEEP
 The benefits of PEEP are:
a. Stabilization and recruitment of lung
volume.
b. Improvement in lung compliance.
c. Improvement in ventilation-perfusion
matching in the lungs.
 Inadvertent PEEP: increase chosen PEEP if
expiration time is too short or airway resistance
is increased
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31. Auto-PEEP
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32. Auto-PEEP
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33. PEEP
HIGH (>8 cm H2O)MEDIUM (4-7 cm H2O)LOW (<4cm H2O)
Adverse
Effects
AdvantagesAdverse
Effects
AdvantagesAdverse
Effects
Advantages
1. PAL
2. Decreases
compliance
if lung
overdistends
3. May
impede
venous
return to the
heart 4. May
increase PVR
5. CO2
retention
1. Prevent
alveolar
collapse in
surfactant
deficiency
states with
severely
decreased CL
2. Improves
distribution
of ventilation
1. May
overdistend
lungs with
normal
compliance
1.Recruit
lung volume
with
surfactant
deficiency
states (e.g.,
RDS
2.Stabilizes
lung volume
once
recruited
3.Improve
V/Q
matching
1. May be too
low to
maintain
adequate
lung volume
2. CO2
retention
from V/ Q
mismatch, as
alveolar
volume is
inadequate
1. Used
during late
phases of
weaning
2.
Maintenance
of lung
volume in
very
premature
infants with
low FRC
3. Useful in
some
extremely
LBW infantsJune 1, 2016 33

34. Gas exchange effects
of PEEP
1. An increase in
PEEP increases FRC
capacity thus
improves ventilation-
perfusion matching
and oxygenation.
2. An increase in
PEEP will increase
mean airway
pressure and thus
improve
oxygenation.
3. An increase in
PEEP will also reduce
the pressure gradient
during inspiration
and thus reduce tidal
volume, reduce CO2
elimination, and
increase PaCO2.
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35. PEEP affect PaO2 & PaCO2
in the same direction.
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36. 7. Peak Inspiratory Pressure
The maximum pressure reached during
inspiration
Primary factor to deliver VT in pressure
ventilators
Adjust PIP to achieve adequate VT as
reflected by chest expansion and adequate
breath sounds
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37. PIP
Gas
exchange
effects of
PIP
1. An increase
in PIP will
increase tidal
volume,
increase CO2
elimination,
and decrease
PaCO2.
2. An
increase in
PIP will
increase
mean airway
pressure and
thus improve
oxygenation.
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38. PIP
 If PIP is too low Low VT Hypoxia
 If PIP is too high High VT
-Barotraumas and BPD
-Hyperinflation and air leak
-Impedance of venous return
 If you PIP PaO2 & PaCO2
 If you PIP PaO2 & PaCO2
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39. PIP affects PaCO2
&PaO2 in different
directions.
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40. June 1, 2016 40
PIP
HIGH (≥20 cm H2O)LOW (≤20 cm H2O)
Adverse effectsAdvantagesAdverse effectsAdvantages
1. Associated
with ↑ PAL,
BPD
2. May impede
venous return
3. May decrease
cardiac output
1. May help re-
expand
atelectasis
2. ↓ Paco2
3. ↑ Pao2
4. Decrease
pulmonary
vascular
resistance
1. Insufficient
ventilation;
may not
control Paco2
2. ↓ Pao2, if too
low
3. Generalized
atelectasis may
occur (may be
desirable in
some cases of
air leaks)
1. Fewer side
effects,
especially BPD,
PAL
2. Normal lung
development
may proceed
more rapidly

41. Mean Airway Pressure(MAP)
It is a measure of the average pressure to which
lung are exposed during the respiratory cycle
It is the factor (other than Fio2) that determine
oxygenation
MAP( calculated by ventilator)
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42. Mean airway pressure
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43. (1) PIP
(2) PEEP
(3) Ti
(4) I : E
ratio
(5)
waveform
(6) Rate
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MAP

44. 8. Trigger sensitivity
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High sensitivity my result in false or auto-
triggering.
Increase the sensitivity improve patient
ventilator synchronization.
It determine how easy to the patient to trigger
the ventilator to deliver a breath.

45. Paw
V
•
insp
exp
Patient or
vent ilator
initiated
inspiration PSV cycled
expiration
Peak flow
Drop to 15%
of peak flow
9. Termination sensitivity of PSV
Set Pinsp
Hera NICU
2016

46. 10. Variable inspiratory and
variable expiratory flow
Continuous expiratory flow can be
adjusted independently of the
continuous inspiratory flow.
The inspiratory flow is effective
during ventilation stroke
While the expiratory flow is effective
during the expiratory phase of
mandatory ventilation, during
spontaneous breathing 46

47. 11. Tidal volume & Minute volume
Vt Preterm = 4-6 ml/kg
Vt Fullterm = 5-7 ml/kg
Vd = 2-2.5 ml/kg
MV = 200- 480 ml/kg/min
Va = 60- 320 ml/kg/min
Vt = Vd + Va
Minute Ventilation = RR x Vt
Minute alveolar ventilation= RR x Va (Vt- Vd)
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48. 12. Ventilator alarm settings
Some alarm limits are set
automatically e.g. airway pressure,
oxygen concentration
Some alarm limits are set
manually e.g. minute
ventilation, apnea time,
frequency
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49. 13. Graphics monitoring settings
Displaying the mode
Displaying curves : pressure , flow and
volume against time.
Displaying measured pressure values:
peak, mean and PEEP
Displaying lung values: R, C and TC
Displaying measured volume values: VT,
MV, leak and spont.
Displaying trends
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50. Goals of mechanical ventilation
 Maintain acceptable gas exchange with a
minimum of:
Lung injury
Hemodynamic impairment
Other adverse events (neurologic
injury)
 Minimize work of breathing.
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51. During assisted ventilation
oxygenation is determined by:
Mean
Airway
Pressure
FiO2
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52. During assisted ventilation
oxygenation is determined by:
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53. Oxygenation
increases
linearly with
increase in
MAP
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54. So
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FiO2
PEEP
PIP
Ti
Flow
PaO2

55. During assisted ventilation CO2
elimination is determined by:
Minute alveolar
ventilation:
2. Effective
Tidal
Volume
1.Respiratory
Rate
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56. During assisted ventilation CO2
elimination is determined by:
1.Respiratory
Rate
2. PIP -
PEEP
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57. June 1, 2016 57

58. In all pressure controlled ventilation
modes
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Tidal Volume supplied
depend on:
1- PIP- PEEP
2- Lung mechanics
3- Respiratory drive of
the patient

59. Tidal volume
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60. SO
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Rate MV CO2 wash
PaCO2
PIP ∆P TV MV
CO2 wash PaCO2
PEEP ∆P TV MV
CO2 wash PaCO2

61. Rate affects PaCO2 mainly.
PIP & PEEP affect PaCO2 & PaO2 together.
PIP affects PaCO2 & PaO2 in different directions.
PEEP affect PaCO2 & PaO2 in the same direction.
FIO2, FLOW & Ti affect PaO2 Only.
June 1, 2016 61

62. Effect of ventilatory setting on
blood gas
PaO2PaCO2Change
PIP
PEEP
Rate
I:E ratio
±Flow
±
June 1, 2016 62

63. June 1, 2016 63