1. Graphics in Neonatal Ventilation
notes:
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2. Airway Monitoring 1. Diagnostics and Quantification
(RDS, BPD, aspiration syndrom ...)
2. Therapy Decisions
(Indication for ventilatory support, surfactant, apnoea therapy ...)
3. Optimizing Ventilator Settings

3. Airway Monitoring
Pressure
Flow
Volume
Lung mechanics

4. Pressure The driving force for all modes of ventilation commonly
used with neonates.
Basic monitoring on neonatal ventilators should include
Peak pressure
Mean airway pressure
Positive end expiratory pressure

5. Pressure Measurement The Pressure Wave Peak Pressure Mean Pressure
PEEP
Quasi Static Dynamics of pressure
Measurements Interaction of ventilator and patient

6. Problems related to pressure measurement hoses
kinking
loose connections
condensation
an extra tube to manage

7. Pressure Wave

8. The Babylog 8000 Pressure Measurements Screen

9. Parameters used to adjust Airway Pressure
Pinsp PEEP/CPAP
Insp. Flow
Standard controls used to
adjust airway pressure
Can be used to attain:
PIP
Shape of Pressure Wave
I:E ratios
Respiratory Rate

10. Setting Lower Flow Rates
Effect on delivered breath Clinical Effect
Slower increase in airway pressure
Sloping pressure wave form
flow into patient is more like a
spontaneous breath
if Ti not long enough, VT may be
impaired, potential  PaC02
Lower MAP thus potential  Pa02
Theorectically less barotrauma

11. Setting Higher Flow Rates
Effect on delivered breath Clinical Effect
May help open up atelectatic alveoli and therefore improve gas distribution.
May impede venous return
Higher MAP thus potential Pa02
Immediate increase in airway pressure
PIP reached early in the Ti. Longer time spent at Peak Pressure
High initial flow rate into patient. VT delivered early in the Ti.

12. Five different ways to increase MAP

13. Changes in Compliance during Pressure Limited Ventilation
The ventilator flow rate and the compliance of patient and tubing determine the pressure rise time (slope) of the pressure wave during an inspiratory cycle
As a result of change in compliance, the pressure rise time of the pressure wave will change
increase in compliance decrease in pressure rise time
decrease in compliance increase in pressure rise time
notes:
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14. Adjusting flow rate will alter MAP without effecting ventilation

15. Mean Airway Pressure Trend

16. PiP and PEEP Measurements
The maximum pressure measured during the last completed ventilatory cycle.
PEEP or CPAP
The baseline pressure.
Controls Functional Residual
Capacity.

17. Adjusting Flow Rate Increase flow rate if Decrease flow rate if
Pressure rise time is too slow
A plateau is desired but pressure does not reach the pressure limit.
flow is insufficient to meet spontaneous demand
Decrease flow rate if
Pressure rise time is too quick
A pressure plateau occurs but is but not wanted.

18. Spontaneous Breaths

19. Conclusion
Pressure waves do provide a lot of information about patient and ventilator interaction.
However pressure is only the driving force for flow and volume.
Detailed feedback on the patients pulmonary status requires assessment of flow wave forms and volume measurements.

20. Lung Mechanics
"The main benefit of the computerised pulmonary function equipment is for the skilled investigator, who may save considerable time with his study"

21. Minute Ventilation
MV = f * VT

22. Tidal Volume
PEEP
PiP
D P Ti
Vinsp Vt Te
trs
Rrs
Crs

23. Placement of a Neonatal Flow Sensor
Tubing System V . Ct
Crs
Respiratory
System

24. How the Babylog Detects Flow Direction
Hot wire 2
Hot wire 1
Shade
exp.
Flow Direction
insp.
Very low flow
insp.

25. Measurement Conditions NTPD versus BTPS
Normal Temperature (20°C)
Normal Pressure (1013 mbar)
Dry Gases (0% rel.humidity)
BTPS:
Body Temperature (37°C)
Body Pressure (ambient pressure + MAP)
Saturated Gases (100% rel.humidity)
Babylog 8000 BTPS conditions
(Conditions at Y-piece):
Calibration temperature 25°C
Measurement temperature 35°C
Relative humidity 90% at 35°C
Pressure 1023 mbar
p*V = m*R*T 8 9

26. How do we interpret the Flow Wave ?

27. Flow Curve during Pressure Limited Ventilation
notes:
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28. Timing and the Flow Wave

29. How can we Recognise Compromise of Inspiratory Flow ?

30. Flow Curve during insufficient Inspiration Time
notes:
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Inspiratory time (set on the ventilator) is shorter than the time required for the lung to expand fully.
clipping of inspiratory flow occurs

31. How can we Optimize Ti ?

32. How can we Detect Compromise of Expiratory Flow and Inadvertent PEEP?

33. Flow Curve during insufficient Expiration Time
notes:
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Clipping of expiratory flow occurs when TE is too short relative to the time the lung needs to empty, and this results in incomplete emptying before the next breath is delivered by the ventilator.
The latter is termed inadvertent PEEP, (also known as occult, intrinsic, and auto- PEEP).

34. Flow Curve due to change in Resistance
notes:
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change in resistance (R) to expiration is indicated by a change in expiratory flow scaling:
increase in expiratory resistance prolonged expiratory flow scale
decrease in expiratory resistance reduced expiratory flow scale

35. Effect of Setting Flow Rates on Pressure Waveform
Effect of different flow rates on airway pressure profile.
(A) Shows a slow increase in airway pressure The absence of a pressure plateau is indicated by a constant flow profile. The preset pressure is not reached. As soon as preset pressure is reached, flow starts to decelerate
(B) The increase in flow results in a steeper slope of the pressure curve. A small pressure plateau is visible. Tidal volume is delivered at the end of TI.
(C) High initial flowrate results in a faster increase in airway pressure, preset pressure reached earlier in the Ti, a pressure plateau results. Tidal volume is applied within the first half of Ti (inspiratory flow curve reaches baseline), no further gas flow into the patient, lung remains inflated for remainder Ti.
notes:
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36. Active Expiration active expiration 15 1 4 20 15
The set inspiratory time is set longer as the time needed to fill the lung(Li). This is when active expiration occurs, Babyfights the ventilator, or the machine fights the baby.
Active expiration leeds to a reduction in VT and deterioration in blood gas status and predisposed the infants to pneumothoraces.
(Remember pneumothoraces are associated with longer periods of active expiration “Study from C. Morley Anne Greenough 1983”).
We could avoid this active expiration by adjusting Ti all the time manually.
But during weaning process that might change from breath to breath. Therefore we have a new weaning mode which is designed expecially for neonatology. PSV
active expiration
notes:
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37. ET-Tube Leakage via Inspection of Volume Curve
notes:
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38. ET-Tube Leakage via Inspection of Volume Curve
notes:
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39. ET-Tube Leakage via Inspection of Flow Curve
Leakflow
notes:
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40. What is the "Normal" VT ?

41. Tidal Volume oriented Ventilator Management
Set Tidalvolume to 5-6 ml/kg
Set Ti, so that
longer Ti does not increase Vt,
shorter Ti does not decrease Vt
Set Frequency to maintain desired PaCO2
Set PEEP to adjust oxygenation
If oxygenation continuous to be a problem
try longer Ti
try reversed I:E ratio

42. PV-Loop of Mechanical Stroke
notes:
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PV- Loops from mechanical breath strokes move in a counter clockwise direction

43. PV - Loop during CPAP without PSV
notes:
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PV - Loops during spontaneous breathing without pressure support move in a clockwise direction.

44. PV-Loop during Pressure Support Ventilation
notes:
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According to each breath of the patient during PSV,
a different airway volume is reached.

45. PV-Loop during CPAP with PSV
PV-Loops in spontaneous breathing with pressure support result in a small twist in the loop just above zero.
The area within this loop represents trigger work of breathing
The large right hand loop represents work of the ventilator to deliver a breath.
notes:
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46. P-V Loop during PSV using BabyView-Graphics
notes:
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47. PV-Loop due to changes in Compliance
notes:
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Change in compliance results in a transformation of the inspiration loop of the PV-Loop during controlled breathing.
increase in compliance slope of inspiratory limb increases
decrease in compliance slope of inspiratory limb decreases

48. PV- Loop due to Lung-Overdistention
notes:
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Should the upward increment of the inspiration loop become flatter, this may indicate overdistention of the lung.
Note: In the presence of a longer pressure plateau, an overdistention can not be detected by PV-Loop inspection!

49. Visible Lung Overdistention using BabyView-Graphics
notes:
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50. Blood Gases Normal RangepH
pCO kPa
pO kPa

51. Respiratory acidosis in a baby with RDS
Example 1
Arterial Blood Gases Settings Volumes
pH pCO2 pO2 bic PIP/ MAP rate Ti Te O Vt MV
PEEP /
Case history:
Baby T. 28 weeks gestation,
birth weight 0.80kg. Ventilated from
birth for hyaline membrane disease,
now 48hrs of age.
Ventilator Settings
Ti : 0.45s
Te : 0.45s
f : 66/min
Peak : 26 mbar
Peep : 5 mbar

52. Respiratory acidosis in a baby with RDS
Example1
Aim
keep PO2 as it is
reduce PCO2 by
increasing MV
Settings Volumes
PIP/PEEP MAP rate Ti Te O Vt MV
28/
1.Step Improve VT
aim : 5mL/kg
Pip ð 28 mbar
PEEP ð 3 mbar
2.Step Increase MV by increasing the rate
Ti = 0.4
Te = 0.4

53. Blood gases after 1 hour Example 1 Arterial Blood Gases
pH pCO pO bic

54. Respiratory alkalosis in a baby with BPD following a PDA ligation
Example 2
prior surgery
Case history:
Baby D. Born at 26 weeks gestation,
birth weight 0.650kg. Ventilated from birth
for RDS, now 29 days old (0.7kg) with BPD.
Still ventilator-dependent, despite two
courses of steroids. Planned surgical
ligation of patent ductus arteriosus.
Arterial Blood Gases Settings Volumes
pH pCO2 pO2 bic PIP/ MAP rate Ti Te O2 Vt MV
PEEP /
Ventilator Settings
Ti : 0.5s
Te : 0.65s
f : 30/min
Peak : 27 mbar
Mean : 9 mbar
Peep : 4 mbar

55. Respiratory alkalosis in a baby with BPD following a PDA ligation
Example 2
after surgery
Arterial Blood Gases Settings Volumes
pH pCO2 pO2 bic PIP/ MAP rate Ti Te O2 Vt MV
PEEP /

56. Respiratory alkalosis in a baby with BPD following a PDA ligation
Example 2
Arterial Blood Gases
pH pCO pO bic
Aim
reduce PO2
allow pCO2 to rise
arterial blood gases
25 minutes later
1.Step reduce VT
aim : 5-6 mL/kg
2.Step reduce rate
Settings Volumes
PIP/PEEP MAP rate Ti Te O Vt MV
20/

57. Normal arterial blood gases but excessive tidal volume in a preterm baby
Example 3
Case history:
Baby K, born at 26 weeks gestation
weighing 700g. Maternal steroids given
during 48hrs prior to delivery. Poor Apgar
scores at birth, intubated immediately
and ventilated. Now 10 hrs old with good
oxygen saturation and CXR looks
almost clear.
Arterial Blood Gases Settings Volumes
pH pCO2 pO2 bic PIP/ MAP rate Ti Te O Vt MV
PEEP /
Ventilator Settings
Ti : 0.5s
Te : 2.10s
f : 23/min
Peak : 22 mbar
Peep : 3 mbar
FiO2 : 35%

58. Normal arterial blood gases but excessive tidal volume in a preterm baby
Example 3
Settings Volumes
PIP/PEEP MAP rate Ti Te O Vt MV
15/
Aim
reduce Vt
maintain MV and
normal gas
1.Step reduce VT
2.Step compensate
for MV
Arterial bloodgas
1 hour later
Arterial Blood Gases
pH pCO pO bic

59. mean optimal ventilation!
Suggested Guidelines
Normal gases may not
mean optimal ventilation!