Neonatal ventilation

1. Neonatal Mechanical Ventilation

2. Introduction:
• Introduction in 1960’s one of major inventions
in Neonatology.
• Along with Antenatal steroids and Surfactant
replacement ,ventilation played imp role in
increasing neonatal survival.
• Although life saving it may cause BPD.

3. Benefits of MV:
• Improve Gas exchange, by lung recruitment to
improve V/Q matching.
• Decrease WOB
• CO2 removal in babies with respiratory
depression and apnea.

4. Indications for Ventilation:
• Respiratory Acidosis,pH<7.2 and PaCO2> 60
mm Hg.
• Hypoxia PaO2<50 mmHg.
• Recurrent Apnea.
• Downes score> 7.

5. Common Conditions:
• RDS
• Apnea of Prematurity.
• Septicemia-Pneumonia
• Post operative recovery.
• PPHN
• MAS
• Congenital pulmonary or cardiac
anomalies(CDH).

6. Types of :
• CMV: Exchange of gas in bulk similar to tidal volume
Initiation of breath-Ventilator (CMV or IMV)
Patient
Tidal volume regulation- PC
VC
Breath is terminated- Volume
Time .
Flow regulated.
• HFV: small volume of gas at extremely rapid rate(300-
1500)
290 Modes on 33 Ventilators .
One ventilator- Care fusion Avea ,offers choice of 44 different modes

7. Initiation of Breath:
 Synchronised Ventilation:(Patient triggered)
-SIMV
-A/C Ventilation
-Pressure support ventilation(PSV)
-NAVA
 CMV or IMV.
Increase in death rate using SIMV(RR-1.19)
No difference in air leak,IVH,BPD,extubation failure
Shorter duration of Ventilation in SIMV(Mean difference -35 hrs)

8. Assist Control SIMV

9. SIMV Mode:

11. PSV +SIMV vs SIMV
PSV+SIMV REDUCES WOB & INCREASES Minute Ventilation.
LESS LIKELY TO REQUIRE MV @ 28 DAYS
COMPLICATION RATES NO DIFFERENCE

12. Flow Sensor and Modes:

13. NAVA
Observational studies have shown better synchrony, less PIP and
sedation with similar ABG
Further research needed to determine effects on outcome

14. Modes in our Ventilator:
SLE 5000 GE CARESCAPE

15. Modality:
• Pressure limited :
PC-SIMV
PC-A/C
PC-PSV
• Volume targeted
VC
VG
PRVC

16. Pressure Limited Ventilation:
• TCPL ventilators are MC used Neonatal
ventilators.
• Amount of pressure during inspiration is
set(PIP).
• TV delivered depends on PIP,Ti,Compliance
and synchrony.

17. Pressure control Waveform:

18. Pressure Limited Ventilation(TCPL):
Advantages
• Relatively easy to use and less
costly.
• Continues flow of gas in circuit
allows for spontaneous
breathing.
• PIP and MAP can be adjusted
to optimize gas exchange and
minimize lung injury
Disadvantages
• Variation in TV from breath
to breath
• Increased WOB during
spontaneous breaths
• Poor synchrony decreased
O2,increase CO2,de TV,de
MV(overcome with
synchronization)

19. Volume Targeted Ventilation:
• Provides consistent TV resulting in less lung
injury.
• In 2011,volume targeted ventilation had
replaced pressure limited ventilation in 25 of
50 neonatal tertiary units.
• Volume control & Volume Guarantee

20. Volume Controlled Ventilation:
• Set TV (4-6ml/kg) is delivered by variation in
PIP.
• RR and max Ti are set.
• Measure TV delivered to circuit ,No
compensation for ET tube leaks

21. Volume Control Waveform:

22. Volume guarntee(VG):
• Modified pressure targeted ventilation.
• Addition of microprocessor that adjusts the
pressure to ensure Targeted Tidal Volume(TTV).
• TV,Ti,Max PIP is set
• Flow sensor senses ex TV to adjust pressure for
next few breaths.

23. Volume Guarantee waveform:

24. Controlling Volume ,a better mode?
• Costly and needs more expertise.
• Lower rate of death and BPD(RR-0.73).
• Reduced rate of Air leak(RR-0.46),days of
ventilation,Hypocarbia and neurologic
injury(RR-0.48)

25. Volume targeted ventilation with either SIMV
or A/C using modified TCPL ventilators with TTV
of 4-6ml/kg with permissive hypercarbia should
be initial mode of ventilation

26. Ventilator settings and strategies:

27. Parameters in Conventional ventilation:
• Mode of ventilation
• PIP
• PEEP
• Flow
• Inspiratory time(Ti)
• Fio2
• Rate.
• Trigger
• Tidal Volume(TTV)
• I:E ratio

28. Setting PIP:
• PIP is the primary factor used to deliver tidal
volume
• PIP required mainly depends on the
compliance of lungs
• Useful clinical indicator of adequate PIP is
gentle chest rise with every vent breath.
• If compliance is normal, initiate with 12-14 If
abnormal, check chest rise on hand ventilation

29. Setting PIP:
Insufficient PIP
• Insufficient ventilation
• Decreased oxygenation
• Generalized atelectasis
High PIP
• Increased barotraumas (air
leaks)
• Increased BPD
• Impede venous return/
cardiac output

30. Setting PEEP:
• Adequate PEEP improves FRC & V/Q mismatch
• PEEP levels between 3 – 6 improve
oxygenation & well tolerated

31. Setting PEEP:
• Choices are between 3 - 6
• If FRC is expected to be:
normal: 3
moderately reduced: 4
severly reduced: 5 – 6
• Low PEEP-Atelectotrauma
Co2 retention due to V/Q mismatch
• High PEEP-Decrease lung compliance
Impede venous return/ shock
Pulmonary air leaks

32. • RR is one of the primary determinants of MV,
thus CO2 elimination
• No conclusive evidence for appropriate RR
• In SIMV mode ventilatory rate may not affect
ABG as much as anticipated
• Choices are between 20 to 60
• Considerations are:
- work of breathing
- Is there asynchrony: need for overdrive?
- pressure requirement ?

33. Setting FiO2:
• Choices are between 21-100%
• Target is Pa02 of 50-70 mm Hg with Spo2 of
88-95%.
• If lung compliance is good start with 21-25%
• Other lung conditions start with FiO2 50%

34. • Very rapid rate may cause insufficient
inspiratory time and decreased tidal volume
• May lead to inadvertent PEEP and gas
trapping due to inadequate expiration
• CO2 retention, impaired cardiac output
High RR
• Low RR

35. Setting Ti:
• The respiratory system time constant
determines optimal Ti & Te
• Ideal Ti = 3 x time constant
• An Ti of 0.3 – 0.4 sec is commonly used
• In conditions like MAS – shorter Ti (0.25sec)
• In severe ARDS / Pulmonary hemorrhage
prolonged Ti (0.5 sec)

36. Setting Flow:
• Adequate flow rate is required for the
ventilator to deliver the desired PIP &
waveform
• Minimum flow rate of about 3 times the
infants MV
• Flows of 4 -10 L/min are sufficient for most
infants

37. Mean Airway
Pressure:

38. How to Increase MAP
• 1. Increase inspiratory flow
rate
• 2. Increase peak inspiratory
pressure
• 3. Increase inspiratory time
• 4. Increase PEEP

39. Increasing Oxygenation:

40. Increasing Ventilation(PaCO2)