1. Introduction to various modes of mechanical ventilation

2. APRV Airway pressure release ventilation
ASB Assisted spontaneous breathing
ASV assisted spontaneous ventilation
ASV Adaptive support ventilation
ASV assisted spontaneous ventilation.
ATC Automatic tube compensation
Automode Automode
BIPAP Bilevel Positive Airway Pressure
CMV Continuous mandatory ventilation
CPAP Continuous positive airway pressure
CPPV Continuous positive pressure ventilation
EPAP Expiratory positive airway pressure
HFV High frequency ventilation
HFFI High frequency flow interruption
HFJV High frequency jet ventilation
HFOV High frequency oscillatory ventilation
HFPPV High frequency positive pressure ventilation
ILV Independent lung ventilation
IPAP Inspiratory positive airway pressure
IPPV Intermittent positive pressure ventilation
IRV Inversed ratio ventilation
LFPPV Low frequency positive pressure ventilation
MMV Mandatory minute volume
NAVA Neurally Adjusted Ventilatory Assist
NIF Negative inspiratory
NIV Non-invasive ventilation
PAP Positive airway pressure
PAV and PAV+ Proportional assist ventilation and proportional assist ventilation plus
PCMV (P-CMV) Pressure controlled mandatory ventilation
PCV Pressure controlled ventilation or
PC Pressure control
PEEP Positive end-expiratory pressure
PNPV Positive negative pressure ventilation
PPS Proportional pressure support
PRVC Pressure regulated volume controlled ventilation
PSV Pressure Support Ventilation or PS
(S) IMV (Synchronized) intermittent mandatory ventilation
S-CPPV Synchronized continuous positive pressure ventilation
S-IPPV Synchronized intermittent positive pressure ventilation
TNI Therapy with nasal insufflation
VCMV (V-CMV) Volume controlled mandatory ventilation
VCV Volume controlled ventilation or VCVS Volume Support

3. Concepts and Modes of Mechanical Ventilation
Spontaneous
Breathing
Mechanical
Ventilation
CMV
Pressure
Time
SIMV
Pressure
Time
Bivent
Pressure
Time
APRV
Pressure
Time
CPAP
Pressure
Time

4. Ventilation modes
Controlled: CMV
Fully or partially assisted: SIMV
SIPPV
A/C / PTV
PSV
SIMV + PSV
SIPPV + PSV

5. CMV

6. Control Modes every breath is fully supported by the ventilator
in classic control modes, patients were unable to breathe except at the controlled set rate
in newer control modes, machines may act in assist-control, with a minimum set rate and all triggered breaths above that rate also fully supported.
In a control mode, the ventilator will guarantee that the patient receives the set tidal volume or PAP with every breath. The patient can breathe “above” the set rate but will receive full support regardless of their effort.

7. IMV
Ref: Ingento EP and Drazen J: Mechanical ventilators, in Hall JB, Scmidt GA, and Wood LDH(eds.): Principles of Critical Care. New York, McGraw-Hill, Inc., 1992, p.145.
“Positive pressure, volume-cycled breaths are delivered at a preset rate similar to control mode ventilation, except that between breaths, the inspiratory valve to the patient is open, allowing for spontaneous breathing.”
Ingento EP & Drazen J: Mechanical Ventilators, in Hall JB, Scmidt GA, & Wood LDH(eds.): Principles of Critical Care

8. SIPPV (or PTV or A/C) and SIMV
Terminology:
Triggered ventilation can be divided into patient triggered (PTV), otherwise known as synchronous intermittent positive pressure ventilation (SIPPV) or assist control (A/C), the infant being able to trigger a positive pressure inflation with each breath,
and synchronized intermittent mandatory ventilation (SIMV), the infant being able to trigger only a pre-set number of positive pressure inflations.

9. Assist-control
Ref: Ingento EP and Drazen J: Mechanical ventilators, in Hall JB, Scmidt GA, and Wood LDH(eds.): Principles of Critical Care. New York, McGraw-Hill, Inc., 1992, p.144.
In assist control modes (pressure control, volume control), the machine will deliver a full breath whether it is triggered by patient effort (note the negative deflection in the uppermost graph indicating patient effort) or triggered by the machine (the machine will act if a set amount of time (T) elapses without discernible patient effort).
Ingento EP & Drazen J: Mechanical Ventilators, in Hall JB, Scmidt GA, & Wood LDH(eds.): Principles of Critical Care

10. SIMV

11. SIMV
Ref: Ingento EP and Drazen J: Mechanical ventilators, in Hall JB, Scmidt GA, and Wood LDH(eds.): Principles of Critical Care. New York, McGraw-Hill, Inc., 1992, p.146.
(Would we also want to put slides with pressure mode graphs as well to show the different flow characteristics ??)
During SIMV, the ventilator divides time by the set rate to determine cycle-length. During the early part of this cycle, the patient may breath spontaneously without support. During the terminal phase of this cycle (% varies by manufacturer) the ventilator will synchronize a full breath with detected effort by the patient.
Ingento EP & Drazen J: Mechanical Ventilators, in Hall JB, Scmidt GA, & Wood LDH(eds.): Principles of Critical Care

13. IMV, SIMV, SIPPV (or A/C or PTV), PSV

14. SIMV versus IMV in neonatal ventilation
Conclusions: We found that SIMV was at least as efficacious as conventional IMV, and may have improved certain outcomes in BW-specific groups.
Bernstein G et al. J PEDIATR 1996;128:453-63

15. PTV (A/C) versus IMV
Baumer JH Arch Dis Child Fetal Neonatal Ed 2000;82:F5–F10
PTV with inspiratory times of between 0.2 and 0.25 seconds, the ventilator set to trigger at each inspiratory effort, backup rate of 35 breaths a minute.
IMV with ventilator rates set initially at between 40 and 65 breaths a minute … and initial inspiratory times between 0.2 and 0.6 seconds.

16. PTV (A/C) versus IMV
Baumer JH Arch Dis Child Fetal Neonatal Ed 2000;82:F5–F10
There was no observed benefit from the use of PTV, with a trend towards a higher rate of pneumothorax under 28 weeks of gestation. Although PTV has a similar outcome to IMV for treatment of RDS in infants of 28 weeks or more gestation, within 72 hours of birth, it was abandoned more often. It cannot be recommended for infants of less than 28 weeks’ gestation with the ventilators used in this study.

17. Greenough A et al. Cochrane Database of Systematic Reviews 2004, Issue 3. CD000456.

18. Volume
PSV
Pressure
IMV

19. IMV, SIMV, SIPPV (or A/C or PTV), PSV

20. Pressure Control vs. Pressure Support
Time Cycled
Pressure
Constant insp. pressure
Decelerating, variable inspiratory flow rate
Time cycled: (A)
Pressure Control
Flow cycled: (B)
Pressure Support
Flow
Flow Cycled A B

21. How to set Ti in a spontaneous breathing patient on a pressure support mode ?
“Flow termination criteria”
Peak Flow
25%
Flow
PIP
Tinsp.
Pressure
Pressure Control
Pressure Support

22. Cycle off with changes in mechanics
Flow
10%
Time T1 T2 T3

24. Pressure-Support and flow termination criteria
The non synchronized patient during Pressure-Support
(inappropriate end-inspiratory flow termination criteria)
Nilsestuen J Respir Care 2005;50:202–232.

25. Pressure-Support and flow termination criteria
Nilsestuen J
Respir Care 2005
Increase in RR, reduction in VT, increase in WOB

26. Termination Sensitivity = Cycle-off Criteria
Flow
Peak Flow (100%)
Set (max) Tinsp.
Leak
TS 5%
Time
Tinsp. (eff.)

27. PSV improves respiratory function in VLBW infants when compared to SIMV
Migliori C et al. Pediatr Pulmonol. 2003;35:364–367

28. SIMV versus SIMV + PSV minimal ventilator settings: PIP 16 cm H2O
FIO2 0.30
PEEP 5 cmH2O
SIMV rate 15 breaths per minute
and remained on these settings for 48 hours
Reyes ZC et al. Pediatrics 2006;118;

29. SIMV versus SIMV + PSV Reyes ZC et al. Pediatrics 2006;118;1409-1417
CONCLUSIONS. The results of this study suggest that the addition of PS as a supplement to SIMV during the first 28 days may play a role in reducing the duration of mechanical ventilation in extremely VLBW infants, and it may lead to a reduced oxygen dependency

30. Compliance Changes During Pressure Controlled Ventilation
Volume
Pressure

31. Volume Ventilation
Tidal volume, is not affected by the rapidly changing pulmonary mechanics
Compliance 
Pressure Ventilation: Volume Ventilation:
Decreased Tidal Volume Increased Pressure
Volume
Volume
Pressure
Pressure

32. Combination “Dual Control” Modes
Combination or “dual control” modes combine features of pressure and volume targeting to accomplish ventilatory objectives which might remain unmet by either used independently.
Combination modes are pressure targeted
Partial support is generally provided by pressure support
Full support is provided by Pressure Control

33. Combination “Dual Control” Modes
Volume Assured Pressure Support (Pressure Augmentation)
Volume Support (Variable Pressure Support)
Pressure Regulated Volume Control (Variable Pressure Control, or Autoflow)
Airway Pressure Release
(Bi-Level, Bi-PAP)

34. PRVC (Pressure regulated volume control)
A control mode, which delivers a set tidal volume with each breath at the lowest possible peak pressure.
Delivers the breath with a decelerating flow pattern that is thought to be less injurious to the lung…… “the guided hand”.
This mode combines the benefit of a volume mode (guaranteed minute ventilation) with the benefits of a pressure mode (decelerating flow pattern and a lower PIP for the same tidal volume as compared to volume control).

35. Volume Guarantee: New Approaches in Volume Controlled Ventilation for Neonates Ahluwalia J, Morley C, Wahle HG. Dräger Medizintechnik GmbH. ISBN X

36. PRVC
Decelerating inspiratory flow pattern (square wave pressure build up)
Pressure automatically adjusted according respiratory mechanics to deliver set tidal volume
Pressure
Flow
Volume
Set tidal volume
© Charles Gomersall 2003

37. PRVC Automatically Adjusts To Compliance Changes

38. Is VTV safe?
Jaecklin T et al. ICM 2007

39. Is VTV safe?
Jaecklin T et al. ICM 2007

40. Advantages of volume targeted ventilation
A significant increase in lung compliance, such as following exogenous surfactant administration will lead to a proportional increase in delivered VT unless the inflating pressure is reduced
As the VT increases due to improving compliance after surfactant administration, the ventilator automatically drops the PIP.
Volume Guarantee: New Approaches in Volume Controlled Ventilation for Neonates Ahluwalia J, Morley C, Wahle HG. Dräger Medizintechnik GmbH. ISBN X

41. PRCV: Advantages Decelerating inspiratory flow pattern
Pressure automatically adjusted for changes in compliance and resistance within a set range
Tidal volume guaranteed
Limits volutrauma
Prevents hypoventilation

42. PRVC: Disadvantages
Pressure delivered is dependent on tidal volume achieved on last breath
Intermittent patient effort  variable tidal volumes
Pressure
Flow
Volume
Set tidal volume
© Charles Gomersall 2003

43. PRVC: Disadvantages
Pressure delivered is dependent on tidal volume achieved on last breath
Intermittent patient effort  variable tidal volumes
Pressure
Flow
Volume
Set tidal volume
© Charles Gomersall 2003

44. Volume Targeted Ventilation
p < 0.001
Concept: deliver the set Vt at the lowest airway pressure possible
p < 0.001
Cheema IU Pediatrics 2001;107:1323–1328

45. Volume Targeted Ventilation
Cheema IU Pediatrics 2001;107:1323–1328

46. IL-8
IL-6
IL-6
TNFa
Lista G Pediatr Pulmonol. 2004; 37:510–514

47. ? Volume targeted ventilation: A Self Weaning Mode Methods:
PSV group: The weaning strategy consisted of reducing the pressure support level progressively over time, so that the work of breathing was shifted from ventilator to the patient.
PSV-VG group: Weaning was a more automatic process once appropriate levels of Vt had been established.
Similar blood gas goals (e.g., pH>7.25; pO2, 50–75 mmHg; pCO2, 40–65 mmHg) were achieved during weaning from mechanical ventilation in both groups.
Methods:

48. Outcome VTV: Death in Hospital
The Cochrane Library 2007, Issue 1

49. Outcome VTV: Duration of mechanical ventilation
The Cochrane Library 2007, Issue 1

50. Pressure-Regulated Volume Control Ventilation vs
Pressure-Regulated Volume Control Ventilation vs. Synchronized Intermittent Mandatory Ventilation for Very Low-Birth-Weight Infants
D’Angio CT et al. Arch Pediatr Adolesc Med. 2005;159:

51. Pressure-Regulated Volume Control Ventilation vs
Pressure-Regulated Volume Control Ventilation vs. Synchronized Intermittent Mandatory Ventilation for Very Low-Birth-Weight Infants
Conclusion:
In mechanically ventilated infants with birth weights of 500 to 1249 g, using PRVC ventilation from birth did not alter time to extubation.
D’Angio CT et al. Arch Pediatr Adolesc Med. 2005;159:

52. Several modes allow for variability in patient efforts while achieving a targeted goal.
Volume support monitors minute ventilation and tidal volume , changing the level of pressure support to achieve a volume target.
Volume assured pressure support allows the patient to breathe with pressure support, supplementing the breath with constant flow when needed to achieve the targeted tidal volume within an allocated time.
Proportional assist varies pressure output in direct relation to patient effort.

53. Performance of neonatal ventilators in
volume targeted ventilation mode
Airway Pressure Waveforms:
Ti of 0.35 sec
Peak inflating pressure of 25 cm H2O
PEEP of 5 cm H2O.
Volume guarantee level 10 mL
Draeger Babylog 8000
(Draeger Medical, Germany),
SLE 5000 infant ventilator
(SLE systems, UK),
Stephanie paediatric ventilator
(F. Stephan Biomedical, Germany)
V.I.P. Bird Gold
(Viasys Healthcare, USA)
Atul Sharma et al Acta Pædiatrica 2007; 96: 176–180

54. Performance of neonatal ventilators in
volume targeted ventilation mode
Settings:
Inflation time of sec
Peak inflating pressure of 25 cm H2O
PEEP of 5 cm H2O
Volume guarantee level 10 mL
Lung model:
Crs = 0.4 mL/cm H2O
Rrs = 70 cm/H2O/L/sec
“similar to the compliance and resistance of babies with the respiratory distress syndrome”
Results: Measured volume delivery
All ventilators delivered a lower Vt than preset
Atul Sharma et al Acta Pædiatrica 2007; 96: 176–180

55. Performance of neonatal ventilators in
volume targeted ventilation mode
Settings:
Inflation time of sec
Peak inflating pressure of 25 cm H2O
PEEP of 5 cm H2O
Volume guarantee level 10 mL
Lung model:
Crs = 0.4 mL/cm H2O
PIP-PEEP = 20 cm/H2O  deliverable Vt = 8 ml
Rrs = 70 cm/H2O/L/sec
“similar to the compliance and resistance of babies with the respiratory distress syndrome”
Results: Measured volume delivery
All ventilators delivered a lower Vt than preset
Atul Sharma et al Acta Pædiatrica 2007; 96: 176–180

56. T = 0.4 mL/cm H2O x 70 cm/H2O/L/sec = 0.028 sec
Time constant: T = Crs x Rrs
T = 0.4 mL/cm H2O x 70 cm/H2O/L/sec = sec
Resulting time constant.
3 x T = 3 x (0.4 mL/cm H2O x 70 cm/H2O/L/sec) = sec
5 x T = 5 x (0.4 mL/cm H2O x 70 cm/H2O/L/sec) = 0.14 sec
Will pressure equilibrium
be reached in the lungs?

57. A total of 24 RCTs and 3 systematic reviews comparing various CMV modes and settings and 2 RCTs investigating permissive hypercapnia reported no differences in mortality or bronchopulmonary dysplasia.
No RCT in newborn infants has substantiated so far that avoiding large tidal volumes and low positive end-expiratory pressure during CMV is lung protective in newborn infants.

59. Positive Airway Pressure Can Be Either Pressure or Flow Controlled—But Not Both Simultaneously
Dependent
Variable
Set Variable
Set Variable
Dependent
Variable