1. Mechanical Ventilation - Introduction
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2. Ventilation is Versatile
Everywhere
Invasive and non-invasive
Short and long term

3. Mechanical ventilation is indicated in many situations
ALS
Pneumothorax
Asthma
Obesity
Spinal cord lesion
Bronchiolitis
Fatigue
When a patient is unable to adequately remove CO2 and maintain adequate levels of O2 in the arterial blood

4. Goals of Mechanical Ventilation
Decrease work of breathing
Enhance the quality of life    
Prolong survival
Provide cost effective care – enable out of hospital care

5. Respiratory failure  2 types
Diaphragm
1. Gas exchange failure (Lungs i.e. alveoli level)
2. “Pump” failure (Diaphragm & accessory muscles, Impaired chest)
Need respiratory assistance if one of failure mentioned append

6. Obstructive Lung Disease
Exhibit increased airway resistance
Air trapping “can’t get air out”
Decreased elastance; increased compliance
Examples: (COPD) a. asthma b. emphysema c. bronchitis d. bronchiolitis

7. Restrictive Lung Disease
Decreased volumes and capacities, normal flow rates
“can’t get volume in”
Exhibit decreased compliance, increased elastance
Examples:
Intrinsic: a. Pulmonary fibrosis b. Pulmonary edema c. Pneumo/hemo thorax d. ARDS/IRDS
Extrinsic e. Chest wall deformities f. Obesity g. Neuromuscular disorders

8. Start-Gas delivery-Stop
Breath Characteristics
Start-Gas delivery-Stop
Trigger: what initiates breath
Gas delivery target or limit: what controls gas flow
Cycle: what terminates the breath

9. Triggering: Starting Inspiration
Breath Characteristics
Triggering: Starting Inspiration
Machine Trigger (Time)
Patient Trigger (Pressure, Flow, Auto)
Caregiver Trigger (Manual Breath)

10. Breath Characteristics Gas delivery

11. Breath Characteristics Ending Expiration (Termination, Cycling)
Reach set volume
Reach set time
Reach certain flow reduction: Flow Termination (% of maximum flow)
30% of peak flow
Peak flow

12. Mandatory & Spontaneous breath
Mandatory breath
The ventilator controls the length and size
Machine or Patient triggered
Spontaneous breath
The patient controls the length and size
Only patient triggered

13. Flight 60 Basic Control Parameters Terminology
Tidal Volume - VCV
Exhaled Minute Volume - MVe
Respiratory Rate - Rate
Inspiratory Time - Ti
PEEP
Trigger: Ptirg or Ftrig

14. Ventilation Parameters Exercise

15. Parameters

16. Mechanical Ventilation
Volume Ventilation
Pressure Ventilation
Mixed mode ventilators

17. Breath Characteristics Gas delivery

18. Volume-Targeted Ventilation
Preset volume is delivered to patient
Inspiration ends once volume is delivered
Volume constant, pressure variable
Ensures proper amount of air is delivered to lungs regardless of lung condition
May generate undesirable(high) airway pressures

19. Volume Ventilation Advantages
Guaranteed Vti and Vte
Full Ventilator Support
Minimal patient WOB (if parameters properly adjusted)
Allows some patient control of RR and Ve
SAFE !

20. Volume Ventilation Disadvantages
High Pressure Limit must be set appropriately
Excessive patient WOB if flow and sensitivity not set appropriately
Flow is fixed, which inhibits the patient who has an unstable inspiratory flow or volume demand
May be poorly tolerated in awake, non-sedated patients

21. Pressure-Targeted Ventilation
Preset inspiratory pressure is delivered to patient
Pressure constant, volume variable
Clinician determines ventilating pressures
Volumes may increase or decrease in response to changing lung conditions

22. Pressure Ventilation Advantages
PS and PCV control peak and mean airway pressures =>
Tidal Volume Varies by patient demand
Inspiratory flow is variable
Rise time variable
COMFORTABLE :-) 21 21

23. Pressure Ventilation Disadvantages
No Guaranteed Vt
Low exhaled Vt and VE alarms must be set properly
Improperly set Rise time or termination can lead to ineffective breath delivery or asynchrony and increased work of breathing 21 21

24. Pressure Support Ventilation vs. Volume Support Ventilation
+++: Good patient tolerance & efficient leak compensation
---: Instability of tidal volume in case of patient respiratory mechanics changes
+++: Stability of Tidal volume even in case of patient respiratory mechanics
changes
---: No leak compensation, high pressure peaks
Use AVAPS.exe to show differences between pressure ventilation, volume ventilation and AVAPS.

25. Basic Modes of Ventilation

26. Ventilation modality types
Pressure
Volume
Controlled breath
Assist/Controlled breath
Spontaneous breath
Patient trigger the breath
Ventilator cycle the breath
Patient trigger and cycle the breath Ti Te
Sedation

27. Spontaneous Mode (SPONT)
Therapy mode in which all breaths are spontaneous
In Spontaneous (S) mode, the device delivers bi-level pressure support. This mode provides only spontaneous breaths. In this mode, an Inspiratory Positive Airway Pressure (IPAP) is delivered during inhalation and a lower Expiratory Positive Airway Pressure (EPAP) is delivered during exhalation.
Patient triggers and cycles
Machine supports based on pressure support settings

28. ACMV (Assist/Control Mandatory Ventilation)
Time activated (mandatory) breaths are delivered in accordance with the breath rate setting
Patients can trigger mandatory breaths in addition to, or in place of, time activated (mandatory) breaths.
Breath rate may be increased
The breath can be volume or pressure controlled
* Mandatory breath: The ventilator controls the timing & size
Show the trainee how to set a multiple choice control (Mode)
Show the trainee how to set a numeric value control (VCV)
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29. ACMV (Assist/Control Mandatory Ventilation)
VCV 500ml, f 20, Ti 1sec
Patient Trigger
Time Trigger
Use the EGD to present the ACMV, trigger few breaths to demonstrate that all breaths are mandatory.
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30. SIMV (Synchronized Intermittent Mandatory Ventilation)
For the first patient trigger detected within a breath period, an assist breath is given.
For all subsequent patient triggers within the same breath period, spontaneous patient breaths are given.
At the beginning of a breath period, if no triggered breaths were given in the previous breath period, a machine breath is given.
Explain that patient triggered mandatory breath will delay the next time triggered mandatory breath.
Use the EGD to present the SIMV, ventilate at 6 b/min PCV 15 PSV 10 and trigger few breaths to demonstrate the combination of mandatory and spontaneous breaths.
Within the expiratory phase the first patient trigger will initiate a mandatory breath and the second trigger will initiate pressure support breath.
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31. SIMV (Synchronized Intermittent Mandatory Ventilation)
Patient receives a fixed number of mandatory breaths (time or patient activated) & may breathe spontaneously in between, with or w/o pressure support
Time triggered mandatory breath
Patient triggered mandatory breath
Spontaneous breaths
Explain that patient triggered mandatory breath will delay the next time triggered mandatory breath.
Use the EGD to present the SIMV, ventilate at 6 b/min PCV 15 PSV 10 and trigger few breaths to demonstrate the combination of mandatory and spontaneous breaths.
Within the expiratory phase the first patient trigger will initiate a mandatory breath and the second trigger will initiate pressure support breath. A B C C A A
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32. SIMV (Synchronized Intermittent Mandatory Ventilation)
PCV 15cmH2O, f 10, Ti 1sec, PSV 10cmH2O
Mandatory
Spontaneous
(PSV)
Within the expiratory phase the first patient trigger will initiate a mandatory breath and the second trigger will initiate pressure support breath.
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33. Ventilators & patient circuit type Different technologies used in mechanical ventilation (IV & NIV)
Inspiratory limb
Expiratory limb
Air wall
Turbine
Piston
O2 wall
Dual limb system with proportional expiratory valve
Inspiration
Exhalation
Single limb system with proximal expiratory valve
Ventilateur
Expiratory valve
O2 wall
O2 low flow
Turbine
Piston
Soufflet
Inspiratory limb
Inspiration
Exhalation
Expiratory leak
Ventilateur
Turbine
O2 wall
O2 low flow
Single limb system with intentional expiratory leak
Inspiratory limb
Inspiration
Exhalation

34. Thank you!
Questions?