Mechanical Ventilator

1. Mechanical Ventilator
Presented by: Khalid Yousef Arab
Respiratory Therapist

2. Mechanical ventilator
Mechanical ventilator is a machine that
generates a controlled flow of gas into
a patient’s airways using one of many
available modes of ventilation

3. TYPES
OF
MACHINE
NEGATIVE
PRESSURE
MACHINE
POSITIVE
PRESSURE
MACHINE
Invasive Mechanical
Ventilator
NON
Invasive Mechanical
Ventilator

4. Classification
Of MV
Volume
Cycled:
Pressure
Cycled
Time
Cycled
Flow
Cycled

5. Goals of ventilation
Oxygenation
FIO2
PEEP
Ventilation
TV
Driving pressure
RR

6. Indications
 Acute Respiratory Failure (ARF):
- Hypoxemic respiratory failure (oxygenation failure):
PaO2<60mmHg on FiO2>0.5 and SaO2<90%
- Hypercapnic respiratory failure (ventilation failure):
PaCO2>5OmmHg or acutely above normal baseline in
COPD with pH<7.30

7. Indications
 cardiopulmonary arrest
 During general anesthesia
 Altered conscious level GCS<8, inability to
protect the airway
 Airway protection following drug overdose
 Control of intracranial pressure in head injury
 Cardiovascular failure with hypotension
 For recovery after prolonged major surgery or
trauma

8. Classifications of Ventilator
1. Volume Cycled: Inspiration ends when preset
tidal volume has been delivered
2. Pressure Cycled: Inspiration ends when preset
inspiratory pressure has been reached

9. Volume Cycle
 Advantages
•Independent of Airway Resistance
• Independent of Lung Compliance
 Disadvantages
• Limited Current Use
• Alveolar Stretch Injury
• High-Pressure Limit Alarm

10. PRESSURE Cycle
1. Constant Inspiratory Pressure
2. Tidal Volume Becomes Variable
3. Volume is determined by set inspiratory
pressure, respiratory rate and inspiratory time.
4. Volume is Affected by Airway Resistance,
Lung Compliance, Patient Effort
5. Common in pediatric population
6. Common in stiff lungs

11. PRESSURE Cycle
 Causes of Decreased Tidal Volume
Increased Resistance
• Decreased Compliance
• increased Patient Effort

12. Modes of ventilators
MODE FUNCTION Clinical use
Control mode
Ventilation (CMV)
Delivers preset volume or
pressure regardless of
patient’s own inspiratory
efforts
Usually used for
patients who are apneic
Assist-Control
Ventilation (A/C)
Delivers breath in response
to patient effort and if
patient fails to do so within
preset amount of time
used for spontaneously
breathing patients with
weakened respiratory
muscles
Synchronize
Intermittent Mandatory
Ventilation ( SIMV)
Ventilator breaths are
synchronized with patient’s
respiratory effort
Usually used to wean
patients from
mechanical ventilation
Pressure Support
Ventilation (PSV)
Preset pressure that
augments the patient’s
inspiratory effort and
decreases the work of
breathing
Often used with SIMV
during weaning

13. Modes of ventilators
MODE FUNCTION Clinical use
Constant Positive
Airway Pressure
(CPAP)
(Conti, flow ,no TV no
rate)
Similar to PEEP but
used only with
spontaneously
breathing patients
Maintains constant
positive pressure in
airways so resistance
is decreased
Inverse Ratio
Ventilation (IRV)
(I:E =2:1)
I:E ratio is reversed to
allow longer
inspiration; requires
sedation/ paralysis
Improves oxygenation
in patients who are
still hypoxic even with
PEEP; keeps alveoli
from collapsing

14. Setting of ventilators
Setting Function Parameters
Respiratory Rate (RR)
or frequency
No. of breaths
delivered by the
ventilator /min
12-20 breaths/min
Tidal Volume (VT) Volume of gas
delivered during each
ventilator breath
10-12 ml/kg
6-8 ml/kg in acute lung
injury
Fractional Inspired
Oxygen (FIO2)
Amount of oxygen
delivered by ventilator
to patient 21% to
100%
set to keep PaO2 > 60
mmHg or SaO2 > 90%
Inspiratory: Expiratory
(I:E) Ratio
Length of inspiration
compared to length of
expiration
1:2 or 1:1.5
unless inverse ratio
ventilation is required

15. Setting of ventilators
Setting Function Parameters
Pressure Limit 10-20 cm H2O above
peak inspiratory
pressure; maximum is
35 cm H2O
Pressure Limit
Maximum amount of
pressure the ventilator
can use to deliver
breath
Positive End
Expiratory Pressure
(PEEP)
Positive pressure
applied at the end of
expiration
Used with CV, A/C,
and SIMV to improve
oxygenation and lung
compliance by
opening collapsed
alveoli

16. Initial Settings
 Pressure Limited
 FiO2
 Rate
 I-time or I:E ratio
 PEEP
 PIP or PAP
 Volume Limited
 FiO2
 Rate
 I-time or I:E ratio
 PEEP
 Tidal Volume

17. Changing the Ventilation Settings
when you are changing the settings, you need to think
about what you are trying to achieve.
 Change Oxygenation (PaO2)
- Alter the FiO2 (turn the knob!)
- Alter the PEEP
 Change Ventilation (PaCO2)
- Change the tidal volume (OR changing the pressure
control)
- Change the frequency of breaths

18. Complications to Mechanical
Ventilation
 Ventilator Induced Lung Injury (VILI)
 Induced by excessive pressure (barotrauma)
 Induced by excessive Volume (volutrauma

19. Complications to Mechanical
Ventilation
 Nosocomial Infection:
Most infections of the
body will travel to the
lungs and result in a
pneumonia. These
are referred to as
Ventilator Associated
Pneumonia (VAP)

20. Complications to Mechanical
Ventilation
 Decreased Cardiac
Output and Blood
Pressure
  pressure in the
lungs=  pressure
surrounding the heart
and major vessels
results in decreased
CO/BP

21. TROUBLESHOOTING

22. TROUBLESHOOTING
 Is it working ?
Look at the patient !!
Listen to the patient !!
 Pulse Ox, ABG, EtCO2
 Chest X ray
 Look at the vent (PIP; expired TV;
alarms

23. Hypoxia
 Turn FiO2 to 100%
 Take Patient OFF Ventilator
 Bag the Patient on FiO2 100%
 Rapid Assessment ABC
 End tracheal Tube: Position, Patency
 Auscultate: Rule Out Tension
Pneumothorax
 Ventilator: Circuit, Functional State,
Oxygen

24. Hypoxia
 Arterial Blood Gas
 Portable CXR
 With No Other Proximate Cause, Adjust
Ventilator Settings
 Chemically paralyze patient

25. TROUBLESHOOTING
 Anxious Patient
 Can be due to a malfunction of
the ventilator
 Patient may need to be
suctioned
 Frequently the patient needs
medication for anxiety or
sedation to help them relax
Attempt to fix the problem
Call your RT

26. TROUBLESHOOTING
 Low Pressure Alarm
 Usually due to a leak in the circuit.
 Attempt to quickly find the problem
 Bag the patient and call your RT.

27. High Pressure Alarm
 Usually caused by:
 A blockage in the circuit (water condensation)
 Patient biting his ETT
 Mucus plug in the ETT
 You can attempt to quickly fix the problem
 Bag the patient and call for your RT.

28. Low Minute Volume Alarm
 Usually caused by:
 Apnea of your patient (CPAP)
 Disconnection of the patient from the
ventilator
 You can attempt to quickly fix the problem
 Bag the patient and call for your RT.

29. Accidental Extubation
 Role of the Nurse:
 Ensure the Ambu bag is attached to the oxygen flow
meter and it is on!
 Attach the face mask to the Ambu bag and after
ensuring a good seal on the patient’s face; supply the
patient with ventilation.
 Bag the patient and call for your RT.

30. OTHER
 Anytime you have concerns, alarms, ventilator
changes or any other problem with your
ventilated patient.
 Call for your RT
 NEVER hit the silence button!

31. Weaning
 defined as the transition from ventilator support
to complete spontaneous breathing.
 Weaning should start when:
1)the underlying disease process is improving;
2) gas exchange is adequate;
3)respiratory mechanics are improving;
4) no conditions exist that imposes an undue
burden on the respiratory muscles
5) the patient is capable of sustaining
spontaneous ventilation as ventilator support is
decreased.

32. Weaning from Ventilator Support
 Weaning Methods
 Rapid Weaning: Post Surgery
 Routine Weaning: RSBI performed daily
 Gradual Weaning: T-collar trials
 Ventilator Dependent patients

33. Ventilator Discontinuance
 Success in discontinuing ventilator support
is related to the patients conditions in four
main areas:
 Ventilator workload
 Oxygenation status
 Cardiovascular function
 Psychological factors

34. Ventilator Weaning
Criteria
• PEEP ≤ 6
• RSBI ≤ 100
• SpO2 ≥ 94% on FiO2 ≤ 40%
• Adequate Cough During Suctioning

35. Criteria for defining weaning failure
1.Tachypnea (respiratory rate)
2. Hypoxemia (oxygen saturation by pulse oximeter, <
90%) with FiO2 >0.4
3. Tachycardia or a sustained rate increase > 20%)
4. Bradycardia (sustained heart rate decrease, > 20%)
5. Hypertension
6. Hypotension
7. Excessive use of accessory muscles
8. Agitation
9. Anxiety
10. Apnea

36. Combination “Dual Control” Modes
 Inverse Ratio Airway Pressure Release
(APRV), and Bi-Level (Bi-PAP)
 Adaptive Support Ventilation
 Proportional Assist Ventilation (PAV)
 Adaptive Pressure Ventilation

37. NIV.
Ventilatory support provided without
invasive airway control
• No tracheostomy
• No ETT

38. Type of NIV
 CPAP :- Continuous Positive Airway
Pressure
 BIPAP :- Bi-level Positive Airway
Pressure

39. NIV

40. Indications of NIV
Decompensated COPD (Hypercapnic Respiratory
Failure)
Cardiogenic pulmonary edema
Hypoxic respiratory failure
Other possible indications
• Weaning (post-extubation)
• Obesity hypoventilation syndrome
• Patients deemed not to be intubated
• Post-surgery
• Asthma

41. Contraindication of NIV
Cardiac or respiratory arrest
Nonrespiratory organ failure
Severe encephalopathy (e.g., GCS < 10)
Severe upper gastrointestinal bleeding
Hemodynamic instability or unstable cardiac
arrhythmia
Facial surgery, trauma, or deformity
Upper airway obstruction
Inability to cooperate/protect the airway
Inability to clear respiratory secretions
High risk for aspiration

42. Advantages and Disadvantages of NIV
 Advantages
Allows the patients to
maintins normal functions
• Speech
• Eating
Helps avoid the risks and
complications related to:
• Intubation
• Sedation
 Less ventilator-
associated pneumonia
 Disadvantages
Less airway pressure is
tolerated
Does not protect against
aspiration
No access to airway for
suctioning

43. Interface
Nasal masks
 less dead space
 less claustrophobia
 allow for
expectoration
vomiting and oral
intake
 vocalize
 facial mask
 dysphonic patients
are usually mouth
breathers
 More dead space

44. Goals of NIV
 Short Term
 Relieve symptoms
 Reduce work of
breathing
 prove or stabilize gas
exchange
 Optimize patient
comfort
 Avoid intubation
 Long Term
 Improve sleep
duration and quality
 Enhance functional
status
 Prolong survival
 Maximize quality of
life

45. Main setting
1. IPAP (Inspiratory positive airway pressure).
2. EPAP (Expiratory positive airway pressure).
3. PS (pressure support )= (IPAP – EPAP).
4. back up rate.
5. Fio2 (21% -100%).
6. Flow or inspiratory time.
7. Pattern of breathing or Rise time.

46. Initial settings
• Spontaneous trigger mode with backup rate
• Start with low pressures
- IPAP 8 - 12 cmH2O
- PEEP 3 - 5 cmH2O
• Adjust inspired O2 to keep O2 sat > 90%
• Increase IPAP gradually up to 20 cm H2O (as
tolerated) to:
- alleviate dyspnea
- decrease respiratory rate
- increase tidal volume
- establish patient-ventilator synchrony

47. Monitoring
Response
Physiological a) Continuous oximetry
b) Exhaled tidal volume
c) ABG should be obtained with 1 hour and, as
necessary, at 2 to 6 hour intervals.
Objective a) Respiratory rate
b) blood pressure
c) pulse rate
Subjective
a) dyspnea
b) comfort
c) mental alertness

48. Monitoring
Mask
Fit, Comfort, Air leak, Secretions, Skin
necrosis
Respiratory muscle unloading
Accessory muscle activity, paradoxical
abdominal motion
Abdomen
Gastric distension

49. Criteria to discontinue NIV
 Inability to tolerate the mask because of
discomfort or pain
 Inability to improve gas exchange or dyspnea
 Need for endotracheal intubation to manage
secretions or protect airway
 Hemodynamic instability
 ECG – ischemia/arrhythmia
 Failure to improve mental status in those with
CO2 narcosis.