Non-invasive ventilation (NIV) provides ventilatory support without intubation through a non-invasive interface like a mask. It is used initially to treat type 2 respiratory failure and prevent need for mechanical ventilation. Benefits include avoiding complications of intubation and improving outcomes by reducing mortality, morbidity, ICU/hospital stay, and costs. NIV is appropriate for patients with acute or acute on chronic respiratory failure who are cooperative, hemodynamically stable, and have an adequate cough reflex. Factors determining success include careful patient selection, skilled application and monitoring, and timely transition to invasive ventilation if needed.

1. NON INVASIVE VENTILATION
(NIV)
Khairunnisa binti Azman
Anaesthesiology department TGH

2. • A method of providing ventilatory support
without needing tracheal intubation
• PPV delivered through a noninvasive interface
• Delivery of ventilatory support via the
patient’s upper airway using a mask or similar
device & include both continuous positive
airway pressure (CPAP) & non invasive positive
pressure ventilation (NPPV)
• Initially used to treat type 2 respiratory failure
& prevent need of MV & Assc complication.

3. Proposed benefits include:
• Avoid complications of intubation & mechanical
ventilation
– Reduce risk of VAP
• Improve clinical outcomes:
– Reduce mortality & morbidity
– Reduce ICU & Hospital stay
– Reduce cost

4. ADVANTAGES DISADVANTAGES
• Preservation of airway defence
mechanism
• Early ventilatory support
• Intermittent ventilation
• Patient can eat, drink &
communicate
• Ease of application & removal
• Patient can cooperate with
physiotherapy
• Improve patient comfort
• Reduced sedation
requirements
• Avoidance of CX of intubation
• Mask is uncomfortable/
Claustrophobic
• Time consuming for
medical & nursing staff
>Slower correction of gas
exchange abnormalities
• Airway is not protected
• No direct access to
bronchial tree for suction.
• Eye irritation

5. Respiratory Mechanics:
• Respiratory effort required for inspiration
needs to overcome:
– Elastic work (Stretch)
– Flow resistance work (Airway obstruction)
• Respiratory failure
– Forces opposing inspiration exceed respiratory
muscle effort

6. Mechanisms of action:
• Improvement in pulmonary mechanics &
oxygenation
Augments alveolar ventilation & allows oxygenation
without raising the PaCO2, reverse respiratory
acidosis & hypercarbia
Recruits alveoli & increases FRC to reverse hypoxia

7. Requirements for successful non invasive
support:
• A co-operative patient who can control their
airway and secretions with an adequate cough
reflex.
• The patient should be able to co-ordinate
breathing with the ventilator and breathe
unaided for several minutes.
• Haemodynamically stable
• Blood pH>7.1 and PaCO2 <92 mmHg
• The patient should ideally show improvement in
gas exchange, heart rate and respiratory rate
within first two hours.

8. Patient Selection
Strong evidence:
• AECOPD
– Complicated by hypercapnic acidosis
• Acute cardiogenic Pulmonary oedema
• Post operative
• Facilitates extubation (weaning)
– Prevent post extubation respiratory failure (those
with COPD & compensatory hypoxaemia during
SBT)

9. INDICATIONS
BEDSIDE OBSERVATIONS GAS EXCHANGE
• ↑Dypsnoea – Mild to
Moderate
• Tachypnoea:
> 24bpm in obstructive
> 30bpm in restrictive
• Signs of increase work of
breathing, accessory muscle
use & abdominal paradox
• Acute OR Acute on chronic
ventilatory failure (Best
indication)
- PaCO2 > 50mmHg
- Ph <7.15
• Hypoxaemia (used with
caution)
- PF Ratio <200
(PaO2<60mmHg despite high
FIO2

10. INDICATIONS
• Acute respiratory failure
• Hypercapnic acute respiratory failure
• Acute exacerbation of COPD
• Post extubation difficulty/Weaning difficulties
• Post surgical respiratory failure
• Thoracic wall deformities
• Acute respiratory failure in obesity hypoventilation
syndrome
• Chronic Respiratory Failure
• Patients 'not for intubation

11. CONTRAINDICATIONS
ABSOLUTE RELATIVE
• Respiratory arrest/unstable
cardiorespiratory status
• Unable to protect airway-
impaired swallowing and
cough
• Facial/oesophageal
• Craniofacial trauma/burns
• Anatomic lesions of upper
airway
• Extreme anxiety
• Uncooperative patient
• Morbid obesity
• Copious secretions
• Swallowing impairment
• Multiple organ failure
• Need for continuous or nearly
continuous ventilatory
assistance

12. INTERFACE ADVANTAGES DISADVANTAGES
Nasal - Less claustrophobic
- Easy to fit
- More comfortable
- Permit speech/cough
• Must be able to nose
breathe, keep mouth
shut most of the time
• Not for ventilators
without leak
compensation
Face
(Oronasal)
- Permits mouth
breathing
- Suitable for moderately
cooperative patient
Visor
(Full Face)
- Avoid pressure on the
nasal bridge
- Increased deadspace
- Not for claustrauphobic
Helmet - Avoid pressure on face
- Suitable for moderately
cooperative patient
- Large leak may interfere
with triggering
- Not for claustrophobic

13. NIV in COPD
• Significantly reduce mortality & Cx compared
to standard medical therapy
• First line therapy
• Growing evidence that maybe applicable to
patient with:
– Severe acidaemia (Ph<7.25)
– Hypercarbic Coma
*cond previously considered contraindication to NIV

14. NIV in Morbid Obesity:
• Assc with certain respiratory syndromes
– Obstructive sleep apnoea
– Chronic alveolar hypoventilation
• Type 2 respiratory failure
– If presenting in early stage, NIV initial treatment of choice
• Post operative period
NIV in Asthma:
• Controversial
• Trial of NIV in acute asthma should only be carried
out in CRITICAL CARE areas.

15. NIV in Neuromuscular disorder
Acute (GBS/Acute myasthenia):
• Often a/w upper airway dysfunction  may
increased incidence of pulmonary aspiration
• Respiratory compromised d/t GBS often a/w
prolonged MV
– Recommended for early tracheostomy

16. NIV in Neuromuscular disorder
Chronic (MND):
• Characterized by an irreversible decline in
respiratory function d/t respiratory muscle
atrophy
• Use of NIV:
– Improve quality of life
– Improve survival in patient with advanced
ND/MND (NICE/AAN)

17. NIV in Cardiogenic Pulmonary Oedema:
• Reduction in both preload & afterload and
improved oxygenation and reduced work of
breathing
NIV in Pneumonia:
• Controversial
• Pneumonia in underlying COPD or
Immunocompromise mortality benefit
• Trial of NIV Should be done in CRITICAL CARE
areas.

18. NIV in Lung Contusion/Chest Trauma:
• Respiratory failure d/t chest trauma or
contusion responds well to NIV
• Combine with effective analgesic regime:
– Favourable outcome
– Reduce mortality & infective complications related
to MV

19. Post Extubation use of NIV
Post extubation in
critical care:
- As a preventive
measures in patient
who have been
extubated but high risk
of developing post-ext
respiratory failure
- Reduce need for re-
intubation & mortality
in selected patient
Weaning from MV:
- Use in patient with
difficult weaning from
MV, aim to reduce risk
a/w prolonged tracheal
intubation
- To help wean patient
not suitable for
extubation from MV by
providing respi support
w/o need of
sedation/NMB/Tracheal
intubation
Postoperative patient
*After abdominal
surgery:
- Basal atelactasis
- Prolonged supine
position
- Diagpragmatic splinting
(Contribute to Post OP
respi failure)
* Post OP prophylactic
CPAP

20. Which Mode??
• Hypoxaemia  CPAP
• hyPERcapnia & hypoxaemia  BiPAP

21. CPAP (Continuous Positive Airway Pressure)
• Constant positive airway pressure throughout cycle.
• Increases FRC & opens collapsed alveoli Improves
oxygenation
• ↓ work of breathing by alveolar recruitment
– ↓ elastic work
– Unload respiratory muscles
• Reduces left ventricular transmural pressure
(↓intrapulmonary shunt) Increases cardiac
output Effective for treatment of Pulmonary
oedema
• PS limited to 5-12cm H20
– Why? Higher pressure tends to result in gastric
distension requiring continual aspiration from Ryles tube

22. BiPAP (Bi-Level Pressure Support):
• Combination of IPAP & EPAP
– Inspiratory PAP  Pressure support
– Expiratory PAP  CPAP
• EPAP:
– Provides PEEP
– Increases FRC
• IPAP:
– ↓ Work of breathing & O2 demand
– ↑ TV
– ↓ RR

23. Monitoring Response
Physiological - Continuous Oximetry
- Exhaled TV
- ABG; Initial, 2-6hrs
Objective - RR
- Chest wall movement
- Coordination of respiratory effort with
NIV
- HR & BP
- Mental state
Subjective - Dypsnoea
- Comfort

24. Persistent Respiratory acidosis?
• Large mask/Circuit leak?
• Expiratory valve wrongly fitted
• Re- breathing?
– Single limb circuit ventilator
– Expiratory pressure is maintained by expiratory
flow & set low
• Failing to synchronized with ventilator

25. Predictors of failure
Hypercapnic Acute respiratory
failure (Ph<7.30)
Hypoxaemic Acute respiratory
failure (P/F<200, not COPD
- No increased pH by 1-2 hrs
- No ↓ RR by 1-2 hrs
- Lack of cooperation
- Minimal ↑ PF by 1-2hr
- Age >40
- ARDS
- CAP/Sepsis
- Multiorgan failure

26. Criteria for teminating NIV &
switching to mechanical ventilation
• Worsening Ph & PCO2
• Tachypnoea
• Hemodynamic instability
• Spo2 < 90%
• Decreased level of conciousness
• Inability to clear secretion
• Inability to tolerate NIV

27. CONCLUSIONS
Key factors in success:
• Careful patient selection/rejection
• Skilled initiation & application
• Algorithmic approach in initiation, use &
discontinuation
• Patient comfort
• Avoid dyssynchrony
• Avoiding complication
Most importantly  decision making on when to
switch to invasive mechanical ventilation

28. THANK YOU

29. References:
1. Non Invasive Ventilation,
http://www.frca.co.uk/article
2. Non invasive ventilation in ICU,
http://www.frca.co.uk/article.aspx?articleid=
100753
3. Clinical application of NIV in critical care,
CEACCP