Non-invasive ventilation (NIV) is the use of breathing support administered through a face mask or nasal mask. Learn more about NIV in this presentation by Dr Somnath Longani, consultant Anaesthesiologist & Intensivist, Midland Healthcare & Research Center, lucknow https://midlandhealthcare.org/

1. Non Invasive Ventilation
DR. SOMNATH LONGANI
CONSULTANT ANAESTHESIOLOGIST & INTENSIVIST
MIDLAND HEALTHCARE & RESEARCH CENTRE
LUCKNOW.

2. Learning Objectives
To learn the indication and contraindications of NIV
To learn the various ventilators which can be used for NIV
To understand the modes of NIV
To learn how to apply NIV
To learn the complications of NIV and solutions

3. NIV in Acute Respiratory Failure
(strong Evidence: A)
AECOPD
Weaning in COPD
Cardiogenic Pulmonary edema
Immunocompromised host

4. Indication (Level B)
Acute Respiratory failure in OSA/OHS
Mild ARDS
Postoperative Respiratory Failure
Pre intubation oxygenation
Trauma- Flail chest

5. Indication (Level-C)
Asthma exacerbations
Post extubation respiratory failure
DO NOT INTUBATE status
Pneumonia
Cystic Fibrosis
Neuromuscular disease

6. Assessment of Need of NIV
Moderate to Severe respiratory distress
Tachypnea (RR>25/min)
Accessory muscle use or Abdominal Paradox
ABG pH <7.35, PaCO2 >45mm Hg
PaO2/FiO2<300 or SpO2<92% with FiO2 50%

7. Contraindication
Inability to protect airway
Comatose patient
Patient with Bulbar involvement
Confused and agitated patients
Patients with upper airway obstruction

8. Contraindication
Non availability of trained personnel
Inability to fix the interface
a) Facial abnormalities
b) Facial Burns
c) Facial Trauma

9. Contraindication
Hemodynamic instability
a) Uncontrolled arrhythmia
b) On very high dose of inotropes
c) Recent myocardial infarction
Pneumothorax
CSF leaks

10. Contraindication
Severe Gastrointestinal symptoms
a) Vomiting
b) Obstructed bowel
c) Recent Gastrointestinal surgery
d) Upper GI bleeding
Life threatening Hypoxemia
Copious secretions
Claustrophobia

11. Investigation
ABG
Chest X-ray

12. Treatment Plan
Treat the reversible causes
Document plan(in case of NIV failure)

13. Types of ventilators
Critical care ventilators
Portable pressure ventilators

14. Choice of ventilator
It can easily trigger into respiratory phase in response to patient effort
Preferably flow based
It is easily cycled to expiratory phase
It should have adequate flow to meet patient demand (60-100LPM)
Pressure preset pressure support, pressure control
Capable of providing pressure at least up to 30cm H2O
Should ideally have spontaneous or timed mode

15. Choice of ventilator
Light weight/Portable
Basic alarms
Capable of supporting breath rate of at least 40/min
Adjustable Pressure rise time
Adjustable inspiratory and expiratory triggers
Battery back up
Simple control knobs and ability to prevent inadvertent change of Parameter.

16. NIV terminolgy
BiPAP
IPAP
EPAP
Trigger
Cycle
Rate

17. Cycle time
I time
Rise time
Fall time
Pressure support
Tidal volume

19. IPAP
Increases tidal volume
Improves ventilation
EPAP
Opens up the airway
Improves oxygenation
Neutralizes auto PEEP
Pressure support= IPAP-EPAP

20. Modes of Mechanical ventilation
Pressure-targeted ventilators are the devices of choices for acute NIV
Both Pressure support and Pressure Control modes are effective
Only ventilators designed specifically to deliver NIV should be used

21. Pressure Targeted Ventilation
Pressure delivered is Constant
Pressure targeted ventilation compensates for air leak
Positive pressure throughout expiration
Flushes exhaled CO2 from the mask and distal ventilator tubing

22. Modes of Ventilation in Portable Pressure
ventilators
CPAP
Spontaneous (S)
Spontaneous / Timed (S/T)
Timed (T- Control)
Pressure assist control (PAC)
Intelligent volume assured pressured support (iVAPS)
Proportional Assist ventilation

23. Modes of NIV in ICU ventilators
Pressure support ventilation (PSV)
Pressure control ventilation (PCV)

24. CPAP
Fixed pressure is applied throughout in both inspiration and expiration
Comfortable for patient
Useful for cardiogenic pulmonary oedema

25. Spontaneous Mode (S)
Devices senses the patient breath and triggers IPAP in response to an increase in flow, and cycles
into EPAP at the end of respiration.
Breath rate and respiratory pattern will be decided by patient.
If the patient fails to make adequate inspiratory efforts, no ventilator support is delivered.

26. Spontaneous Mode (S)

27. Spontaneous/ timed mode
In the S/T mode (Assist control) mode, a back up rate is set by the operator
If the patient’s RR is slower than the back up rate , machine determined breath will be delivered
If the patient breath faster than the back up rate, no machine determined breath will be
delivered and all breath will be triggered ( or assisted)
The proportion of controlled and assisted breaths often varies, depending on the patients state
of alertness and respiratory drive.

28. Spontaneous/ timed mode

29. Timed mode (T)
Also known as control mode
Fixed breath rate and the fixed inspiratory time set by the clinician are supplied regardless of
patient efforts.

30. Timed mode (T)

31. Pressure Assist Control (PAC)
Inspiration time is set
No spontaneous or flow cycling
Inspiration can be triggered by patient when respiratory rate is above a preset value.
Ti will be fixed in all breath cycle

32. Pressure Assist Control (PAC)

33. Intelligent Volume Assured Pressure Support
(i-VAPS)
Indicated for patient of 30kg and above
Designed to maintain a preset target alveolar ventilation, adjusting the pressure support and
providing an intelligent back up breath automatically.
Auto EPAP automatically adjust the EPAP to maintain upper airway patency.

34. i-VAPS

35. i- VAPS

36. Proportional Assist Ventilation (PAV)
The ventilator assists the patient by generating volume and pressure in proportion to patient’s
effort creating a ventilator pattern that matches metabolic demands on a breath-by-breath
basis.
Till date,there is no data to show any advantage of PAV.

37. Technique to minimise CO2 rebreathing

38. Technique to minimise CO2 rebreathing
Increase EPAP level
Increase leak in system
Fixed leak in the mask rather than hose
Titrate O2 into mask rather than hose
Plateau exhalation valve

39. Interfaces
Interfaces are devices that connect the ventilator tubing to the patient and facilitate the entry of
pressurized gas into the upper airways during NIV.
Full face masks (oro-nasal masks)
Total face masks
Nasal face masks
Nasal Pillow
Mouthpieces

40. Choice Of Interface for NIV
A Oro-nasal mask or full face mask should usually be the first type of interface used acutely
dyspnoeic patient
A range of masks and sizes should be available
NIV circuits must allow adequate clearance of exhaled air through an exhalation valve or an
integral exhalation port on the mask.

41. Oro nasal mask or, Full face mask

42. It permits mouth breathing and reduces air leaks through the mouth
May be preferred by acutely dyspneic patient who are mouth breathers
Interfere more with speech, eating and expectorations and may contribute more dead space
than nasal masks.

43. Total face Mask

44. Nasal mask

45. Nasal Masks
Advantages Disadvantages
Less risk of aspiration Mouth leak
Enhance secretion clearance Less effectiveness with nasal obstruction
Less claustrophobia Nasal irritation and rhinorhea
Easier speech Mouth dryness
Less dead space

46. Nasal pillows

47. Helmet in NIV

48. Mouthpieces

49. Non Invasive Ventilation
Patient
Ventilator Interface

50. How to Initiate NIV in Portable pressure
ventilator

51. Choose the correct interface.
Explain therapy and its benefit to the patient in detail. Also discuss the possibility of intubation.
Set the NIV portable pressure ventilator in spontaneous or spontaneous /timed mode.
Start with very low settings. Start with low inspiratory positive airway pressure (IPAP) of 6 – 8
cm H20 with 2 to 4 cm H20 of EPAP (Expiratory positive airway pressure). The difference
between IPAP and EPAP should be at least 4 cm H20.
Administer oxygen at 2 liters per minute.
Hold the mask with the hand over his face. Do not fix it.

52. Increase EPAP by 1-2 cm increments till all his inspiratory efforts are able to triggers the
ventilator.
If the patient is making inspiratory effort and the ventilator does not respond to that
inspiratory effort, it indicates that the patient has not generated enough respiratory effort to
counter auto PEEP and trigger the ventilator (in COPD patients).
Increase EPAP further till this happens. Most of the patients require EPAP of about 4 to 6
cmH2O.
Patient who are obese or have obstructive sleep apnea require higher EPAP.

53. Now start increasing IPAP in increments of 1-2 cm up to a maximum pressure, which the
patient can tolerate without discomfort and there is no major mouth or air leaks.
In some NIV machine, inspiratory time(Ti) can be adjusted. Setting the Ti at one second is a
reasonable approach.
Now secure interface with head straps. Avoid excessive tightness. If the patient has a
nasogastric tube put a seal connector in the dome of the mask to minimize air leakage.
After titrating the pressure, increase oxygen to bring oxygen saturation to around 90%.
As the settings may be different in wakefulness and sleep, readjust them accordingly.
When all the patient’s efforts are triggering the ventilator, leave EPAP at that level.

54. Titration- Set respiratory rate and
inspiratory time
Set Back up Rate 2-3 breaths below patient spontaneous breathing
Obstructive Patients Ti from 25-33%
Restrictive Patients Ti from 33-50%
Ti (Second)= (60/RR) x %Ti

55. The tolerance and acceptance of the
patient to the mask and pressure setting
The degree of upper airway obstruction or intrinsic PEEP pressure
Respiratory drive during wakefulness and sleep
Ability of the patient to trigger the device
IPAP-EPAP difference, ie. Pressure support
Airflow resistance
Compliance of the respiratory system
Inspiratory time

56. Alarm setting
Adjust high and low tidal volume
Alarm 10% above and below average value for tidal volume
Adjust high and low pressure alarms (5cm above and below the peak airway pressure)

57. Application of NIV using ICU ventilators

58. Application of NIV using ICU ventilators
First step is to select the right ventilator and mask
Explain the therapy to the patient
Choose an appropriate interface
Put in NIV mode
Keep FiO2 -50%
Start with lower setting of PS 8-10 and PEEP of 4-5cm H2O

59. Initiate NIV while holding the mask in place and confirm optimum fit. Change if it is too big or
small
Hold the mask and don’t fix the headgear
Once the patients inspiratory efforts trigger the ventilator, start increasing pressure support
further keeping the patient comfort in mind
Increase FiO2 to maintain target oxygen SpO2
Secure interface with the headgear
It should be tight but not over tight
Small leaks are acceptable

60. Humidification in NIV
No evidence to guide the use of humidification in Acute NIV
Humidification is not routinely required
Heated humidification may be useful where mucosal dryness and respiratory secretions are
thick and tenacious.
It may reduce upper airway resistance and increase comfort when leak is high

61. Humidification devices includes
i. Heated or unheated pass over devices
ii. Pass through devices
iii. Heat and moisture exchangers
With pressure targeted ventilators only pass-over humidifiers should be applied, since pass
through devices and Heat and moisture exchangers may compromise pressure and flow delivery
and triggering.

63. Bronchodilator therapy in NIV
Nebulised drugs-during breaks from NIV
If the patient is dependent on NIV, bronchodilator drugs can be given via a nebuliser inserted
into the ventilator tubings

64. Sedation with NIV
Sedation should be avoided and only be used with close monitoring

65. Monitoring Of NIV
Mask comfort
Tolerance of ventilator setting
Respiratory distress
Respiratory rate
HR, SpO2, pH, pCO2
Sensorium
Accessory muscle use
Abdominal paradox

66. Monitoring Of NIV
Ventilator parameter
Air leaking
Adequacy of pressure support
Adequacy of PEEP
Tidal volume (6-8ml/kg)
Patient-ventilator synchrony

67. To control pH and pCO2 manipulate the RR, Tidal volume and Minute ventilation
To control pO2 adjust the FiO2 and the mean airway pressure( PEEP and PIP)

68. Discontinuation of NIV
NIV failure:
Worsening mental status
Detioration in pH and pCO2 after 1-3hours of NIV
Refractory hypoxemia: even a brief discontinuation of NIV leads to significant fall in SpO2
Intolerance to NIV
Hemodynamic instability
Inability to clear secretions

69. NIV complications
Nasal bridge necrosis/Pressure sores
Air leak
Aerophagia/ Gastric distension
Aspiration
Hypotension
Mucus plugging
Barotauma

70. Nasal bridge necrosis / pressure sores

71. Air leaks
Air leak in NIV
Increase flow to maintain pressure of IPAP
Inspiration is prolonged into patient expiratory efforts
Dysynchrony or Non triggering

72. NIV complications
Complications Corrective actions
Mask discomfort
Excessive leaks
Check mask for correct size and fitting
Minimize headgear tension
Pressure sores Use forehead spacers or change to a different masks
Apply Duoderm, wound care dressings
Nasal or oral dryness or nasal congestion Add or increase humidification
Irrigate nasal passage with saline
Apply topical decongestants
Aerophagia/gastric distension Use lowest effective pressure for adequate tidal volume
Use simethicone agents
Aspirations Make sure patient are able to protect airways
Mucus Plugging Ensure adequate hydration
Ensure adequate humidifications
Avoid excessive O2 flow rates (>20L/min)
Allow short breaks from NIV to directed coughing technique.
Hypotension Avoid excessively high airway pressure
Barotrauma Use PCV, Low PIP, Avoid desynchrony

73. Conclusions: Making NIV successful
Select right patient, Interface and Ventilator
Rule out contraindications
Monitor closely for comfort, air leak and desynchrony
Dedicated and trained staff

74. Take Home Message
NIV is Healing when used judiciously and Hurting when used non selectively and
inappropriately.