Non Invasive Ventilation (NIV) involves delivering mechanical ventilation without the use of an endotracheal tube or surgical airway, instead using a tight-fitting face or nasal mask. NIV has been used since the 1940s but became more widely used starting in the 1980s for conditions like sleep apnea. It is now commonly used to treat acute respiratory failure from COPD exacerbations and cardiogenic pulmonary edema. NIV can be delivered via CPAP or BiPAP and involves optimizing settings like IPAP, EPAP, respiratory rate and oxygen flow to improve ventilation and oxygenation without the need for intubation. Proper patient selection, interface choice, and monitoring are important for successful NIV treatment.

1. Non Invasive Ventilations
(NIV)
Dr. P K Maharana,
KIMS.

2. NIV
• Pt on NIV

3. Definition
 Noninvasive ventilation (NIV): Is defined
as a ventilatory mode that delivers a
mechanical supported breath without
use of an endotracheal tube or surgical
airway, but using a tight-fitting face or
nasal mask.

4. History
• The application of intermittent positive inspiratory pressure
via an anesthesia mask in the treatment of acute
respiratory illness was studied by Motley and colleagues at
Bellevue Hospital in the 1940s.
• These clinician-investigators used a mask and bag
apparatus to deliver intermittent positive-pressure
ventilation to patients with pneumonia, pulmonary edema,
near-drowning, GuillainBarre´ syndrome, and acute severe
asthma.
• However, this approach to life support in the acute-care
setting took a back seat to invasive mechanical ventilation
as the latter emerged and was refined during the next 2
decades.

5. History ( Conti-i)
• The clinical application of NIV re-emerged in
the 1980s when it was successfully used to
treat obstructive sleep apnea, and respiratory
failure in patients with neuromuscular
diseases.
• In following years NIV used extensively to
treat Acute Hypercapnic Respiratory
Failure(COPD) and Cardiogenic Pulmonary
Oedema.

6. History(Conti-ii)
• Since 2000, NIV has been used widely in the
treatment of acute respiratory failure,
particularly in people with COPD, including on
general wards rather than the intensive care
unit setting.
• Currently NIV is a modality of choice in the
management of severe acute exacerbation of
chronic obstructive pulmonary disease (COPD)
and cardiogenic pulmonary edema.

7. NIV is a clinical decision
• Respiratory failure in the ED is almost
always—and most appropriately—a clinical
decision.
• The decision to intubate and mechanically
ventilate or to institute noninvasive
ventilation support is generally made purely
on clinical grounds without delay for
laboratory evaluation.

8. Types of NIV
It is broadly of two types: CPAP & BiPAP.
o CPAP does not directly increase either the
tidal volume or minute ventilation.
o In contrast, bilevel positive airway pressure
(BiPAP) provides supplemental inspiratory
tidal volume.

9. Indications of NIV
Absolute Indications:
o Exacerbation of chronic obstructive airways disease
(COPD).(Grade 1 )
o Pulmonary oedema.(Grade 1 )
o Respiratory failure in immunocompromised patients.
E.g. AIDS, malignancy.
o Weaning from conventional ventilation and prevention
of need for reintubation in high risk patients.
o Chest trauma.
o Asthma.

10. Indications of NIV( Conti-)
 Relative Indications
 Community acquired
Pneumonia
 Immunocompromised
patients with hypercapnic
respiratory failure.
 Asthma
 Rib fracture (Traumatic
with non penetrating
chest injury).
 Do-not - intubate status in
terminal illness or
malignancies.
 Idiopathic Pulmonary
Fibrosis.
 Support during invasive
procedures i.e..
Bronchoscopy
 Pneumocystis carinii
Pneumonia.
 Obesity hypoventilation.
 Neuromuscular Respiratory
Diseases.

11. Contra Indications.
Absolute
o Coma
o Cardiac arrest
o Respiratory arrest
o Severe haemodynamic instability
o Multiorgan failure
o Any condition requiring Intubation.
o Non-compliant patient
Relative

12. Contraindications(Conti-)
o Cardiac instability.
– Shock and need for pressor support
– Ventricular dysrhythmias
– Complicated acute myocardial infarction
o GI bleeding.
- ( Intractable emesis and/uncontrollable bleeding)
o Inability to protect airway.
– Impaired cough or swallowing reflex
– Poor clearance of secretions
– Depressed sensorium and lethargy
o Status epilepticus.
o Potential for upper airway obstruction.
– Extensive head and neck tumors
– Any other tumor with extrinsic airway compression
– Angioedema or anaphylaxis causing airway compromise

13. Protocol for initiation of NIV
 1. Appropriately monitored location.
 2. Patient in bed or chair sitting at > 30‐degree angle.
 3 A full‐face mask should be used for the first 24
hours, followed by switching to a nasal mask if
preferred by the patient (Evidence C).
 4.Encourage patient to hold mask
 5. Apply harness; avoid excessive strap tension
 6 .Connect interface to ventilator tubing and turn on
ventilator
 7. Check for air leaks, readjust straps as needed

14. Guidelines for NIV settings
 1.An initial IPAP of 10 cm H2O & EPAP of 4–5 cm
H2O should be used (Evidence A).
 2.IPAP should be increased by 2–5 cm increments at
a rate of approximately 5 cm H2O every 10mins,
with a usual IPAP target of 20 cm H2O or until a
therapeutic response is achieved or patient
tolerability has been reached (Evidence A).
 3. O2 should be entrained into the circuit and the
flow adjusted to SpO2 >88–92% (Evidence B)
(BTS: NIV in COPD: management of acute type 2
respiratory failure)

15. OXYGENATION AND HUMIDIFICATION
 Oxygen is titrated to achieve a desired
oxygen saturation of 90% to 92%.
Use of oxygen blenders is necessary.
 Adjusting liter flow delivered via oxygen
tubing connected directly to the mask or
ventilator circuit.
Heated blow over vaporizer should be used if
longer application intended.

16. Bronchodilators
 Preferably administered off NIV
 If necessary be entrained between the
expiration port and face mask
 Delivery of both oxygen and nebulized
solutions is affected by NIV pressure settings
(Evidence A)
 If a nasogastric tube is in place, a fine bore
tube is preferred to minimize mask
leakage(Evidence C).

17. Guidelines for continuing NIV
 Duration of treatment
 Patients who benefit from NIV during the
first 4 hours of treatment should receive NIV
for as long as possible (a minimum of 6
hours) during the first 24 hours (Evidence A)
 Treatment should last until the acute cause
has resolved, commonly after about 3 days
 When NIV is successful (pH>7.35,resolution
of cause, normalization of RR), after 24
hrs/more plan weaning.

18. Weaning strategy(A)
1. Continue NIV for 16 hours on day 2
 2.Continue NIV for 12 hours on day 3
including 6–8 hours overnight use
 3.Discontinue NIV on day 4, unless
continuation is clinically indicated.

19. Criteria for Terminating NIV and
Switching to Mechanical ventilation
 Worsening pH and PaCO2
Tachypnea (over 30 bpm)
Hemodynamic instability
SpO2 < 90%
 Decreased level of consciousness
Inability to clear secretions
 Inability to tolerate interface

20. Assess
ment
of NIV

21. Interface for delivery of NIV

22. Total face Mask
Equally comfortable
• Similar
– Application times
– Early NIV discontinuation
rates
– Improvements in vital
signs and gas exchange
– Intubation and mortality rate.

23. Nasal masks
• Better tolerated than full
face masks for longterm
&chronic applications
• Less claustrophobia and
discomfort and allow
eating, conversation, and
expectoration

24. Nasal Masks
Pressure over nasal
bridge
– forehead spacers
– ultrathin silicon seals or
heat‐sensitive gels that
minimize skin trauma
• Problem‐ Air leakage
through mouth

25. CPAP
 Continuous positive airways pressure (CPAP):
Implies application of a preset positive
pressure throughout the respiratory cycle (i.e.
inspiratory and expiratory phases) in a
spontaneously breathing patient.

26. CPAP
Normal Respiration
CPAP 
Provides static positive airway
pressure
throughout the respiratory cycle‐
both nspiration & expiration.

27. How CPAP works?
1.CPAP splints the airway throughout the respiratory
cycle.
2. Increases ↑ (FRC) the functional residual
capacity of the lungs by holding airways open and
preventing collapse.
3.Also causes the patient to breathe at higher lung
volumes, making the lungs more compliant.
4. Provides effective chest wall stabilization.
5. Improves ventilation-perfusion mismatch and
thereby improves oxygenation.

28. Benefits of CPAP
• ↑O2 saturation
• ↓ Work of breathing
• ↓ cardiac workload by(↑ Intrathoracic
Pressure which will ↓ preload ).

29. Use of CPAP
• 1.In the U.K., guidelines call for using CPAP
with patients being weaned from ventilation;
patients who are hypoxemic following
extubation; or patients with a variety of acute
conditions “who are hypoxic but not
exhausted” (i.e., those who are ventilating
themselves adequately).
• 2.OSA ( obstructive sleep apnoea syndrome)

30. OSA ( Obstructive Sleep Apnoea)
• Sleep-disordered breathing (upper airway obstruction
during sleep) occurs in around 20% of the adult population.
It ranges from snoring to obstructive sleep apnoea (OSA),
the latter being characterized by cessation of breathing for
at least 10 s in the presence of inspiratory effort.
• The incidence of clinically relevant OSA has been
estimated to be around 22% in the general surgical
population, with 70% of patients being undiagnosed at
preoperative evaluation.
• Patients with OSA are at increased risk of perioperative
complications: including hypoxaemia, hypercapnoea,
arrhythmias, myocardial ischaemia, delirium, and
unplanned intensive care unit admissions.

31. BiPAP( Bilevel Positive Airway Pressure)
 BIPAP: has two levels of continuous airway pressure
IPAP & EPAP.
• IPAP: The machine senses the occurrence of patient's
inspiratory flow , it increases the inspiratory pressure
applied, so that air flow is enhanced and the patient's
own inspiratory tidal volume is augmented.
• EPAP. When the machine senses that the flow is
slowing or stopped, it reduces the applied airway
pressure so the patient has less work upon exhaling,
but maintains a continuous positive expiratory
pressure.

32. BiPAP
Increases in
inspiratory pressure
are helpful to
alleviate dyspnea
• Increases in
expiratory pressure
are better to
improve oxygenation

33. BiPAP

34. Desk Board
of a BiPAP
machine

35. Ventilator settings
• IPAP/ EPAP  start with 10/5 cm H2O
(With a goal to achieve VT of 6-7ml/kg)
• Increase IPAP  by 2 cm H2O increments up
to maximum 20-25 cm H2O,if hypercapnia
persists. Do not exceed 25cm H2O at any
point of time.
• Increase EPAP  by 2 CmH2O if hypoxia,
maximum 10-15 cm H2O.
• Back up respiratory rate  12-16/minute.
• FIO2  1.0 to be adjusted to have SaO2 90%

36. Conventional pressure settings for
BiPAP© spontaneous mode?
 Commonly the IPAP is set to 10 cmH2O and
the EPAP to 5 cmH2O.
o The response to these pressures should
determine future changes.
o Most machines can generate maximal
pressures of 20-23 cmH2O.
o If higher pressures are required leakage
around the mask is usually a problem, and
conventional invasive ventilation is indicated.

37. What FiO2 to choose?
 Choose an initial FiO2 slightly higher to that what the
patient received prior to NIV.
 Adjust the FiO2 to achieve an SaO2 that you deem
appropriate for their underlying disease. (Generally
SaO2 above 92% is acceptable).
 If a patient is hypoxic while breathing 100% oxygen on a
CPAP circuit, their hypoxia will not improve if they are
placed onto a BiPAP circuit (in spite of the increased
ventilatory assistance) because the FiO2 will drop
significantly.
 Similarly if a patient starts to work harder on a BiPAP
circuit they may become more hypoxic due to a drop in
FiO2 caused by increased gas flow through the breathing
circuit.

38.  BiPAP can only augment the patient's
respiration; it should not be used as a
primary form of ventilation.
The tidal volume received by the patient
depends upon:
 Airway resistance,
Lung and chest wall compliance
Patient synchrony with machine, and
 Absence of air leakage around the mask.

39. How to monitor the patient’s
response to NIV?
• 1.The most useful indicator is  Patient
compliance. How the patient feels? Patient
should be able to tell if feels better or worse.
• 2.Where available,(ABG) are useful to assess
changes in oxygenation & CO2 clearance.

40. Predictor of Success of NIV
With a trial of ventilation for 1-2 hours
↓
Normally Leads to
 Decrease in ↓PaCO2 > 8 mm Hg
Increase in ↑ pH > 0.06

41. How to Predict failure?
 Again, this is largely based on how the patient
feels and what is the ABG results?
 If the patient is getting increasingly tired, or their
ABG deteriorating despite optimal settings, then
they will probably need tracheal intubation and
mechanical ventilation.
 It is important to recognize the failure to respond
to NIV as soon as possible, so that further
management can be planned before the patient
collapses.

42. Predictor of Failures
 1. Severity of illness:
• Acidosis (pH <7.25)
• Hypercapnia (> 80 and pH <7.25)
• (APACHE II) score higher than↑ 20.(Acute Physiology and Chronic Health Evaluation
II)
2. Level of consciousness:
• Neurologic score > 4 . (stuporous, arousal only after vigorous
stimulation; inconsistently follows commands)
• Encephalopathy score >3 .( major confusion, daytime sleepiness
or agitation)
• Glasgow Coma Scale score lower than < 8.
3.Failure to improve with 12-24 hours of NIV

43. Monitoring
1.Vital Signs: BP, RR, HR & rhythm, O2
saturation, Level of conscious state. SPO2:
Aiming for 94-98% (or 88-92% in CO2
retainers).
2.Treatment tolerance:
o Initially,@ 15 minutely for 1 hour, @30
minutely for 2 hours, @ 1 hourly for 2 hours,
then 4 hourly
3.ABGs : Prior to commencement, at 1 hour,
within 1 hour of setting changed, then as
clinically needed.

44. Advantages of NIV
Easy to administer
Decreases the incidence of Intubation.
Decreases Mortality.
Decreases ICU & Hospital Stay.
VAP can be avoided.
Intubation related complications can be
avoided.
Cost effective.

45. Complications
• 1.Facial & Nasal pressure injury.
• 2.Gastric distention
• 3.Drying of mucous membranes of nose,
nasal congestion & thick secretions.
• 4.Aspiration of Gastric contents.
• 5.General discomfort
• 6.Claustrophobia

46. Literature review
A 1995 study in the New England Journal of
Medicine found BiPAP ↓reduced the need for
endotracheal intubation, as well as hospital length of
stay and mortality, in acutely ill COPD patients with a
 PaO2 less than 45 mm Hg, (pH) level less than 7.35,
and (RR) greater than 30 breaths/minute.
A 2003 Cochrane review of studies with mostly COPD
patients also found that BiPAP ↓ decreased
mortality, incidence of ventilator-associated
pneumonia, ICU and hospital length of stay, total
duration of mechanical support and duration of
endotracheal mechanical ventilation.

47. Strong Evidence – Level A (multiple
controlled trials)
• Acute hypercapnic COPD
• Acute cardiogenic Pulmonary Oedema – most evidence for
CPAP
• Immunocompromised patients
• Less strong – Level B (single controlled trials,
multiple case series)
• Asthma
• Community Acquired Pneumonia in COPD patients
• Facilitation of weaning in COPD
• Avoidance of extubation failure
• Post Operative Respiratory Failure
• Do not intubate patients

48. Weak Evidence (few case series).
( No benefit in controlled trials)
• ARDS
• Community acquired pneumonia – non COPD
• Cystic fibrosis
• Weaning – non COPD
• OSA/ obesity hypoventilation
• Trauma

49. Not indicated
o Acute deterioration in DILD.
o Severe ARDS with multi organ failure.
o Post op Upper airway, esophageal surgery.

50. Present Status of NIV
• The application of mechanical
ventilatory support through a mask
in place of endotracheal intubation is
becoming increasingly accepted and
used in the emergency department &
ICU settings.

51. Summery
 COPD is the most suitable condition for noninvasive
ventilation.
 Noninvasive ventilation is most effective in patients with
moderate-to-severe disease.
 Hypercapnic respiratory acidosis may define the best
responders (pH 7.20-7.30).
– Noninvasive ventilation is also effective in patients with a pH
of 7.35-7.30, but no added benefit is appreciated if the pH is
greater than 7.35.
– The lowest threshold of effectiveness is unknown, but success
has been achieved with pH values as low as 7.10.
 Obtunded COPD patients can be treated, but the success rate is
lower.
 Improvement after a 1- to 2-hour trial may predict success.

52. Conclusion
 NPPV has to be considered as a rational art
and not just as an application of science,
which requires the ability of clinicians to both
choose case-by-case the best “ingredients” for
a “successful recipe” (i.e. patient selection,
interface, ventilator, interface, etc.) and to
avoid a delayed intubation if the ventilation
attempt fails.