What is NIV, types,indications, failure etc

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 ventilatory
support breath without use of an
endotracheal tube or surgical airway,
but using a tight-fitting face or nasal
mask.

4. NIV is a clinical decision
• Respiratory failure in the ED is almost
always—and most appropriately—a clinical
diagnosis.
• 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.

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

6. Indications for the use of NIV
 NIV is commonly used for the treatment of respiratory
failure from:
Absolute Indications:
o Exacerbation of chronic obstructive airways disease
(COPD).
o Pulmonary oedema.
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.

7. 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.

8. Contra Indications
Absolute:
• Coma
• Cardiac arrest
• Respiratory arrest
• Any condition requiring Intubation.
• Non-compliant patient

9. Relative Contraindications
o Cardiac instability
– Shock and need for pressor support
– Ventricular dysrhythmias
– Complicated acute myocardial infarction
o GI bleeding (- Intractable emesis and/or uncontrollable
bleeding)
o Inability to protect airway
– Impaired cough or swallowing
– 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

10. Guidelines for providing 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

11. 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

12. Guidelines for providing NIV
 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)

13. OXYGENATION AND HUMIDIFICATION
 Oxygen is titrated to achieve a desired
oxygen saturation of 90% to 92%.
Use of oxygen blenders
 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.

14. 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).

15. 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

16. 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.

17. Assess
ment
of NIV

18. Interface for delivery of NIV

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

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

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

22. 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.

23. CPAP
Normal Respiration.
CPAP:
Provides static positive airway
pressure
throughout the respiratory cycle‐
both
inspiration & expiration.
• Facilitates inhalation by
reducing pressure
thresholds to initiate airflow.

24. 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.

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

26. 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)

27. 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.

28. BiPAP( Bilevel Positive Airway Pressure)
 BIPAP: has two levels of continuous airway pressure.
• IPAP: When the machine senses the patient's
inspiratory flow starting to increase, 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 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.

29. BiPAP

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

31. BiPAP

32. 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%

33. Which initial pressure settings to use 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.

34. 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.

35. How to monitor the patient’s
response to NIV?
• The most useful indicator is  How the
patient feels. Patient compliance is the best
indicator.
(Patient should be able to tell you if feels
better or worse).
• Where available arterial blood gases (ABG)
are useful to assess  changes in
oxygenation and CO2 clearance.

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

37. How to Predict failure?
 Again, this is largely based on how the
patient feels and 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 as soon as possible so that
management may be planned before the
patient collapses.

38. Predictor of Failure
 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)
 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.
Failure to improve with 12-24 hours of NIV

39.  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 the absence of air leakage around the
mask.

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

41. Advantages of NIV
Decreases incidence of Intubation.
Decreases Mortality.
Decreases ICU & Hospital Stay.
VAP can be avoided.
Intubation related complications can be
avoided.
Cost effective.

42. 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

43. 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

44. 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

45. 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

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

47. 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.

48. 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.

49. THANKS

50. History of Mechanical ventilation

51. History
• An interest in the methods of providing
artificial respiration has long persisted,
stimulated by attempts at resuscitation of
drowning victims.
• This dates back to the mid 1700s, where it is
documented that a bellows-type device being
the most commonly used form of respiratory
assistance.

52. Negative-pressure tank-type
ventilators
• Negative-pressure tank-type ventilators came
into use in the next century, with a prototype
developed by Dalziel in 1832.
• This spawned a variety of cuirass and tank
negative-pressure ventilators, with the general
principle of enclosing the thorax, creating
negative pressure to passively expand the
chest wall and lungs.

53. History of Mechanical ventilation
• The concept of applying negative pressure to
the chest wall led to the Drinker-Shaw iron
lung in 1928, which was the first widely used
negative-pressure ventilator.
• In 1931, Emerson modified these large devices,
and the Emerson tank ventilator became the
standard for ventilatory support.
• The Emerson tank ventilator was especially
crucial in the treatment of poliomyelitis victims.

54. Blegdam Hospital & Polio Epidemic of 1952
• At the start of the epidemic, the Blegdam
Hospital had only seven ventilators, yet up to
70 patients required ventilatory support
simultaneously.
• Lassen and Ibsen developed the technique of
tracheotomy and manual intermittent
positive-pressure ventilation and described
their success in 1953.

55. IPPV
 The success of this form of “invasive”
positive-pressure ventilation was described
during the Copenhagen polio epidemic of
1952.
• Development of positive-pressure valves
helped to delivered a breath through
tracheostomy tubes during inspiration and
lead to the development of intermittent
positive pressure ventilation .

56. Recognition of Drawbacks of IPPV
• Positive-pressure ventilation delivered
through either a translaryngeal endotracheal
tube or a tracheostomy tube helped to
provide a successful breath but was also
associated with a host of complications,
specifically injury to the larynx and trachea, as
well as other issues involving the timing of
extubation, preservation of speech, and the
ability to continue swallowing.

57. NIV
• In the 1980s, increasing experience with
positive-pressure ventilation delivered through
a mask in patients with obstructive sleep
apnea led to the use of this type of ventilatory
support in other conditions, initially in patients
with neuromuscular respiratory failure but
soon it became a promising mode of therapy in
COPD.

58. Negative Pressure Ventilation (NPV)
• Negative pressure ventilators apply a negative
pressure intermittently around the patient’s
body or chest wall
Negative pressure is applied intermittently to
the thoracic area resulting in a pressure drop
around the thorax.
• This in tern lead to the drop in pressure in
pleural space and alveoli creating a pressure
gradient between the alveoli and the mouth
and establishing a flow of air.
• The patient’s head (upper airway) is exposed to room air

59. 1952 the worst Polio Epidemic
• 1952 the worst Polio Epidemic affected about
58000 cases were reported that year out of which
3200 cases died and 21000 were left with mild to
moderate disability. Use of Iron Lung to provide
respiratory support saved many lives. The iron
lung, also called the “Drinker Respirator”
(invented by Dr. Philip Drinker in 1929) was
employed to help the patient breathe. Support of
one to two weeks made the patient to breath of
their own and survive.

60. 1952 Polio Epidemic
(Ventilation through bag, IPPV)

61. Polio Patient with Positive Pressure
Ventilation

62. Iron Lung

63. Bjørn Ibsen (1915

64. First instance of IPPV
Ibsen related how the first patient was a 12-year-old
girl who had paralysis of all four extremities, had
atelectasis of the left lung, and who was gasping for
air and drowning in her own secretions . She was
pyrexic, cyanotic, and sweating.
A tracheotomy was done under local anesthesia, a
cuffed endotracheal tube was placed, and she was
eventually ventilated satisfactorily. The girl survived
He was successful..

65. Conti-
• Not so long ago professor Bjørn Ibsen was
lauded at a conference here in Denmark,
“He sat on a chair in the front row when a
woman of ∼65 yr quietly went up to him,
kissed him on the cheek and said ‘Thank you
for my life!’; She was that 12 yrs old girl.

66. A turning Point
• This event was a turning point in critical care
medicine, partly because it was one of the first
occasions when an anesthesiologist moved out of
the operating room into another environment.
• Positive pressure ventilation had previously been
used for short periods in a polio epidemic in Los
Angeles in 1948–1949 (7, 8), but this work had been
published in an obscure journal and was not well
known.

67. Medical students & Polio epidemic of 1952
• History speaks about the 1500 medical and dental
students ventilating polio patients for 165,000 h at
the Blegdam Hospital in 1952 thereby saving ∼100
people who would have been lost without this effort
.
• The students worked 6- or 8-h shifts, which was both
emotionally and physically demanding. During an 8-h
shift, there was a 10-min “smoke” break each hour,
and a half-hour meal break in the middle, but
otherwise the student was continually compressing
the bag.

68. The publication of The Lung by
Comroe et al. in 1955.
• The rapid advances made in departments of
physiology were translated to the clinical
setting with one of the most influential factors
being the publication of The Lung by Comroe
et al. in 1955.
• The result was a greatly improved
understanding of applied respiratory
physiology that continues to benefit patients
even today.

69. (BIPAP)
• Note that bi-phasic positive airways pressure
(BIPAP) is different to BiPAP and less commonly
encountered.
• The patient breathes at a preset level of CPAP and
at timed intervals (not synchronised to the
patient’s inspiratory efforts) the level of CPAP is
reduced to a lower level.
• The intermittent reduction in CPAP leads to a
large expiration and therefore increases
CO2 elimination.

70. • Pkm