3. DEFINITION
NIV is alveolar ventilation without invasive airway
control (ET tube/Tracheostomy)
It can avoid complications related to endotracheal
intubation and invasive mechanical ventilation and
provide advantages such as patient comfort, reduced
incidence of trauma to the respiratory tract, infections,
avoidance of excessive sedation, neuromuscular
weakness and even death in selected patients
5. NEGATIVE PRESSURE VENTILATION
• Main means of NIV during the 1st half of the 20th century
• Extensively used during polio epidemics
• Tank ventilator “iron lung”
• Negative pressure ventilators apply a negative pressure intermittently
around the patient’s body or chest wall
• The patient’s head (upper airway) is exposed to room air
• Negative pressure is applied intermittently to the thoracic area
resulting in a pressure drop around the thorax
• This negative pressure is transmitted to the pleural space and
alveoli creating a pressure gradient between the inside of the
lungs and the mouth
10. Nasal Mask. This mask covers the nose only and rests on the upper lip, the sides of the
nose, and the nasal bridge
Oro-Nasal Mask (face mask). This mask covers the nose and mouth and rests on the
chin, the sides of the nose and mouth, and the nasal bridge
Nasal Pillow Mask. This mask fits on the rim of the nostrils. This type of mask is
usually recommended for individuals who find nasal or oro-nasal masks uncomfortable
or experience skin breakdown on the nasal bridge. Nasal pillows are used mainly in
stable patients with sleep- disordered breathing
Oral Mask. This mask fits inside the mouth between the teeth and lips and has a
tongue guide to prevent the tongue from obstructing the airway passage. This type is
not common in practice
Total Face Mask. This mask covers the whole face and is used mainly in patients with
ARF
Helmet. The helmet is a transparent hood that covers the entire head and face of the
patient and has a rubber collar neck seal. It is used as an alternative to the oro-nasal
mask in patients with acute hypoxemic respiratory failure or acute cardiogenic
pulmonary edema. It was developed to improve tolerability and reduce complications in
patients with ARF on NIV.It is not commonly used in patients with acute hypercapnic
respiratory failure.
11. variables nasal oronasal
comfort
+++ ++
clasutraphobia + ++
rebreathing
+ ++
lowers co2 + ++
permits expectoration ++ +
permits speech ++ +
permits eating + -
function if nose
obstructed
- +
12. The Ventilator for NIV
Bilevel ventilator
Bilevel ventilators use internal blowers to generate flow through a single
limb circuit during both inhalation and exhalation.
A passive leak port, either in the circuit or the interface, is open throughout
the respiratory cycle. An active exhalation valve is not needed because the
exhaled gas passes through the leak port.
Intermediate ventilator
These ventilators are most commonly used for patient transport or home
care ventilation. They utilize a single limb circuit with either an active
exhalation valve near the patient or a passive leak port. In the past, these
devices have been leak intolerant. However, newer designs offer leak
compensation.
13. Critical care ventilator without NIV mode
In the past, critical care ventilators were designed primarily for
invasive ventilation. As such, they were leak intolerant. Although these
ventilators have been used for NIV, the absence of leak compensation
often resulted in asynchrony and much clinician time and effort to
minimize leak.
Critical care ventilator with NIV mode
Newer generation critical care ventilators have NIV modes, with dual
limb circuits that separate the inspiratory from expiratory gases. NIV
modes offer leak compensation, but the ability of the ventilator to
compensate for leaks varies among manufacturers.
14. Ventilator Modes and Settings for NIVPressure-limited modes
1) Continuous positive airway pressure (CPAP) :
It consists of a single selected pressure
Applied via a noninvasive interface to the upper airway
CPAP can be applied using bilevel ventilators or flow regulators using
mixtures of compressed air and oxygen, usually at pressures between 5
and 10 cm H2O.
Advantages:
Low cost (if flow regulators are used) and a lack of issues related to
asynchrony.
Disadvantage:
No active respiratory assistance during inspiration, and thus less
effectively reduces respiratory muscle workload than bilevel positive
airway pressure.
15. . 2) Bilevel positive airway pressure (bilevel NIV)
.
Most commonly used mode
Consists of a higher inspiratory pressure (IPAP) and lower expiratory
pressure (EPAP)
IPAP and EPAP are time cycled
IPAP is typically set to reduce respiratory rate to 20/min – 25/min
and to increase tidal volume to 6 to 8 ml/kg predicted body weight
Higher EPAP is used to improve oxygenation
IPAP=EPAP+pressure support
Advantages : Leak compensation to maintain targeted pressures and
special algorithms that help to facilitate synchrony in the face of air
leaks.
16. . 3) Pressure support ventilation (PSV)
Similar to bilevel NIV but is provided on critical care
ventilators or a few dedicated NIV ventilators.
Pressure support is patient triggered (flow or pressure
trigger) and flow cycled depending on the Expiratory
time Sensitivity
Ventilator settings in PSV are essentially the same as
with bilevel NIV, but it is important to recall that the
terminology is different
EPAP=PEEP,
IPAP = pressure support plus PEEP.
17. 4) Pressure Control Ventilation (PCV)
PCV is flow triggered
It uses preset inspiratory and expiratory pressures
Backup rate is mandatory
Breaths are time-cycled.
Setting inspiratory and expiratory pressures with PCV is
the same as with PSV, but inspiratory time is set using
absolute time or an I:E ratio.
18. . 5) Average Volume Assured Pressure Support (AVAPS)
. A proprietary mode found on some noninvasive ventilators that
uses an algorithm to enable the ventilator to automatically
adjust inspiratory airway pressure (adaptive pressure support) to
achieve a target tidal volume.
. The operator sets a target tidal volume, range of inspiratory
pressures, EPAP and a backup rate and the ventilator seeks the
lowest inspiratory pressure within the targeted pressure range
that provides the target volume
. Advantages: a higher likelihood that patients will reach the
targeted tidal and minute volumes and therefore improve
hypercarbia.
. A limitation of this mode is that support is reduced if patient
effort results in a tidal volumes that exceeds the target and
respiratory muscles of such patients may fatigue.
19. 6) Intelligent Volume Assured Pressure Support (iVAPS)
Another proprietary mode that is similar to AVAPS but
targets alveolar ventilation
Alveolar ventilation (obtained by subtracting anatomic
dead space from target tidal volume)
20. VOLUME TARGETED MODES
Volume control can be applied, with set tidal
volumes of 6 - 8 mL/kg PBW.
The chief limitation of volume-targeted modes
has been an inability to compensate for leaks,
leading to failure to provide the targeted tidal
volume
21. Modes to enhance synchrony
1) Proportional Assist Ventilation (PAV)
It was developed to match ventilator response with
breathing effort.
It tracks instantaneous inspiratory flow and its
integral, tidal volume, and delivers flow and volume
to match patient demand.
An issue with PAV for NIV is the difficulty in
measuring resistance and compliance, which is an
important limitation of this mode for NIV
PAV should be avoided if patients have depressed
drive to breathe or neuromuscular weakness.
22. Neurally adjusted ventilator assist (NAVA)
NAVA uses esophageal electrodes to track electrical
activity of the diaphragm as an index of breathing effort.
Accordingly, it has the potential to use neural respiratory
drive to control the ventilator, thereby optimizing
synchrony.
As it tracks electrical activity rather than inspiratory
flow, it delivers flow without delay, even in the face of
auto-PEEP.
NAVA may be helpful in situations involving difficult
synchrony during NIV such as COPD patients with auto-
PEEP
25. COPD
Should NIV be used in COPD exacerbation?
Bilevel NIV may be considered in COPD patients with an acute exacerbation in
three clinical settings
1) To prevent acute respiratory acidosis, i.e. when the arterial CO2 tension
(PaCO2) is normal or elevated but pH is normal.
2) To prevent endotracheal intubation and invasive mechanical ventilation in
patients with mild to moderate acidosis and respiratory distress, with the aim of
preventing deterioration to a point when invasive ventilation would be
considered
3) As an alternative to invasive ventilation in patients with severe acidosis
and more severe respiratory distress
26. RECOMMENDATION:
We suggest NIV not be used in patients with hypercapnia who are not acidotic in the setting of
a COPD exacerbation. (weak recommendation)
Keenan SP, Powers CE, McCormack DG. Noninvasive positive-pressure ventilation in patients
wimilder chronic obstructive pulmonary disease exacerbations: a randomized controlled trial.
Respir Care 2005; 50:
52 patients with COPD comparing bilevel NIV to standard oxygen therapy
Inclusion criteria of recent onset of shortness of breath and a pH >7.30 (average pH of
randomised patients was within the normal range),
NIV was poorly tolerated
NO effect of NIV on intubation rate (8% in NIV arm and 7% in control arm) or mortality (4% in
NIV arm and 7% in control arm).
Should NIV be used in ARF due to a COPD exacerbation to prevent the development
of respiratory acidosis?
27. RECOMMENDATION:
Bilevel NIV for patients with ARF leading to acute or
acute-on-chronic respiratory acidosis (pH ⩽7.35) due to
COPD exacerbation. (Strong recommendation, high
certainty of evidence.)
A trial of bilevel NIV in patients considered to require
endotracheal intubation and mechanical ventilation, unless the
patient is immediately deteriorating. (Strong recommendation,
moderate certainty of evidence.)
Should NIV be used in established acute hypercapnic
respiratory failure due to a COPD exacerbation?
28. Bilevel NIV to prevent intubation
Patients with a pH of 7.25–7.35, in the absence of a metabolic cause
for the acidosis,
Strongest evidence base to support the use of bilevel NIV
Bilevel NIV
• Reduces the sensation of dyspnoea,
• The need for immediate intubation, and intensive care unit (ICU)
• Probably hospital length of stay, and improves survival.
• There is a reduction in both respiratory and nonrespiratory infectious
complications
29. Bilevel NIV as an alternative to first-line endotracheal intubation
Two studies have compared bilevel NIV directly with invasive ventilation
Conti G, Antonelli M, Navalesi P, et al. Noninvasive vs. conventional mechanical ventilation in
patients with chronic obstructive pulmonary disease after failure of medical treatment in the
ward: a randomized trial.
Intensive Care Med 2002; 28: 1701–1707.
Survival was similar in both groups,
But in patients in whom NIV was successful the advantages included shorter duration of ICU and
hospital stay, fewer complications, reduced need for de novo oxygen supplementation, and fewer
hospital readmissions in the subsequent year.
Jurjevic M, Matic I, Sakic-Zdravcevic K, et al. Mechanical ventilation in chronic obstructive
pulmonary disease patients, noninvasive vs. invasive method (randomized prospective study)
Invasive ventilation was associated with more rapid improvement in physiological abnormalities
in the first few hours, but was also associated with a longer total duration of ventilation and ICU
stay. Mortality was similar in the two groups. Patients receiving bilevel NIV had fewer episodes
of ventilator-associated pneumonia and less requirement for tracheostomy.
30. . 1) Bilevel NIV should be considered when the pH is
⩽7.35, PaCO2 is >45 mmHg and the respiratory rate is
>20–24 breaths·min–1 despite standard medical
therapy.
2) Bilevel NIV remains the preferred choice for
patients with COPD who develop acute respiratory
acidosis during hospital admission. There is no lower
limit of pH below which a trial of NIV is
inappropriate; however, the lower the pH, the greater
risk of failure, and patients must be very closely
monitored with rapid access to endotracheal intubation
and invasive ventilation if not improving.
31. The use of noninvasive mechanical ventilation (NIV) is preferred
over invasive ventilation (intubation and positive pressure
ventilation) as the initial mode of ventilation to treat acute
respiratory failure in patients hospitalized for acute exacerbations of
COPD.
NIV has been studied in RCTs showing a success rate of 80-85% `
INDICATIONS FOR NIV IN COPD
Respiratory acidosis( paco2>45 mm hg, and arteria ph<7.35)
Severe dysopnea with clinical signs suggestive of respiratory
muscle fatigue,increased work of breathing, such as use of
respiratory accessory muscles,paradoxical motion of abdomen or
retraction of intercostal spaces
Persistent hypoxemia despite oxygen therapy
GOLD 2019 UPDATE
T
32. ACUTE CARDIOGENIC PULMONARY OEDMA
Gray A, Goodacre S, Newby DE, et al. Noninvasive ventilation in
acute cardiogenic pulmonary edema. N Engl J Med 2008; 359: 142
151.
They conclude that:
1) NIV decreases the need for intubation,
2) NIV is associated with a reduction in hospital mortality,
3) NIV is not associated with increased myocardial infarction
4) CPAP and NIV have similar effects on these outcomes.
RECOMMENDATION:
Either bilevel NIV or CPAP for patients with ARF due to cardiogenic
pulmonary oedema. (Strong recommendation, moderate certainty of evidence.)
33. RECOMMENDATION:
We suggest that CPAP or bilevel NIV be used for patients with
ARF due to cardiogenic pulmonary oedema in the pre-hospital
setting. (Conditional recommendation, low certainty of
evidence.)
Emphasised the need for appropriate training and adequate
infrastructure, including coordination with emergency departments
before initiating a programme.
More research is needed, including pre-hospital use of bilevel NIV
versus CPAP, selection of patients, personnel on ambulances and
role of communication with emergency departments.
Should a trial of CPAP prior to hospitalisation be used to prevent
deterioration in patients with ARF due to cardiogenic pulmonary
oedema?
34. Should NIV be used in ARF due to acute asthma?
Due to uncertainty of evidence they were unable to
offer a recommendation on the use of NIV for ARF
due to asthma.
However, given the possibility of overlap between
asthma and COPD, bilevel NIV may be considered in a
subgroup of patients diagnosed with asthma who are
behaving more like patients with COPD (i.e. fixed
airway obstruction).
35. RECOMMENDATION:Early initiation of NIV for
immunocompromised patients with ARF. (Conditional
recommendation, moderate certainty of evidence.)
NIV use led to
1. A decrease in mortality
2. The need for intubation
3. The rates of nosocomial pneumonia in this population.
One recent RCT showed benefits of high-flow nasal cannula
oxygen therapy over bilevel NIV with regard to intubation and
mortality,
Should NIV be used for ARF in immunocompromised patients?
36. No clear recommendation regarding use of NIV in denote
ARF.
De novo respiratory failure refers to respiratory failure
occurring without prior chronic respiratory disease. Most
patients in this category have hypoxaemic respiratory failure,
usually defined as significant hypoxemia (PaO2/FO2) ⩽200),
tachypnoea (respiratory rate >30–35breaths·min–1) and a non-
COPD diagnosis (e.g. pneumonia and/or acute respiratory
distress syndrome (ARDS))
NIV is used in these patients with the aims of improving
oxygenation, facilitating ventilation, decreasing the work of
breathing and dyspnoea, avoiding intubation, and reducing the
complications associated with invasive mechanical ventilation.
Should NIV be used in de novo ARF?
37. Limitations of NIV is its lack of efficacy in
reducing work of breathing
The high pressures causes increase air leaks,
gastric insufflation and patient intolerance
Hypoxaemia and high work of breathing return
immediately when NIV is removed, explaining the
risk associated with NIV interruptions
Early predictors of NIV failure include higher
severity score, older age, ARDS or pneumonia as
the aetiology for respiratory failure, or a failure to
improve after 1 h of treatment
38. Should NIV be used in ARF in the post-operative setting?
RECOMMENDATION:
Suggested NIV use in postoperative ARF
Physiological studies have shown that CPAP and bilevel NIV
are effective at improving lung aeration and arterial
oxygenation and decreasing the amount of atelectasis without
adverse haemodynamic effects during the post-operative
period after extubation
NIV reduces intubation rates, nosocomial infections, lengths
of stay, morbidity and mortality. Before initiating NIV in
post-operative patients with ARF, surgical complications such
as anastomotic leak or intra-abdominal sepsis should be
addressed first.
39. Supradiaphragmatic surgery
STEPHAN et al. reported that, in 830 patients following
cardiothoracic surgery with or at risk for respiratory failure,
the use of high-flow nasal cannula therapy compared with
intermittent NIV did not result in a worse rate of treatment
failure defined as need for re-intubation.
40. Abdominal and/or pelvic surgery
JABER et al : The use of NIV resulted in avoidance of intubation in 67% cases,
and a reduction in the hospital length of stay and mortality, compared with
intubated patients.
ANTONELLI et al: 40 patients undergoing solid organ transplantation (mainly
liver transplantation) and developing post-operative respiratory failure, NIV
improved oxygenation and decreased the need for tracheal intubation compared
with conventional therapy.
SQUADRONE et al. evaluated the use of helmet-CPAP after abdominal surgery
in 209 patients who developed hypoxaemia without respiratory symptoms
immediately after extubation. Their early use of CPAP significantly decreased the
incidence of re-intubation from 10% to 1% .
JABER et al.: In patients with hypoxaemic ARF following abdominal surgery,
the use of NIV compared with standard oxygen therapy reduced the risk of
tracheal re-intubation within 7 days and the incidence of healthcare-associated
infections
41. Should NIV be used in patients with ARF receiving palliative care?
Recommendation
We suggest offering NIV to dyspnoeic patients for palliation in
the setting of terminal cancer or other terminal conditions.
(Conditional recommendation, moderate certainty of evidence.)
NIV improved patient dyspnoea as assessed by the Borg scale and
led to decreased morphine requirements
The use of NIV in “do not intubate” patients was associated, at
least in some subsets of patients (COPD and congestive heart
failure), with a surprisingly high (>30–60%) hospital survival and a
3-month quality of life equivalent to patients treated with NIV and
having no limitation placed on support.
42. Should NIV be used in ARF due to chest trauma?
Recommendation
We suggest NIV for chest trauma patients with ARF.
(Conditional recommendation, moderate certainty of
evidence.)
NIV use led to
A decrease in mortality
The need for intubation
The incidence of nosocomial pneumonia
There was also a decrease in ICU length of stay
43. Should NIV be used in ARF due to pandemic viral illness?
Recommendation
Given the uncertainty of evidence we are unable to offer
a recommendation for this question.
A cautious NIV trial in carefully selected patients at
experienced centres, in a protected environment (i.e.
negative pressure rooms)
44. Should NIV be used in ARF following extubation from invasive mechanical
ventilation?
Recommendations
NIV to be used to prevent post-extubation respiratory failure in
high-risk patients post-extubation.
NIV should not be used to prevent post-extubation respiratory
failure in non-high-risk patients.
At risk patients
Patients >65 years and with underlying cardiac or respiratory
disease
45. Should NIV be used in the treatment of respiratory failure that develops post-extubation?
Recommendation
We suggest that NIV should not be used in the treatment of patients
with established post-extubation respiratory failure
NIV use led to
An increase in mortality
With an uncertain effect on intubation.
The use of NIV to avoid re-intubation in patients with overt respiratory
distress and/or respiratory failure consequent to failed planned
extubation is not advisable.
This recommendation may not apply to post-extubation COPD patients
with respiratory failure.(requires further studies)
46. Should NIV be used to facilitate weaning patients from invasive mechanical ventilation?
Recommendations
We suggest NIV be used to facilitate weaning from mechanical
ventilation in patients with hypercapnic respiratory failure.
We do not make any recommendation for hypoxaemic patients.
NIV use led to a decrease in mortality
Weaning failure and the incidence of ventilator-associated pneumonia in this
population.
Anticipated desirable effects of NIV applied immediately following
extubation in patients with an acute COPD exacerbation who fail the SBT
outweigh the anticipated undesirable effects.
47.
48. CONTRAINDICATIONS
• ABSOLUTE:
1. COMATOSE PATIENT
2. UPPER AIRWAY OBSTRUCTION
3. IMMEDIATE NEED TO INTUBATE-RESPIRATORY
ARREST
4. COPIOUS SECRETIONS IN RESPIRATORY TRACT
5. ILEUS
6. VOMITING, UPPER GI BLEED
7. EXTENSIVE FACIAL INJURY/ TRAUMA
49. • RELATIVE
1. HIGHLY CONFUSED/UNCO-OPERATIVE PATIENT
2. UNSTABLE HAEMODYNAMICS
3. EVOLVING MYOCARDIAL INFARCTION/ UNSTABLE
ANGINA
4. RECENT OESOPHAGEAL/GASTRIC SURGERY
5. FACIAL DEFORMITY
6. NON RESTRICTIVE ORGAN FAILURE NEEDING
RESPIRATORY SUPPORT
7. MORE THAN TWO ORGAN SYSTEM FAILURE
50. Disadvantages
System
Slower correction of gas exchange abnormalities
Increased initial time commitment
Gastric distension (occurs in <2% patients)
Mask
Air leakage
Transient hypoxemia from accidental removal
Eye irritation
Facial skin necrosis
Lack of airway access and protection
Suctioning of secretions
Aspiration
51. PROTOCOL FOR INITIATION OF NONINVASIVE POSITIVE PRESSURE VENTILATION
1. Appropriately monitored location; oximetry, respiratory
impedance, vital signs as clinically indicated
2. Patient in bed or chair sitting at 30-degree angle
3. Select and fit interface
4. Select ventilator
5. Apply headgear; avoid excessive strap tension (one or two
fingers under strap); encourage patient to hold mask
6. Connect interface to ventilator tubing and turn on ventilator
7. Start with low pressures/volumes in spontaneously triggered
mode with backup rate; pressure-limited: 8 to 12 cm H2O
inspiratory; 3 to 5 cm H2O expiratory volume-limited: 10
ml/kg
52. 8. Gradually increase inspiratory pressure (10 to 20 cm H2O) or tidal
volume (10 to 15 ml/kg) as tolerated to achievealleviation of dyspnea,
decreased respiratory rate, increased tidal volume (if being monitored),
and good patient-ventilator synchrony
9. Provide O2 supplementation as needed to keep O2 sat 90%
10. Check for air leaks, readjust straps as needed
11. Add humidifier as indicated
12. Consider mild sedation in agitated patients
13. Encouragement, reassurance, and frequent checks and adjustments as
needed
14. Monitor occasional blood gases (within 1 to 2 h and then as needed)
Am J Respir Crit Care Med Vol 163. pp 540–577, 2001 Internet
address: www.atsjournals.org
53. NIV monitoring requirements.
Subjective Responses: respiratory distress, dyspnea, anxiety,
claustrophobia, discomfort with mask or air pressure, dryness of mouth
or eyes, gastric insufflation.
- At NIV intiation
- Every 15 to 30 min for first 2 hours of therapy
- Hourly or as needed after first 2 hours
54. . Physical findings: respiratory rate, heart rate,
blood pressure, level of consciousness,
accessory muscle use, abdominal paradox,
comfort, skin breakdown.
- At NIV initiation
- Every 15 - 30 min for first 2 hours of
therapy
- If stable after 2 hours of therapy, then
hourly assessments.
55. . Ventilator parameters: tidal volume, minute ventilation,
leak under mask or through mouth, inspiratory pressure
setting, expiratory pressure setting, FIO2, synchrony
Gas Exchange: pulse oximetry, arterial blood gases, end-
tidal PCO2, transcutaneous PCO2
- At NIV initiation
- Every 15 - 30 min for first 2 hours of therapy
- If stable after 2 hours of therapy, then assessments
every 4 - 6 hours.