NON INVASIVE VENTILATION
Definition:
NIV is the delivery of mechanical ventilation to the lungs
using techniques that do not require an endotracheal
airway
Types:
negative pressure NIV
Main means of NIV during the
1st half of the 20th century
o positive pressure NIV
resurgence in the early 1980s
due to the development of nasal
CPAP
o
Why the interest in NIV
The desire to avoid complications of invasive
ventilation
 Complications related to the process of
intubation and mechanical ventilation
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•
•
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Aspiration
Trauma
Arrythmias and hypotension
barotrauma
 Complications
caused by loss of airway
defense mechanisms
•
Direct conduit to lower airway  chronic bacterial
colonization
 Complication
that occur after
removal of ETT
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•
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Hoarseness, sore throat, cough
Sputum production
Upper airway obstruction
hemoptysis
 From
•
•
the patient’s point of view
Discomfort
Decreased ability to eat and communicate
Advantages of NIV
Leaves upper airway intact
 Preserve airway defense mechanisms
 Allows patient to eat, drink, verbalize and
expectorate
 Enhance comfort, convenience and portability
 Less cost

Interfaces
Devices that connect the ventilator‘s tubing
to the face allowing pressurized gas to enter
into upper airway
Nasal
Cone
shaped clear plastic device with soft
cuff
Multiple sizes and shapes
Chronic application
Better tolerated by patients with
claustrophobia
Exert pressure over the bridge of the nose
 Avoided
by
Fore head spacer
o Nasal mask with gel seal
o Mini-masks
o Custom-molded individualized masks
o Thin plastic flap
o Nasal pillows (pledgets directed to the
nostrils)
o
Oronasal ( full face mask)
Preferred
o in acute settings
o for patients with copious air leaking through
the mouth
o For edentulous patients
 Interferes with speech, eating and expectoration
 Increase risk of aspiration, rebreathing
 Increase likelihood of claustrophobic reaction
 Total face mask (hockey goalie‘s mask)

Mouth pieces
Provides NIPPV to patients with chronic
respiratory failure
 Simple inexpensive
 Nasal air leaking decrease its efficacy
o Managed by increasing ventilator‘s tidal
volume
o Occluding nostrils with cotton pledgets or
nose clips

Ventilators for NIPPV
CPAP


Delivers constant pressure during both inspiration and
expiration
Increase functional residual capacity
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•
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•


Improve lung compliance
Open collapsed alveoli
Improve oxygenation
Decrease work of breathing
Decrease left ventricular transmural pressure, ↓ afterload
and ↑COP
Simple, small and cheap portable units are available
Pressure limited ventilators
 PCV
 Delivers
time- cycled preset inspiratory and
expiratory pressures with adjustable I/E ratio
 Permits patient triggering with a back up rate
 PSV
 Assist
spontaneous breathing
 Peak inspiratory and expiratory pressures are
selected
 Close matching with patient‘s spontaneous breathing
 Allow patient to control rate and inspiratory duration
 Portable devices (bilevel devices)
Volume limited ventilators
 Vt
is usually set higher (10→ 15ml/kg )
 Usually set in the A/C mode, RR set
slightly below the patient’s rate
 Portable devices are more convenient,
cheap, have more sophisticated alarm
system, generate high pressure
Proportional assisted ventilation
(PAV)
 Targets
and respond rapidly patient‘s
effort ( inspiratory flow and volume)
 Able to select the proportion of breathing
work that is to be assisted
Negative pressure ventilation
 Intermittently
apply a sub atmospheric
pressure to the chest wall and upper
abdomen
 Efficiency depends on chest wall and
abdomen compliance and surface area
over which negative pressure is applied

E.g.
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•
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Tank ventilator
Cuirass
Wrap
Shell
Iron lung
Rocking belt and pneumobelt (work by displacing
abdominal viscera)
Goals of NIV
Short term (acute)







Relieve symptoms
Reduce work of
breathing
Improve or stabilize gas
exchange
Good patient-ventilator
synchrony
Optimize patient
comfort
Avoid intubation
Minimize risk
Long term (chronic)




Improve sleep duration
and quality
Enhance functional
status
Prolong survival
Maximize quality of life
PROTOCOL FOR INITIATION OF NIV
1.
2.
3.
4.
5.
6.
7.
Appropriately monitored location
Patient in bed or chair sitting at > 30-degree
angle
Select and fit interface
Select ventilator
Apply headgear; avoid excessive strap tension
encourage patient to hold mask
Connect interface to ventilator tubing and turn
on ventilator
8.
9.
10.
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
Gradually increase inspiratory pressure (10 to 20
cm H2O) or tidal volume (10 to 15 ml/kg) as
tolerated to achieve alleviation of dyspnea,
decreased respiratory rate, increased tidal volume
, and good patient-ventilator synchrony
Provide O2 supplementation as needed to keep
O2 sat > 90%
PROTOCOL FOR INITIATION OF NIV
11.
12.
13.
14.
15.
Check for air leaks, readjust straps as needed
Add humidifier as indicated
Consider mild sedation (i.e., intravenously
administered lorazepam 0.5 g) in agitated
patients
Encouragement, reassurance, and frequent
checks and adjustments as needed
Monitor occasional blood gases (within 1 to 2 h
and then as needed)
Monitoring
Subjective responses
o
o
Bed side observation
Ask about discomfort related to the mask or airflow
Physiologic response
o
o
o
o
↓ RR, ↓ HR
Patient breath in synchrony with the ventilator
↓ accessory muscle activity and abdominal paradox
Monitor air leaks and Vt
Gas exchange
o
o
Continuous oximetry
Occasional ABG
Uses of NIV

Respiratory failure
Hypercapnic respiratory failure
 Obstructive
diseases
 Restrictive diseases
Hypoxic respiratory failure
 Acute
pulmonary edema
 Acute pneumonia
 ARDS
 Trauma

Imunocomprimized patients
 Avoid
ETT→ ↓infectious and hemorrhagic
complications

Morbidly obese patients
 used

in obstructive sleep apnea
Do not intubate patients
 ETT
is contraindicated or postpond
 Refuse intubation

Post operative patients
 Avoid
reintubation if RF develops
 Improve gas exchange and pulmonary function

Weaning and extubation
 Before
meeting extubation criteria
Adverse effects and complications of
NIV
Mask related
 Nasal pain
 Nasal bridge erythema and ulceration
Ventilator air flow or pressure complications
 Conjunctival irritation
 Sinus or ear pain
 Nasal or oral dryness
 Nasal congestion or discharge
 Gastric insufflation
Failure of NIV
Mask intolerance
 Failure to improve ventilation
 Claustrophobia
 Sensation of excessive air pressure
 Patient-ventilator asynchrony

MI

Specially with BIPAP
ANY QUESTIONS?
THANK YOU