Mechanical ventilation

1. Mechanical Ventilation
Dr Satyadeo Choubey
With special credit to
Dr. Rajnish Gupta
Chest Specialist
1

2. • Mechanical ventilation is a method to
mechanically support or replace spontaneous
breaths
• Used in patients who are unable to sustain
the level of ventilation necessary to maintain
the gas exchange functions -oxygenation and
carbon dioxide elimination
• Could be invasive or non-invasive
Introduction
2

3. ● To facilitate CO2 release and maintain normal
PaCO2 (Ventilation)
● To maximize O2 delivery to blood and maintain
PaO2 (Oxygenation)
Primary Goals
3

4. When to Intubate /Ventilate ?
● Acute Ventilatory Failure - pH <7.30, PaCO2 >50 mm Hg
● Impending Ventilatory Failure - Progressive acidosis & hypoventilation
to pH <7.30, PaCO2 >50 mm Hg
- TV < 3-5 ml/kg
- RR > 25 -35/min, laboured or irregular
- MV > 10 L/min
- VC < 15 ml/kg
- Max. Insp. Press. (MIP) < -20 cm H2O
- Vital Signs (rise in HR, BP, use of
accessory muscles, diaphoresis, cyanosis
● Severe Hypoxaemia - PaO2 < 60 mm Hg on FiO2 50% or >,
or PaO2 < 40 mm Hg on any FiO2
● Prophylactic Ventil. Support - Post anaesth. recovery, prologed shock,
head injury , smoke inhalation 4

5. Origins of mechanical ventilation
•Negative-pressure ventilators
(“iron lungs”)
• Non-invasive ventilation first used in
Boston Children’s Hospital in 1928
• Used extensively during polio outbreaks
in 1940s – 1950s
•Positive-pressure ventilators
• Invasive ventilation first used at
Massachusetts General Hospital in 1955
• Now the modern standard of
mechanical ventilation
The iron lung created negative pressure in abdomen
as well as the chest, decreasing cardiac output.
Iron lung polio ward at Rancho Los Amigos
Hospital in 1953. 5

6. Ventilator Settings
• Select mode of ventilation ………
• Set Tidal Volume ………
• Set Respiratory Rate ………
• Set PEEP ………
• Set Inspiratory: Expiratory Ratio ………
• Set FiO2 ………
• Set Alarm Limits ………
• Humidification ………
6

7. Terminology
• Tidal Volume (TV) - Amount of gas delivered with each breath.
(8-10 ml/kg, 6-8 ml/kg in ARDS based on Ideal Body Weight in
kgs)
IBW for Man = 50 + 2.3 (Ht in inches – 60)
IBW for Woman = 45.5 + 2.3 (Ht in inches – 60)
• Minute Ventilation (MV) = TV x Respiratory Rate
• Inspiratory:Expiratory (I:E) Ratio - Normally 1:2 to 1:3
(Inverse Ratio in ARDS)
• Inspiratory Flow - Varies with TV, I:E and RR. Normally about 60
l/min. Can be increased up to 100- 120 l/min in COPD.
7

8. •FiO2 - The usual goal is to use the minimum FiO2
required to have a PaO2 > 60 mm Hg or a sat >90%.
Start at 100% and bring down to avoid oxygen
toxicity.
•Trigger – Refers to initiation of breath on ventilator.
This occurs when a certain amount of time has
elapsed [e.g., 5 seconds if the rate is 12 (60 sec/12
b/m = 5 sec)] or when the patient makes an effort. A
patient’s effort may be sensed as a change in
pressure in the circuit (negative deflection) or as a
change in flow. Flow sensors tend to have a more
rapid response time.
Terminology
8

9. Terminology
• Peak Inspiratory Pressure (PIP)
Pressure used to deliver the tidal volume
by overcoming resistance in airways and
lungs. Should be kept <45 cm H2O to
minimise barotrauma.
• Plateau Pressure
It is the end inspiratory pressure needed
to maintain lung inflation in the absence
of air flow. Should be kept <30 cm H2O to
minimise barotrauma.
• Mean Airway Pressure (MAP)
It is the average pressure in the airway
during the complete Insp.-Exp. Cycle.
Normally < 30 cm H2O.
9

10. Terminology
• Positive End Expiratory Pressure (PEEP)
- PEEP is the amount of pressure remaining
in the lung at the END of the expiratory
phase.
- PEEP keeps collapsing lung units open
and improves oxygenation.
- PEEP diminishes work of breathing
- PEEP can cause barotrauma and diminish
cardiac output.
- Usually kept 5 to 10 cm H2O
10

11. Terminology
• Lung compliance: Is the change in volume per unit change in pressure
Compliance =  Volume /  Pressure
• 2 Types:
Static compliance (CST) - measured when there is no air flow
- CST = Corrected Tidal Volume
Plateau pressure-PEEP
- Normal Value is 40 to 60 ml/cm H2O
- Decreased in Atelectasis, ARDS, Pneumonia,
Obesity, Retained secretion
Dynamic compliance (CDYN) - measured when there is air flow
- CDYN = Corrected Tidal Volume
Peak Inspiratory Pressure-PEEP
- Normal Value is 30 to 40 ml/cm H2O
- Decreased in bronchospasm, kinking of tube, airway
obstruction 11

12. A. Trigger …….
What causes the breath to begin?
----Patient’s effort
B. Limit ……
What regulates gas flow during the breath?
----Volume /Pressure/Time
C. Cycle …….
What causes the breath to end?
----Volume/Pressure/Time/Flow
A
B C
Basic Variables
12

13. Types of Ventilators
A. Volume Cycled
• Delivers a fixed volume that terminates the breath
• Easy to manage and used commonly
B. Pressure Cycled
• Breath terminated by attainment of specific pressure
• Used previously, found difficult to manage
C. Time Cycled
• Inspiratory phase ends when a set time has elapsed
• Used in paediatrics
D. Flow Cycled
• Not commonly used
13

14. Common Modes
 Controlled Mandatory Ventilation (CMV)
 Assist Control (AC)
 Intermittent Mandatory Ventilation (IMV)
 Synchronized Intermittent Mandatory Ventilation (SIMV)
 Pressure Support Ventilation (PSV)
14

15. Controlled mandatory
ventilation(CMV)
The ventilator delivers
 Preset tidal volume (or pressure) at a time triggered
(preset) respiratory rate.
 As the ventilator controls both tidal volume (pressure)
and respiratory rate, the ventilator “controls” the
patients minute volume.
Pressure

16. Controlled mandatory
ventilation(CMV)
Volume
controlled
Pressure
controlled

17. Preset
VTVolume
Cycling
Dependent on
CL &Raw
Time
Flow
(L/m)
Pressure
(cm H2O)
Volume
(mL)
Preset Peak
Flow
Time triggered, Flow limited, Volume cycled Ventilation
Controlled mandatory
ventilation (Volume- Targeted)

18. Flow
(L/min)
Pressure
(cm H2O)
Volume
(ml)
Time (sec)
Set PC
level
Time Triggered, Pressure Limited, Ventilation
Controlled mandatory
ventilation (Pressure-Targeted)

19. Controlled mandatory ventilation
(CMV)
 Patient can not breath spontaneously
 Patient can not change the ventilator
respiratory rate
 Suitable only when patient has no
breathing efforts
 Disease or
 Under heavy sedation and muscle
relaxants

20. Controlled mandatory
ventilation(CMV)
 Asynchrony and increased work of breathing.
 Not suitable for patient who is awake or has own
respiratory efforts
 Can not be used during weaning

21. Assist Control
Ventilation

22. Time
(sec)
Control ventilation
(CMV)
Assist / control
ventilation
Pressure
Contr
ol
Contr
ol
Assist
ed
Assist Control
Ventilation

23. Control ventilation
(CMV)
Assist / control
ventilation
Pressure
Assist Control
Ventilation A set tidal volume (volume control) or a set pressure and time
(pressure
control) is delivered at a minimum rate
 Additional ventilator breaths are given if triggered by the patient
 Mandatory breaths: Ventilator delivers preset volume
and preset flow rate at a set back-up rate
 Spontaneous breaths: Additional cycles can be
triggered by the patient but otherwise are identical to
the mandatory breath.

24. Assist Control
Ventilation
 Tidal volume (VT) of each delivered breath is the
same, whether it is
assisted breath or controlled breath
 Minimum breath rate is guaranteed (controlled
breaths with set VT)
Control ventilation
(CMV)
Assist / control
ventilation
Pressure

25. Assist Control
Ventilation
(volume) Assist
Control
Ventilation
(Pressure) Assist
ControlVentilat
ion

26. Time
Patient / TimeTriggered, Pressure Limited,
Press
ure
Flo
w
Volu
me
Set PC
level
Pt
triggered
Time
triggered
Assist Control Ventilation (Pressure)

27. Patient / Time triggered, Flow limited, Volume
cycled Ventilation
Assist Control Ventilation
(Volume)
Time
(sec)
Flow
Pressure
Volume
Preset
VT
Volume
Cycling

28. Assist Control Ventilation
 Asynchrony taken care of to
some extent
 Low work of breathing, as
every breath is supported and
tidal volume guaranteed
Natural breaths are not allowed
 Hyperventilation
 Respiratory alkalosis.
Control ventilation
(CMV)
Assist / control
ventilation
Pressure

29. Intermittent Mandatory Ventilation
(IMV)
Pressure
 Machine breaths are delivered at a set rate
(volume or pressure limit)
Time
(sec)

30. Intermittent Mandatory Ventilation
(IMV)
Pressure
 Machine breaths are delivered at a set rate (volume or
pressure limit)
 Patient is allowed to breath spontaneously from
either a demand valve or a continuous flow of
gases but not offering any inspiratory assistance.
Time
(sec)

31. Intermittent Mandatory Ventilation
(IMV)
Pressure
 Patient’s capability determines Tidal volume
of spontaneously breaths
 Some freedom to breath naturally even on
mechanical ventilator
Time
(sec)

32. Intermittent Mandatory Ventilation
(IMV)
Pressure
 Random chance of breath stacking and
asynchrony: Increased WOB
 Uncomfortable feeling
Time
(sec)

33. Intermittent Mandatory Ventilation
(IMV)
Pros:
 Freedom for natural
spontaneous
breaths even on machine
 Lesser chances of
hyperventilation
Cons:
 Asynchrony
 Random chance of
breath stacking.
 Increase work of
breathing
 Random high airway pressure
(barotrauma) and lung volume
(volutrauma)
Setting appropriate pressure limit is important to reduce
the risk of barotrauma

34. Can we
synchronize
it?

35. Synchronized Intermittent
Mandatory Ventilation
 Ventilator delivers either patient triggered
assisted breaths or time triggered mandatory
breath in a synchronized fashion so as to avoid
breath stacking
 If the patient breathes between mandatory breaths,
the ventilator will allow the patient to breathe a
normal breath by opening the demand
(inspiratory) valve but not offering any inspiratory
assistance.

36. Synchronization
window
Pressure
 Time interval just prior to time triggering in
which the ventilator is responsive to the
patient’s inspiratory effort.
Time trigerring
Time (sec)

37. SIMVPressure
If the patient makes a spontaneous inspiratory effort that
falls in sync window, the ventilator is patient triggered to
deliver an assisted breath and will count it as mandatory
breath
Patient trigerred
synchronized breath
Time
trigerred
mandatory
breath

38. SIMVPressure
if patient does not make an inspiratory effort then
ventilator will deliver a time triggered mandatory
breath.
Patient trigerred
synchronized breath
Time
trigerred
mandatory
breath

39. Synchronized Intermittent
Mandatory Ventilation
Pressure
3 types of breathing:
1. Patient initiated assisted
ventilation,
2. Ventilator generated controlled
ventilation,
3. Unassisted spontaneous
breath.

40. Synchronized Intermittent
MandatoryVentilation
 It allows patients to assume a portion of their
ventilatory drive: Weaning is possible
 Greater work of breathing than AC ventilation
and therefore some may not consider it as the
initial ventilator mode
 Friendly cardiopulmonary interaction: Negative
inspiratory pressure generated by spontaneous
breathing leads to increased venous return,
which theoretically may help cardiac output and
function

41. Pressure Support Ventilation
 Pressure (or Pressure above PEEP) is the setting
variable
 No mandatorybreaths
 Applicable on Spontaneous breaths: a preset
pressureassist,
 Flow cycling: terminates when flow drops to a
specified fraction (typically 25%) of its
maximum.
 Patient effort determines size of breath and
flowrate.

42. Pressure Support Ventilation
 Pressure (or Pressure above PEEP) is the setting
variable
 No mandatory breaths
 Applicable on Spontaneous breaths: a preset
pressure assist,
 Flow cycling: terminates when flow drops to a
specified fraction (typically
25%) of its maximum.
 Patient effort determines size of
breath and flow rate

43. Pressure Support Ventilation
 Pressure (or Pressure above PEEP) is the setting
variable
 No mandatory breaths
 Applicable on Spontaneous breaths: a preset
pressure assist,
 Flow cycling: terminates when flow drops to a
specified fraction (typically
25%) of its maximum.
 Patient effort determines size of breath
and flow rate.

44. Pressure Support Ventilation
 It augments spontaneous VT decreases spontaneous
rates and WOB
 Used in conjunction with spontaneous breaths in any
mode of ventilation.
 No guarantee of tidal volume with changing
respiratory mechanics,
 No back up ventilation in the event of apnea.

45. Pressure Support Ventilation
 Provides pressure support to overcome the
increased work of breathing
imposed by the disease process, the endotracheal tube, the
inspiratory
valves and other mechanical aspects of
ventilatory support
 Allows for titration of patient effort during
weaning.
 Helpful in assessing extubation readiness

46. SIMV + PS VentilationPressure
Spontaneous breath
with PS

47. Volume Controlled Ventilation
• CMV
• Every breath is fully supported by the
ventilator which ensures that the
patient receives the set tidal volume at
set rate.
• Time triggered, volume limited,
volume cycled
• Assist Control
• Like CMV with a trigger.
• Patient can trigger the ventilator and
his breath is fully supported with a set
volume and flow over and above the set
rate.
• Pressure/ Flow triggered, volume
limited, volume cycled
• CMV & Assist Control are Controlled Modes. The patient CANNOT
generate spontaneous breaths, volumes, or flow rates.
• Ventilator delivers a fixed volume at set rate. Pressure varies
Patient’s Effort
47

48. Volume Controlled Ventilation
• IMV
• Pt receives a set number of ventilator
breaths.
• Pt can initiate own (spontaneous)
breaths. Thus different from Control.
• Spontaneous breaths are not
supported by machine with a fixed TV.
Thus different from Assist.
• Ventilator always delivers breath,
even if pt is exhaling.
• SIMV
• Spontaneous breaths of pt and
mandatory ventilatory breaths are
synchronized.
Patient’s Effort
• IMV & SIMV are Partially Controlled. The patient can have spontaneous
breaths in between the mandatory ventilator breaths.
• Triggered by Pressure/Flow (Assist) or Time (Control), limited and Cycled by Volume48

49. Control Mode
• Every breath is supported
regardless of “trigger”
• Can’t wean by decreasing
rate
SIMV Mode
• Vent tries to synchronize
with pt’s effort
• Patient takes “own” breaths
in between (+/- PS)
Control Mode vs SIMV Mode
49

50. Pressure Controlled Ventilation
A Controlled Mode. No participation by patient
•Parameters
• Triggered by time
• Limited by pressure
• Cycled by time
• Affects inspiration only
•Disadvantage
• Patient may hyoventilate or
hyperventilate
• Requires frequent adjustments
to maintain adequate MV
50

51. Pressure Limited
• Controls oxygenation
(FiO2 and MAP)
• Decelerating flow pattern
(lower PIP for same TV)
• Tidal volume may change
suddenly leading to
hypoventilation or
overexpansion of lung
Volume Limited
• Controls minute
ventilation
• Square wave flow pattern
• PIP may rise to any level
Pressure Limited vs Volume Limited
51

52. Pressure Limited
– Mode (PCV)
– FiO2 (100%)
– Rate (12-16 BPM)
– I-time (Inverse Ratio +/-)
– PEEP (5-10 cmH2O)
– PIP (30-35 cm H2O)
(Tidal Volume & MV Varies)
Volume Limited
– Mode (CMV)
– FiO2 (100%)
– Rate (12-16 BPM)
– Tidal Volume
(8-10 ml/kg; 6-8 ml/kg in
ARDS)
– PEEP (5-10 cmH2O)
– I- time (1:2 to 1:3
(PIP & MAP Varies)
Initial Settings
{Flow /Pressure Trigger is set in A-C Mode} 52

53. Pressure Support Ventilation
• A purely spontaneous mode. Ventilator provides only pressure support.
• Patient determines RR, Minute Ventilation & Inspiratory Time.
• Decreases work of breathing by increasing inspiratory flow that overcomes
the resistance of tubing and helps to generate larger tidal volume
• Parameters
• Triggered by pt’s own breath
• Limited by pressure
• Cycled by flow
• Affects inspiration only
• Uses
• Used with other volume-
cycled modes e.g. SIMV
• Used alone during weaning
now
• Used as BiPAP (CPAP plus PS)
53

54. Advanced Modes
• Pressure Regulated Volume Control (PRVC)
• Inverse Ratio Ventilation (IRV)
• Airway Pressure Release Ventilation
• Volume Assured Pressure Support (VAPS)
• Proportional Assist Ventilation (PAV)
• High Frequency Ventilation
54

55. Advanced Modes
PRVC
• Basically a volume controlled mode (assured MV) with the
benefits of a pressure mode (a lower PIP).
•Delivers a set tidal volume with each breath at the lowest
possible peak pressure. Delivers the breath with a decelerating
flow pattern, that is less injurious.
Inverse Ratio Ventilation
• I:E > 1 used commonly with a Pressure Control Mode
• Can increase MAP without increasing PIP; improves
oxygenation and limits barotrauma
• Risk for air trapping
• Patient will need to be sedated and paralyzed 55

56. Adjunctive Therapies
Prone Positioning
• Re-expands collapsed dorsal areas of the lung
• Heart moves away from the lungs
• Net result is usually improved oxygenation
• Suctioning difficult
Inhaled Nitric Oxide
•Vasodilates blood vessels that supply ventilated alveoli
and thus improve V/Q
• No systemic effects due to rapid inactivation by
binding to hemoglobin
•Does not improve outcome
56

57. Complications
• Ventilator Induced Lung Injury
-Oxygen toxicity
-Barotrauma / Volutrauma
• Cardiovascular Complications
-Impaired venous return to RH
-Bowing of the Interventricular Septum
-Decreased left sided afterload (good)
-Altered right sided afterload
(Cardiac output may decrease)
• Other Complications
-Ventilator Associated Pneumonia
-Sinusitis
-Risks from associated devices (CVLs, A-lines)
-Unplanned Extubation 57

58. Recording and Monitoring
• Consciousness
• Vitals (Pulse, BP, Temperature, RR)
• Oxygen Saturation, ABG, CXR
• Intake/Output Charting
• Ventilator Settings
• Airway Pressures
• Compliance
• Suctioning
• Humidification
• Dates of intubation & catheterisation (CVP, Foley’s)
• Central Venous Pressure, Blood Sugar Monitoring
• Treatment (Drug Chart and RT Feeding Chart) 58

59. Ventilator Chart
59

60. Troubleshooting
• Anxious Patient
• Pain & Discomfort
• Fighting or Asynchrony with Ventilator
• Distress and high RR
• Ventilator alarming
60

61. Troubleshooting
61

62. • Check patency of all connections
• Check circuit leaks, tube position & cuff pressure
• Check vitals, oxygen saturation
• Need to suction / nebulise
• Check if patient biting the tube
• Communicate with patient in order to allay
anxiety, look for cause and assure
• Call a doctor
Troubleshooting
(Assessment & Interventions)
62

63. Troubleshooting
(Assessment & Interventions)
• Assess PIP and Plateau Pressures
• May need to perform a CXR or an ABG
63

64. Troubleshooting
(Assessment & Interventions)
• May need to rule out a VENTILATOR MAL-FUNCTION on a Test
Lung
- Will need to remove pt from ventilator
- Initiate manual ventilation with ambu bag connected to an
oxygen flowmeter with oxygen supply on
- Re-connect on ventilator
• Assess & manage accordingly
• NEVER TRY TO SILENCE THE ALARM
(LOOK FOR THE CAUSE)
64

65. Weaning
Weaning is the gradual withdrawal of
mechanical ventilation
65

66. •Resolution or stabilization of disease process
•Normal ABG on FiO2 of 0.5 (except in COPD)
•Normal electrolytes
•No significant pulmonary infection, pulmonary oedema,
atelectasis or AW obstruction
•Intact cough/gag reflex
•Spontaneous respirations
•Patient alert and cooperative
•Haemodynamically stable & off inotropic support
•No fever, seizures or organ failure
•Nutritional and neuromuscular status needs assessment
Clinical Considerations
66

67. Bedside Weaning Parameters
Numerical Parameters Normal Range Weaning Threshold
PaO2/FiO2 > 400 > 200
Tidal volume 5 - 7 ml/kg 5 ml/kg
Respiratory rate 14 - 18 breaths/min < 40 breaths/min
Vital capacity 65 - 75 ml/kg 10 ml/kg
Minute ventilation 5 - 7 L/min < 10 L/min
Greater Predictive Value Normal Range Weaning Threshold
NIF (Negative
Inspiratory Force)
> - 90 cm H2O (F)
> - 120 cm H2O (M)
> - 25 cm H2O
RSBI (Rapid Shallow
Breathing Index)
RSBI = RR / TV (in litres)
< 50 breaths/min/L <100 br/min/L
FiO2 of 0.5 or < and PEEP of 5cm H2O or <
67

68. Method of Weaning
•Abrupt Withdrawal Method (T-Piece Weaning)
- The inhaled gas is delivered at a high flow rate through T-
piece (preferably with venturi mask)
•Gradual Withdrawal Method (IMV Weaning)
- The number of machine breaths are gradually decreased
over variable time depending upon the patient’s condition
- PS often added to assist spontaneous breathing (to
counter the resistance of ventilator circuit)
- SIMV with PS often used in past for weaning
• Current practice is weaning by PS mode
Note: A Spontaneous Breathing Trial can be given with either T-Piece, CPAP
or PS 68

69. Tracheostomy - Need
•Advantages
• Better clearance of secretions
• Decreases work of breathing
• Continued vocal cord injury avoided
• Helps extubation
•Disadvantages
• Long term risk of tracheal stenosis
• Procedure-related complication rate (4% -
36%)
Prolonged intubation may injure airway and cause airway edema
1 - Vocal cords. 2 - Thyroid cartilage. 3 - Cricoid cartilage. 4 -
Tracheal cartilage. 5 - Balloon cuff.
69

70. Difficult Weaning
Causes Treatment
Anxiety/Agitation Benzodiazepines or haldol
Infection Appropriate antibiotics
Electrolyte abnormalities
(K+, PO4-)
Correction
Pulmonary edema, cardiac
ischemia
Diuretics, nitrates
Under/Overnutrition Appropriate correction
Neuromuscular disease Bronchopulmonary hygiene,
early consideration of trach
Increased intra-abdominal
pressure
Semirecumbent positioning, NGT
Excessive auto-PEEP (COPD,
asthma)
Bronchodilator therapy,
extrinsic PEEP
70

71. Extubation
• Pre-Extubation Preparation
• Check vitals and ABG
• Assure the patient
• Nebulise and do ET & oral suctioning
• Keep prior intubation set, emergency tray, oxygen delivery system and NIV
ready
• Extubation Process
• Bulb deflated and extubation done with simultaneous ET suctioning to
prevent aspiration of secretions above cuff
• Send ET tip for culture
• Post-Extubation Care
• Chest physiotherapy to clear secretions
• Oral hygiene
• Encourage cough
• Watch vitals and ABG
• Use NIV 71

72. Self-Extubation
• Immediately put an oxygen face mask on the patient’s
face and attach with an ambu bag connected to the
oxygen flowmeter with O2 on. Ventilate the patient with
the Ambu bag.
• Try possible conservative measures (Nebulisation,
physiotherapy etc.)
• Use NIV
• Monitor consciousness, vitals, oxygen sat., ABG
(About 50% patients do not require re-intubation)
72

73. 73

74. NON-INVASIVE VENT. (NIV) in Operation
Hose Pipe
BIPAP
Head Gear
Mask
74

75. NIV – Setting
•Choose between a BIPAP (Bi-level Positive Airway Pressure) or a CPAP
(Continous Positive Airway Pressure) non-invasive ventilator
•Set Mode- Spontaneous / Spont.-Timed /Timed
- Patient needs to be conscious in spont. & S/T modes
• Choose interface - Nasal / Facial Masks, Nasal Pillows
- Used in different sizes and materials
- Face mask used in pt. with mouth breathing
•Usually set with IPAP of 8 cms and EPAP of 4 cms with a minimum
difference of 4 cms.
75

76. •IPAP and EPAP increased by 1-2 cm as per requirement. For
hypoxaemia, EPAP and IPAP are increased at a time. For
hypercapnia, IPAP is increased that increases the IPAP-EPAP
gap.
• High pressures can produce air leaks from mouth decreasing
machine effectiveness and tolerance.
•Clinical signs, ABG and pulse oximetry should be monitored
periodically.
•Oxygen supplementation should be given as required.
•Heated humidification should be given to prevent dryness.
NIV Titration
76

77. NIV Chart
77

78. •Inability to maintain O2 saturation around 90 %
•Haemodynamic instability
•Worsened sensorium
•Inability to clear secretions
•Intolerance to device
•Extreme distress or anxiety
Discontinue NIV
78

79. Conclusions
•A patient in respiratory failure should be put on mechanical
ventilator if NIV and other supportive measures fail to
improve the condition.
•Controlled mode (CMV) is used initially, while weaning is
done by Pressure Support mode.
•Regular recording, charting and monitoring of the patient’s
vitals, oxygen saturation and the ventilator (or NIV) settings
helps to detect problems early and prevent complications.
• In all cases of troubleshooting, the doctor should be called
immediately.
79

80. 80