This document provides an overview of non-invasive ventilation. It discusses the history and development of respiratory support and mechanical ventilation. The objectives, definitions, theories, effects, advantages, disadvantages, indications, contraindications, modes, settings, monitoring, documentation, treatment failure criteria and discontinuation criteria of non-invasive ventilation are described. Key points include that non-invasive ventilation can avoid intubation for certain patients with acute respiratory failure from conditions like heart failure or COPD exacerbation. Close monitoring is required and intubation may still be necessary if the patient does not improve or their condition deteriorates.

1. NON-INVASIVE
VENTILATION
Manish Masih
Critical Care Therapist (B.Sc.)
DHR

2. History
 Respiratory and mechanical ventilation – most important aspect
of patient care existing today.
 In ACLS and BLS, the ABCs are drilled into your mind.
 Respiratory is 2/3rd
of the ABCs (airway and breathing). Even in the
bible, the significance of the airway is discussed. Genesis 2:7(kjv)
 Pracelsus (1493-1541) – 1st
MV – placed a tube into a patient’s
mouth and vented the patient with fireplace bellows.
 Andreas Vesalius (1514-1564) was the 1st
person to have placed a
reed or cannula into trachea of an animal and blow into it.
 Rocking bed was laid during the early 1930s by Eve,
 Polio epidemic of the 1950s- brought on the rapid advancement
of negative Pr Vent.

3. Objectives:
 Definitions
 Advantages and Disadvantages
 Indications
 Contraindications
 Modes

4. Non-invasive ventilation
“The delivery of mechanical ventilation to the lungs
using techniques that do not require endotracheal
intubation”

5. Background
 Initially used in the treatment of hypoventilation with
Neuromuscular Disease
 Now accepted modality in treatment of acute respiratory
failure

6. theories
 One postulates that NIV rests chronically fatiguedrespiratory
muscles, thereby improving daytime respiratory muscle
function.
 A second theory proposes that NIV improves respiratory system
compliance by reversing microatelectasis of the lung, thereby
diminishing daytime work of breathing.
 A third theory proposes that NIV lowers the respiratory center
“set point” for CO2 by reversing chronic hypoventilation

7. Respiratory mechanics
 Respiratory effort required for inspiration needs to overcome
 Elastic work (stretch)
 Flow resistance work ( airway obstruction)
 Respiratory failure – forces opposing inspiration exceed
respiratory muscle effort

8. Respiratory failure
Failure to maintain adequate gas exchange
 Hypoxic ( Type 1)
or
Hypercapnic /Hypoxic (Type 2)
 Acute /Chronic / Acute on Chronic

9. Effects of NIV
 Improves alveolar ventilation to reverse respiratory acidosis
and hypercarbia
 Recruits alveoli and increases FRC to reverse hypoxia
 Reduces work of breathing
 reducing shunt and enhancing ventilation–perfusion ratios in
certain forms of respiratory failure

11. Advantages
Non-invasiveness
 Application - easy to implement or remove
 it avoids the complications of invasive ventilation
 leaves the upper airway intact, preserves airway defense mechanisms, and
allows patients to eat, drink, verbalize, and expectorate secretions.
 complications have been lumped into three main categories:
 complications related to insertion of the tube and mechanical ventilation,
 Those caused by loss of airway defense mechanisms, and
 those that occur after removal of the endotracheal tub
 Improves patient comfort
 Reduces the need for sedation
 Oral patency
(preserves speech, swallowing, and cough)

12. Advantages 2
 Avoid the resistive work of ETT
 Avoids the complications of ETT
 Early (local trauma, aspiration)
 Late (injury to the the hypopharynx, larynx, and trachea,
nosocomial infections)
 Reduced Cost and Length of Stay

13. Disadvantages
1.System
Slower correction of gas exchange abnormalities
Gastric distension (occurs in <2% patients)
2.Mask
Air leakage
Eye irritation
Facial skin necrosis (most common complication)

14. Disadvantages
3.Lack of airway access and protection
Suctioning of secretions
Aspiration
4. Compliance / claustrophobia
5. Work load and supervision

15. Which mode?
 Hypoxaemia = CPAP
 Hypercapnia and hypoxaemia= Bi Level

16. CPAP
CONTINUOUS POSITIVE AIRWAY PRESSURE (AKA
PEEP)
 Constant positive airway pressure throughout
cycle
 Improves oxygenation
 Decreases work of breathing by alveolar
recruitment (Dec elastic work) and unloads insp
muscles
 Decreases hypoxia by alveolar recruitment and
reduces intrapulmonary shunt

17. Indications
 Acute pulmonary oedema
 Pneumonia

18. Bi-level Pressure Support
 Combination of IPAP and EPAP
Inspiratory PAP = Pressure Support
Expiratory PAP = CPAP

19. Respiratory Effects Bi-PAP
 EPAP
 Provides PEEP
 Increases Functional Residual Capacity
 Reduces FiO2 required to optimise SaO2
 IPAP
 Decreases work of breathing + oxygen demand
 Increases spontaneous tidal volume
 Decreases spontaneous respiratory rate

20. Indications for Bi Level
 Acute Respiratory Failure
 Chronic Airway Limitation/COPD
 Asthma?
 Respiratory failure in immunocompromised patients
 End-of-life care and DNI orders

21. When to use NIV/CPAP
 Indication: APO, COAD
 Two or more of the following should be present:
• Use of accessory muscles
• Paradoxical breathing
• Respiratory rate ≥25 breaths/min
• Moderate to severe dyspnea (increased dyspnea in COPD
patients)
• PaCO2 >45 mm Hg with pH <7.35
• PaO2/FIO2 ratio <200
 Assessment
 Sick not moribund
 Able to protect airway
 Conscious/cooperative
 Haemodynamic stability
 Premorbid state / Ceiling of therapy?

22. Contraindications
 Impaired consciousness, confusion, agitation
 Inability to protect airway
 Excessive secretions or vomiting
 Haemodynamic instability
 Untreated pneumothorax
 Bowel obstruction
 Facial trauma, burns, recent surgery
 Fixed upper airway obstruction

23. Complications
 Hypoxia
 Pulmonary barotrauma
 Reduced cardiac output
 Vomiting and aspiration
 Pressure areas
 Gastric distension

25. Ventilator Settings- LVF
 CPAP at 5-8 and increase to 10-15 cm H20
 Mask is held gently on patient’s face.
 Increase the pressures until adequate Vt (7ml/kg), RR<25/min,
and patient comfortable.
 Titrate FiO2 to achieve SpO2>90%.
 Keep peak pressure <25-30 cm

26. COAD exacerbation: NIV
 increases pH, reduces PaCO2, reduces the severity of
breathlessness in first 4 h of treatment
 decreases the length of hospital stay
 mortality and intubation rates are reduced

27. Ventilator settings COAD
 Mode- Spontaneous/Timed
 EPAP- 4-5 cm H20 IPAP- 12- 15 cm H20
 Trigger- maximum sensitivity
 Back up rate- 15 breaths/min
 Back up I:E 1:3

28. Setting It Up
 No contraindications
 O2 medical therapy underway
 Explanation and reassurance
 Correct mask size
 Ventilator set up
 Commence NIV hold mask in place
 Reassure and fix mask
 Monitor and observe, regular assessment

29. Monitoring response
Physiological
a) Continuous oximetry
b) Exhaled tidal volume
c) ABG- Initial, 1, 2-6 hrs
Objective
a) Respiratory rate
b) Chest wall movement
c) Coordination of respiratory effort with NIV
d) Accessory muscle use
e) HR and BP
f) Mental state
Subjective
a) Dyspnoea
b) Comfort

30. Documentation
 Mode of ventilation
 Flow rate of oxygen, percentage of oxygen
 TPR and BP
 Respiratory assessment
 Conscious level (GCS)
Obs - 15 minutely for first hour, then hourly if condition stable

31. Treatment Failure
 Deterioration in condition
 Worsening or non improving ABG
 Intolerance or failure to coordinate with machine

32. Treatment Failure
 Back to the patient- ABC
 Medical therapy optimised
 Treatment of complications

33. Criteria to discontinue NIV
 Inability to tolerate the mask
 Inability to improve gas exchange or
dyspnoea
 Need for endotracheal intubation
 Hemodynamic instability
 ECG – ischaemia/arrhythmia

34. Withdrawal of NIV
 Clinical improvement
 Aim for
 RR<24
 HR <110
 pH>7.35
 Sats >90% on <40%

35. Most important Ps
 Selection of patient really vital to success - need to have reversible
pathology
 Aim for gradual improvement over hours with good supportive
nursing
 In ED, main use is to avoid intubation / ventilation in LVF and COAD

36. Any ?