This document discusses non-invasive ventilation (NIV) including definitions, advantages, indications, contraindications and modes. It describes how NIV can improve gas exchange in respiratory failure by reducing work of breathing. Two main modes are described: CPAP and bi-level ventilation. Key points are that NIV can avoid intubation in acute respiratory failure if the patient is able to protect their airway and is hemodynamically stable. Close monitoring is needed and intubation may be required if the patient does not improve or deteriorates on NIV.

1. Dr Hamed Obeid
Anaesthetist

2.  Definitions
 Advantages and Disadvantages
 Indications
 Contraindications
 Modes

8. “The delivery of mechanical ventilation to the lungs
using techniques that do not require endotracheal
intubation”

9.  Initially used in the treatment of hypoventilation
with Neuromuscular Disease
 Now accepted modality in treatment of acute
respiratory failure

10.  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

11. Failure to maintain adequate gas exchange
 Hypoxic ( Type 1)
or
Hypercapnic /Hypoxic (Type 2)
 Acute /Chronic / Acute on Chronic

12.  Improves alveolar ventilation to reverse
respiratory acidosis and hypercarbia
 Recruits alveoli and increases FRC to reverse
hypoxia
 Reduces work of breathing

14. Noninvasiveness
 Application - easy to implement or remove
 Improves patient comfort
 Reduces the need for sedation
 Oral patency
(preserves speech, swallowing, and cough)

15.  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

16. 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)

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

19.  Hypoxaemia = CPAP
 Hypercapnia and hypoxaemia= Bi Level

20. 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

22.  Acute pulmonary oedema
 Pneumonia

23.  Combination of IPAP and EPAP
Inspiratory PAP = Pressure Support
Expiratory PAP = CPAP

25. • 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

26.  Acute Respiratory Failure
 Chronic Airway Limitation/COPD
 Asthma?

27.  Indication: APO, COAD
 Contraindications excluded
 Assessment
◦ Sick not moribund
◦ Able to protect airway
◦ Conscious/cooperative
◦ Haemodynamic stability
 Premorbid state / Ceiling of therapy?

28. • 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

29.  Hypoxia
 Pulmonary barotrauma
 Reduced cardiac output
 Vomiting and aspiration
 Pressure areas
 Gastric distension

31. • 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

32.  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

33. • 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

34.  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

35. 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

36.  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

37.  Deterioration in condition
 Worsening or non improving ABG
 Intolerance or failure to coordinate with machine

38.  Back to the patient- ABC
 Medical therapy optimised
 Treatment of complications

39. • Inability to tolerate the mask
• Inability to improve gas exchange or dyspnoea
• Need for endotracheal intubation
• Hemodynamic instability
• ECG – ischaemia/arrhythmia

40.  Clinical improvement
 Aim for
◦ RR<24
◦ HR <110
◦ pH>7.35
◦ Sats >90% on <40%

41.  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