NON IVASIVE VENTILATION

1. Non Invasive Ventilation
When?
Why?
How?
Dr Jay Bhanushali
MD Pulmonary Medicine PGY 1

2. Respiratory Failure
• Respiratory failure is a syndrome in which the respiratory system fails in one or
both of its gas exchange functions: oxygenation and carbon dioxide elimination
• Failure of Pulmonary Gas Exchange to maintain normal Arterial O2 and CO2 levels
Type 1
Hypoxia Pao2 <60mmhg with Fio2 >60%
Type 2
Hypercarbia PaCO2 >45mmhg pH< 7.3

3. DIAPHRAGM
CHEST WALL
ACC RESPIRATORY MUSCLES
ALVEOLAR VENTILATION
DIFFUSION
PERFUSION

6. Selection Criteria for NIV
Acute Respiratory Failure
• Respiratory Distress
- Moderate to severe dypnea
- Use of accessory muscles
- Abdominal paradox
• Respiratory Rate
- >25/min with hypercapnia
- >30/min with hypoxia not corrected by 02 support
• pH< 7.35 and PaCO2 > 45mmhg Respiratory Acidosis
• PaO2< 60mmhg (spo2 90%) PaO2/FiO2 <200 moderate to severe hypoxia

7. Thoracic Restrictive/Cerebral Hypoventilation Diseases
-Fatigue, morning headache, hypersomnolence,nightmares, enuresis, dyspnea
(signs of CO2 retention)
-ABG PaCO2> 45mmhg
-Nocturnal SpO2 <90% for more than 5minutes sustained or 10%of total monitoring
time
-Symptoms and Signs of Cor Pulmonale seen with advance respiratory illness

8. Chronic Respiratory Failure
COPD
- Dyspnea, Fatigue, Somnolence
- ABG shows pH<7.35 PaCO2 > 55mmhg
- PaCO2 50-54mmHg with Oxygen Saturation <88% despite of O2 support
(Chronic Respiratory Acidosis)
Acute Cardiogenic Pulmonary Oedema
- CPAP is effective and should be considered in patients who fail to improve with medical
management alone

9. Benefits of NIV
• Decrease need of mechanical ventilation in appropriately selected patients
• Superior benefits in patients with Neuro muscular Disease, COPD, Pulmonary
oedema, post op respiratory insufficiency.
• Patient can communicate.
• Reduced length of ICU stay and reduced Mortality rates
• Complications related to Catheters
• Avoid invasive Ventilation related complications such as VAP, Upper Airway
trauma, post intubation tracheal stenosis
• Ceiling treatment in patients where invasive ventilation is not suitable /palliative
support
• Bridge treatment while patient awaiting lung transplant

10. Goals of NIV
• Reduce WOB
• Improve ABG
• Optimize patient comfort
• Avoid intubation
• Long term: Prolong survival, improve sleep, Maximize Quality of life, improve
Functional status

11. Contraindications
• NIV is not an alternative for Invasive Ventilation, decision for invasive ventilation
must not be delayed eg: Severe Asthma
• Poor GCS
• Severe hypoxia
• Facial trauma
• Bowel obstruction, upper GI surgery
• Hemodynamic Instability
• Uncooperative patient
• Cardio Respiratory Arrest

12. Problems with NIV
• Skin damage due to pressure ulcers in prolonged continuous use
• Air leak causing eye irritation.
• Claustrophobia, Aerophagia
• Requires continuous monitoring

13. Available Modalities of NIV
• High Flow Nasal Canula
- Heated humidified oxygen at high concentrations such that it flushes out a significant amount of
non oxygenated air from the upper airway. (Decreases Anatomical Dead Space and improves
alveolar
- Enhanced comfort, increased humidification of secretions to facilitate expectoration, washout of
nasopharyngeal dead space to improve efficiency of ventilation, provision of a small positive
airway pressure effect
- Similar efficacy rates compared to NIV Bi-level in Hypoxaemic non hypercarbic respiratory failure
patients in avoiding Intubation. Significant improvement in 90 day mortality compared to patients
who received other modalities.

14. Bi level PAP
• Positive pressure ventilation via a sealed face mask. It delivers 2 different airway
pressures while inspiration and expiration thus reducing the work of breathing.
• IPAP – EPAP = drive pressure (determinant of ventilation)
• Titrate IPAP upwards for adequate Vt and Minute ventilation
• BiPAP useful in COPD exacerbation, Weaning off Ventilator, Neuromuscular disorders

15. Continuous PAP
• Prevents alveolar collapse during expiration
• Initial setting to start : 5cm H20
• Titrated upwards with increments of 3cm H20 until hypoxia resolves or upto 10-
15cm H20
• CPAP can cause increase in CO2 retention if patient has weak expiratory effort.
• CPAP is useful in OSA and Pulmonary edema.

18. NIV Setting up
• Explaination and Preparation
- Explain the procedure
- Reassure
- Semi recurrent position 30-45 degrees
- propped up
• Mask Application
- Appropriate Size mask : Nasal Bridge to Chin
- Hold the mask over the patient’s face till patient is comfortable before tightening the straps
- Masks may be vented or nonvented; non-vented masks fixed tightly to the patient are utilized with a
device which has an exhalation valve, permitting release of carbon dioxide without (open)
exhalation ports.

19. • Pressurization
- Start with low settings
- IPAP 8cm H2o
- EPAP 4cm H20
- 02 at 2liters per minute
- Increase EPAP and IPAP in same proportion to maintain drive pressure
(minimum difference: 4cm of H20)
- Increase EPAP by 2 cm H20 till patient triggers the ventilator in all his inspiratory efforts
- Now start increasing IPAP further in increments of 2cm of H20 upto Maximum pressure that
can be tolerated by the patient without discomfort or 20mmhg whichever is higher
- Titrate IPAP to reach Goal of RR<25/min , Vt> 6ml/kg
- Check for leaks
- Increase o2 if hypoxia is persistent

20. • NEVER FORCE PATIENT TO USE THE DEVICE AGAINST THEIR WILL

21. Monitoring
• RR will reduce if NIV is effective (RR<25)
• Heart Rate
• Blood Pressure
• Abdominal Paradox
• Improvement of neurological status
• ABG to monitor adequate gas exchange @1hr and 4hr
• Continuous in 1st 24 hours
• Discontinue if no clinical improvement in 30 mins

23. BiPAP algorithm

30. Thank you
• References
-BTS guidelines
-ACS guidelines
-Oxford Handbook of respiratory medicine
-Washington manual of medical therapeutics
-Fishman’s principles of respiratory diseases
-images from internet