Non-invasive ventilation (NIV) is an effective treatment for acute respiratory failure, particularly in conditions like acute exacerbations of COPD and acute cardiogenic pulmonary edema, offering benefits such as improved oxygenation and reduced need for intubation. Different NIV types (CPAP, BiPAP, and HFNC) are recommended for specific conditions, but factors like patient cooperation and mask fit are crucial for success. However, NIV is not recommended for certain patient groups, such as those with altered mental status or rapidly progressive neuromuscular diseases, and its efficacy should be evaluated quickly after initiation.

1. NIV in Acute
Respiratory Failure
PR Waheed Shouman
Chest Department
Zagazig University
Egypt

2.  NIV ventilators:
1-ICU ventilators
2-Dedicated NIV
 NIV Types:
1-CPAP
2-BIPAP
3-HFNC

3.  CPAP is effective in hypoxemic ARF
 BIPAP is effective in both hypoxemic
and Hypercapnic ARF
 HFNC is used in hypoxemic ARF but may
be helpful in hypercapnic type
Narendra et al 2017

4. Mechanism of HFNC:
1. Correction of hypoxemia by O2 supply
2. Dead space washout
3. Small level of positive airway pressure
4. ??????????
Narendra et al 2017

5.  NIV decrease WOB (~60%)through:
1. Counteract intrinsic PEEP
2. Decrease patient contribution to transpulmonary
pressure generation
3. Overcome atelectasis
4. Decrease O2 by respiratory muscles
Leading to:
1. Improved V/Q
2. Improved oxygenation
3. Improved CO2 removal Narendra et al 2017

6. NIV
 Leaks are the main problem of NIV
 Dedicated NIV machines are better than ICU
ventilators as regard synchrony
 It should be evaluated for efficacy within one hour
of initiation
Carteaux et al 2012

7. NIV masks
 Nasal mask
 Nasal pillows
 Oronasal mask
 Full face mask
 Helmet

8. NIV settings
CPAP:
 Start by 5 cm H2O go up by 2 every 15 minutes to
target except in ACPE start high: 10-12 cm H2O as
most studies did that
 Initial FIO2 40-100% then titrate
BIPAP
 EPAP 5-8 cm H2O
 PS 7-10 (IPAP 12-15)
 PIP not more than 20-25 (that of lower esophageal
sphincter that is lower in critically ill)

9. NIV settings
 Expiratory trigger of ~40 in AECOPD and ~ 5-25%
in restrictive lung disease e.g. ACPE
 Better inspiratory flow triggering
 Conscious sedation may help in synchrony
without affecting outcome
 Use either sedation or analgesia not combined
Bello et al 2016

10. Avoid NIV
 Seizures
 Inability to clear secretions or protect airways
 Hemodynamic instability
 Upper airway obstruction
 Severe Upper GIT bleeding
 Recent gastroesophageal surgery
 Recent facial surgery, trauma or burn
 Deformity preventing fit mask
 Undrained pneumothorax
 Vomiting Bello et al 2016

11. Indications of NIV
Level 1:
1. AECOPD
2. ACPE
3. Facilitate weaning in AECOPD
4. Immunocompromised
Nava and Hill 2009

12. Indications of NIV
Level 2:
1. DO not intubate patients
2. Extubation failure
3. CAP
4. Perioperative ARF
5. Prevent ARF in AEBA
Nava and Hill 2009

13.  33% of hospitalized patients die although of
appropriate treatment
 NIV is one of the most effective treatment to
improve outcome in these patients
 NIV spare life of one of each 4 patients
hospitalized with AECOPD
COPD

14.  Most evidence is derived from studies
using BIPAP
 BIPAP should be started early in these
patients
 It is helpful even with patients with pH
less than 7.35
Narendra et al 2017
COPD

15. NIV failure in COPD
 Lower pH (less than 7.25)
 Greater disease severity (APACHE II)
 Asynchrony
 Greater leak
 Slow correction of hypercapnia in 1-4 hours
Bello et al 2016

16. AE of Non COPD Hypercapnic ARF
 OSA and OHV are better than COPD
 Non-COPD respond better than COPD in worse
acidosis
 Effective in slowly progressive NMD as Duchenne
dystrophy and ALS
 Ineffective in rapidly progressive NMD as MG,
GBS, and inflammatory neuropathies
Gregoretti et al 2015

17. Acute Exacerbation of Cardiogenic
Pulmonary Edema (ACPE)
 In-hospital death ~12%
 NIV spared intubation in one of each 8
patients
 NIV decrease LV afterload
 NIV Decrease preload (venous return)
 NIV helps Redistribution of lung water
 Recruit collapse alveoli
Narendra et al 2017

18. ACPE
 Previously, it was considered that only CPAP
carries better prognosis
 Previously, BIPAP was considered as having high
death rate due to aggravated cardiac ischemia
 Now, Both carry the same good response
(evidence-based)
 ACPE with hypercapnia have better prognosis
with BIPAP
Narendra et al 2017

19. NIV failure in ACPE
 Higher class Killip classification
 Lower LVEF
 Higher BNP
 More positive fluid balance in the 1st 24 h
Luo et al 2017

20. Immunocompromised patients
 Patients with hematologic malignancies have
similar outcome with both NIV and IMV
 50% success rate
 Conclusion : try it

21. Altered Mental status
 Consensus report : do not use in GSC less than 8
(can’t protect airways)
 But in large study of 958 patients : no change in
rate of intubation between patients with GCS <8
or >8
 NIV best results are in patients with altered
mental status due to AECOPD

22. NIV in perioperative settings
 Prevent or treat ARF
 Reduce pneumonia
 Prevent or treat atelectasis
 Decrease reintubation
 Decrease overall mortality
 Helpful in all (cardiac, thoracic and abdominal
surgeries)

23. Trauma Patients
 NIV decrease intubation rate, LOS and
complications
 No set standard criteria
 Not to be used when patients need IMV
 Conclusion: Further studies are needed
Hua and Shah 2014

24. Pneumonia
 NIV may help in some patients
 Mixed results
 Better in less severe cases
 No improved mortality
 Predictors of NIV in Pneumonia:
1. Anemia
2. Need for vasopressors
3. Development of ARDS
As a guidelines : not recommended

25. Bronchial asthma
 No early studies demonstrated improvement
 No controlled study of NIV in BA
 No improved mortality or morbidity in asthma
patients
 2012 Cochrane review concluded that NIV in BA is
controversial
 Small studies concluded: NO harm , No benefit
 Not recommended as primary treatment choice

26. ARDS
 Failure rate 50% with more mortality in failed
cases
 Conclusion: Don’t use it

27. NIV failure in hypoxemic ARF
 Higher severity score (APACHE II)
 Age more than 40
 ARDS, Pneumonia
 Failure to improve O2 in one hour
 Higher RR under NIV
 Need for vasopressors
 Need for renal replacement therapy
Bello et al 2016

28. Take home message
 NIV use :
COPD: Sure
OSA OHS: Sure
ACPE: Sure
Slow NMD: Sure
Postoperative: Preferred
Trauma: Try (need research)
Altered mentality : May be Yes (need research)
Pneumonia: May be No (need research)
Br Asthma: No (need research)
ARDS: No (Research may fail)
Rapid NMD: No