1. Non-InvasiveNon-Invasive
VentilationVentilation
Dr Duncan MitchellDr Duncan Mitchell
Ealing HospitalEaling Hospital

2. What we are going to cover…What we are going to cover…
 What is NIV?What is NIV?
 Ventilation Physiology & TerminologyVentilation Physiology & Terminology
 Types of NIVTypes of NIV
 Indications for NIVIndications for NIV
 Contra-indicationsContra-indications
 Case examplesCase examples

3. What is Non-InvasiveWhat is Non-Invasive
Ventilation (NIV)Ventilation (NIV)
‘‘Delivery of ventilatory support without theDelivery of ventilatory support without the
need for an invasive artificial airway’need for an invasive artificial airway’

4. SomeSome
Physiology…….zzzzzzz!Physiology…….zzzzzzz!
 VentilationVentilation
- process by which O2 and CO2 are- process by which O2 and CO2 are
transported to and from the lungstransported to and from the lungs
 Venous bloodVenous blood
- lower pO2 higher pCO2 than inspired- lower pO2 higher pCO2 than inspired
gasgas
- partial pressure gradient driving O2 in- partial pressure gradient driving O2 in
and CO2 outand CO2 out

5.  Ventilation of lungs with inspired gasesVentilation of lungs with inspired gases
leads to mixing with alveolar gasleads to mixing with alveolar gas
 If no ventilation at all, no replenishmentIf no ventilation at all, no replenishment
of O2 and no removal of CO2of O2 and no removal of CO2
 Arterial pO2 falls and pCO2 risesArterial pO2 falls and pCO2 rises
towards that of venoustowards that of venous
 If ventilation greater than needed,If ventilation greater than needed,
alveolar gas closer to inspired gasalveolar gas closer to inspired gas

6. TerminologyTerminology
 Tidal Volume (VT) – amount of gas expiredTidal Volume (VT) – amount of gas expired
per breath (~ 500ml at rest)per breath (~ 500ml at rest)
 Minute Volume – amount of expired gas perMinute Volume – amount of expired gas per
minuteminute
 Alveolar Ventilation – amount of gas reachingAlveolar Ventilation – amount of gas reaching
functional alveolifunctional alveoli
 Work of Breathing – usually ~5% of total bodyWork of Breathing – usually ~5% of total body
work – most used to overcome lung and chestwork – most used to overcome lung and chest
wall stiffness during inspirationwall stiffness during inspiration

7.  PEEPPEEP
 Pressure Support (cmH2O) – positivePressure Support (cmH2O) – positive
pressure applied to airway to supportpressure applied to airway to support
patients own breathpatients own breath
 Opening Pressure – pressure requiredOpening Pressure – pressure required
to open collapsed alveolito open collapsed alveoli

8. Types of NIVTypes of NIV
 Negative-Pressure Ventilation (IronNegative-Pressure Ventilation (Iron
Lung)Lung)
 Continuous Positive Airway PressureContinuous Positive Airway Pressure
(CPAP) (Not really NIV!)(CPAP) (Not really NIV!)
 Bi-level Positive Airway PressureBi-level Positive Airway Pressure
(BiPAP)(BiPAP)

9. Negative-Pressure VentilationNegative-Pressure Ventilation
 Late 1880s – iron lungsLate 1880s – iron lungs
first usedfirst used
 Early 1900s – iron lungsEarly 1900s – iron lungs
used for polio epidemicsused for polio epidemics
 This continuedThis continued
throughout the 20throughout the 20thth
century until 1960s whencentury until 1960s when
invasive ventilationinvasive ventilation
became availablebecame available

10. CPAPCPAP
 Nasal or face maskNasal or face mask
 Continuous positive pressureContinuous positive pressure
applied to the airwaysapplied to the airways
 Usually well-toleratedUsually well-tolerated
 Similar to use of PEEPSimilar to use of PEEP
 Reduces work of breathingReduces work of breathing
 Improve ventilation toImprove ventilation to
collapsed areas of lungcollapsed areas of lung

11. BiPAPBiPAP
 Bi-Level pressure supportBi-Level pressure support
 Inspiratory Positive Airway Pressure (IPAP) &Inspiratory Positive Airway Pressure (IPAP) &
Expiratory PAP (EPAP)Expiratory PAP (EPAP)
 IPAP is the pressure support machine givesIPAP is the pressure support machine gives
to help patients own inspirationto help patients own inspiration
 Helps to reduce WOB and increase alveolarHelps to reduce WOB and increase alveolar
ventilationventilation
 EPAP is essentially PEEP and help toEPAP is essentially PEEP and help to
prevent alveolar collapseprevent alveolar collapse

12. Indications for CPAPIndications for CPAP
 Cardiogenic Pulmonary OedemaCardiogenic Pulmonary Oedema
 Obstructive Sleep ApnoeaObstructive Sleep Apnoea
 Chest Wall Trauma if hypoxic onChest Wall Trauma if hypoxic on
adequate analgesiaadequate analgesia
 PneumoniaPneumonia

13. Indications for BiPAPIndications for BiPAP
 Exacerbation of COPD with RespiratoryExacerbation of COPD with Respiratory
acidosisacidosis
 Type II respiratory failure with chest wallType II respiratory failure with chest wall
deformity or neuromuscular diseasedeformity or neuromuscular disease
 Failure of CPAPFailure of CPAP
 Pneumonia with respiratory acidosisPneumonia with respiratory acidosis
 Therapeutic trial with a view to intubation if itTherapeutic trial with a view to intubation if it
failsfails
 Others (ARDS, post-op respiratory failure, toOthers (ARDS, post-op respiratory failure, to
buy time prior to intubation)buy time prior to intubation)

14. Patient SelectionPatient Selection
 Sick but not moribundSick but not moribund
 Able to protect airwayAble to protect airway
 Conscious and co-operativeConscious and co-operative
 Haemodynamically stableHaemodynamically stable
 No excessive secretionsNo excessive secretions
 Few co-morbiditiesFew co-morbidities
 Improvement on ABG with NIVImprovement on ABG with NIV

15. Patient RejectionPatient Rejection
 Respiratory arrestRespiratory arrest
 Haemodynamically unstableHaemodynamically unstable
 UncooperativeUncooperative
 Unable to protect airway (swallowing andUnable to protect airway (swallowing and
cough impaired or vomiting)cough impaired or vomiting)
 Facial, oesophageal, or gastric surgeryFacial, oesophageal, or gastric surgery
 Craniofacial trauma or burnsCraniofacial trauma or burns
 Airway obstructionAirway obstruction
 Undrained PneumothoraxUndrained Pneumothorax

16. Case 1Case 1
 76yr old female76yr old female
 Lifelong smokerLifelong smoker
 1/52 productive cough1/52 productive cough
 BP140/90 P120 RR40 SaO2 89% on 10LBP140/90 P120 RR40 SaO2 89% on 10L
pHpH 7.37.3
pCO2pCO2 8.28.2
pO2pO2 6.96.9
HCO3HCO3 2020
BEBE – 4.2– 4.2

17. Case 2Case 2
 83yr old man83yr old man
 Known IHD, previous MIKnown IHD, previous MI
 Wife says he has “not been well”Wife says he has “not been well”
 BP170/95 P120 RR38 SaO2 87% on 15LBP170/95 P120 RR38 SaO2 87% on 15L
pHpH 7.287.28
pCO2pCO2 5.25.2
pO2pO2 7.17.1
HCO3HCO3 2121
BEBE -3.2-3.2

18. Case 3Case 3
 49yr old man49yr old man
 2/52 Hx of feeling unwell with D&V2/52 Hx of feeling unwell with D&V
 Not eating or drinkingNot eating or drinking
 Not passing urineNot passing urine
 BP89/50 P130 RR40 SaO2 96% on NRBMBP89/50 P130 RR40 SaO2 96% on NRBM
pHpH 6.986.98
pCO2pCO2 2.92.9
pO2pO2 14.214.2
HCO3HCO3 13.913.9
BEBE -21.4-21.4

19. Case 3 Contd….Case 3 Contd….
 UreaUrea 3232
 CreatCreat 444444
 KK 6.26.2
 HbHb 9.29.2
 WCCWCC 2424
 PLTPLT 4747
 PTPT 2020
 APTTAPTT 100100

20. Case 4Case 4
 50yr old man50yr old man
 On the wardOn the ward
 Nurses report that he snores a lotNurses report that he snores a lot
 Wife tells you he has seen a specialistWife tells you he has seen a specialist
and has a machine at home that makesand has a machine at home that makes
a lot of noisea lot of noise
 What is it ???!!!What is it ???!!!

21. SummarySummary
 What NIV is and the different typesWhat NIV is and the different types
 Basic respiratory physiologyBasic respiratory physiology
 Indications for NIVIndications for NIV
 When not to use itWhen not to use it
 Thought about some casesThought about some cases

22. Any Questions?Any Questions?
??