Oxygenation. Anaesthesia,apneic thrive

1. Oxygenation –
Peri intubation, Apnoeic,
THRIVE
Dr Mahima Lakhanpal
Assistant Professor
Santosh Medical College

2. PREOXYGENATION

3. Preoxygenation
 Administration of Oxygen prior to induction of
Anaesthesia.
 To increase the oxygen reserve.
 Thereby delay the onset of arterial
oxyhemoglobin desauration during apnea.

4. Preoxygenation Goals
 Achieve 100% oxygenation saturation prior to
procedure.
 Denitrogenate the residual capacity of the lung,
maximizing oxygen storage.
 Denitrogenate and maximally oxygenate the
bloodstream.
 Thus prolong SAFE APNEA TIME

6. Whole
body
FRC
Blood
Tissue

8. Pregnancy
Pregnancy

9.  “Preoxygenation before intubating management
of the difficult airway” added by ASA Task Force
on Management of the Difficult Airway in 2003.
 Cannot Intubate Cannot Ventilate largely
unpredictable.
 Routine preoxygenation has become a new
minimum standard of care.
 Preoxygenation before tracheal extubation is vital
- added in 2012 guidelines by Difficult Airway
Society.

10. Techniques Of
Preoxygenation
 A) Tidal Volume Breathing
- For 3 min
- Flow rate as low as 5L/min is effective.
- Increasing FGF from 5- 10 L/min has little effect.
 B) Deep Breathing
- 4 Deep Breaths in 0.5 min
- 8 Deep Breaths in 1 min
- Extended Deep Breathing (12, 16 breaths)
- Single Vital capacity breath.

11. Comparison of Tidal Volume or Deep Breathing
technique

12.  C) Preoxygenation and an Additional
Maneuver
- CPAP
- O2 insufflation
- BiPAP

13. Steps for Proper
Preoxygenation
 Anaesthesia circuit flushed by high O2 flow.
 Non leaking face mask used to avoid air
entrainment.
 An O2 flow of 5L/min for TVB and 10L/min for
deep breathing.
 Can be improved by putting the patient in
30ᴼ - 45ᴼ head up position. (FRC increases)

14. Clinical End Points of
Preoxygenation
 Movement of reservoir bag in and out with
inhalation and exhalation.
 Presence of normal capnogram and end tidal
CO2.
 End tidal O2 Conc (EtO2) > 90% (lung contain
>2000 ml of O2 i.e 8-10 times VO2).
 End tidal N2 Conc (EtN2) - 5%.

16. Breathing Systems for
Preoxygenation
 Mapelson A
 Mapelson D
 Circle system
 NasOral system
 Mapelson A & Circle system- O2 flow 5 L/min For TVB.
 Mapelson D – O2 flow 10 L/min for TVB.
 Irrespective of anaesthesia circuit – 10 L/min for DB

17. NasOral System

18. Factors Affecting Efficacy Of
Preoxygenation
 Inspired O2 concentration
- Leak
- System used
- FGF, types of breathing (TVB or DB)
 Duration of Breathing
 VA/FRC

19. Factors Affecting Efficiency Of
Preoxygenation
 Capacity of O2 Loading
- PAO2 and FRC
- Arterial O2 content (CaO2)
- Cardiac Output (CO)
 Oxygen Consumption (Vo2)

20. APNEIC
OXYGENATION

21. APNEIC OXYGENATION
 Persistant oxygenation in absence of ventilation.
(Aventilatory Mass Flow – AVMF)
 First described in 1956 Holmdahl during
bronchoscopies.
 Apneic oxygenation in conjunction with traditional
preoxygenation techniques can extend the
SAFE APNEA PERIOD.

22. Physiology of Apneic
Oxygenation

23. Physiology of Apneic
Oxygenation
 O2 diffuses to the capillary blood with 250 mL/min rate.
 During apnea, CO2 production does not change, but
elimination is almost paused.
 Diffusion slows down to only 10-20 mL/min .
 As a result of this negative pressure gradient, a mass flow of
gas from pharynx to alveoli occur.
 CO2 levels keep increasing.
 This causes a decrease in pH and respiratory acidosis.

24. Methods of Apneic Oxygenation
 1) Nasal Prongs
 (Low flow nasal Oxygen – NO DESAT i.e Nasal
Oxygenation During Efforts Securing a Tube)
 Flow 5-15 L/min
 FiO2 of 24%- 44 %

25. Methods of Apneic Oxygenation
 2) Nasopharyngeal Catheter
Naso-Flo nasopharyngeal airway in mannequin’s right naris.
Arrow indicates oxygen insufflation port of the Naso-Flo airway
connected to auxiliary oxygen tubing

26. Methods of Apneic Oxygenation
 3) Buccal Oxygen Insufflation
Modified 3.5 mm Ring-Adair-Elwyn (RAE) tube for
insufflation of buccal oxygen. Image from left to
right demonstrates: intact RAE tube; connector
removed from tube and distal end cut above the
Murphy eye; modified RAE tube with oxygen tubing
attached to cut end.

27. Methods of Apneic Oxygenation
 4) Laryngeal Oxygen Insufflation
Dual use laryngoscope blade
with am internal lumen within the
blade that allow for laryngeal O2
insufflation.
Adapted macintosh laryngoscope
blade for laryngeal oxygen
insufflation. A 14 fr suction catheter is
secured to the blade. Proximal end of
the catheter is connected to
secondary oxygen tubing.

28. Methods of Apneic Oxygenation
 5) Nasal Continuous Positive Airway Pressure
.

29. Methods of Apneic Oxygenation
 6) High Flow Nasal Oxygen – THRIVE
(THRIVE – Transnasal humidified rapid insufflation
ventilator exchange)
.

30. THRIVE
Transnasal humidified rapid
insufflation ventilator exchange
 Technique that uses warmed and humidified
oxygen administrated via high flow nasal cannula
to achieve apneic oxygenation and ventilation.
• Flow rate upto 70 litres per min.
• Heated and Humidified- 100% relative humidity ,
37 degree celsius.
.

31. THRIVE
Transnasal humidified rapid
insufflation ventilator exchange
• Prevents drying up of oral
and nasal mucosa.
• Improve ciliary function
with removal of secretions.
• Creates a flow-dependent
positive airway pressure.
.

32. THRIVE
Transnasal humidified rapid
insufflation ventilator exchange
 Every 10 L/min increase in airflow increases airway
pressure by 0.5-1 cm H2O.
 Continuous positive airway pressure opens upper
airway.
 Possible to obtain FiO2 0.21-1 with 60-70 L/min flow.
 Improved washout of CO2 – Flow dependent dead
space flushing
.

33. THRIVE
Transnasal humidified rapid
insufflation ventilator exchange
Advantage:
 Continuous flow dependent positive pressure.
 Reduces atelectasis.
 Elimination of CO2
.

34. Methods of Apneic Oxygenation
 7) Supraglottic Jet Oxygenation and
Ventilation (SJOV)
.

35. Methods of Apneic
Oxygenation
 Novel minimally invasive technique of jet ventilation
above the level of vocal cords using a specialised nasal
tube.
 Feasible ventilation technique in both spontaneously
breathing and apnoeic patients.
 Also been used as a rescue oxygenation/ventilation
method in complete ventilation failure scenarios.

36. Methods of Apneic
Oxygenation
 A jet of High oxygen flow (>30 L/min at high
frequency) is delivered using driving pressures
between10 and 30 psi.
 This ensures rapid delivery of oxygen in a pulsatile
manner into the trachea leading to an exchange of
gases.
 Complications – Barotrauma, Mucosal drying, Nasal
bleed

37. Key points
 Routine preoxygenation with 100% O2 is considered a
safety measure.
 Essential in patients with decrease O2 loading or
increased VO2 or difficult airway.
 Most common and effective method – TVB for 3-5 min
or deep breathing for 1 – 1.5 min.
 Apneic oxygenation should be considered in anticipated
difficult airway and other special conditions.