This document discusses preoxygenation and apneic oxygenation techniques. It defines preoxygenation as administering oxygen prior to anesthesia induction to increase oxygen reserves and prolong safe apnea time. Effective preoxygenation requires achieving near 100% oxygen saturation through tidal volume breathing or deep breathing. Apneic oxygenation can further extend safe apnea time by allowing oxygen diffusion during apnea. The document describes several methods of apneic oxygenation including nasal prongs, nasopharyngeal catheters, and THRIVE which uses high flow humidified nasal cannula. Key points emphasize preoxygenation as a safety measure and the effectiveness of tidal volume breathing for preoxygenation.

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.