This document discusses different oxygen therapy techniques including conventional oxygen therapy and high flow nasal cannula (HFNC) oxygen therapy. It provides details on: - How HFNC works by using an air/oxygen blender to deliver high flows of humidified oxygen at variable concentrations. - The physiologic effects of HFNC including improved oxygen delivery to the alveoli and prevention of adverse effects from lack of humidification. - Techniques called THRIVE and STRIVE-Hi that use HFNC to provide apneic oxygenation and tubeless anesthesia, extending the time available to secure an airway without risk of hypoxemia.

1. THRIVE / STRIVE-Hi
Dr Shreyas Kate

2. Conventional O2 Therapy
• First line therapy for acute resp failure
• Nasal Prongs, Non Rebreathing face mask
• Limitation:
– Mismatch b/w oxygen flow and patient ‘s
inspiratory flow
– Peak inspiratory flow may vary b/w 30 and 120
L/min during resp failure

3. Low Flow High FLow
nasal cannula aerosol masks
simple face mask air-entrainment nebulizers
partial rebreathing mask air-O2 blenders
nonrebreathing mask Venturi masks
Tracheostomy collar
Conventional O2 Therapy

4. Preoxygenation

5. • The end points of maximal alveolar
preoxygenation
– end-tidal O2 concentration (EtO2) of approximately
90%
– Endtidal nitrogen concentration (EtN2) of 5%
• Factors affecting the efficacy
– FIO2,
– duration of breathing
– and the VA/FRC ratio
Preoxygenation

7. HIGH FLOW NASAL CANNULA
HFNC

8. • What is HFNC Oxygen therapy?
– Uses air/oxygen blender to deliver FiO2 range
from 0.21 to 1.0
– Active humidity /temperature controlled -37 Cel
and humidified at 44 mg H2O/L
– Generates flows up to 40,60,70 L/min
HFNC

9. • Oxygen delivery to the alveoli depends on
many factors
– Oxygen flow rate
– FiO2 being delivered
– Device interface
– Patient demand (Vt, RR, PIFR)
HFNC

10. Equipment

12. Different devices

13. Physiologic effects of HFNC

15. • Adverse Effects of Lack of Humidification
– cessation of the flow of tracheal mucus
– widespread loss of the cilia
– detachment or sloughing of the epithelium
– subepithelial vascular congestion
– excessive water loss by the nasal mucosa
HFNC

16. • USES:
– Neonates (counteract a lack of surfactant)
– Hypercapnic Respiratory Failure
– Hypoxemic Respiratory Failure (FLORALI trial)
– Postextubation
– Preoxygenation (denitrogenate the lungs)
– Acute Heart Failure
– Sleep Apnea
HFNC

17. TRANSNASAL HUMIDIFIED RAPID-
INSUFFLATION VENTILATORY EXCHANGE
THRIVE

18. • Apnoeic window
• Cannot intubate, cannot ventilate
• Apnoeic oxygenation
Introduction

19. • 1909 by Samuel Meltzer : Ventilation without
ventilatory movements (direct and continuous
intratracheal oxygen insufflation)
• Arthur Slutsky using tracheal insufflation of
O2 (TRIO) 1980s and 1990s, ‘oscillatory
ventilation’, which continues to be used in
highly-selected cases in paediatric ventilation,
and ‘constant-flow ventilation’
History

20. • Aventilatory mass flow (AVMF)
• Negative pressure gradient of up to 20 cmH2O
• Apnoeic oxygenation has been used both
experimentally and clinically as a strategy to
extend the apnoeic window
Physiology

21. Physiology
rate of rise of carbon dioxide levels was between
0.35 and 0.45 kPa.min1( 2.62 to 3.37 mm Hg/min)

22. • Pre-oxygenate for 10 min at 40 degrees of
head-up inclination with the nasal cannula (70
L/min)
• Intravenous induction of anaesthesia then
commenced with boluses of propofol,
fentanyl, and rocuronium, followed by a
peripheral infusion of propofol
• Nasal oxygenation maintained at the same
rate of 70 l/min until the definitive airway was
secured
Technique

23. Uses of THRIVE
• Reduced oxygen reserve
• Procedural sedation
• Difficult airway
• Shared Airway

24. SPONTANEOUS RESPIRATION USING IV
ANAESTHESIA
STRIVE-hi

26. • Spontaneously breathing
• HFNO
– An increased FiO2
– Generation of positive airway pressure
– Improved respiratory mechanics
– Reduced upper airway resistance
Introduction

27. Technique
• Tubeless anaesthesia
• Use of a standardized propofol titration
method
• use of HFNO
– 30 L/min for 01 min
– 50 L/min for 02 min in a 10–20 degrees reverse
Trendelenburg position
– 70 L/min when loss of consciousness occurred

28. – Awake patients
• respiratory supportive care
• preoperative preoxygenation
• postoperative support
– Sedated patients
• procedural bronchoscopy
• awake fibreoptic intubation
– Asleep patients with obstructive sleep apnoea
(OSA)
Clinical Benefits

29. THANK YOU