Anaes · Airway management
Apnoeic oxygenation and THRIVE
Also known as Apnoeic oxygenation · THRIVE · Transnasal humidified rapid-insufflation ventilatory exchange · High-flow nasal oxygen · NO-DESAT · Pharyngeal oxygen insufflation
Exam-pass apnoeic oxygenation: aventilatory mass flow physiology, preoxygenation/denitrogenation, nasal low-flow NO-DESAT, Patel THRIVE high-flow humidified oxygen, CO2 limits, obesity/obstetric/difficult airway applications, and hard limits (obstruction, aspiration) for ANZCA Final and FRCA.
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- Apnoeic oxygenation needs a patent upper airway — complete obstruction means zero alveolar oxygen delivery.
- It buys time against hypoxaemia, not against hypercarbia/acidosis — CO2 still rises; intubate or ventilate within a planned window.
- It is not aspiration prophylaxis — RSI and full-stomach logic still apply.
- Obesity and pregnancy desaturate fastest — combine ramp/HELP, thorough denitrogenation, and high-flow apnoeic O2.
- Falling SpO2 or extreme hypercarbia means the window is closed — ventilate; do not keep 'trying the view'.
- Apnoeic O2 does not rescue oesophageal intubation — waveform capnography still rules.
Meet the patient
A man with a predicted difficult airway — a radiation-scarred neck and a heavy beard — is booked for elective surgery. After three minutes of preoxygenation the breathing circuit is switched off and the high-flow nasal cannulae are left running. Twelve minutes later the saturation is still 100 per cent, and the fibreoptic intubation proceeds without time pressure.[1]
Two questions frame this topic: how does oxygen keep entering a lung that is not being ventilated? (aventilatory mass flow — a patent airway and a partial-pressure gradient), and what is the technique buying — time against hypoxaemia, or time against hypercarbia? (the first, emphatically not the second). Hold those two and the limits slot into place.[1][4]
References7ShowHide
- [1]Patel A, Nouraei SA Transnasal Humidified Rapid-Insufflation Ventilatory Exchange (THRIVE): a physiological method of increasing apnoea time in patients with difficult airways Anaesthesia, 2015.PMID 25388828
- [2]Mir F, Patel A, Iqbal R, Cecconi M, Nouraei SA A randomised controlled trial comparing transnasal humidified rapid insufflation ventilatory exchange (THRIVE) pre-oxygenation with facemask pre-oxygenation in patients undergoing rapid sequence induction of anaesthesia Anaesthesia, 2017.PMID 28035669
- [3]Weingart SD, Levitan RM Preoxygenation and prevention of desaturation during emergency airway management Ann Emerg Med, 2012.PMID 22050948
- [4]Patel A, El-Boghdadly K Apnoeic oxygenation and ventilation: go with the flow Anaesthesia, 2020.PMID 32350853
- [5]Sud A, Patel A THRIVE: five years on and into the COVID-19 era Br J Anaesth, 2021.PMID 33546843
- [6]Dixon BJ, Dixon JB, Carden JR, Burn AJ, Schachter LM, Playfair JM, Laurie CP, O'Brien PE Preoxygenation is more effective in the 25 degrees head-up position than in the supine position in severely obese patients: a randomized controlled study Anesthesiology, 2005.PMID 15915022
- [7]Salhotra R, Kemprai R, Rautela R, Kapoor R, Armo M Comparative efficacy of NO-DESAT and THRIVE for peri-oxygenation in patients with anticipated difficult airway Indian J Anaesth, 2026.PMID 42145287