ARTICLE REVIEW
The OPTINIV trial
For patients with hypoxemic respiratory failure, tracheal intubation is a potentially life-threatening procedure. Indeed, it exposes hypoxemic patients to the risk of severe desaturation potentially resulting in cerebral anoxia, cardiac arrest and death.
Non-invasive ventilation (NIV) has been investigated as a method for preoxygenation of patients with hypoxic respiratory failure, with less hypoxemia developing after NIV when compared with non-rebreather bag-valve mask preoxygenation [1]. However, NIV has to be interrupted to allow laryngoscopy and intubation, and hypoxemia may occur during this phase. High-flow nasal cannula oxygen (HFNC) provides up to 60 L/min of heated and humidified flow, with a reliable and modifiable fraction of inspired oxygen (FiO2) via nasal prongs. When HFNC was investigated as a method for preoxygenation of patients with hypoxemic respiratory failure compared to non-rebreather bag-mask or 15 L/min facial mask, authors reported conflicting results [2-4]. Notably, nasal prongs allowed an apneic oxygenation during laryngoscopy and intubation, with a theoretical advantage over NIV and facial mask preoxygenation during these phases.
In the OPTINIV trial, Jaber et al. [5] investigated the combination of NIV and HFNC oxygen administration for preoxygenation of patients with severe hypoxemic respiratory failure. They performed a single-centre, blinded, randomised controlled trial.
In the intervention group, patients received 4-minute (30° head-up position) preoxygenation with NIV (10 cmH2O of pressure support and 5 cmH20 of PEEP, FiO2 100%) combined with HFNC 60 L/min and FiO2 100%. The control group received the same preoxygenation procedure with the exception of the HFNC. Authors provided a description (and a picture) of the adopted masking procedure and in this sense the trial may be considered at low risk of detection bias.
The primary outcome was the minimal SpO2 during the intubation procedure. Secondary outcomes were preoxygenation quality, complications related to intubation procedures and morbidity in ICU. Authors included 25 and 24 patients in the intervention and control group respectively in the intention to treat analysis. Minimal SpO2 values were significantly higher in the intervention arm compared to controls [100 (95–100) % vs. 96 (92–99) %, p = 0.029].
Authors did not observe a statistically significant difference in secondary outcomes. However, five patients in the control group developed severe hypoxemia (SpO2 below 80%) while this occurred in only one patient in the intervention group (p = 0.098).
Take home message
The combination of HFNT and NIV, when compared to NIV alone, was associated with higher minimal SpO2 values during the endotracheal intubation of ICU patients with severe hypoxemic respiratory failure. If the findings of this proof-of-concept study will be confirmed by a larger, multicentre study, this may represent the standard of preoxygenation of the severely hypoxic patient in ICU.
Article review submitted by NEXT member Vincenzo Russotto on behalf of the ESICM Journal Review Club.
References
1. Baillard C, Fosse JP, Sebbane M, Chanques G, Vincent F, Courouble P, Cohen Y, Eledjam JJ, Adnet F, Jaber S: Noninvasive ventilation improves preoxygenation before intubation of hypoxic patients. American journal of respiratory and critical care medicine 2006, 174(2):171-177.
2. Miguel-Montanes R, Hajage D, Messika J, Bertrand F, Gaudry S, Rafat C, Labbe V, Dufour N, Jean-Baptiste S, Bedet A et al: Use of high-flow nasal cannula oxygen therapy to prevent desaturation during tracheal intubation of intensive care patients with mild-to-moderate hypoxemia. Critical care medicine 2015, 43(3):574-583.
3. Vourc’h M, Asfar P, Volteau C, Bachoumas K, Clavieras N, Egreteau PY, Asehnoune K, Mercat A, Reignier J, Jaber S et al: High-flow nasal cannula oxygen during endotracheal intubation in hypoxemic patients: a randomised controlled clinical trial. Intensive care medicine 2015, 41(9):1538-1548.
4. Semler MW, Janz DR, Lentz RJ, Matthews DT, Norman BC, Assad TR, Keriwala RD, Ferrell BA, Noto MJ, McKown AC et al: Randomized Trial of Apneic Oxygenation during Endotracheal Intubation of the Critically Ill. American journal of respiratory and critical care medicine 2016, 193(3):273-280.
5. Jaber, S., Monnin, M., Girard, M. et al. Apnoeic oxygenation via high-flow nasal cannula oxygen combined with non-invasive ventilation preoxygenation for intubation in hypoxaemic patients in the intensive care unit: the single-centre, blinded, randomised controlled OPTINIV trial. Intensive Care Med 42, 1877–1887 (2016).
