Authors: Rob Hirst, Liz Farah, Chris Connolly, Becky Maxwell, Andy Neill, Dave McCreary / Codes: NeuC11, NeuC6, ResP2, SLO10 / Published: 09/09/2024
Clinical Question
Should we be using NIV to preoxygenate our patients for RSI?
Title of Paper
Noninvasive Ventilation for Preoxygenation during Emergency Intubation
Journal and Year
NEJM. 2024
Lead Author
Gibbs
Background
- Pre-oxygenating patients via NIV (BiPAP) became a bit more common, at least in Australia, during COVID as a safer means of pre-oxygenating out patients who all had very impressive hypoxemic respiratory failure.
- It’s a bit fiddly, annoying, and resource intensive to get it set up just for preoxygenation and carries a risk of aspiration, particularly once you obtund a patient with induction drugs
- Apparently some people are still using face masks such as a NRB to pre-oxygenate their patients for RSI. International guidelines apparently say either method is ok.
- The authors suspected hypoxemia would be less common in patients preoxygenated with NIV.
Study Design
- Multicentre, RCT
- 24 EDs and ICUs in the USA
Patients Studied
- Adults undergoing emergency intubation
- Exclusions included those already having positive pressure ventation (NIV) or if provider felt either NIV or O2 were necessary or contraindicated.
Intervention
- Noninvasive-ventilation - from the start of Preoxygenation until initiation of laryngoscopy
- FiO2 1.0
- EPAP (PEEP) 5 cmH2O at least
- IPAP 10 cmH2O (same as PS 5 cmH2O) at least
Comparison
- O2 via non-rebreather or BVM without manual ventilation before induction of anaesthesia
- Highest O2 flow rate available (>15l/min)
- Patients in both groups preoxygenated for minimum 3 minutes if feasible
- Operators were allow to provide BVM ventilation in either group after induction
- They were also allowed to use nasal oxygenation
Outcomes
- Primary: hypoxemia during intubation (sats <85% in the interval between induction and 2 minutes after intubation)
- Secondary: Lowest sats during intubation
- “Exploratory”:
- haemodynamics: severe hypotension, increased pressors, cardiac arrest during intubation period
- Safety:
- Aspiration during intubation
- New infiltrates on CxR in 24h post induction
- Sats and FiO2 at 24h
Summary of Results
- 1301 enrolled
- Mean 61 years
- 48.1% had hypoxemic respiratory failure
- 73% on ICU; 27% in ED
- 96.6% of NIV and 955 of O2-mask group got 3 minutes of preoxygenation
- 8.3% of NIV vs 17.4% of O2-mask group had sats <95% at start of induction
- -9.1% absolute risk difference [95%CI -12.7 to -5.5]
- Primary outcome (hypoxemia during intubation):
- 9.1% NIV vs 18.5% O2-mask group
- -9.4% absolute risk diff [-13.2 to -5.6; p<0.001]
- Subgroup analysis suggests difference greatest in the high BMI subgroup
Other outcomes of interest:
- Sats <80%: 6.2% vs 13.2% (-6.9% [-10.2 to -3.7])
- Sats <70%: 2.4% vs 5.7% (-3.2% [-5.4 to -1.1])
- Cardiac arrest: 0.2% vs 1.1% (-0.9% [-1.8 to -0.1])
- Aspiration: no difference; 0.9% NIV vs 1.4% O2-mask
Table 2 of note:
- BVM ventilation during apnoea period: 8.9 (NIV) vs 30.8% (O2-mask)
- The O2 group may have needed it more
- But I wonder if they had done that for both groups more as standard (unless contraindicated), whether there would have been such a big difference?
Authors Conclusion
In this trial involving critically ill adults undergoing tracheal intubation in an emergency department or ICU, the incidence of hypoxemia was lower with Preoxygenation with non-invasive ventilation that with an oxygen mask.
Clinical Bottom Line
I would like to see how the use of formal NIV would compare to a good old Water’s circuit with ventilation during apnoic period. That being said, I would imagine that NIV would provide more consistency with mask seal, PEEP and inspiration support.
I also don’t know who out there is preoxygenating their patients with a face mask, but please don’t. A non-rebreather O2 mask will never get you an FiO2 of 1.0, and won’t denitrogenate your patient.
I’ll probably start using NIV more routinely to preoxygenate, resources allowing. And I will continue to BVM ventilate through the apnoic period, where safe.
RSI in the ED
This blog looks at RSI from the eyes of the “assistant” - this might be the resus nurse, the ED FY2, or a non-airway trained ED registrar. Please send your thoughts, feedback and comments.
Rapid Sequence Inductions in the Emergency Department
Intubation forms an integral role in the treatment of the critically ill or injured patients presenting to the ED with a failed or at-risk airway.
August 2021
This month we have a slightly different format. Andy and Dave are here with 3 New in EM and Becky and Chris join us for a guideline review. We discuss Are you learning from Podcasts While Driving?, metoclopramide for post traumatic headache, EM Pain Management and Awareness and paralysis with intubation in the ED
1 Comments
good very uptodate