Despite decades of experience with endotracheal intubation, we continue to find approaches to improving the process of how we intubate. In today’s post we are not only going to talk about how to avoid post intubation cardiac arrest, but we are also going to cover 5 rather controversial topics in airway management including: Apneic oxygenation (ApOx), use of video laryngoscopy (VL) compared to direct laryngoscopy (DL), bougie 1st intubation, back up head elevated (BUHE) intubation, and finally bag valve mask ventilation (BVM) prior to intubation.
How Common is Post-Intubation Cardiac Arrest   ?
- 1.5 – 4% or 1 in 25 – 60 intubations
Is There a Way to Predict Post-Intubation Cardiac Arrest  ?
- Pre-Intubation Hypotension (SBP < 90mmHg)
- Pre-Intubation Hypoxemia (SpO2 < 90%)
- Pre-Intubation Shock Index (≥0.9)
- Retrospective cohort study  of 300 patients undergoing emergency intubation. Pre-intubation SI ≥0.9 was independently associated with post intubation hypotension (OR 55.1) and Mortality (35% vs 20%)
- Another retrospective cohort study  of 140 patients requiring emergent intubation performed in the ICU, showed that a SI ≥0.9 was independently associated with post-intubation hypotension (OR 2.13) and Mortality (OR 4.00)
How Do we Fix Pre-Intubation Hypotension?
- Resuscitate Before you Intubate (RBI)
- Run Fluids or blood
- Boom Sticks = Push Dose Pressors (9mL of NS + 1mL Epi (100mcg/mL) = 10mcg/mL)
- Increase Pressure = Norepinephrine drip 0.02 – 1.0 ug/kg/min
How Do we Fix Pre-Intubation Hypoxemia?
- Resuscitate Before you Intubate (RBI)
- NO DESAT = Nasal Oxygenation During Efforts Securing a Tube = 15LPM NC + Flush Rate NRB
- If O2 saturation not ≥95% change to BVM + PEEP valve or NIPPV (Should be thinking pulmonary shunt physiology (i.e. pneumonia, pulmonary edema, etc…). Oxygenation will not help as much as PEEP to help recruit atelectatic alveoli
- When O2 saturation <95%
- Run O2 15LPM NC
- BVM at Flush Rate Oxygen
- Increase PEEP with PEEP valve
Apneic Oxygenation (ApOx) in the ED ?
- RCT of 200 patients requiring intubation in the ED randomized to ApOx vs No ApOx
- No difference in primary outcome of mean lowest SpO2
- ApOx 92%
- No ApOx 93%
- 2 important caveats should be kept in mind about this study
- Patients were preoxygenated on average for 13 minutes
- Although 13 minutes is a lot of preoxygenation, a more important point to remember is that good preoxygenation, makes apneic oxygenation superfluous
- There are times that we don’t have time in the ED to do all the necessary steps due to a crash intubation and ApOx may have a role in this situation
- The second point is successful intubation compared to time:
- 70% intubated by 60 seconds
- 80% by 80 seconds
- 90% by 100 seconds
- 100% by 195 seconds
- Patients were preoxygenated on average for 13 minutes
- These are fast times, and therefore apneic oxygenation wouldn’t have time to show benefit. The problem is, we don’t have a way to predict which airways are going to take long apnea times
- ApOx is essentially no cost, no cognitive load, and not been shown to be harmful
- Bottom Line: ApOx in the ED…Just Do It!!!
VL vs DL During RSI ?
- 5 RCTs with 1250 patients
- 1stPass Intubation = No Difference
- Esophageal Intubation = Decreased with VL (NNT = 16)
- Mean Time to Intubation = No Difference
- In-Hospital Mortality = No Diffference
- One caveat to remember, is that not all laryngoscopy is the same (i.e. Hyperangulated vs standard geometry)
- In this meta-analysis, 3 RCTs were C-MAC VL (standard geometry) vs Macintosh DL, and 2 RCTs were glidescope VL (hyperangulated geometry) vs Macintosh DL
- There is no perfect tool for intubation
- Any tool is only as good as the operator using it
- Choose the right tool for the job at hand
- Bottom Line:Train in both VL and DL. There is a reason we have multiple tools at our disposal when it comes to airway management.
Bougie 1stIntubation ?
- This was a single center RCT of 750 patients randomized to bougie 1stvs ETT + Stylet intubation.
- 380 patients had one difficult airway characteristic
- FPS rate in ED trials is about ≈85%
- Successful ETT intubation on initial attempt is vital to reduce likelihood of adverse events
- Although the numbers from this single center study look amazing, readers have to remember that bougie 1stintubation is common practice at this one institution. This may not be generalizable to all institutions not as comfortable with the use of bougie
- Another major caveat to this trial is bougie works great with standard geometry blades but not hyperangulated blades. There are malleable bougie’s available, but they are more expensive and not the standard equipment found in most EDs
- Bottom Line: Train in both Bougie 1stand standard ETT + Stylet intubation as every airway is unique
Back Up Head Elevated (BUHE) Intubation ?
- Observational trial of ≈500 adult patients undergoing emergent tracheal intubation outside of the operating room by the anesthesiology-based airway service at 2 university-affiliated teaching hospitals. (Not an ED study)
- Primary outcome was a composite of any intubation related complication (difficult intubation ≥3 attempts or >10min, Hypoxemia <90% O2 sat, Esophageal intubation, or esophageal aspiration)
- BUHE Intubation: 9.3%
- Standard Supine Intubation: 22.6%
- Bottom Line: BUHE decreases intubation -related complications in comparison to standard supine intubation
BVM Prior to Intubation ?
- RCT of ≈650 patients in the ICU randomized to BVM vs no BVM during induction
- Primary Outcome was lowest O2 saturation observed during the interval between induction and 2 minutes after tracheal intubation
- Secondary Outcomes included incidence of severe hypoxemia (<80%) and aspiration
- Potential caveat is patients in the BVM group received pre-oxygenation with BVM more often than in patients in the no BVM group (39.7% vs 10.9%)
- No difference in median lowest O2 sat between groups (BVM 96% vs No BVM 93%)
- Less severe hypoxemia in the BVM group (10.9%) vs the no BVM group (22.8%)
- Operator reported aspiration was also lower in the BVM group (2.5%) vs the no BVM group (4.0%), but this study was not powered to assess safety outcomes
- The application of BVM was standardized, which is the crux of this study. Poor BVM technique will lead to more issues with regurgitation and aspiration
- BVM with flush rate oxygen
- PEEP valve set to 5 – 10 cm of water
- Two-handed mask seal with head tilt and chin lift
- Ventilate at 10 breaths/minute
- Use the smallest tidal volume to generate chest rise
- Bottom Line: Consider BVM in patients who do not reach appropriate preoxygenation (>95%) despite the use of non-rebreather and nasal cannula at >15LPM.
Clinical Bottom Line:
- ApOx in the ED: Just do it. No cost, no cognitive load, and not been shown to be harmful
- VL vs DL: Train in both VL and DL. There is a reason we have multiple tools at our disposal when it comes to airway management.
- Bougie 1st Intubation: Train in both Bougie 1st and standard ETT + Stylet intubation as every airway is unique
- Back Up Head Elevated Intubation: Decreases intubation-related complications in comparison to standard supine intubation
- BVM Prior to Intubation: Consider BVM in patients who do not reach appropriate preoxygenation (>95%) despite the use of non-rebreather and nasal cannula at >15LPM
- Heffner AC et al. Incidence and Factors Associated with Cardiac Arrest Complicating Emergency Airway management. Resuscitation 2013. PMID: 23911630
- Kim WY et al. Factors Associated with the Occurrence of Cardiac Arrest After Emergency Tracheal Intubation in the Emergency Department. Plos One 2014. PMID: 25402500
- De Jong A et al. Cardiac Arrest and Mortality Related to Intubation Procedure in Critically Ill adult Patients: A Multicenter Cohort Study. Crit Care Med 2018. PMID: 29261566
- Heffner AC et al. Predictors of the Complication of Postintubation Hypotension During emergency Airway management. J of Crit Care 2012. PMID: 22762924
- Trivedi S et al. Evaluation of Preintubation Shock Index and Modified Shock Index as Predictors of Postintubation Hypotension and Other Short-Term Outcomes. J of Crit Care 2015. PMID: 25959037
- Caputo N et al. EmergeNcy Department use of Apneic Oxygenation Versus Usual Care During Rapid Sequence Intubation: A Randomized Controlled Trial (The ENDAO Trial). Acad Emerg Med 2017 PMID: 28791755
- Bhattacharjee S et al. A Comparison Between Video Laryngoscopy and Direct laryngoscopy for Endotracheal Intubation in the Emergency Department: A Meta-Analysis of Randomized Controlled Trials. J Clin Anesth 2018. PMID: 29549828
- Driver BE et al. Effect of Use of a Bougie vs Endotracheal Tube and Stylet on first-Attempt Intubation Success Among Patients with Difficult Airways Undergoing Emergency Intubation: A Randomized Clinical Trial. JAMA 2018. PMID: 29800096
- Khandelwal N et al. Head-Elevated Patient Positioning Decreases Complications of Emergent Tracheal Intubation in the Ward and Intensive Care Unit. Anesth Analg 2016. PMID 26866753
- Casey JD et al. Bag-Mask Ventilation During Tracheal Intubation of Critically Ill Adults. NEJM 2019. PMID: 30779528
For More on This Topic Checkout:
- REBEL EM: The ENDAO Trial: Is Apneic Oxygenation a Futile Intervention in ED RSI?
- REBEL EM: Apneic Oxygenation (ApOx): A Review of the Evidence in Critical Care & Emergency Medicine
- REBEL EM: Should we be Using Apneic Oxygenation (ApOx) in the ED?
- REBEL EM: Is Apneic Oxygenation Overhyped with Scott Weingart?
- REBEL EM: Video Laryngoscopy (VL) OR Direct Laryngoscopy (DL) in the ED
- REBEL EM: Bougie use in Emergency Airway Management (BEAM)
- REBEL EM: Bougie 1st Intubation in the ED?
- REBEL EM: Critical Care Updates: Resuscitation Sequence Intubation – Hypotension Kills (Part 1 of 3)
- REBEL EM: Critical Care Updates: Resuscitation Sequence Intubation – Hypoxemia Kills (Part 2 of 3)
Post Peer Reviewed By: Anand Swaminathan, MD (Twitter: @EMSwami)