ADVERTISEMENT
The Edge: How We Think About First-Pass Success Matters
The Edge is a monthly blog series developed by EMS World and FlightBridgeED that features top EMS leaders exploring the intricacies of critical care in EMS practice. In this installment FlightBridgeED chief medical director Jeffrey Jarvis, MD, discusses the optimal approach to first-pass success in intubation.
Intubation first-pass success (FPS) matters. How we think about it matters even more.
The literature is clear that FPS matters. Adverse-event rates increase with each additional attempt. Chief among those events are hypoxia and hypotension, both of which are associated with peri-intubation cardiac arrest and increased mortality in patients with traumatic brain injury.1–3 In cardiac arrest each additional intubation attempt has been shown to decrease neurologically intact survival by 59%.4 But FPS alone is not enough; peri-intubation hypoxia is common even with success on the first attempt.5
How we think about FPS drives where we focus our systems’ performance improvement efforts and how we treat individual patients. If FPS, by itself, is the most important metric we focus on, we will drive performance to emphasize FPS at all costs. I learned this the hard way with my own system. We determined our FPS was unacceptably low and implemented a package of video laryngoscopy and intensive training to improve it. Part of this focused on the metric of FPS. We were successful, and our FPS rates greatly improved.6 Unfortunately, focusing only on FPS led us to pay less attention to what was happening to our patients during our attempts. We identified that more than 44% of our patients being intubated for indications other than cardiac arrest suffered peri-intubation hypoxia, and 3% of them went into cardiac arrest during the intubation attempt, even though we had a high FPS rate.7 Clearly FPS alone wasn’t enough.
The Plateau Point
The first step in any improvement effort is to agree on a standard definition of success. With intubation, this definition exists: An intubation attempt is what takes place between insertion of the laryngoscope blade and withdrawal of that blade, regardless of whether a tube is passed.8 This is important for several reasons. Most important is that what matters is what happens to the patient. While apneic oxygenation is possible during an intubation attempt, apneic ventilation is not. If a patient is not being ventilated during laryngoscopy, regardless of the purpose of that laryngoscopy, it doesn’t matter if it’s to “just take a look” or suction the oropharynx, ventilation still isn’t taking place. Additionally, using a standard definition of an intubation attempt is vital to research and benchmarking.9 Comparing apples to oranges doesn’t help drive understanding or improvement.
Once we adopt a universal definition of an intubation attempt and begin to measure FPS, we should begin to use that information to drive changes in our systems’ processes. For example, how many attempts should we allow before moving to an alternative airway device? Using the ESO data collaborative research data set that includes over 1000 EMS agencies, we determined the statistical point of futility—what we called the plateau point.10 This varied by device, indication, and the use of medications but ranged between 3–4. That means that after 3 or 4 attempts, subsequent attempts were no more likely to succeed than prior attempts. For example, there were patients who underwent 10 intubation attempts for cardiac arrest. Perhaps without surprise, these 10th attempts were no more successful than the prior 9.
Our research on the plateau point can help drive the discussion on when to move to a backup strategy but is based on statistics and not patients. Each additional attempt comes at a physiologic “cost” to the patient, so this plateau point should be considered the absolute “ceiling” of attempts and not the actual limit. In practice we should move to a backup device much sooner than after 3 or 4 attempts.
The Tyranny of Small Numbers
In addition to setting a system limit for when to move to an alternative airway, how else should we think about FPS? First we should think about it as a system measure, not an individual measure. Any individual clinician will have a small number of intubations in any given period. This means 1 patient with a particularly difficult airway and missed first attempt may make a large difference in a medic’s FPS rate. It would not be a valid conclusion to assume a medic with, say, an FPS rate of 50% was substantially worse than one with 100% success when they each had only 2 intubations. Because of this, focusing on only individual performance can put undue pressure on clinicians to, shall we say, take liberties with the accuracy of their documentation. Likewise, using performance on very rare events in a punitive fashion is unfair and intrinsically counterproductive. Instead we should focus on system performance to identify areas for improvement.
Measure What Matters
Most important, we need to think about FPS from the patient’s perspective. FPS by itself is not a patient-oriented metric, meaning it measures something that is a surrogate measure for what matters most to patients. Patients likely don’t care that much about how many attempts it takes to intubate them. They are more interested in us avoiding harm during those attempts.
For example, we know cardiovascular instability and severe hypoxemia occur often during emergency intubation (43% and 9% respectively), and somewhere between 1%–3% of emergency intubations result in cardiac arrest, largely driven by hypoxia and hypotension.1,11,12 We need to measure, then, not just FPS but FPS without adverse events. This is commonly thought of as FPS without hypoxia or hypotension.9,13 This is the patient-oriented outcome we should focus on. In my system our initial focus on intubation success certainly improved FPS, but we realized we needed a broader measure that encompassed adverse events as well. After we implemented a bundle of clinical care around intubation, we were able to decrease our peri-intubation hypoxia rates from 44% of intubations to just over 3%.7
By thinking about FPS differently and keeping our attention on our patients, we can improve our intubation performance in a way that matters most.
References
1. Mort TC. The incidence and risk factors for cardiac arrest during emergency tracheal intubation: a justification for incorporating the ASA Guidelines in the remote location. J Clin Anesth. 2004; 16(7): 508–16. doi: 10.1016/j.jclinane.2004.01.007
2. Spaite DW, Hu C, Bobrow BJ, et al. The Effect of Combined Out-of-Hospital Hypotension and Hypoxia on Mortality in Major Traumatic Brain Injury. Ann Emerg Med. 2017; 69: 62–72. doi: 10.1016/j.annemergmed.2016.08.007
3. Sakles JC, Chiu S, Mosier J, Walker C, Stolz U. The importance of first pass success when performing orotracheal intubation in the emergency department. Acad Emerg Med. 2013; 20: 71–8. doi: 10.1111/acem.12055
4. Murphy DL, Bulger NE, Harrington BM, et al. Fewer Tracheal Intubation Attempts are Associated with Improved Neurologically Intact Survival Following Out-of-Hospital Cardiac Arrest. Resuscitation. 2021; 167: 289–96. doi: 10.1016/j.resuscitation.2021.07.001
5. Walker RG, White LJ, Whitmore GN, et al. Evaluation of Physiologic Alterations During Prehospital Paramedic-Performed Rapid Sequence Intubation. Prehosp Emerg Care. 2018; 22(3): 300–11. doi: 10.1080/10903127.2017.1380095
6. Jarvis JL, McClure SF, Johns D. EMS Intubation Improves with King Vision Video Laryngoscopy. Prehosp Emerg Care. 2015; 19(4): 482–9. doi: 10.3109/10903127.2015.1005259
7. Jarvis JL, Gonzales J, Johns D, Sager L. Implementation of a Clinical Bundle to Reduce Out-of-Hospital Peri-intubation Hypoxia. Ann Emerg Med. 2018; 72: 272–9. doi: 10.1016/j.annemergmed.2018.01.044
8. Wang HE, Domeier RM, Kupas DF, Greenwood MJ, O’Connor RE. Recommended Guidelines for Uniform Reporting of Data from Out-of-Hospital Airway Management: Position Statement of NAEMSP. Prehosp Emerg Care. 2004; 8(1): 58–72. doi: 10.1080/31270300282x
9. Jarvis JL, Lyng JW, Miller BL, et al. Prehospital Drug Assisted Airway Management: An NAEMSP Position Statement and Resource Document. Prehosp Emerg Care. 2022; 26(sup1): 42–53. doi: 10.1080/10903127.2021.1990447
10. Jarvis JL, Barton D, Wang H. Defining the plateau point: When are further attempts futile in out-of-hospital advanced airway management. Resuscitation. 2018; 130: 57–60. doi: 10.1016/j.resuscitation.2018.07.002
11. Russotto V, Myatra SN, Laffey JG, et al. Intubation Practices and Adverse Peri-intubation Events in Critically Ill Patients From 29 Countries. JAMA. 2021; 325(12): 1164–72. doi: 10.1001/jama.2021.1727
12. Heffner AC, Swords DS, Neale MN, Jones AE. Incidence and factors associated with cardiac arrest complicating emergency airway management. Resuscitation. 2013; 84(11): 1500–4. doi: 10.1016/j.resuscitation.2013.07.022
13. Powell EK, Hinckley WR, Stolz U, Golden AJ, Ventura A, McMullan JT. Predictors of Definitive Airway Sans Hypoxia/Hypotension on First Attempt (DASH-1A) Success in Traumatically Injured Patients Undergoing Prehospital Intubation. Prehosp Emerg Care. 2020; 24(4): 470–7. doi: 10.1080/10903127.2019.1670299
Jeffrey L. Jarvis, MD, MS, EMT-P, FACEP, FAEMS, is chief medical director for FlightBridgeED, LLC and cohost of the FlightBridgeED EMS Lighthouse Project Podcast. He also serves as EMS medical director for the Williamson County EMS system and Marble Falls Area EMS and is an emergency physician at Baylor Scott & White Hospital in Round Rock, Texas.
