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By Terry Riddle, BSN, BHS, FP-C; Lane Matheny, BAS, LP, FP-C and John Wheeler, BHS, LP, FP-C
Introduction
In emergency medical services, success in airway management has traditionally been defined by first-pass success. However, in today’s clinical landscape, the definition of success has evolved beyond merely passing the endotracheal tube through the vocal cords. True success includes achieving first-pass success without adverse events detrimental to patient outcomes such as hypoxia and hypotension.
Thus, in modern EMS practice, advanced airway management success is now defined by the DASH-1A (Definitive Airway Sans Hypoxia/Hypotension on First Attempt) metric.1 While many providers have been performing advanced airway management for years, the data has “found that the odds of peri-intubation cardiac arrest were increased six-fold with hypotension, three-fold with hypoxia, and almost two-fold with an inability to properly prepare for intubation.”2
Utilizing all the concepts of Resuscitated Sequence Intubation, EMS providers can continue to avoid adverse events and improve patient outcomes. Optimizing ventilation, oxygenation, and perfusion have proven to be hallmarks of a successful prehospital intubation process.3 Redefining “RSI”, by focusing on optimizing each patient through a series of interventions, has shown to “mitigate the risk of harm to the patient.”4
RSI Definition
To quote Richard Rhodes, “Words are the model, words are the tools, words are the boards, words are the nails.” The power of words, means that healthcare professionals must examine the terminology associated with “RSI.” Regardless of past definitions, one thing is clear moving forward, “Rapid” has no place in advanced airway management.
EMS providers do not perform anything rapidly, procedures and interventions may happen in rapid sequence, but only because of the providers’ knowledge and experience. EMS professional must take a scientific approach to airway management. Dr. Richard Levitan concept of “Resuscitation Sequence Intubation” is a critical shift in the approach to airway management in critically ill patients.3
Dr. Levitan emphasizes the importance of resuscitation efforts prior to airway intervention by optimizing oxygenation and hemodynamic stability before attempting intubation and significantly reducing the risks of hypoxia and hypotension. This approach not only improves first-pass success, but also mitigates the potential for peri-intubation cardiac arrest; a complication often associated with rapid, uncoordinated attempts to secure the airway.3
As an industry, it is imperative to understand and utilize Resuscitation Sequence Intubation, a deliberate, patient-centered process. EMS providers who optimize ventilation, oxygenation, and perfusion with all airway procedures, can obtain better outcomes for their patients.
Indications for Advanced Airway Management
The use of advanced airway management procedures may differ depending on protocols, but most encompass four main scenarios: failure to oxygenate, failure to ventilate, failure to maintain a patent airway, and anticipated airway complications.
Failure to oxygenate occurs when a patient’s oxygen levels remain critically low despite supplemental oxygen, such as in severe hypoxia or respiratory distress.5 Failure to ventilate refers to inadequate removal of carbon dioxide due to conditions like severe asthma, COPD exacerbations, or neuromuscular disorders.6
Failure to maintain a patent airway arises when the airway is blocked or at risk of obstruction, as seen in facial trauma, swelling, or altered mental status.7 Anticipating future airway complications is crucial in cases where swelling is expected to worsen, such as with burns, anaphylaxis, or neck trauma.7
None of these scenarios represent anything groundbreaking in making airway management decisions, but represent a standard that EMS personnel can utilize in making airway management decisions.
Optimizing Ventilatory Status
Patients experiencing respiratory distress frequently require ventilatory support prior to advanced airway management. Conditions such as acute pulmonary edema, asthma exacerbations, and opioid overdoses can cause hypoventilation or increased work of breathing, putting patients at risk of desaturation.8
Optimizing ventilatory status prior to RSI is critical for reducing peri-intubation complications, particularly in patients with impending respiratory failure. Attention to ventilation and not oxygen therapy alone, aids in the removal of carbon dioxide and offers support of respiratory mechanics which can significantly improve outcomes. Noninvasive positive pressure ventilation (NIPPV), including continuous positive airway pressure (CPAP) and bilevel positive airway pressure (BiPAP), has shown benefit in enhancing alveolar ventilation by reducing atelectasis and improving functional residual capacity.9
In the pre-intubation period, applying BiPAP can assist in offloading respiratory muscles and improving tidal volume in patients with obstructive or hypercapnic respiratory processes.10 This proactive ventilatory support not only extends the safe apnea period but also stabilizes the patient’s acid-base status prior to sedation and paralysis, which is critical in avoiding rapid decompensation during RSI.11
Incorporating positive pressure techniques is a cornerstone of comprehensive ventilatory preparation, especially in high-risk patients. Recent evidence from the PREOXI trial further supports the use of noninvasive ventilation (NIV) for pre-oxygenation.
The study found that pre-oxygenation with NIV significantly reduced the incidence of hypoxemia during intubation for patients in hospital emergency departments and intensive care units,. Hypoxemia, defined as oxygen saturation falling below 85%, was observed in 9.1% of patients receiving NIV, compared to 18.5% of those using a standard oxygen mask.12
EMS agency equipment varies, but providers have always been adept at utilizing what is available, and the same approach can be taken towards optimizing ventilation. Combining medications, positioning, and positive pressure ventilation; to optimize ventilatory status should be addressed prior to RSI to improve patient outcomes.
Optimizing Oxygenation
“Pre-oxygenation is a critical step…aimed at maximizing oxygen reserves and extending the safe apnea period—the duration during which a patient can tolerate apnea without significant desaturation.”13 EMS providers have training and experience in dealing with individuals having respiratory issues, whether it is a basic adjunct or an advanced procedure. It is important to use this knowledge in determining the approach to the pre-oxygenation process.
Effective pre-oxygenation techniques include tidal volume breathing for three minutes, or eight vital capacity breaths over 60 seconds, both of which help to replace nitrogen in the lungs with oxygen, thus increasing oxygen reserves.14 The use of a non-rebreather mask (NRB) with flush rate oxygen (50–60 L/min) can achieve high fractions of inspired oxygen (FiO₂) similar to bag-valve-mask ventilation, effectively prolonging the safe apnea period.6
Additionally, positioning the patient in a semi-upright position can significantly increase functional residual capacity and improve oxygenation, a practice particularly beneficial for obese patients.15 Something as simple as, “Placing the SpO₂ sensor on the ear rather than the finger may provide a more accurate and earlier indication of desaturation, as the ear’s blood flow is less affected by peripheral vasoconstriction, a common occurrence during hypoxia or shock.”16
The goal of the oxygenation process is to prolong our safe apnea period or how long the patient can maintain appropriate SpO2 levels while paralyzed. Appropriate pre-oxygenation measures are not only imperative to improve outcomes in advanced airway management, but most are simple maneuvers that take few resources away during a high stress situation.
Optimizing Perfusion
The methods used to optimize perfusion status are dependent on proper assessment and diagnosis of the patient. Implementation of blood products, fluid boluses, vasopressors, and other interventions may be indicated based on patient assessment.
While protocol driven treatment may address perfusion concerns, providers must also considering the other treatments that may affect perfusion status. “Several components of airway management may compromise perfusion.
Positive-pressure ventilation may create or exacerbate hypotension…medications used to facilitate airway management during Drug Assisted Airway Management (DAAM) may have cardiovascular side effects, such as negative inotropy, bradycardia, or vasodilation.”2
A 2013 article by Heffner, et al.17 found that cardiac arrest was more common in patients experiencing pre-intubation hypotension (12% vs 3%), making optimizing perfusion an indicator for better patient outcomes.
A valuable tool to evaluate perfusion status is“ Shock index (SI) is defined as the heart rate (HR) divided by systolic blood pressure (SBP)… SI >1.0 has been widely found to predict increased risk of mortality and other markers of morbidity, such as need for massive transfusion protocol activation and admission to intensive care units.”18
“A pre-RSI shock index ≥ 0.9 has been associated with cardiac arrest.19 Shock index is one method for evaluating perfusion status that can provide guidance, along with local protocol, in managing an advanced airway patient.
Post-Intubation Management
According to the 2022 NAEMSP position statement, “Physiological derangement is common following advanced airway insertion, and efforts should be focused on maintaining optimal perfusion, oxygenation, and ventilation.” Placement of an advanced airway should be viewed as a stabilizing procedure, not a cure.
Due to the paralysis, the EMS professional now has full control over the patient’s outcome and must continue with optimizing ventilation, oxygenation, and perfusion post intubation. Some agencies may have a form of mechanical ventilation that assists the provider with optimizing ventilation and oxygenation, in conjunction with continuing any medicinal treatments that the patient requires.
For agencies that do not have mechanical ventilation available, using appropriate ventilators techniques and closely monitoring rate and volume can continue to improve the patient.
As ventilator technology continues to advance in the prehospital environment, it can help to reduce the providers’ workload, and potentially increase focus on the last two keys in post intubation management: perfusion and sedation.
Close monitoring of perfusion status, with appropriate interventions applied as needed, will improve patient outcomes. The final aspect of post intubation management is sedation. “Neuromuscular paralysis without sedation is an avoidable medical error with negative psychologic and potentially physiologic consequences.”20
Sedation medications all have different time ranges of effectiveness; it is important for providers to have a plan in place to ensure appropriate sedation for patients that have been paralyzed.
Check List
“Acute stress is widely observed to impair cognitive abilities across a number of central executive-dependent cognitive tasks, an effect that is often attributed to fundamental impairments to executive-dependent cognitive processing.”21
Advanced airway management often involves complex patients that present with co-morbidities. Checklists can have positive effects on outcome in the prehospital setting by significantly increasing adherence to guidelines.22
EMS providers should use recent evidence and the examples by the military and aviation industry, the application of a checklist. “Checklists protect against forgetfulness, minimize omissions of critical steps, and can prompt users to adopt a ‘rules-based’ decision-making model, making it easier to work in stressful or pressured situations.”23
There is no universal checklist that can be applied to every agency due to the variety of equipment and medications, but the basic building blocks are present that can be modified to fit each agency’s approach.
Conclusion
The definition of successful prehospital airway management has evolved beyond the placing an endotracheal tube (ET) in the fewest attempts possible. Emergency Medical Service (EMS) advanced airway management success is now measured by patient outcomes utilizing the DASH-1A metric.1
As first-line providers, EMS personnel treat patients at the onset of an airway emergency with interventions and the timing of which they are performed result in a life altering consequence for the patient.
By adhering to the new standards, EMS professionals can optimize ventilation, oxygenation, and perfusion that evidence shows are the hallmarks of a successful prehospital intubation process.3
The ultimate goal of prehospital airway management is good patient outcomes, which is achieved not only through placement of an ET tube, but by ensuring we are addressing ventilation, oxygenation, and perfusion status.
About the Authors
Terry Riddle, BSN, BHS, FP-C, works for Parker County (TX) Hospital District EMS as a critical care paramedic and supervisor. He, along with a supportive team, engage in airway and critical care training, while also partnering with University of North Texas Health Science Center on prehospital medical research.
Lane Matheny, BAS, LP, FP-C, works for Parker County Hospital District EMS as a critical care paramedic and supervisor. Lane specializes in training emergency responders in advanced airway management. His instruction is grounded in real word experience and cutting-edge techniques, ensuring participants acquire the practical skills needed to excel in even the most challenging airway scenarios.
John Wheeler, BHS, LP, FP-C is a field supervisor and critical care paramedic with Parker County Hospital District EMS in Texas. He has over 13 years of experience in prehospital care and holds a Bachelor of Science in Health Sciences. He is dedicated to advancing EMS education and improving clinical outcomes through high-performance training and protocol innovation.
References
1. Truskinger, S., Coe, J., & Lewis, S. (2024).Beyond First Pass Success: Implementing DASH- 1A for Improved Outcomes. Open repository.com. https://wlv.openrepository.com/server/api/core/bitstreams/6fd5c072-2e1e-4cd8-ac40-37b66c99a3b2/content
2. Jarvis, J., Bosson, N., Guyette, F., Wolfe, A., Bobrow, B., Olvera, D., Walker, R., & Levy, M. (2022, January 10).Optimizing Physiology During Prehospital Airway Management: An NAEMSP Position Statement and Resource Document. tandfonline.com. https://www.researchgate.net/publication/232173635_httpwwwtandfonlinecomdoiabs101080009140390909763
3. Levitan, R. (2015). Timing Resuscitation Sequence Intubation for Critically Ill Patients. ACEP now. Retrieved from https://www.acepnow.com/article/timing-resuscitation-sequence-intubation-for-critically-ill-patients/
4. Davis, D., Bosson, N., Guyette, F., Wolfe, A., Bobrow, B., Olvera, D., Walker, R., & Levy, M. (2022, January 10).Optimizing Physiology During Prehospital Airway Management: An NAEMSP Position Statement and Resource Document. Tandfonline.com. https://www.tandfonline.com/doi/full/10.1080/10903127.2023.2273890
5. Weingart, S. D., & Levitan, R. M. (2021). Difficult Airway Management in the Emergency Department: An Update. Emergency Medicine Clinics of North America, 39(3), 489-503. Retrieved from https://pubmed.ncbi.nlm.nih.gov/34521876/
6. Robinson AE, Pearson AM, Bunting AJ, et al. A Practical Solution for Preoxygenation in the Prehospital Setting: A Nonrebreather Mask with Flush Rate Oxygen. Prehosp Emerg Care. 2024;28(2):215-220. doi:10.1080/10903127.2023.2213761
7. Sakles, J. C., et al. (2022). Advanced Airway Management in Trauma: A Review of Current Practices and Controversies. Journal of Trauma and Acute Care Surgery, 93(4), 789-797. Retrieved from https://pubmed.ncbi.nlm.nih.gov/36655876/
8. Brown, C. A., & Thomas, M. L. (2016) Airway Management in Emergency Medicine. McGraw-Hill Education.
9. Frat, J. P., Thille, A. W., Mercat, A., et al. (2015). High-flow oxygen through nasal cannula in acute hypodermic respiratory failure. The New England Journal of Medicine, 372(23), 2185-2196.
10. Mosier, J. M., Sakles, J. C., Whitmore, S. P., et al. (2015). Failed noninvasive positive-pressure ventilation is associated with an increased risk of intubation-related complications. Annals of Intensive Care, 5(1), 4.
11. Moses, D. A., et al. (2018). Noninvasive positive pressure ventilation for pre-oxygenation and prevention of desaturation during emergency airway management. The Journal of Emergency Medicine, 55(5), 647.
12. Gibbs, K. W., Semler, M. W., Driver, B. E., et al. (2024). Noninvasive Ventilation for Pre-oxygenation during Emergency Intubation. The New England Journal of Medicine, 390(23), 2165–2177. Retrieved from https://www.nejm.org/doi/full/10.1056/NEJMoa2313680
13. Nickson, C. (2024, July 2).Preoxygenation. Life in the Fast Lane • LITFL. https://litfl.com/preoxygenation/
14. Byrne, F., et al. (1987). The effect of pregnancy on pulmonary nitrogen washout. Anaesthesia, 42(4), 346–351. Retrieved from https://pubmed.ncbi.nlm.nih.gov/3826588/
15. Chrimes, N. (2013).Preoxygenation. The Vortex Approach. https://www.vortexapproach.org/preox
16. Rezaie, S. S. (2017, September 14).Turn it (all the way) up: Flush rate O2 for pre-oxygenation. REBEL EM – Emergency Medicine Blog. https://rebelem.com/turn-way-flush-rate-o2-pre-oxygenation/
17. Heffner, A., Swords, D., Neale, M., & Jones, A. (2013, August 1).Incidence and factors associated with cardiac arrest complicating emergency airway management. Resuscitation. https://pubmed.ncbi.nlm.nih.gov/23911630/
18. Koch, E., Lovett, S., Nghiem, T., Riggs, R. A., & Rech, M. A. (2019, August 14).Shock index in the Emergency Department: Utility and limitations. Open access emergency medicine : OAEM. https://pmc.ncbi.nlm.nih.gov/articles/PMC6698590/
19. Behgam, B., Hagahmed, M., Zimmerman, D., & Haywood, S. (2020, August 3).Resuscitate before you intubate. ResusNation. https://criticalcarenow.com/resuscitate-before-you-intubate/
20. Chong, I., Sandefur, B., Rimmelin, D., Arbelaez, C., Brown, C., Walls, R., & Pallin, D. (2014, January 15).Long-acting neuromuscular paralysis without concurrent sedation in emergency care. The American journal of emergency medicine. https://pubmed.ncbi.nlm.nih.gov/24650718/
21. Bagdanvo, M., Nitschke, J., LoParco, S., Bartz, J., & Otto, R. (2021, August 31).Acute psychosocial stress increases cognitive-effort avoidance – Mario Bogdanov, Jonas P. Nitschke, Sophia Loparco, Jennifer A. Bartz, A. Ross Otto, 2021. journals.sagepub.com. https://journals.sagepub.com/doi/10.1177/09567976211005465
22. Droege, H., Trentzsch, H., Zech, A., Prückner, S., & Imach, S. (2023, November 17).A simulation-based randomized trial of ABCDE style cognitive aid for Emergency Medical Services Checklist in Prehospital Settings: The Chips-Study – Scandinavian Journal of Trauma, resuscitation and emergency medicine. BioMed Central. https://sjtrem.biomedcentral.com/articles/10.1186/s13049-023-01144-3#:~:text=are%20not%20diminished.-,Conclusion,of%20content%20and%20increases%20compliance.
23. Greig, P., Maloney, A., & Higham, H. (2020, May 28).Emergencies in general practice: Could checklists support teams in stressful situations?. The British journal of general practice : the journal of the Royal College of General Practitioners. https://pmc.ncbi.nlm.nih.gov/articles/PMC7194010/#b7
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