What is the future of airway management in the ED? How can we make our practice more effective and more efficient? In this journal club recap, we focus on 2 topics emerging in the literature - flush rate O2 for pre-oxygenation and head of bed elevation during intubation. Take a listen to the podcast below and read the recaps of the articles to consider the evidence for yourself!
Driver B, Prekker M, Kornas RL, Cales EK, Reardon RF. Flush Rate Oxygen for Emergency Airway Preoxygenation. Annals of Emergency Medicine 2017;69(1):1–6.
The concept of “flush rate” oxygen is discussed in this paper along with the efficacy of its use in airway pre-optimization in the ED. It is already known that BVM at 15 L/min O2 has shown to be superior to NRB at 15 L/min O2 in this use for pre-oxygenation. Flush rate oxygen, which is essentially, turning the oxygen flowmeter knob all the way until it cannot be rotated farther, was measured against BVM to determine if this is as effective. Using a crossover study, healthy volunteers undertook trails of pre-oxygenation using BVM at standard O2, NRB at flush rate, NRB at standard O2, and simple face mask. FeO2 was measured from each participate following each trial following the concept of nitrogen wash out. This study did show that using this idea of flush rate oxygen with a NRB, was noninferior, if not more effective (though this was not their goal), than a BVM at standard rate.
Why is this good? BVM relies on resources- 1 way PEEP valves are necessary in order to adequately pre-oxygenate a spontaneously breathing patient, and these are commonly not supplied with standard BVMs. BVM relies on a tight mask seal. This can cause patient discomfort, be difficult to obtain, and also relies on the provider to hold the mask seal correctly during the pre-oxygenation process. Using a NRB at flush rate on a spontaneously breathing patient, frees the provider to continue preparing for intubation without the worry and tiring out of holding a mask seal, all while maximizing patient comfort.
This was a fantastic, simplified study that shows the potential of flush rate oxygen. The subjects in this study were all overall healthy, and not completely applicable to the general ED population that needs intubation. However, this is an easy intervention, go ahead and turn that dial up and maximize your chance for success.
Khandelwal N, Khorsand S, Mitchell SH, Joffe AM. Head-Elevated Patient Positioning Decreases Complications of Emergent Tracheal Intubation in the Ward and Intensive Care Unit. Anesthesia & Analgesia 2016;122(4):1101–7.
This article is a retrospective, observational study that aimed at exploring the relationship between patient positioning during intubation and airway-related complications. Given the nature of their retrospective analysis a causal relationship could not be explored and instead they were able to evaluate the odds of airway related complications based upon patient positioning. The population they studied were patients from a large academic medical center that required intubation via direct laryngoscopy in either the ICU or hospital ward setting. They specifically excluded patients intubated in the operating room or emergency department.
The bottom-line of this article is that the authors found that placing patients in a back-up, head-elevated position reduced the odds of an airway related complications. Specifically, they evaluated for the occurrence of a difficult airway (defined as requiring greater than three attempts, longer than 10 minutes, or conversion to a surgical airway), hypoxemia (oxygen saturation less than 90%), esophageal intubation, or pulmonary aspiration.
The study evaluated the chart documentation for 528 patients. In the supine position group 22.6% of patients suffered at least one airway-related complication in comparison to the bed-up, head-elevated position group where only 9.3% experienced at least one complication. Interestingly, the authors performed three linear regression models (composite, difficult airway only, and hypoxemia/esophageal intubation/pulmonary aspiration only) and found that the difference noted above was driven by fewer occurrences of hypoxemia, esophageal intubation, and pulmonary aspiration with no significant difference in difficult airway rates.
Although this article specifically excludes emergency department intubations (as well as any intubation performed by an emergency medicine provider) it still warrants consideration by Emergency Medicine providers. The patients evaluated in this study were all intubated under emergent conditions which is reflective of our patient population. Additionally, the authors evaluated for airway-related complications that have clinical value as I consider the risks and benefits of my airway management strategy. The retrospective nature of the study prohibits the ability to draw a causal relationship but does suggest that elevated patient positioning could provide beneficial.
Overall, this article alone is not sufficient to change my practice by itself as the nature of the study is not rigorous enough to allow us to draw those types of conclusions. With that in mind, there are some patients in the ED who, due to their body habitus or chronic medical conditions, would intuitively benefit from a more upright intubation attempt. In my opinion this article does support considering a more upright position for their intubation strategy. Ultimately, a bed-up, head-elevated position for intubation does show promise and this article adds to the growing literature base supporting the need for additional research.
Turner JS, Ellender TJ, Okonkwo ER, et al. Feasibility of upright patient positioning and intubation success rates At two academic EDs. American Journal of Emergency Medicine 2017;35(7):986–92.
In this journal club article, Turner et al. investigated whether having patients in a head elevated position during emergent intubation resulted in a significantly significant increase in first pass success when performed by emergency medicine residents. This study was a prospective, observational study at two academic emergency departments. A total of 231 intubations were performed by 58 different residents to compile the results of their study. First pass success was 65.8% for the supine group (0-10 degrees of head elevation), 77.9% for the inclined group (11-44 degrees of head elevation), and 85.6% for the upright group( (p = 0.024).
Weaknesses of this study included that they did not have "undergoing CPR" as an exclusion criteria. 13.2% of the supine patients were undergoing CPR during intubation, which could serve as a significant cofounder, making it more difficult to intubated these patients. Additionally, it was an observational study so patients were not randomized when selecting elevation of the head-of-bed.
Strengths included that the study authors had rigid protocol for what constituted an attempt at intubation, who was collecting data for their secondary endpoints, and how to resolve discrepancies in data collection. This helped preserve the integrity of the data collected. Additionally, the study was applicable to our practice given that it studied an ED patient population.
- Driver, et al - Kevin Randolph, MD
- Khandelwal, et al - Gerard Colmer, MD
- Turner, et al - Issac Shaw, MD
Edited and Posted by Jeffery Hill, MD MEd