From the Departments of *Anesthesia, Dalhousie University, Halifax, Nova Scotia, Canada; and †Department of Anesthesiology, University of Alberta, Edmonton, Alberta, Canada.
The authors declare no conflict of interest.
Reprints will not be available from the authors.
Address correspondence to Orlando Hung, MD, Department of Anesthesia, Dalhousie University, Queen Elizabeth II Health Sciences, 1278 South Park St., Halifax, NS, Canada B3H 2Y9. Address e-mail to firstname.lastname@example.org.
Accepted September 20, 2011
Catastrophes are inevitable when backup plans fail. We witnessed what happened to New Orleans when the flood walls and levees failed during Hurricane Katrina in 2005, and more recently, on the northeastern coast of Japan when a backup power system failed to help cool the Fukushima nuclear power plant following an earthquake and resulting tsunami.
What about backup plans in airway management? Can we be relied upon to prevent catastrophes? During the last 2 decades, strategies, tactics, and guidelines for airway management have been developed to improve patient outcomes in managing difficult and failed airways.1–4 While these strategies have limitations, they serve to remind clinicians about the importance of careful and thoughtful strategic planning when dealing with patients with a challenging airway. Clinicians rely on 4 basic methods of ventilation and oxygenation: bag-mask, extraglottic devices such as the laryngeal mask airway (LMA), tracheal tubes, or when everything else fails, a surgical airway. In other words, a surgical airway represents “insurance” against failure to secure an airway by all other methods. But is this strategy working?
In 2008, a prospective United Kingdom audit attempted to capture all major airway events that occurred in operating rooms, intensive care units, and emergency departments.5–7 One hundred eighty-four “sentinel events” were identified, leading to 80 attempts at an emergency surgical airway, 58 of which took place in the operating room. Analysis revealed 3 important themes related to the performance of the surgical airway. First, surgeons were much more successful than anesthesiologists at securing surgical airways. While the overall failure rate of surgical airway was 16%, anesthesiologists failed to secure a surgical airway in 16 of 25 attempts (64%), and were “rescued” by their surgical colleagues in 11 of these cases. Second, emergency tracheotomies or surgical (open) cricothyrotomies were much more successful than needle or Seldinger cricothyrotomies. All of the 29 surgical tracheotomies and 3 surgical cricothyrotomies succeeded. In contrast, when needle or Seldinger cricothyrotomies were performed (mostly by anesthesiologists), 15 of the 26 attempts (58%) failed. The final and perhaps the most important lesson from this audit was that better planning and decision making could have avoided most of the emergency surgical airways. On the basis of the data presented, it is clear that despite substantial advancements in airway management tools and techniques, many anesthesia practitioners still do not have a sound strategy for managing the airway, and when faced with an emergency surgical airway, many fail to secure it.
Aslani et al.,8 in this issue of the Journal, studied the accuracy of identification of the cricothyroid membrane using the traditional palpation technique by 17 anesthesiologists and 7 obstetrical trainees. Using ultrasound to confirm the location, the authors reported that these clinicians performed poorly at identifying the cricothyroid membrane: only 23 of 112 (20.5%) identification attempts were accurate. Of 30 identification attempts in 15 obese patients, only 1 was correct. Surprisingly, there was no difference in success rates between the anesthesiologists and the obstetrical trainees. One could reasonably assume that these alarming findings are due to a small sample size were it not for an earlier study with similar disappointing results reported by Elliott et al.9 Eighteen anesthesiologists were asked to mark an entry point for cricothyroid membrane puncture on 6 healthy subjects of widely varying body habitus. An ultrasound technique was again used to confirm the borders of the cricothyroid membrane. Of the 108 identification attempts, only 32 (30%) were correct, and only 11 (10%) located the center of the membrane. In contrast to Aslani et al.'s study, this study failed to show a significant correlation between obesity and difficulty identifying the cricothyroid membrane.
A practitioner's inability to identify the cricothyroid membrane is a setup for an airway catastrophe. While recognizing the limitations of these studies, we cannot help but be disturbed by the consistent finding that anesthesia practitioners cannot reliably identify an important, and sometimes life-saving, anatomic landmark. The standard of care in airway management expects clinicians to promptly perform a surgical airway when faced with a “cannot intubate, and cannot ventilate” situation. Sadly, the findings of these reports suggest that the success rate of a surgical airway performed by anesthesia practitioners would be alarmingly low. The frequency of this failed “backup” plan should serve as a wake-up call for all of us. Perhaps it is time to re-evaluate the surgical airway as a rescue technique in airway management. Should surgeons perform all surgical airways? Is tracheotomy comparable to cricothyrotomy as an emergency surgical airway? Is there any evidence to suggest that open cricothyrotomy is easier to perform and more successful than a Seldinger cricothyrotomy? Is there a better Seldinger cricothyrotomy tool or technique? Would the use of an adjunct, such as an Eschmann Tracheal Introducer (“bougie”) or ultrasound, improve the success rate of cricothyrotomy? What is the role of transtracheal jet ventilation? While it is unlikely that there is only one simple solution, we believe that the answer lies in the application of 2 fundamental principles: education and embracement of a team approach.
First, we must properly educate health care providers in airway management skills and strategies. Emphasis ought to be placed on airway assessment, including airway anatomy, airway techniques, application of alternative nonsurgical airway techniques in appropriate clinical situations, and the development of proficiency in the attainment of a surgical airway. Practitioners need regular practice to perform a surgical airway on high-fidelity simulators, cadavers, and/or animal models. Like the ABCs of resuscitation, surgical airway should be included in all airway management training and simulation programs. To increase the accuracy of identifying the cricothyroid membrane, we recommend that all clinicians palpate and identify the location of the membrane prior to managing a patient's airway. We should also take every opportunity to teach our trainees how to perform a cricothyroid membrane puncture. This can be done, when clinically appropriate, by performing a transtracheal injection of local anesthetic through the cricothyroid membrane to topicalize the upper airway for awake intubation in patients with a difficult airway. Education plays the pivotal role in improving how we manage the airway.
Second, airway management must embrace a team approach. Collaboration and communication among health care providers, including our surgical colleagues, are critically important to airway management, particularly when a surgical airway is indicated. Anesthesia practitioners must engage our colleagues from emergency medicine, surgery, otolaryngology, and intensive care medicine in the development of educational and research initiatives, including the performance of a surgical airway.
It is likely that a failed airway, demanding the performance of a surgical airway, will occur at least once in the career of an anesthesia practitioner. It is thus imperative and expected that this practitioner be willing and able to perform a surgical airway. It is the standard of care. When all else fails to provide ventilation and oxygenation, an emergency surgical airway is no longer just an option, but rather, it is a necessity.
But even beyond the ability to correctly identify the cricothyroid membrane, we may have another problem: if most anesthesia practitioners cannot find the cricothyroid membrane to perform a cricothyrotomy, it is likely that most of them will not be able to identify the cricoid cartilage and apply appropriate cricoid pressure for rapid sequence induction and intubation in emergency airway management.
We have learned important lessons from Katrina and Fukushima about system errors, human errors, and performance errors. We have learned to take warning signs very seriously. The catastrophe of the failed airway can often be avoided if evaluation and planning are done appropriately. Failing that, it ought to be managed appropriately. Education is key to success. We must ask ourselves whether the findings reported by Aslani and colleagues are cause for concern. We must find out soon because, until then, we are left holding our breath.
Name: Orlando Hung, MD.
Contribution: Manuscript preparation.
Name: Jeanette Scott, MB CHB.
Contribution: Manuscript preparation.
Name: Tim Mullen, MD.
Contribution: Manuscript preparation.
Name: Michael Murphy, MD.
Contribution: Manuscript preparation.
This manuscript was handled by: Sorin J. Brull, MD.
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