Airway management is arguably the most important capability the prehospital provider brings to the patient. The ability to mitigate issues involving the airway is something that could be the proverbial difference between life and death. Now with the variety of techniques and tools, the well trained and well equipped prehospital care provider can essentially deal with any airway issue. In this post I want to discuss one of the main tools in our toolbox, the supraglottic airway.
Supraglottic airways are any advanced airway that does not have to enter the trachea directly (sits above the glottis). While there are a variety of different style supraglottic airways, the goal is the same. They are intended to be placed rapidly allowing for quick airway control and reliable ventilation and oxygen delivery. Most of these devices sit above the glottis, blocking the esophageal opening and directing oxygen towards the tracheal opening. Over the past decade, many new generations of these devices have been introduced, proving them to be more effective and efficient than ever before. It is been demonstrated that newer generations of supraglottic airways can now provide successful rescue ventilation in > 90% of patients in whom mask ventilation or tracheal intubation is found to be impossible (or difficult).
The mantra from the EMS industry is that these are second line airways and that endotracheal intubation reigns supreme. I would argue the opposite. What is the goal of airway management? As mentioned above it is to secure the airway, ventilate to allow for the regulation of carbon dioxide and deliver much needed oxygen, all while (most importantly) preventing or minimizing any hypoxic event. As prehospital professionals, we can all agree that the faster we can accomplish these goals, the better outcomes we can expect for our patients. This begs the question, can placing a supraglottic airway often times be more appropriate than intubation? I would say, for good of our patients, yes.
This is for a variety of reasons. First, placing a supraglottic airway is fairly simply. By having less steps involved in the process, there is less of a risk for human error. Secondly, these airways are designed to be placed blindly, decreasing the chance of a misplaced airway. Lastly, most of these devices come equipped with a gastric channel or port. This allows for a gastric tube to be easily placed to allow for decompression of the stomach after BLS bagging.
Successful intubation on the other hand relies heavily on technique, experience and patient anatomy. This makes intubation a less desirable airway management technique in comparison to the supraglottic airway. A 2011 study out of Japan looked at the efficacy of supraglottic airways vs endotracheal intubation in out of hospital, non-traumatic cardiac arrests and found no difference in their ability to deliver ventilations and oxygen. Given that the supraglottic airway took less time to place, one can infer that it was superior for this reason. To be fair, the study looked at the EMS system out of Osaka (no disrespect to the prehospital care providers in Japan) which may not offer the same level of care as their US, European and Australian counterparts. It would appear that their providers were the equivalent to US EMT-Intermediates. This was my perception so please correct me if I am wrong.
So, why would we intubate? I can only think of a couple reasons that intubation should be your initial thought. First, any sort of airway trauma that could compromise the patency of the a supraglottic airway. Second, burn or medical patients that require early elective intubation prior to worsening edema of the airway. Otherwise, I will give strong consideration to supraglottic airways for my patients that need rapid airway management.
Rapid Sequence Airway
All that being said, how do we safely introduce a supraglottic airway in the semiconscious patient or someone with an intact gag reflex? This concept of RSA (rapid sequence airway) serves a role, especially in a patient with an anticipated difficult airway. The idea is that you can administer a sedative and paralytic to ease the placement of a supraglottic airway. After the supraglottic airway is placed, the patient’s oxygenation can be optimized and then the decision to replace it with an ET tube can be made. This may be a particularly useful procedure in the prehospital setting, where the personnel available to intubate may be limited.
Quick Notes on Supraglottic Airways
- Supraglottic airways are potentially faster and easier to place than an ET tube
- 4 quick steps: Right patient, right size, right positioning, right technique.
- Find out if your supraglottic airway has a gastric tube port. Use it.
- Some supraglottic airways are capable of being intubated through, if feasible attempt intubation.
- RSA is a useful method to rapidly secure an airway in your patients who are predicted to have a difficult airway. Supraglottic airways are not JUST backup airways. Placement of an LMA, King LT, iGel, etc. does not mean the practitioner is unskilled or failed at intubation
- RSA Proceduer is RSI with placement of a supraglottic airway rather than an ET tube
- Prepare equipment
- Administer sedation
- Administer paralytic
- Position patient
- Place supraglottic airway
- Secure and assess placement
- Post sedation
- Assess need for eventual ET tube placement
- Rapid sequence airway vs rapid sequence intubation in a simulated trauma airway by flight crew: http://www.ncbi.nlm.nih.gov/pubmed/20171002
- Japanese Suppraglottic Airway Study: