Review of:Tumpach EA, Lutes M, Ford D, et al: “The King LT versus the Combitube: Flight crew performance and preference.” Prehospital Emergency Care. 13(3):324 328, 2009.
The Science
This interesting and straight-forward study looked at the ease of use of the King LT and Combitube, both blind insertion rescue airways. The authors used volunteers from a flight team consisting of physicians, flight nurses and flight paramedics operating out of Milwaukee. There were 27 participants with a wide range of experience, from first-year residents to 20-plus year paramedics.
The participants, who all had experience with the Combitube, were given a 10-minute instructional video followed up with one practice attempt with the King LT. They were timed while inserting each rescue airway. On average, the Combitube took 37.9 seconds to insert while the King LT took 24.4 seconds, a difference of 13.5 seconds. The time started when the subject placed their hands on the airway and ended when auscultation occurred.
The authors readily noted the limitations of this study, which include using a SimMan, being in a controlled environment and lacking the ability to measure the effectiveness of either device. The authors concluded that, after brief instruction and practice, aeromedical personnel were able to successfully insert both devices 100% of the time in a controlled setting, but they were able to insert the King LT quicker than the Combitube and overwhelmingly preferred it.
The Street
We should look further into the use of blind insertion rescue airway devices as a primary method of airway management in the prehospital setting. Let’s take it from two different perspectives — the physician and the paramedic.
Doc Wesley:For the airway folks out there, this study has some significant implications. Our patients who require advanced airway maintenance — cardiac arrests, RSI patients, and patients in severe respiratory distress — need this advanced airway maintenance to be performed quickly. Generally speaking, when we get to the side of our patients who require an advanced airway, they may have already passed that critical threshold beyond which we can pre-oxygenate them while preparing our equipment.
Imagine a patient in cardiac arrest who has only been down four minutes prior to EMS getting to their side. Unfortunately, that patient has already not been breathing for four minutes and is now hypoxic. Now, think how long it takes to prep all the equipment for endotracheal intubation (ETI). This includes inserting a nasal pharyngeal airway (NPA) or oral pharyngeal airway (OPA), ventilating the patient, pulling out and testing the correct endotracheal (ET) tube, pulling out and assembling the laryngoscope with blade, preparing the gum bougie or stylet and the EtCO2 device, etc. The point is, there are many steps to performing ETI, and these steps take valuable time.
The King LT provides a huge advantage over ETI. It’s fast, effective and, most importantly, easy to use. Though I don’t foresee ETI ever going away as a paramedic skill, this study reinforces the potential value of blind insertion airway devices, and we should consider changing their role from rescue airways to first-line measures for securing an airway in the prehospital setting.
Medic Marshall:As a medic, I find this study interesting but not surprising. I think the authors did an excellent job of evaluating and demonstrating the ease of using the King LT compared to the Combitube while realizing the limitations of the study, which include using a Laederal SimMan instead of measuring actual field use. Furthermore, the authors note they didn’t evaluate the effectiveness of oxygenation, ventilation and airway protection.
I find it conceivable that King LTs will surpass ETI for primary airway management in the prehospital setting if research continues to demonstrate the ease of use and effectiveness. It’s noted in procedural textbooks and international guidelines that airways need to be established 30 seconds before patients reach the critical point of hypoxia. Personally, as a “street medic,” I much prefer the use of the King LT over ETI and Combitube because I have found it to be fast. I also find it to be efficient, effective and easy to use.
I hope these researchers take the next to step to look at the effectiveness of the King LT and make a stronger argument for its use as a primary method of airway management in the prehospital setting. ETI is a great skill, and I realize those before me fought very hard to put such a difficult procedure into the hands of paramedics. But, technology has provided us with a new means of airway management, one I think we should all begin to adopt.
The “gold standard” of airway management in the prehospital setting isn’t an ET tube, but the establishment of an airway. Without it, we can’t get to that next critical step breathing.
