When faced with a “can't intubate, can't oxygenate” crisis, the decision to move to a surgical airway must be made rapidly and deliberately. A surgical cricothyroidotomy is debatably the better approach in these situations, but a needle cricothyroidotomy may sometimes be indicated. It may be easier to perform in a very small child, for example, and although it is probably less than ideal in an adult, a rapid needle cricothyroidotomy may provide an oxygenation bridge that will prevent a critically hypoxic patient from arresting until a more definitive airway is secured.
Cricothyroidotomy with an over-the-needle catheter itself may be easy to perform, but the more technically and logistically difficult part of the procedure remains how to deliver oxygen through a 14G catheter. In the absence of a proper percutaneous transtracheal catheter oxygenation setup such as an Enk oxygen flow modulator or a Roy Rapid-O2 device, many different improvised setups have been described. These all have advantages and disadvantages, but the main disadvantage is that they involve putting together parts that were not designed to play nice with each other.
I explain this novel setup that may be effective in providing percutaneous transtracheal catheter oxygenation in a video posted on EMN's website. (http://bit.ly/1EluCy0.) The system, consisting of large-bore suction tubing and a meconium aspirator, plus-or-minus zip ties, is connected to the oxygen regulator Christmas tree. A maximum flow rate can then be set at the oxygen regulator (typically 1 liter per minute per year of age to a maximum of 15 liters per minute,) with further regulation of flow and delivery of breaths by occlusion of the side port on the meconium aspirator. The large diameter of the exhalation port (the same side port on the meconium aspirator) should allow for adequate exhalation, although the limiting factor here will likely be the caliber of the catheter.
I requested FOAM community feedback on Twitter, YouTube, and Google+, and the PHARM Podcast comments section has helped improve on the concept, with a few notable changes. The use of zip ties to secure the tubing to the regulator and to the aspirator is likely unnecessary. (Thank you, @ketaminh, @TBayEDguy, and @MikeSteuerwald.) The system coming apart under excessive pressure may provide an extra layer of safety over providing too much pressure to the patient.
The other major change came at the suggestion of Scott Weingart, MD (@emcrit), who, like many others, was concerned about the feasibility of putting together the homemade ETT to male Luer lock adapter. His brilliant solution is to use a male Luer lock to Christmas tree adapter, which is commercially available and designed for this very purpose (Multipurpose Tubing Adapter, Cook Medical; http://bit.ly/1KLe341.) Attach a cut-off ETT to the Christmas tree end and screw the Luer lock end into the catheter. The meconium aspirator can then be connected to the ETT adapter, as shown in the video and oxygen can be delivered by occluding the port of the meconium aspirator as described.
The multipurpose tubing adapter from Cook Medical is a male Luer lock to a universal taper. (http://bit.ly/1KLe341.)
The advantages of this setup is that all parts are stock, and nothing has to be manufactured; it just has to be put together in the right order. Another advantage of the multipurpose tubing adapter is that, like the meconium aspirator, it has several uses because it can be used for draining fluid after paracentesis or thoracentesis and for irrigating through a chest tube as may be needed in the severely hypothermic patient.
My recommendations, still being studied and revised, are:
- Put the kit together ahead of time. Suction tubing, a meconium aspirator, a male Luer multipurpose tubing adapter, ETT, and an old-fashioned nonsafety 14G catheter are required. The zip ties are optional.
- Have a backup plan. The methods previously described do work. A 7.0 mm ETT adapter will fit directly into the barrel of a 3 ml syringe, which has a male Luer lock tip. I would avoid the 3 mm ETT adapter directly into the catheter method as well as the three-way stopcock method unless that's all you have.
- High flows may not be needed. 1 LPM per year of age to a maximum of 15 LPM is probably adequate and a safe starting point. Alternatively, 15 LPM is probably safe on everyone.
- Using a BVM is inadequate and will not work because you cannot generate enough pressure or flow. Get or put together a proper PTJV setup that allows for adequate flow and exhalation.
There's a long story behind the birth of this setup. Back in the late 1990s and early 2000s, in the early stages of the Internet, and before blogs or FOAM, there were Usenet newsgroups. A popular Usenet newsgroup among paramedics and a few EMS physicians was misc.emerg-services. There, a motley group of providers with strong opinions and a passion for learning gathered to discuss cases and prehospital care. It was a discussion on that newsgroup that made me question what I had always been taught and had taught others that using an adult BVM to ventilate through a 3 mm ETT adapter straight into the 14G catheter hub or through a 6.5 mm ETT fit into the barrel of a 3 ml syringe Luer-locked to the catheter or hooking O2 tubing to a three-way stopcock would be effective.
Through trial and error, I practiced all these methods ahead of time and found them clunky and ineffective. I then started to play with all the equipment available and see what fit well with what, trying to find equipment that was designed to fit each other. I needed something that would hook up to tubing of some sort that had a ventilation hole and would fit a 15 mm port. Of course, the answer was the meconium aspirator. I played with the setup and was happy about how easy it was to put together and how easy it was to deliver flow.
The one problem was that the system came apart at very high flows. The answer to that was the zip ties. (Our ETT holders at the time came with small zip ties, so they were already available in our airway bags.) The only weakness remaining was the connection between the meconium aspirator and the 14G catheter. I could not find anything that went from a 15 mm port (ET adapter) to a Luer lock. Finally, I decided to make my own, finally arriving to the IV port cap to ETT adapter solution described in the video. This is the setup I've had with me for years. I am thankful to Scott Weingart, MD, for his elegant improvement to the setup and to the rest of the FOAM community for their comments and contributions.
Input from FOAM
Dr. Solis asked the FOAM community for assistance in refining his technique. Read some of their comments in Dr. Mellick's blog on our website at http://bit.ly/1IDFzyR.
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