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ALTERNATIVE AIRWAYS impacting cerebral perfusion due to infla- tion of the cuffs on the airways. Specifically at question was whether the cuffs presented a danger by pressing directly or indirectly on the carotid ves- sels. 19 This concern was recently countered with a case series based on human patients who had CT scans of their neck performed while being ventilated through alternative airways. Neuroradiologists could not iden- tify any mechanical impact on the carotid vessels. 20 We certainly need more studies on this issue, but for now it appears men are not actually pigs! If ongoing research continues to reflect positively on the use of extraglottic airways, we envision these devices being used not only in EMS, the OR and the ED, but for cardiac arrests throughout the hospital, not just as backup airways but increasingly as airways of choice in situations where time and training are critical. Imagine being called for a patient who has suffered a cardiac arrest or similar life- threatening situation. Whether you are an EMS provider, an ED staff member or part of the rapid response team, an alternative airway can be placed immediately without stopping compressions. Even better, you can decompress the stomach and continue ACLS without becoming distracted by intubation. If there is return of spontaneous circula- tion, the airway can later be exchanged for an ETT. How: Questions and Answers How do you figure out which size? • For the King airway, estimate the patient height. (For pediatrics you can also use ideal body weight.) Look at the packag- ing for sizing information. • For lar yngeal mask air ways and i-gels, estimate the patient's ideal body weight (adults and pediatrics). Look at the packaging for sizing information. (An exception is the size 5 LMA Supreme, which is based more on height than weight. Ask a company representative for more information if using this device.) How much air do you need to inflate the device with? • For the King airway, look at the outside of the package or side of the device for a range. If a range is given, inf late with the range's average volume and attempt venti- lation. Adjust the volume in small incre- ments as needed to prevent detectable air leaks and achieve good chest rise. Better yet, use a manometer! (The desired pressure is 40–60 cm H 2 O.) • For laryngeal mask airways, look at the outside of the package or the device/pilot balloon. If a range is given, inflate with the range's average volume and attempt ventila- tion. Adjust the volume in small increments as needed to prevent detectable air leaks and achieve good chest rise. Better yet, use a manometer! (The desired pressure is 40–60 cm H 2 O.) If a < symbol is present, start with half of what is recommended and increase as above. • For i-gels, no inflation is needed. How do you know if the device is in the right spot? • Supraglottic devices will "seat." • The LMA Supreme has a fixation tab that can be used to assist in determining the correct depth. This tab should be about one finger's breadth above the lip when device "seats." If it's farther out, a smaller size is most likely needed. If you hit the lip before it seats, a larger size is most likely needed. • With retroglottic devices, it is easy to overinsert. Pay attention to teeth markings. When in doubt, it usually needs to be with- drawn a bit. How do you confirm effective ventilation? • Use capnography if it's available. When successfully utilized, these devices will have a detectable EtCO 2 reading. Presence of a near- normal EtCO 2 waveform is crucial. If EtCO 2 is not detected, suspect that a retroglottic device is placed way too deep or a Combitube is being ventilated from the incorrect port. • Chest rise and fall (as opposed to increas- ing abdominal distention) is important. • Oxygen saturation readings and/or patient color should be improving (or at least not worsening). How do you secure the airway to make it stay in the right spot? • With the i-gel and O2 Resus, tape it to the face or use an airway support strap. • If using a commercial securing device, be aware that not all of them fit all extra- glottic devices. • Although alternative airway devices are much more forgiving than an endotra- cheal tube, failure to secure can still lead to inadequate and even failed ventilation. How long can you leave an alternative airway in place? • In most EMS systems this is not an issue—simply leave it in. When care of the patient has been transferred to the ED staff, they will follow their own protocol. • Manufacturers recommend removing or exchanging the extraglottic device for an ETT after a few hours. • There are reports of military cases where the devices have been left in place for several days without complications. 21 How do you exchange an extraglottic airway for an ETT? • First of all, if it's working, consider leaving it alone! • For the King airway, don't try the bou- gie trick. This is no longer recommended by the manufacturer. Make sure the patient is well oxygenated and the stomach is emp- tied. Then def late the balloon and sweep the device over to the left side of the mouth. This technique usually allows enough work- ing room to intubate while keeping the suc- tion going and the esophagus blocked. And now there's just one hole available! • For the Combitube and Easy Tube, def late the proximal pharyngeal balloon, but leave the distal esophageal balloon inflated. Sweep the device all the way to the left of the mouth as with the King airway. • For the LMA Supreme, no good option is readily available. Oxygenate the patient as well as possible, empty the stomach, then pull the device out. An exceptionally profi- cient practioner can work around it with a video device, but this method is not gener- ally recommended. • For the air-Q, it is reasonable to try blind intubation using the manufacturer's 42 OCTOBER 2015 | EMSWORLD.com