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View Full Version : The basic airway modalities (part 2)


jagdkampf
02-23-02, 06:20
Now that we have looked at airway assessment and can get a general idea what we are faced with let's look at some of the tools we use to manage airways.

(1) The most basic is mouth to mouth resuscitation that we learn in BLS. It still works guys! In the field, you may not have many tools at your disposal but this still works. I won't go into the technique here as most of you probably know how to do this. If not, consult a first aid or BLS guidebook. They will cover it in detail. The biggest downside to this technique is exposure to body fluids and resultant infection and the potential for aspiration of stomach contents by the patient. The second is the delivery of sub normal oxygen percentages and high carbon dioxide percentages. The first pitfall we can avoid by carrying a pocket mask. This is a collapsible barrier mask that will easily fit in a jacket pocket, cargo pocket or backpack. This should be a mandatory part of your first aid kit. The second problem (low 02 - high co2), is not a problem we can do much about in the field. Just recognize the consequences. Delivery of low 02 and high co2 brings about a condition called acidosis. This is where the blood becomes more acidic than normal. It causes a host of bad things to happen. But if mouth to mouth is all you have -- use it.
(2) The Bag/Mask resuscitator - Most hospital providers and Paramedics/EMT's will recognize this device. It is basically an self inflating bag with an O2 port and resevoir connected to a mask. Given a supply of oxygen, you can deliver 100% O2 and diminish the risk of acidosis, if the patient has adequate circulation. It does not diminish the risk of aspiration but used properly it protects you from body fluids. While it is a little large for field transport, it can easily be placed in the trunk of your car or prepositioned in a remote field hospital. The bag/mask resuscitator is readily available on the surplus market and possibly through this board.

(3) The oropharyngeal airway - This a small curved plastic device that is placed in the mouth to provide a pathway for air to follow. It supports the tonque and keeps it from falling back and obstructing the airway. There are two general types, the Berman and Hudson type. It really doesn't make much difference which you use and they essentially look the same. I prefer the Hudson as it is softer and is easier on the teeth but whatever you can snag is fine. They come in different sizes (0 thru 5)or measured in millimeters (40 thru 105mm). 0 and 40mm are for infants, 5 and 105mm for large adults, and the other sizes for everybody in between. These are relatively compact and in my opinion, you should pack some of these with your pocket mask. Just carry the appropriate size for the party you are with. These are readily available on the surplus market. The technique for insertion is as follows: grasp the lower jaw and tonque between your thumb and forefinger, open the mouth and begin insertion with the curved/non flanged end into the mouth in a sideways position. As you advance the airway, turn it so that the curve is down toward the lower body. Make sure that you do not push the tonque back with the airway. Remove your fingers from the tonque and hold up on the chin firmly holding the airway in place with the teeth.
From this position, you can place your pocket mask over the nose and mouth and begin ventilation if necessary or use the bag/mask resuscitator. The disadvantages of the oropharyngeal airway are that they are not tolerated well by responsive patients and they do not prevent aspiration.

(4) The nasopharyneal airway - This is a small curved rubber tube with a flange on one end. It comes in several different sizes (usually 28 - 32mm). This is primarily intended for adult usage and is not generally recommended in the infant or pediatric population. While not as good as the oropharyngeal airway for manually ventilating a patient, it is better tolerated by a conscious or semiconcious patient and works pretty well for those patients who are spontaneously breathing and just need a little help opening the airway. It also works very well for patients who are clenching their teeth, i.e., seizure disorders. The technique for insertion is as follows: (1) lubricate the airway with KY jelly or water. (2) push gently up on the tip of the nose and look down the nose holes (nares), generally you will see the nasal septum in the midline. (3) put the non-flanged end of the airway into the nares that appears the most open with the curved end down toward the body. (4) push gently but firmly until the flange seats against the base of the nose. You should hear air passing through the tube. If you meet obstruction, stop and try the other nares.
The downside of this techniques is the potential for causing nosebleed. I generally spray my patient's nose with Afrin nasal spray prior to starting this but you may not have it in the field. Use good judgement and discretion here, you don't want to complicate a marginal airway with a nosebleed. No fun whatsover! Again, this does nothing to prevent aspiration.

This concludes what I consider the basic airway modalities. Next installment will cover intermeadiate airway modalites. Any questions?
Jag

tangent
02-23-02, 14:42
Q: any rules of thumb for sizing naso/oropharyngeal airways? - ie: RR had mentioned that a good rule of thumb for ET tubes was to find a tube that is the diameter of the patients little finger - anything like that?

Q2: what's the cut off point for going from a pedi BVM to an adult BVM? (like age).

jagdkampf
02-24-02, 11:40
Q1 -- Airway sizing

On children and infants, I generally discourage the use of nasopharyngeal airways because of adenoid tissue. A nasal airway can dislodge adenoid tissue and cause bleeding or push the adenoid tissue into the oropharynx causing obstructions. If you have to use one, the size of the little finger would be a good reference.
In adults, I generally use a 28F on females and a 32F on males, but the little finger trick will work here as well.

Oropharyngeal airways are generally sized in reference to the distance between the corner of the mouth and the ear lobe. Just lay the tip of the airway at the corner of the mouth and the flange should come within 1/2 inch of the ear lobe. It should not be longer than this distance.

Q2 -- BVM cutoff

I double checked with my wife on this one (She was a NICU nurse). I use an adult BVM on anyone greater than 10 years of age. From 2 - 10 years of age, I use a pedi BVM. My wife says they use infant BVM clear down to preemies but I use a little different setup for infants. I prefer the Jackson/Rees circuit. It is a non - self inflating bag. It requires a constant flow of oxygen coupled with an adjustable valve to keep the bag inflated. It also has a pressure port which can be coupled to a manometer to measure airway pressures. It is quite possible to produce a pneumothorax in infants/neonates with aggressive ventilation. The Jackson/Rees allows you to precisely control and regulate inflation pressures, although most pedi BVM's have a pop off valve to prevent over pressurization.

good questions tangent, any others?
Jag

SwedeGlocker
02-24-02, 12:19
My favorite is nasal airways. I not a big fan of J-tubes but keep a few in my first line kit. Some Qs 1 I have not heard mutch about bleedings from the nose when you use nasal airways( exept for nasal intubation in Hyperthermia patients). A guick searth didnt find anything. I saked some people with more than 20 years experience and they didnt think that it was common. How often does this happen? With type of nasal airways do you use when this happen.

jagdkampf
02-24-02, 12:30
SG
I do not encounter nose bleeds often in adults. I do spray the nose with Afrin prior to inserting nasal airways and copiously lubricate them. In my opinion, nosebleed are not common, particularly if you use the soft nasal airways. Some of the nasal airways on the market are quite stiff. These are more problematic. I have not used nasal airways in children. I have done one nasal intubation in 16 years of practice on an infant that required reconstructive mandibular surgery and did encounter adenoid tissue on the end of the tube as I passed it. I had to suck off the adenoid prior to advancing the tube into the trachea. I do like nasal airways in adult patients, particularly those who are semi-concious, sedated or awake.
Jag

RESQDOC
03-03-02, 10:27
Outstanding post.

I love nasal airways and put them down anyone I am concerned about having the potential for possible airway compromise. They are included in all of our personal aid kits and equipment kits. Ditto Jag on use in smaller kids and babies. Don't leave home without them. In the field I do not bother with Afrin, but it's nice if you have it. Lubricate well. KY is nice, more than once in the field I have simply used my own spit, don't tell the patients. :grin: