# laryngoscope blade question



## alright35 (Oct 28, 2009)

ok guys, i am doing my homework for medic class tomorrow and our teacher told us to look up the differences between 5 laryngoscope blades and to explain them. i can't find anything in my book or online as to advantages or disadvantages of these blades, besides straight and curved. any help whether it be info or a website or anything would help thanks guys. below are the five blades he asked about

miller, macintosh, wisconsin, flagg, phillips
 i know miller, wisconsin, and flagg are straight, but thats all
and i know macintosh is curved

o and i did search, found nothing


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## HuiNeng (Oct 28, 2009)

*Well, here's something about Flaggs*

Google "Flagg laryngoscope"; yields
http://www.egeneralmedical.com/welalflaglar2.html

Features:

    * Flagg blades are a traditional style with a "C" shaped cross-section.
    * The tip has a small curve, and the width of the blade decreases gradually from proximal to distal end. 

Product Information:

The Welch Allyn Flagg Laryngoscope Blades, Size 2 (Model 63482) offer quality in a traditional style.  

The Flagg is the precursor of the traditional Miller blade and was originally designed for intubation of Flagg catheters and tubes  

Key Components:  
Flagg Laryngoscope Blades, Size 2  
2.5v Vacuum Lamp (Large)  

Technical Specifications:  
Inside Vertical Measure: 13 mm  
Length Inside Base to Tip: 102 mm


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## VentMedic (Oct 28, 2009)

Different manufacturers make different styles of each type of blade.

http://www.laryngoscopes.net/

Once you learn about assessing the factors that determine intubation difficulty, you will know why the shape of each blade my be important.  There is a little more to it than "I like curved".  Those that just state personal preference and can not tell you "why" have not properly learned the fundamentals of intubation and probably shouldn't be intubating to add to some of the poor stats. 

Look up Intubation Difficulty Scale, Mallampati, and LEMON.


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## alright35 (Oct 28, 2009)

*thanks*

thanks guys, i figured i would just go in with basic info, i mean i am paying to learn so hopefully lecture and lab will explain more tomorrow. i figured intubation is one of those procedures you eventually pick up your own tips/tricks and preferences for, which i am sure comes with practice, and actually doing it to figure out.


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## mycrofft (Oct 28, 2009)

*Skip the Ginsu blade.*

.............


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## MasterIntubator (Oct 28, 2009)

Like Vent in saying... once you learn "Why" and know your "whys", it all comes together nicely.  Like you said.... takes time and practice.  There are sooooo many types and styles, many are not worth the money spent on them, but the most simplist of designs will usually always win.

Good job searching and doing your own homework... that is the skill many lack

:-/


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## emtfarva (Oct 28, 2009)

alright35 said:


> ok guys, i am doing my homework for medic class tomorrow and our teacher told us to look up the differences between 5 laryngoscope blades and to explain them. i can't find anything in my book or online as to advantages or disadvantages of these blades, besides straight and curved. any help whether it be info or a website or anything would help thanks guys. below are the five blades he asked about
> 
> miller, macintosh, wisconsin, flagg, phillips
> i know miller, wisconsin, and flagg are straight, but thats all
> ...


I know with millers and macs, they are used differently...
Millers are used for trauma and kids...
Thats all I know...


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## Shishkabob (Oct 28, 2009)

In reality it's whatever your comfortable with, while still being proficient with whatever blade is thrown your way in a call.


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## VentMedic (Oct 29, 2009)

Linuss said:


> In reality it's whatever your comfortable with,


 
Which is why a lot of people fail at intubations or do unnecessary damage to the patient.  You need to assess the patient and take into consideration their structure rather than what you liked best on a manikin in school.


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## emtlady76877 (Oct 29, 2009)

I am sorry that I am about to take this in a different direction but I am about to do my first OR rotation in my clinicals to get my intubations. I was reading these post and I just have to ask. I was trained with only the Mac & Miller and I am just as comfortable using either one. But how do I know which one to use on which patient I read it wasn't what we was more comfortable but it was the anatomy of the airway of the patient. I don't want to damage anybody's airway or vocal cords.


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## EMSLaw (Oct 29, 2009)

VentMedic said:


> Which is why a lot of people fail at intubations or do unnecessary damage to the patient.  You need to assess the patient and take into consideration their structure rather than what you liked best on a manikin in school.



I'm not a medic, though I'm seriously considering more advanced medical studies at some point, so bear with me if this is a silly question...

But don't most medics only carry Miller (straight) and McIntosh (curved) blades, rather than all the available options listed on the page you gave?


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## VentMedic (Oct 29, 2009)

EMSLaw said:


> But don't most medics only carry Miller (straight) and McIntosh (curved) blades, rather than all the available options listed on the page you gave?


 
Yes, usually different sizes of a straight and curved blade are carried. However, if you notice between my link and HuiNeng's link, there are different manufacturers with different variations or styles of the two basic shapes. Thus, if you went to a different company, you may have to get used to a slightly different angle, glide or slide on the blades. Some may be a little thicker, broader or taller. You may not have the clearance with one that you have with another or the weight might feel different for balance.


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## fma08 (Oct 29, 2009)

VentMedic said:


> Different manufacturers make different styles of each type of blade.
> 
> http://www.laryngoscopes.net/
> 
> ...



So after one assess the airway using one or more of the aforementioned techniques, how does the information from that assessment determine which blade is to be used? (Went back to my books before asking and found nothing)


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## EMSLaw (Oct 29, 2009)

I was doing a little reading on some of what Vent discussed, and found the following powerpoint presentation, that I thought was very interesting.  It's from a lecture on managing the difficult airway.  

Warning: Don't view right after eating.  Some of the pictures are a little graphic.

Here's the link.


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## Dominion (Oct 29, 2009)

In my recent OR clinicals I spent time with an SRNA student and the Anestheiologist assigned to our cases.  She swore by millers and said she only uses miller blades.  

The doc on the other hand said he liked Mac better for adults and some kids, and miller only on very specific circumstances.  But he preferred a mac+he recommended a mac to a new person. 

I used both and I found on the miller I would go to the esophagus and start withdrawing the blade till I saw cords.  While this isn't probably the most ideal way to do it, it worked for 3 patients but took longer and was more delicate of a procedure.

I then did several patients on the mac and I found the mac MUCH easier to use until I got my first 'bigger' patient.  This is a peds clinical and my Mac blades worked great till we got a 9year old and I started having problems although I did finally view the cords and pass the tube.  

Neither of them really mentioned when and why to use mac over miller in the assessment of a patients airway.  But I will ask the next time I go.


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## VentMedic (Oct 30, 2009)

The link EMSLaw posted is very good and worth watching. 



Dominion said:


> In my recent OR clinicals I spent time with an SRNA student and the Anestheiologist assigned to our cases. She swore by millers and said she only uses miller blades.
> 
> The doc on the other hand said he liked Mac better for adults and some kids, and miller only on very specific circumstances. But he preferred a mac+he recommended a mac to a new person.


 
Did either doctor show you their custom straight and curved blades?

Few Anesthesiologist will use "everyday" blades that we use in the field or even in the ICU or ED. If called to assist, they bring their own. The staff in the OR sterilizing department are also reminded every day about how much the blades cost. I must admit some are really nice but I would rather spend the budget on another piece of equipment for very difficult airways.

Once you understand where each blade is suppose to fit in the anatomy, you will understand why curved or straight is better. You will get to know if it visualization that may be the problem, for which the straight blade is better or if the tongue or jaw might be that problem and for that a curved blade might be better. Too many become accustomed to just sticking a blade in some manikin to see if they can pry the tongue away enough to see the hole and pass the class. Unfortunately many intubation manikins are not that realistic and it is difficult to say "do you see what anatomy your blade is not positioned by?" In the OR a good teaching Anesthesiologist will first initiate the intubation and hold the blade in place long enough for you to visual every landmark. 

Laryngoscopes are reviewed in professional journals for Anesthesia and RT much like tools are reviewed in fine wood working magazines.

Example:

*The McCoy laryngoscope in infants and children*

http://springerlink.com/content/b51340k775770662/fulltext.pdf

Look at the reference section at the end of the above article and see how many articles have been written comparing the blades.

Good article about the various devices used in difficult airways. You may have to register to Medscape to pull these up but it is free and worth it. 

*The Difficult Airway in Adult Critical Care* 

http://www.medscape.com/viewarticle/578622

*The Difficult Airway in Adult Critical Care.: Choice of Laryngoscope Blade*

http://www.medscape.com/viewarticle/578622_14

Another good article from Medscape with case studies of very difficult intubations.
*Use of the McGrath® Videolaryngoscope in the Management of Difficult and Failed Tracheal Intubation *
http://www.medscape.com/viewarticle/574213

Here's a good comparison study:
*Straight blades improve visualization of the larynx*
*while curved blades increase ease of intubation: a*
*comparison of the Macintosh, Miller, McCoy,*​
*Belscope and Lee-Fiberview blades*

http://springerlink.com/content/3n25gm726n5249j3/fulltext.pdf

*Lower flange modification improves performance*
*of the Macintosh, but not the Miller laryngoscope*
*blade*​

http://springerlink.com/content/54r5581202488553/fulltext.pdf

*The Cardiff paediatric laryngoscope blade: a comparison with the Miller size 1 and Macintosh size 2 laryngoscope blades*
http://www3.interscience.wiley.com/journal/118744974/abstract?CRETRY=1&SRETRY=0


If you fail to understand when you are up against a difficult airway or just do repeated intubation attempts with the "try this and that blade until something works" mentality without fully understanding the advantages of assessing or the equipment, you will do damage. Thus, many hospitals are prepared with a difficult intubation cart with the expensive devices. However, it is very easy for those with poor training/education and a lack of understanding of the equipment and anatomy to turn a relatively simple intubation into a nightmare by traumatizing the soft tissues. Also, not knowing your limitations due to lack of medications to facilitate intubation. Even those that have an RSI protocol may find that the dosages allowed may only do a half-arsed job and medical control will have to be contacted in attempts to get the job done. 

Even if you somehow manage to get the tube through the cords after a struggle, that patient may not be able to be extubated from the ventilator for many days due to swelling and some may require a trach. If the cords are badly damaged, the trach could be permanent. This is a rough time for a young college student who got intubated after drinking more than he/she should. 

This is not an attempt to frighten one from intubation but rather to stress the importance of knowing the anatomy, assessing and anticipating the difficulty, the equipment and what your own limitations are. This may also help you determine if ETI or alternative means of ventilation might be appropriate especially after you have already poked around with the tube a couple of times.


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## mct601 (Oct 30, 2009)

the airway power point is very interesting


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## redcrossemt (Nov 2, 2009)

I agree that the Powerpoint referenced above is well-worth looking at, but would also recommend attending a Difficult Airway class if at all possible. Actually seeing more cases and practicing with different equipment will definitely help hone your airway skills. And, even better if you can do OR rotations, or even postmortem intubations.


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