good read: article by Dr. Levitan in EP Monthly. Click through for the whole article, but here’s a 10-second highlight:
“Combining nasal and face mask oxygen tremendously boosts the FiO2.
This happens because the nasal oxygen addition doubles flow rates (15 lpm via nose and 15 lpm via non-rebreather), it forces open the soft palate, and the nose is a significant oxygen reservoir. When the patient takes their next breath, they inspire a higher FiO2 than with a face mask alone.
While we are taught a non-rebreather at 15 lpm is almost 100% FiO2, it is actually closer to only 60% due to the accumulation and rebreathing of CO2 in the mask, hypopharynx, and nasopharynx.
With nasal cannula and non-rebreather mask combined we can effectively reach almost 100% FiO2.”
For more, check out some previous posts on passive pre-oxygenation:
References: article; picture
recent JEM article, good for background and pictures, with their study proposing 7mm outer appendiceal diameter on ultrasound vs. 6mm currently used cutoff.
Thought it was a good chance to review some basic numbers and throw up some visual aids on appendiceal ultrasound.
current widely accepted outer diameter cutoff: 6mm
- sensitivity 88%
- specificity 94%
- sensitivity 83%
- specificity 93%
a picture’s worth…
References: JEM article; ACEP “Focus” w/some pictures; appendix tip picture; perf picture
some nice tips for a less commonly used (but good to know) approach to the subclavian central line.
Some tips from a July EMN article:
best with ultrasound
+/- Trendelenburg position
first find the IJ (internal jugular vein)
IJ is compressible; usually oval or triangular (vs the more circular carotid, with its thicker walls)
trace it inferiorly to the supraclavicular fossa, see where it meets the SCV (subclavian vein) — [spare 30 seconds to watch the youtube video below, starting at the 1 min mark, to see this]
AVOID the pulsatile subclavian ARTERY (duh)
in-plane approach is handy, helpful [spare 30 sec to watch this, too, starting at the 2:30 mark]
References: EMN article + picture; youtube video
some vent machines aren’t designed to nebulize in-line, so if you want to give albuterol to a ventilated patient, how else can you do it?
I’ve seen some RT’s use the vent tubing like a big spacer and just puff in an MDI PRN.
One cool idea: via crashingpatient.com:
MDI canister in a 60 cc syringe
tape it into a port, or hook up some IV tubing and thread it in, tape it down.
References: crashingpatient.com (includes picture)
If you can remember one number to get the ball rolling on an acetaminophen overdose….
150 mcg/mL is the 4 hr acetaminophen level of possible toxicity
150 mg/kg is the initial loading dose of IV N-acetylcysteine (NAC)
After that, you can look up the infusion doses, but here’s a nice chart from an EMN article.
Also, just to scare you: an article on IV NAC overdose.
- The quick lession: be VERY clear on your doses, and write the infusions out as mg/kg/hr.
References: EMN article & picture; scary article
quick review of some basics numbers for your common intubation paralytics, cribbed from a couple 2011 Annals articles/comments:
- typical dose: 1.5 mg/kg
- time of onset: 45 sec
- duration of muscle relaxation: 6-10 min
- risk profile: hyperkalemia, malignant hyperthermia (rare)
- time of onset (at 1mg/kg dose): 60 sec
- time of onset (at 1.2 mg/kg dose): 40 sec
- duration of action: 25-60 min
References: article 1, article 2; picture
crashingpatient.com has a good summary of Awake and Fiberoptic intubation with some neat pictures of a disposable atomizer assembly.
I’ve also seen a Weingart video someplace where he puts the same setup together with a 14 g IV and uses it as an improvised jet ventilator, putting his hand on the open end of the T-piece not connected to the IV to deliver breaths, and letting go to allow for expiration (if anyone can find that link, please let me know, I’ve since lost that link).
check out the pics below from the crashingpatient.com post:
There you go.
References: crashingpatient post (with pictures).