Can You ID this Seldom-Needed, but Essential EM Tool?

1) Name that tool. This device goes by the name “Compass.” It is similar to a model manufactured by Stryker, which is also highly distributed, but tends to have less accurate readings than the Compass.

2) Why do you need it?

It’s most critical function is for measurement of compartment pressures (it has other uses, as well, such as measurement of opening pressure for LP). Although compartment syndrome is really a clinical diagnosis (remember your “6 P’s”), you or your consultants may want to use this device for diagnostic confirmation before fasciotomy.

3) How does it work?

Your Compass will likely come in a kit containing the necessary accessories for its use. The kit stocked in our ED looks like this:

Ready to confirm your diagnosis? Prep skin and find your sterile gloves. Remove the caps from the ports on both ends of the Compass monitor. Attach an 18 G needle to the longer port. Attach a syringe with sterile water to the other and inject ~ 0.5 cc to remove air in the monitor. Hold down the red button on the side of the monitor until the reading “00” appears. Now you’re set to go.

For a review of how and where to check compartments, check out this video by EM:RAP (which gives instructions for the Stryker model, but the same principles apply for both devices).

https://www.youtube.com/watch?v=XXp0EtKtlF8

Finally, remember the number 30.

For the diagnosis of compartment syndrome:

Delta Pressure (= diastolic BP - compartment pressure) < 30

Or an absolute compartment pressure > 30

Want to learn more?

https://www.youtube.com/watch?v=_J4Bdssj4kk

https://lifeinthefastlane.com/trauma-library/basics/compartment-syndrome/

https://emedicine.medscape.com/article/307668-overview

POTD: Gyromitra - The seizure causing mushroom.

Gyromitra Esculenta

Today we are discussing a poisonous mushroom named Gyromitra esculenta (false morel). Originally, they were thought to be a very edible mushroom, even being encouraged to be eaten during times of famine across Poland and Scandinavia.  Esculenta even means “good to eat” in latin. They are even sold as “morschels” in Europe.Despite all of this misdirection, they are poisonous. They are the target of many a novice forager, pet, or small child and can arrive for medical evaluation without clear history.

First, let's be shallow and talk about looks because Gyromitra obviously tried to mess with Darwin and grow into a brain - hence "gyrus."

They are confused with the regular Morel (an edible/desirable mushroom) quite often.

The toxin in the Gyromitra Esculenta is..... gyromitrin. It is both moderately volatile and heat sensitive. The thought being that if you cook and discard the liquid, your savory poverty truffles will be less toxic. Alas I do not recommend this as symptoms can still occur and there is great variation in the concentration of toxin within each mushroom - perhaps even cumulative poisoning.

Mechanism: The metabolites of the toxin competitively inhibit pyridoxal phosphate and drop GABA levels (need pyroxidine to convert L-glutamate to GABA). The GABA deficiency leads to low seizure threshold. Oxidated metabolites in the liver then cause hepatic necrosis. If you survive all that, the toxin is also carcinogenic.

LD-50 (dose required to kill 50% of the people):

ADULT: 20-50mg/kg (0.4-1kg of fresh mushrooms)

PEDIATRIC: 10-30mg/kg (0.2 – 0.6 kg of fresh mushrooms)

Symptoms: Nausea, Vomiting, and Diarrhea (delayed 4-50 hours) Average onset 5-12 hours Neurologic symptoms (coma, headache, ataxia, delirium, seizures) The brain looking mushroom causes brain related problems. Hepatic failure 2-4 days afterwards and hypoglycemia

Treatment: Activated Charcoal 1g/kg PO if <60 min from ingestion Seizures/neurologic symptoms: pyridoxine 25mg/kg IV with repeat doses up to 20g/day

Further Work-Up: Send CBC, BMP, LFTs, Coags Transfer to liver transplant center if AST/ALT >2000, or PTT > 50

Auerbach, P. S. (2007). Wilderness medicine. Ch 66: Toxic Mushroom Ingestions 1464-1490.e3

https://www.michiganmorels.com/morels2.shtml

https://lifeinthefastlane.com/ccc/mushroom-toxicity/

POTD: Can You ID the Indication for this Seldom-Needed, but Essential EM Rescue Med?

It’s not propofol. This milky-white substance is Intralipid solution.  There are plenty of uses for intralipid infusions in medicine; for the purpose of this blog, take note that we are discussing the 20% solution.

1) So why do you need it?

For reversal of local anesthetic-induced systemic toxicity (aka “LAST”) manifested as either: cardiac arrest that is refractory to standard ACLS therapy, or neurotoxicity manifested as status epilipticus.

It’s use has also been suggested in algorithms for reversal of cardiotoxicity caused by numerous other lipophilic drugs, such as TCAs and beta-blockers.  However, the optimal administration and dosage recommendations for use in PO ingestions are not clear yet... so keep your ears open!

2) How does it work?

Proposed mechanism for reversal of anesthetic-induced toxicity: well, it’s again not quite clear, but the term “lipid sink” is thrown around quite a bit (see links at bottom of page for more info).

Somewhat easier to figure out is how to give it.  As a general rule, for a 70 kg adult in cardiac arrest:

Give a 70 mL bolus over 1 minute. Wait 3 minutes.  Repeat x 2 if no response to initial bolus (hopefully by now you’ve achieved ROSC).  Then hang the bag and give the remainder as an infusion over 15 minutes.

The suggested max dose is 8mL/kg, which for a 70 kg adult is conveniently just over the size of a 500ml container in which it is usually packaged.

Want to learn more?

http://rebelem.com/local-anesthetic-systemic-toxicity-last/

http://www.thepoisonreview.com/2015/06/09/how-lipid-rescue-therapy-works-its-more-than-just-a-sink/

https://www.ncbi.nlm.nih.gov/pubmed/19845549

http://lipidrescue.org