Spontaneous Cervical and Intracranial Arterial Dissections

(scroll to bottom for quick hits)

Background
-Arterial dissections can cause stroke in both young in old populations, and is the most common cause of stroke in the young

-Extracranial dissection is more common than intracranial dissection

-Stroke is generally caused by either diminished blood flow from intraluminal thrombus or embolized clot


Pathogenesis (stick with it)
-Dissection are believed to begin with a tear in the media of the vessel wall, leading to bleeding in the wall itself

-partially coagulated intramural blood can enter the lumen which activates platelets and
the coagulation cascade leading to intraluminal thrombus.

-Intramural blood can accumulate leading to compression of the lumen



Risk Factors
-Connective tissue and vascular disorders are thought to be main risk factors:
(e.g. Ehlers-Danlos Syndrome (type IV), Marfan Syndrome, Polycystic kidney disease, cystic medial necrosis, Fibromuscular dysplasia)

-many are caused by trauma




Diagnosis
-based on radiologic criteria taken from the Strategies Against Stroke Study for Young Adults in Japan (SASSY) using CTA or MRI/MRA

-Primary rules are based on finding an intimal flap or double lumen on Angiogram or MRI/MRA, or repeated non-specific findings associated with dissection on multiple studies.



Symptoms
-Head or neck pain

-Horner Syndrome - occurs when the sympathetic fibers on the ICA are stretched. It is usually just partial with ptosis and miosis but no anhidrosis.


Difference between Carotid and Vertebral Dissections
-Transient monocular blindness occurred only with internal carotid dissection

-Ischemic stroke is more common in vertebral dissections

-Neck pain and recent minor cervical trauma are more common in vertebral dissections

-Proportion of men and a recent infection are more common in ICA



Treatment
-Antithrombotic therapy (antiplatelet or anticoagulation) is the primary initial treatment for ischemic stroke and TIA caused by arterial dissection

-For intracranial dissection, antiplatelet therapy is often the treatment of choice

-For extracranial dissection, anticoagulation initially followed by 6 months of warfarin therapy as opposed to antiplatet therapy is often chosen

-Endovascular and surgical therapy are generally only reserved for recurrent ischemic events


BOTTOM LINE:
-arterial dissection is more common cause of stroke in the young
-extracranial (vertebral, carotid) more common than intracranial dissection
-sx: headache, neck pain, stroke-like symptoms, Horner's syndrome (for ICA)
-risk factors: connective tissue disorders, trauma
-dx: angiography, MRI/MRA
-tx: antithrombotics/anticoagulation (aspirin, heparin, coumadin, etc.); surgical/endovascular for recurrent events


Submitted by J. Grover.


Reference(s): Caplan, LR and Biousse V. “Cervicocranial Artery Dissections.” J Neuro-Opthalmol. 2004; 24:299-305. Maruyama, H et al. “Spontaneous Cervicocephalic Arterial Dissection with Headache and Neck Pain as the Only Symptom.” J Headache Pain (2012) 13: 247-253. “Spontaneous Cerebral and Cervical Artery Dissection: Treatment and Prognosis”. Uptodate.  “Spontaneous Cerebral and Cervical Artery Dissection: Clinical Features and Diagnosis”. Uptodate., picture

octreotide in sulfonylurea overdose

BASIC IDEA:
--Octreotide inhibits the secretion of several neuropeptides, including insulin
--if someone overdoses on a sulfonylurea (e.g. glipizide), would giving octreotide help reduce the hypoglycemia problem?


(straight to the) BOTTOM LINE:
--limited studies out there, but reviews tend to say the same thing...
--octreotide is probably safe and beneficial in sulfonylurea overdose/hypoglycemia


Reference(s): http://www.ncbi.nlm.nih.gov/pubmed/17764782 , http://www.ncbi.nlm.nih.gov/pubmed/16356235, http://www.ncbi.nlm.nih.gov/pubmed/17652687, http://www.ncbi.nlm.nih.gov/pubmed/20352540

fat pad on x-ray

WHAT IS THE FAT PAD?
--might be only subtle sign of a fracture on x-ray

--broken bones leak fat & blood, which also moves existing soft tissue



COOL TRICK:
--courtesy of EM News article (check out the pic on their website)
--if you're aspirating a joint (e.g. knee effusion), and you aspirate blood, take a look under a light, look for the sheen of fat on top (suggests fracture)

--might want to get a CT or MRI next, if those x-rays were negative



Reference(s): EM News article with picture, x-ray, diagram, oil&water

hydrofloric acid burns

HYDROFLUORIC ACID:
--one of the strongest inorganic acids
--can cause significant systemic toxicity due to fluoride poisoning.

--is used mainly for industrial purposes (eg, glass etching, metal cleaning, electronics manufacturing)--may be found in home rust removers.

 
TREATMENT TOOLBOX:
--can be soaked in magnesium hydroxide containing solutions (e.g. Mylanta) or soaked in ice water to help decrease the amount of absorption. 

--decontaminate appropriately and wash with water. 

--apply 2.5% calcium gluconate gel to burn (10% Ca Gluconate solution in 3 times the volume of KY gel) and place hand into latex glove. 

--if pain persists >30 minutes and not on fingers, infiltrate margins of burn with 10% calcium gluconate solution. 

--if severe burns, can inject 10ml of 10% Ca gluconate in 40ml of D5 intra-arterially over 4 hours. 

--repeat as necessary.  For oral, ocular, or inhalation burns, calcium will also have to be given in different concentrations. 

--Consult Toxicology. 

--Treat pain with opioids.


Submitted by T. Boyd.


Reference(s): http://emedicine.medscape.com/article/773304-treatment, picture

bedside ultrasound vs. supine chest x-ray for pneumothorax

RAGING HYPOTHETICAL:
--trauma patient, worried about pneumothorax
--how good is the bedside ultrasound? (sliding lung sign)








YOUTUBE ASSIST:

STUDY 1 (176 patients):

• sensitivity (CXR): 75.5%
• sensitivity (US): 98.1%
• specificity (CXR): 100%
• specificity (US): 99.2%

STUDY 2 (120 patients):

• sensitivity (CXR): 82.7%
• sensitivity (US): 89.7%
• specificity (CXR): 100%
• specificity (US): 97%

REVIEW ARTICLE (4 articles, 606 patients):

• sensitivity (CXR): 28-75%
• sensitivity (US): 86-98%
• specificity (CXR): 100%
• specificity (US): 97-100%  

BOTTOM LINE:
--bedside ultrasound vs. supine CXR for pneumothorax...
--both are very specific
--ultrasound is more sensitive than supine CXR


Submitted by S. Lee.


Reference(s): youtube video, study 1, study 2, review article, picture

decision rule for subarachnoid hemorrhage?

THOSE CANADIANS ARE AT IT AGAIN:
--study by Ottawa docs, Perry et al. reviewed nicely in an AAEM/Common Sense article (see reference)
--tried to identify a set of clinical characteristics to make a decision rule for those who need SAH workup


BASIC STRUCTURE:
--1,999 patients, 130 diagnosed with SAH
--SAH diagnosis defined by +CT, xanthrochromia, or >5 x 10^6/L RBCs + aneurysm/AVM on cerebral angiography

--included:

• adults (>16 yo)
• chief complaint = headache
• GCS 15
• non-traumatic
• peak intensity of HA within 1 hr

--excluded:

• >2 wks after symptom onset
• prior SAH
• previous CT and/or LP workup
• 3 similar HA's within past six months
• papilledema/focal neuro symptom
• prior hydrocephalus or cerebral neoplasm

RULES THEY CAME UP WITH:
--all have sensitivity 100%, but specificity sucked (28-39%)

--the rules (each set works to help rule-out SAH):

• age >40, neck pain/stiffness, witnessed LOC, DBP > 100mmHg
• arrival by EMS, age>45, vomiting, DBP > 100
• arrival by EMS, age 45-55, neck pain/stiffness, SBP > 160

BOTTOM LINE:
--nice study, helps think about why we do what we do, but isolated population
--the extra H&P details (age, BP, vomiting, neck pain/stiffness, etc.) are not very specific for SAH, but together might be sensitive (reminds me of appendicitis)
--not ready for primetime just yet, but food for thought


Submitted by S. Lee.


Reference(s): AAEM/RSA review, picture

what's a TAVI?

RAGING HYPOTHETICAL:
--Hypotensive, elderly gentleman presents to your ED, records show he's had a TAVI

--You nod your head with a reassurring look, then run to google...

--Next time you won't need to - because you read this post.

WHAT'S A TAVI?

Transcatheter Aortic-Valve Implantation (TAVI) for patients with severe aortic stenosis who are not candidates for surgery.

What it looks like:

How it is placed: (so cool and worth watching)
The implantation procedure involves accessing a femoral artery, performing balloon valvuloplasty, then advancing the device across the native valve. During rapid right ventricular pacing, a balloon is inflated to deploy the valve and the frame.

Video animation: http://youtu.be/_eiI6S62zOs

and http://www.nejm.org/doi/full/10.1056/NEJMoa1008232 (NEJM)

Evidence it works:

At one year, the rate of death from any cause was 30% with TAVI vs. 50.7% with standard treatment (balloon aortic valvuloplasty and or medical therapy)

Not so good: TAVI had a higher incidence of strokes and major vascular complications compared to standard treatment, however this was included in rate of death.

Now you know :)

Submitted by S. Morris.

Reference(s): Leon MB, Smith CR, Mack M, Miller DC, Moses JW, Svensson LG, et al. PARTNER Trial Investigators. Transcatheter aortic-valve implantation for aortic stenosis in patients who cannot undergo surgery. N Engl J Med. 2010;363(17):1597–607.; http://medgadget.com/2010/09/transcatheter_aorticvalve_implantation_tavi_reduces_mortality_rate_compared_to_standard_therapy.html (image)

fear the low quantitative hCG

CONCERNED FOR ECTOPIC PREGNANCY?

--first trimester, vaginal bleeding, abdominal pain

--fear the low quant.

STUDY:

--by Kohn et al in 2003 from Acad EM
--looked at beta HCG levels in normal and abnormal early pregnancies

• 730 ED pt's (retrospective chart review)
• 253 abnormal IUP (mostly miscarriage)
• 381 normal IUP
• 96 Ectopics 

--Abnormal IUP and ectopic pregnancies had similar low beta HCG levels.

--Patients with HCG <1500 were twice as likely to have ectopic pregnancy (LR 2.24).

• 42% of the ectopics had HCG <1500
• only 7% of the normal IUP's had HCG <1500

BOTTOM LINE:

--Remember that the descriminatory beta HCG for TV US is >1500, making early pregnancy vs.ectopic with unclear ultrasound a tough decison without surgical pathology.

--HCG <1500 but non-diagnostic ultrasound, fear the ectopic

--stable patient: typical course of action is repeat HCG in 48 hrs

--unstable/borderline patient: have a low threshold of suspicion for ectopic

SCARY PARTING THOUGHT:

--case report of a ruptured ectopic with negative serum beta HCG

Submitted by S. Morris.

Reference(s): study, case report, picture 

plastic bronchitis

PMID: 22430124
--Do P, Randhawa I, Chin T, Parsapour K, Nussbaum E., Successful Management of Plastic Bronchitis in a Child Post Fontan: Case Report and Literature Review. Lung. 2012 Mar 20. [Epub ahead of print]



QUICK LEARNING POINTS:
--Plastic bronchitis is a rare, potentially fatal, condition noted in patients after Fontan surgery.

--The mucoid impaction with cast formation occludes the major bronchi with firm, gelatinous material. 

--Acute management involves ABCs (airway, breathing, circulation), potentially requiring intubation for respiratory failure. 

--General airway clearance measures with bronchodilators and chest physiotherapy should be initiated.

--In emergent cases, immediate bronchoscopy, whether rigid or flexible, should be considered.  Bronchial casts are unique foreign bodies that may be friable or dissolvable, making lavage a necessary component of its removal.

--While bronchoscopy can be effective for acute therapy, it does not prevent recurrence nor should it be utilized on a chronic basis. 

BOTTOM LINE:

--Plastic bronchitis is a rare, potentially fatal, condition noted in patients after Fontan surgery.

--treatment toolbox: inhaled mucolytics, bronchodilators, intubation & bronchoscopy if necessary

Submitted by J. Gullo.




Reference(s): article, picture

does replacement pancreatic enzymes affect lipase levels?

HEADLINE:
--According to the study below (even though its in pigs), being on replacement enzymes shouldn't affect your lipase levels. 

PMID: 14707735
--The enzyme levels in blood are not affected by oral administration of a pancreatic enzyme preparation (Creon 10,000) in pancreas-insufficient pigs.

--The current study investigated whether orally administered pancreatic enzymes were absorbed from the intestine.
 

--28 pigs; 3 control pigs with intact pancreatic function and 25 pigs that were made exocrine pancreas insufficient by duct ligation (20 pigs) or total pancreatectomy (5 pigs).

--pigs received a pancreatic enzyme preparation (0, 2, 4, or 8 g of Creon 10,000) together with the feed. The blood plasma was analyzed for pancreatic lipase activity.

--Administration of Creon (0–8 g) caused no significant changes in plasma (pro)colipase or cationic trypsin(ogen) levels.

BOTTOM LINE:

--According to the study below (even though its in pigs), being on replacement enzymes shouldn't affect your lipase levels. 


Submitted by J. Gullo.


Reference(s): article, picture

urine pregnancy test using whole blood

NEAT IDEA:
--case report (link in references)

--drop of blood applied to urine HCG point-of-care test

--tested positive in the unstable ruptured ectopic patient who couldn't pee just then


BOTTOM LINE:
--patient can't/won't pee, try some blood on the urine pregnancy test

--don't know if there's any potential for false +, but in a pinch with a crashing patient, might be worth a shot


Submitted by S. Lee.


Reference(s): article, picture