UMEM Educational Pearls

Popsicle or cold panniculitis is an inflammation of the subcutaneous fat after prolonged exposure to cold.  It is thought to occur more often in infants and young children because they have a higher percentage of saturated fatty acids than older children and adults.  Pediatric patients may present to you to be evaluated/ruled out for abuse by social workers, schools, or police and if you have the correct history it is easy to dispo quickly.

Clinical Features of Popsicle Panniculitis

• Absence of systemic signs
• Minimal pain, with or without
• Skin is red to purplish, indurated, may have discrete nodules or plaques
• perioral location for popsicles, but may occur at any other area of skin exposure
• resolves in 2-3 weeks without scarring
• hyperpigmentation may persist
• arises within hours to to 1-2 days after exposure to a cold object

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Several antihypertensive agents raise intracranial pressure. Normal cerebral blood flow (CBF) is constant within normal cerebral perfusion pressure (CPP) ranges, recalling that CPP=MAP-ICP.

If CPP is outside the range in which autoregulation occurs, e.g. due to a structural lesion, ischemic stroke, or head trauma, CBF decreases and can adversely affect the patient.

• Nitroprusside
  • Vasodilates both cerebral arteries and veins, increasing ICP
  • Inhibits the normal vasoconstrictive response to hypocapnia
• Nitroglycerin
  • Causes cerebral venodilation, increasing ICP
  • Impairs vasodilatory response to hypercapnia
• Hydralazine (varying effects)
  • Vasodilates cerebral arteries > cerebral veins
  • Impairs cerebral autoregulation
• Nicardipine
  • Other calcium channel blockers increase ICP by vasodilating arteries
  • Has been used to treat vasospasm in SAH
  • Increases cerebral blood flow in patients with SAH and acute stroke

In patients with ischemic stroke or intracerebral pathology, labetalol or esmolol may be used to lower blood pressure without raising ICP. Nicardipine is recommended for use in patients with ischemic stroke or SAH but not in patients with brain injury

If the patient has NO structural abnormalities, but has hypertensive encephalopathy, nitroglycerin, nitroprusside, labetalol, esmolol, or nicardipine may be used.

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• Encephalomalacia, also known as cerebromalacia, is a softening of brain tissue that results from ischemia or inflammation, most typically due to vascular insufficiency or degenerative changes.

• On Brain CT, it appears as a darkened area and can be confused for cerebral edema due to acute ischemia (i.e stroke).

• Unlike edema, encephalomalacia on CT is often accompanied by:

                    ---  well defined, circular vacuoles

                    ---  presence of good gray-white matter differentiation in surrounding areas

                    ---  a lack of significant effacement or lost of sulcus definition

                    ---  a history of prior stroke or head injury

Subcutaneous Insulin in the Critically Ill

• Although intensive insulin therapy in the critically ill remains controversial and a matter of much debate, hyperglycemia is common in the critically ill ED patient
• Hyperglycemia is associated with worse outcomes in this patient population
• When treating hyperglycemia in the critically ill ED patient, use caution with subcutaneous insulin
• Absoprtion of insulin administered subcutaneously is slow, erratic, and highly variable often due to poor perfusion, hypotension, and/or vasopressor therapy
• In these patients, IV insulin is a better route of administration and leads to more reliable control of hyperglycemia
• Recall that the onset of action of insulin given IV is 10 - 30 minutes, with a duration of action of about 1 hour

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Avoidable Pitfalls in Managing the Hypertensive Patient

We all see very hypertensive patients on almost every shift. Dr. Winters has an earlier pearl related to pitfalls in treating patients with hypertensive encephalopathy, but I thought it was time to reiterate just a few points.

• No evidence to date has ever shown a benefit to acutely lowering someone's BP in the ED prior to discharge
• Probably the best thing you can do for the patient with out of control BP is to arrange (and make sure they have) followup for the next day or two after discharge
• In patients with severe HTN (eg. admitted patients with pressure to high to go to their inpatient bed), avoid agents like IV Hydralazine. This agent is pretty reliable in being completely unpredictable when it comes to BP response. Some will really bottom out their BPs.
• Avoid Clonidine unless the patient is on it and stopped taking it recently (rebound HTN). May worsen someone's already crappy mental status.
• If a patient is being admitted, say to a unit or step down unit, don't bother titrating oral agents for people with pressures > 240/130 mm Hg or so. Consider a drip-oral agents may "stack" and take effect, thus lowering someones BP way lower than you wanted.
• Don't treat the number, treat the patient.

 A normal ECG should not be a huge source of relief when evaluating patients with possible or confirmed myocardial infarction. 8% of acute myocardial infarctions have a completely normal ECG at the time of presentation, and these patients have a 5.7% in-hospital mortality. Serial electrocardiography can certainly improve the yield of electrocardiography but does not rule out AMI with 100% accuracy.

Like most tests in medicine, the ECG is very useful at ruling in disease, but it is limited at ruling out disease.

[The Prognostic Value of a Normal or Non-specific Initial ECG in AMI. JAMA 2001.]
 

Paracentesis Part II- Ascites Fluid Analysis:

See last weeks procedure pearl for some hints on doing a paracentesis..

Now that you have the fluid what should you send it for:

• Cell Count
• Gram Stain and Culture
• Amylase (normal value is half serum)
• Albumin
• Consider cytology if  cancer is a consideration

Now for the analysis:

• WBC Count >250 PMNs generally accepted as consistent with infection.  Especially if there is more than 70% PMNs which is the upper limit of normal. SAAG (Serum - Ascites Albumin Gradient) an easy calculation to differentiate what the cause of the ascites might be from:
  • Subtract the patient's ascites albumin from the serum albumin (Serum Albumin - Ascites Albumin = SAAG)
  • SAAG > 1.1 mg/dL(Due to items that increase portal pressures)
    • Cirrhosis
    • Alcoholic Hepatitis
    • Cardiac Ascites
    • Hepatic Failure
    • Budd-Chiari Syndrome
    • Portal Vein Thrombosis
    • Myexdema
    • Others
  • SAAG < 1.1 mg/dl (due to intraabdominal forces causing increased oncotic pressure)
    • Tuberculosis Peritonitis
    • Pancreatitic Ascites (typically while have elevated amylase in ascitic fluid)
    • Bowel Obstruction
    • Nephrotic Syndrome
    • Biliary Ascites
    • others

** Corrected definition of SAAG as it was initially reversed.  Thanks to Dr. McCurdy on his proof reading.

 Melamine

• In case you thought the chinese only sent their toxin filled products to the USA, a massive scandal has been occurring with their milk.
• Adding melamine to their milk, companies were able to get falsely elevated readings of protein which is measured by the government to make sure the milk was not watered down.
• 53,000 illnesses, over 12,000 hospitilizations and at least 4 infant deaths have been attributed to their milk supply - 20% of China's milk supply is thought to be contaminated
• Melamine or melamine resin is used to make plastics and involved in other polymeric reactions.
• Toxicity involves the creation of kidney stones - imagine the pain in these poor children
• These children died from renal failure from multiple kidney stones.
• Check the link below to the news article

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• Acceleration, deceleration, and rotational forces cause diffuse axonal injury (DAI).
• It is characterized by widespread shearing and retraction of axons during traumatic brain injury (TBI).
• DAI often results in coma and is associated with poor prognosis.
• In addition to cortical white matter injury, it often also involves the corpus callosum, basal ganglia, brainstem, and cerebellum.
   

AIDS: coming to a critically ill patient in your ED

• Acute intestinal distress syndrome (AIDS) is a recently coined term used in the continuum of intraabdominal hypertension (IAH) to abdominal compartment syndrome (ACS)
• In previous pearls we have discussed the importance of IAH in the critically ill and how to measure intraabdominal pressure (IAP)
• Recall that IAH is defined as a sustained elevation of IAP > 12 mmHg
• The focus of attention is shifting to "secondary ACS" - it is highly prevalent in the critically ill and is independently associated with increased mortality
• Sepsis is a cause of secondary ACS and is the most likely condition we will encounter in our critically ill patient population
• Current recommendations suggest that IAP be measured daily in patients at risk for IAH (i.e. the septic ED patient)

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So, how good is a screening CXR for aortic dissection?

• Classic CXR finding is a wide mediastinum
• Pooled literature shows that the overall sensitivity of a CXR is about 67-70% for aortic dissection (even if upright, or PA and Lateral)
• Most authorities agree that a screening CXR alone is not sufficient to r/o aortic dissection

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17-18% of cases of syncope are attributable to dysrhythmias.
The best predictors of dysrhythmias in these patients are:
1. abnormal ECG (odds ratio 8.1)
2. history of CHF (odds ratio  5.3)
3. age > 65 (odds ratio 5.4)

[reference: Sarasin FP, et al. A risk score to predict arrhythmias in patients with unexplained syncope. Acad Emerg Med 2003.]

Paracentesis:

Since we have covered so many other procedures I though I would include paracentesis for completion.

A diagnostic paracentesis (typically 30-60 ml)  is indicated to:

• Determine etiology of new ascites (transudate vs exudate, cancer, infection)
• Rule out spontaneous bacterial peritionitis...(suspect this in any patient with a history of ascites that has fever, mental status changes, or diffuse abdominal pain)

A therapeutic paracentesis (large volume >1L) is indicated in the emergency department for:

• Respiratory distress from abdominal distension
• Abdominal compartment syndrome.  See Dr. Winters Pearl

Remember large volume paracentesis can result in profound fluid shifts and subsequent hypotension.

Absolute Contraindications to paracentesis include:  Acute abdomen requiring surgery

Relative contraindications are:

• Platelets <20,000
• INR > 2
• Pregnancy
• h/o adhesions
• abdominal wall cellulitis (just don't stick the needle through the cellulitis)
• Distended bowel or bladder

To view a video on how to do a paracentesis please visit the New England Journal of Medicine http://content.nejm.org/cgi/content/short/355/19/e21

Next I will address how to interpret the paracentesis fluid results.

Oxycodone v. Codeine for Fracture Pain Management in Children

• When choosing an oral narcotic to give a child for fracture analgesia oxycodone is a better choice than codeine. 
• In this study children were randomized to recieve equianalgesic oral doses of either oxycodone (0.2 mg/kg, max 15 mg) or codeine (2mg/kg, max 120 mg) for forearm fractures
• Children given oxycodone reported a pain score significantly lower than children given codeine
• And children given oxycodone had less itching than those given codeine

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 Cheese Heroin: a slang term for the combination of heroin with an over-the-counter antihistamine

• The two are combined and forms a cheesy like powder that is different from pure heroin
• A string of deaths were reported between 2005-2007 in Texas, many adolscents
• This concoction is more often insufflated than smoked or injected
• Combines opioid effect with the anticholinergic confusion and hallucinations
• Scorpion was a heroin that was combined with scopolamine that had similiar effect

Treatment

• Find the anticholinergic toxidrome, place the foley and supportive care are mainstays
• Consider administration of physostigmine 1mg IV slowly over 2-5 minutes (call toxicologist)
• The anticholinergic effects will linger much longer than the heroin effects ( <1hr)

tPA should NOT be used to treat ischemic stroke in the following instances:

• Platelet count < 100,000
• INR > 1.7 or PT > 15
• Heparin administration within past 48 hours with subsequent PTT above upper limits of normal

Health care-associated pneumonia

• Health care-associated pneumonia (HCAP) is a distinct entity
• HCAP includes any patient with pneumonia and 1 or more of the following:
  • hospitalization for 2 or more days in an acute care facility within the preceeding 90 days
  • nursing home patients
  • patients of long-term care facilities
  • patients who attend a hospital or hemodialysis clinic
  • patients who received IV antibiotics, chemotherapy, or wound care within 30 days of infection
• Data indicate that the mortality for HCAP is higher than CAP
• The most common organisms in HCAP include S.aureus, P.aeruginosa, Klebsiella species, Haemophilus species, and Escherichia species
• An initial recommended antibiotic regimen includes a combination of an antipseudomonal cephalosporin plus a fluoroquinolone plus an agent active against MRSA

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Key Cardiovascular complications of cocaine:

• Myocardial ischemia and infarction
• Myocarditis and cardiomyopathy
• Aortic dissection
• Vessel thrombosis
• Stroke (usually hemorrhagic) 
• Visceral ischemia

Pearls:

• Cocaine and abdominal pain=mesenteric ischemia, hemoperitoneum (described)
• Cocaine and chest pain=MI, aortic dissection
• Cocaine and extremity pain=arterial thrombosis, aortic dissection
• ~ 6% of cocaine chest pain patients rule in for MI

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 HIV positive patients are at increased risk of premature atherosclerosis for at least a few reasons:
1. HIV disease causes increased activation of platelets.
2. HIV produces arterial endothelial dysfunction [which promotes thrombosis formation].
3. Protease inhibitors produce dyslipidemias and insulin resistance.

HIV-associated CAD is also unusual in that the vessel involvement is frequently diffuse and circumferential along the whole artery.

HIV positive patients are known to have their first MI at an earlier age than non-HIV controls, and the effect is not related to CD4 count (not related to severity of disease).

The takeaway point here is to always strongly consider ACS in the differential diagnosis of patients with HIV that are presenting with cardiopulmonary complaints, even in relatively younger patients.

Amal

[reference: Khunnawat C, Mukerji S, Havlichek D, et al. Cardiovascular Manifestations in Human Immunodeficiency Virus-Infected Patients. Am J Cardiol 2008;102:635-642.]

Dental Pain and Blocks:

I am sure that most of us have felt like we should  have attended dental school when we see the fifth toothache of the day, but for those with true dental pain it can be severe and debilitating.  For these patients the only way to truly get their paint under control is to perform a dental block.  This will provide the patient with several hours of excellent pain relief, and may be all they need before seeing a dentist the next day.

For those that are not familiar with dental blocks, a great web page that I found that covers the advantages and disadvantages of the more common blocks is http://www.septodont.ca/Septodont/english/other/cea_di01.html

So for your next dental pain consider performing a dental block instead of just sending them home with a P&P pack (percocet and penicillin)