UMEM Educational Pearls

You are seeing a high school football player following a head injury.  After your exam or head CT, you determine the child to have had a mild traumatic brain injury (aka concussion).  You are ready to discharge him home when the parents or coach ask you when he can return to playing football.

A concussion is a form of functional, rather than structural, brain injury that displays no evidence of injury on structural neuroimaging.   Symptoms include transient loss of consciousness, amnesia, vomiting, headache, poor school work, sleep changes, and emotional lability.  Remember that children’s brains (even adolescents) are still developing, and are more prone to prolonged recovery following injury.

Recovery of symptoms usually follows a sequential course.  Current guidelines recommend a stepwise return to play (aka concussion rehabilitation) involving both physical and cognitive rest (e.g. no texting, video games, limited school work).  Once asymptomatic, the patient goes through each stage with at least 24 hours between stages.  If symptoms return during a stage, then the patient is expected to return to the previous stage for 24 hours before attempting the higher stage again. 

Return to Play Guidelines:

References:

1. Halstead ME, Walter KD, and The Council on Sports Medicine and Fitness.  Pediatrics. 2010;126:597-615.

A growing trend in EDs is to have a dedicated ED Pharmacist present to assist with the evaluation of a patient's medication list, appropriate and safe drug administration and to improve drug delivery times. To date, it has been difficult for hospitals to determine if this was a cost-effective measure. There has been increasing research that has shown the proven benefits that physicians feel when they have an ED Pharmacist. With the aging population, increasing polypharmacy, core measure and national patient safety goals all rising to the top of hospital initiatives, the ED pharmacist will be proven to be a valuable cog of the ED - as UofMd already knows

1) Improved safety - this study showed an ED pharmacist caught 2.9 errors/100 medications, very important considering the cost of just one severe reaction can cause a hospitalization or even litigation(1)

2) Improved time to delivery of medication - this study showed improved time of delivery of medications not found in a Pyxis from 61 min with no pharmacist  decreased  to 47 min with ED pharmacist.(2)

Further studies will be needed to determine the true cost:benefit however with core measures like 6hr time to administration of antibiotics and the safe/timely adminstration of tPA combined with patient safety/quality goals - the value of an ED pharmacist will only be accentuated.

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• Marcus Gunn Pupil is a highly objective and significant clinical manifestation of a relative afferent pupillary defect (RAPD), indicating decreased pupillary response.

• The "swinging flashlight test" whereby a light is shone alternately back and forth between both eyes, can be used to elicit this finding.  A normal response results in constriction of both pupils, which indicates intact direct and consensual pupillary light reflex.  An abnormal response due to RAPD, however, results in minimal constriction of both pupils when the light in shone in the affected eye, causing one to perceive the presence of pupillary dilation.

• See the attached image which contrasts a normal response (top) to an abnormal response (bottom).

• Marcus Gunn Pupil is most commonly associated with lesions at the level of the optic nerve (proximal to the optic chiasm) or severe retinal disease.  Associated conditions include severe glaucoma, optic nerve tumors, and ocular trauma.

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• 1109281911_Marcus_Gunn_Pupil.jpg (35 Kb)

·  The use of epinephrine in cardiac arrest is currently standard of care.

·  Several observational and non-randomized trials have demonstrated the efficacy of epinephrine in cardiac arrest, but there has never been a randomized double-blind placebo-controlled trial in humans.

·  A recently published Australian trial randomized cardiac patients (of any type) to receive either 1 mg of epinephrine (n=272) or 0.9% normal saline (n=262); the primary end-point was survival to hospital discharge. Secondary end-points were pre-hospital return of spontaneous circulation (ROSC) and neurological outcomes at hospital discharge.

·  Significantly more patients had pre-hospital ROSC in the epinephrine group (regardless of the underlying rhythm), however, there was no statistically significant difference in survival to discharge (the primary outcome) between groups.

·  This randomized double-blinded placebo-controlled trial raises many new and interesting questions about epinephrine, but more study is needed before changing current practice.

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Elderly patients in general have a lower baseline body temperature than younger patients. Consequently, it makes sense to redefine the definition of what constitutes a "fever" in the elderly. Rather than using the typical oral temperature cutoff of 38^o C (100.4^o F) for defining a fever, instead consider using 37.2^o C (99^o F). Redefining fever in this way increases the sensitivity for detecting bacterial infections from 40% to 83% while retaining an 89% specificity.

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Saturday night palsy - radial nerve mononeuropathy due to improper arm positioning associated with inebriated sleep.

Physical examination - Wrist and finger drop. 

Patients may have findings suggestive of ulnar nerve co-involvement (interossei testing)  which may falsely lead the examiner to consider a more proximal location for the lesion such as the brachial plexus.

The finger drop caused by the radial nerve lesion places the hand at a mechanical disadvantage.  Adjust for this by examining the hand on a flat surface (stretcher, counter top). With the fingers now supported in extension at the MCP joint  (no longer "dropped"), the interossei can now be tested in isolation and will be normal.

• The Glascow Coma Scale (GCS) was originally derived from data from adult head injuries; its use is therefore not always applicable or reliable in non-traumatic cases (particularly those which are complex) or children under a certain age.
• Scoring Range = 3 to 15.
• Severe is less than 9.
• Scores of 8 or less should prompt strong consideration for airway management via intubation.
• The motor score is the most predictive and clinically useful component.
• See GCS Score below:

EYE OPENING
4 = spontaneous
3 = to voice
2 = to pain
1 = none

VERBAL RESPONSE
5 = orientated
4 = confused
3 = inappropriate
2 = incomprehensible
1 = none

MOTOR RESPONSE
6 = obeys command
5 = localizes pain
4 = withdraw to pain
3 = decorticate
2 = decerebrate
1 = none

Spontaneous Bacterial Peritonitis

• Critically ill patients with end-stage liver disease (ESLD) may be some of the sickest patients you'll ever manage.
• Recall that patients with ESLD have higher rates of infection and worse outcomes.
• Always consider spontaneous bacterial peritonitis (SBP) in the sick patient with ESLD.  In fact, SBP is the most common infection in ESLD patients.
• Physician impression alone has been repeatedly shown to be inaccurate in ruling out SBP.
• In the critically ill patient with ESLD and ascites, tap the belly!

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Question

19 year-old male s/p high-speed MVC with hypotension and diminished breath sounds on left. Diagnosis?

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A patient presents to the ED in pulmonary edema, hypotensive, and has JVD. There's a new systolic murmur. The patient had an acute MI 7-10 days ago and had appropriate treatment and uncomplicated course, then discharge. What's the diagnosis and what do you do?

Step 1: Sign out immediately.

Step 2: If it's not time to sign out (just kidding about step 1), listen carefully to the murmur. If it's heard best at the lower sternal border, it's probably a ruptured papillary muscle with acute MR. If it's a "machinery" type murmur heard throughout the precordium loudly, it's probably an acute VSD.

Step 3: VSD patient is likely to die, but with either one, you've got to move quickly. IMMEDIATELY call cardiology AND cardiac surgery. The patient is in need of a balloon pump and OR.
All you can do is buy time until the patient goes upstairs....pressors for BP, IV NTG as tolerated for preload reduction, and be judicious with diuretics. Vasodilators might help unload the heart also. This patient may end up on 2-3 drips, and make sure ALL meds are titrateable. And just keep your fingers crossed!

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Posterolateral Corner Injuries

The posterolateral corner “PLC” of the knee is becoming increasingly recognized as an extremely important structure to maintain the stability of the knee joint.

PLC injuries occur with hyperextension, varus load and tibial external rotation.  So the most common mechanism is a posterolaterally directed blow to the anteromedial tibia when the knee is hyperextended. PLC injuries are commonly associated with injury to other ligaments (ACL, PCL, LCL) and occur in isolation in <5% of cases.  If suspected make sure to check for other ligamentous injuries.

Since this injury can be missed and is associated with significant disability it is important to test for it.  This YouTube video, http://youtu.be/bnXaTdvZZ6o, demonstrates several examination techniques that can identify the injury. 

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• Bell Palsy is a condition associated with the acute onset of facial paralysis due to palsy of the seventh lower motor neuron (cranial nerve seven).
• The presence of mastoid pain might be a diagnostic clue, as this symptom often precedes the onset of actual facial paresis.
• Other associated findings include:  typically unilateral facial muscle paralysis affecting both the upper and lower parts of the face; tear overflow and dry eyes; altered taste; hyperacusis or sound sensitivity; sensation spared; no other cranial nerves involved.
• It is often associated with viruses such as HIV, Epstein-Barr, and Hepatitis B, but most commonly herpes simplex.
• If facial paralysis is bilateral, consider Lyme disease as a possible etiology.

Radial and femoral arteries are common sites for arterial-line placement, but are not without complications (e.g., Radial artery: malfunction with positioning and Femoral artery: contamination and infection); an alternative site to consider is the axillary artery.

The axillary artery's superficial location and large size make it a desirable choice for cannulation.

The "anatomical-landmark" and "palpation" methods have been the traditional techniques of axillary arterial cannulation, however these methods may be difficult for to a variety of reasons (e.g., obesity, anasarca, arterial disease, etc.)

Ultrasound allows visualization of the axillary artery and avoids unintended injury to structures in close proximity (e.g., brachial plexus, pleura, axillary vein, etc.); please see figures 1 and 2 in the referenced Sandhu article and http://www.youtube.com/watch?v=Z31YiyV7cNQ.

A recent study (Killu, 2011) found that ultrasound increases success rates when compared to the traditional landmark approach.

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Question

A 50 year-old patient presents after a self-inflicted eye injury. The patient had taken some type of needle and inserted it into their eye.

What is the diagnosis and what complications might result?

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SVT is rarely, if ever, the presenting rhythm associated with an acute MI. As a result, physicians should not feel compelled to send troponin levels and perform rule-outs purely based on an SVT presentation. Instead, the decision to rule out a patient presenting with SVT should be based on whether there is a constellation of other concerning symptoms, exclusive of the SVT (e.g. if the patient presented with chest pressure radiating down the arm and diaphoresis, in addition to the SVT).

Two recent studies confirmed that routine troponin testing in patients with SVT is extremely low-yield, and instead often produces false-positive troponin results that lead to unnecessary admissions and workups. In other words, mild troponin elevations may occur in SVT but they do not correlate with true ACS.

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Evaluation of circulatory status is the most important aspect of post reduction care.

Look for hard findings such as cool/cold lower extremity, diminished or absent pulses, pale or dusky skin, paralysis, etc.

However, the absence of these findings should not lull the clinician into a false sense of security. The degree of initial joint deformity, presence of full bounding pulses and warm skin over the dorsum of the foot can all be present in the setting of vascular injury.

The next step will be to perform an ABI (ankle-brachial index).

In one small study, no patient with an ABI greater than or equal to 0.9 had a vascular injury.

Patients with a reassuring physical exam and ABIs should be admitted for vascular checks without further imaging.

Patients with a reassuring physical examination but with an abnormal ABI should have an imaging study obtained (arteriogram/CT angiogram).

Patients with hard findings of a vascular injury should have an emergent vascular surgery consultation.

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• newborns have a thick right ventricle resulting in a mean QRS axis which points anteriorly and to the right demonstrating a right axis deviation (70-180degress) and large R waves in the precordium
• by 3 months of age, the QRS axis in the frontal plane shifts to the left with a mean of 65degress (0-125degress)
• by older childhood, the normal mean QRS axis is -30-100degress)
• thus, with age the R wave decreases in V1 and increases in V6
• take home:  right-axis deviation is often a normal finding in children and young adults when you see left-axis deviation in children consider tricuspid atresia, atrioventricular septal defects, and LVH as the most associated conditions

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Every so often a patient arrives in PSVT with their only intravenous access being through a hemodialysis port.

Initial dose of adenosine should be reduced to 3 mg if administered through a central line.  Remember a central line delivers the adenosine right where you need it.  This recommendation is supported by the 2010 ACLS guidelines.  Second and third doses should be 6 mg (instead of 12 mg).

Cases of prolonged bradycardia and severe side effects have been reported after full-dose adenosine through a central line.  Other situations to consider lower doses include patients currently receiving carbamazepine or dipyridamole or in those with a transplanted heart.

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• Encephalitis, inflammation of the brain, is associated with the following signs and symptoms:  fever, headache, altered mental status, neurologic deficit, hallucinations, behavioral changes, photophobia, seizures, neck stiffness (when associated with meningitis), preceding viral prodrome, recent mosquito/tick/animal bites, and/or immunocompromised state/use of immunosuppressant medications.   
• The presence of focal neurologic deficit and/or altered mental status is more predictive of encephalitis than meningitis.
• The emergent management goal is to rule out and/or empirically treat bacterial meningitis and other treatable infectious sources such as Herpes Simplex Virus (HSV), Varicella Zoster Virus (VZV), and Cytomegalovirus (CMV); these carry significant mortality and morbidity risks.  Remember to have patient's cerebrospinal fluid (CSF) specifically analyzed for etiologies such as these (i.e. via PCR). 
• Treat presumed encephalitis aggressively by adding acyclovir to the antibiotic/steroid regimen administered, particularly when there is altered mental status and/or focal neurologic deficit.