Management of VF arrest

Passive rewarming

• Temperature is very important during rewarming as temperature commonly overshoots normal. Warming the patient too quickly or allowing continued shivering causes dangerous electrolyte shifts, leading to potentially lethal arrhythmias. 
• Controlled rewarming of 0.15° to 0.5° C per hour is recommended. 
• To maintain tight temperature control throughout rewarming a neuromuscular blockade is usually employed.  
• Careful fluid monitoring during rewarming is crucial because of the vasodilation that accompanies a body temperature rise. Volume replacement may be needed to prevent fluid deficit and hypotension.
• Electrolytes shift out of the cells back into the serum during rewarming, so frequent electrolyte monitoring is needed during this phase to prevent critically elevated levels. Slow, controlled rewarming allows the kidneys to excrete excess potassium, preventing hyperkalemia. 
• Hypoglycemia can occur during rewarming as the insulin resistance of earlier hypothermia phases diminishes. Glucose levels must be monitored frequently, with insulin titration and dextrose boluses used as needed to maintain the patient within ordered ranges.

References

• http://www.americannursetoday.com/article.aspx?id=8014&fid=7986
• http://ccforum.com/content/16/S2/A25/ 

Resources for lumbar puncture

• http://www.med.uottawa.ca/procedures/lp/index.htm
• http://www.articlealley.com/article_596234_17.html
• http://www.unboundmedicine.com/harrisons/ub/view/Harrisons-Manual-of-Medicine/148408/all/Lumbar_Puncture,
  

CHAD2 (CHADS) score

The CHADS score is a clinical prediction rule for estimating the risk of stroke in patients with non-rheumatic atrial fibrillation (AF) and is used to determine the degree of anticoagulation therapy required.

To Score...

C ongestive heart failure (1 point)
H ypertension > 160mmHg systolic (or treated hypertension) (1 point)
A ge > 75 (1 point)
D iabetes (1 point)
S - previous stroke or TIA (2 points)

Risk of stroke based on CHADS score

Recommendations for anticoagulation

• High risk (score >= 2) - warfarin (unless contrainidcated)
• Moderate risk (score 1) - aspirin or warfarin
  
• Low risk (score 0) - aspirin
  

References

• http://en.wikipedia.org/wiki/CHADS_Score
• http://www.cardiology.org/tools/risk_of_stroke_AF.html
  

ABCD^2 (ABCD squared) post TIA stroke risk assessment tool

The Tool

AGE: greater than or equal to 60 years – 1 point
Blood Pressure: Systolic >= 140, diastolic >= 90 (when first assessed after TIA) – 1 point
Clinical Features: unilateral weakness – 2 points, isolated speech disturbance – 1 point, other – zero
Duration of TIA symptoms: greater than or equal to 60 minutes – 2 points, 10 to 59 minutes – 1 point, <10 minutes zero
Diabetes present – 1 point

Estimated two day stroke risks determined by the ABCD^2 score:

• Score 6 to 7: High two day stroke risk (8.1%)
• Score 4 to 5: Moderate two day stroke risk (4.1%)
• Score 0 to 3: Low two day stroke risk (1.0%)
• Score < 1: Very low two day stroke risk (0.0%)

In versus outapatient management

People with a high risk of stroke (ABCD2 score of 4 or above) should have:

• Aspirin (300 mg daily) started immediately
• specialist assessment and investigation within 24 hours of onset of symptoms
• measures for secondary prevention introduced as soon as the diagnosis is confirmed, including discussion of individual risk factors

People who are at lower risk of stroke (ABCD2 score of 3 or below) should have:

• Aspirin (300 mg daily) started immediately
• specialist assessment and investigation as soon as possible, but definitely within 1 week of onset of symptoms
• measures for secondary prevention introduced as soon as the diagnosis is confirmed, including discussion of individual risk factors

Investigations

1. CT scan without enhancement should be done in all patients to exclude other causes of neurological deficit (e.g. hemorrhage, subdural hematoma)

The presence of an infarct on CT is highly predictive of subsequent stroke

Early CT showing hemorrhage makes carotid imaging unnecessary

2. Carotid imaging should be done for all patients with symptoms in anterior circulation territory.

The presence of carotid disease is highly predictive of recurrent stroke.

Consider CT angiogram if Carotid Ultrasound cannot be obtained in reasonable time.

3. ECG and occasionally Holter monitoring to detect atrial fibrillation.
4. ECHO cardiogram for persons with suspect underlying cardiac abnormalities.
5. Blood sugar to detect extremes in glucose levels.

References

• http://bmhgt.com/2009/03/stroke-information-abcd2/
• http://www.gpnotebook.co.uk/simplepage.cfm?ID=x20080723164438749131
• http://www.palmedpage.com/Text_files/Neurology/ABCD/TIA%20Management.html
• http://www.stroke.org/site/DocServer/NSA_ABCD2_tool.pdf?docID=5981
  

Focal neurological symptoms

A focal neurologic symptom is a problem that affects either:

• A specific location - such as the left face, right farm or even just a small area such as the tongue
• A specific function - for example, speech may be affected, but not the ability to write

The problem occurs in the brain or nervous system. The type, location, and severity of the change can indicate the area of the brain or nervous system that is affected.

In contrast, a non-focal problem is NOT specific - such as a general loss of consciousness.


References:

• MedLine Plus Medical Encyclopedia, http://www.nlm.nih.gov/medlineplus/ency/article/003191.htm
  

Giant cell arteritis (GCA)

Giant cell arteritis is a vasculitis of large and medium size vessels. Although it can affect arteries in the neck, upper body and arms, it occurs most often in the arteries in the temples. For this reason, giant cell arteritis is sometimes called temporal arteritis or cranial arteritis.

Giant cell arteritis is also known as granulomatous arteritis — a reference to a particular type of inflammation it causes.

Epidemiology & Aetiology

• Adults older than age 50 are at greatest risk of giant cell arteritis.
• Women and caucasians are most commonly affected.
• The exact cause isn't known, but researchers believe that genetic, viral and environmental factors may play roles in the inflammation.

Clinical presentation

Giant cell arteritis frequently causes headaches, jaw pain, and blurred or double vision, but the most serious potential complications are blindness and, less often, stroke. These problems occur when swelling in the arteries impairs blood flow to the eyes or brain.

The onset of the symptoms tends to be gradual and includes low grade fever, fatigue, weakness and weight loss.

• A new headache, mild or severe, occurs in at least two-thirds of patients with the pain tending to be located over the sides of the head in front of the ears but may be frontal or other located.
• Nearly one-half of patients suffer from jaw claudication after chewing.
• Impaired vision is often an early manifestation of the disease.
• Permanent partial or complete loss of vision in one or both eyes has been observed in 15-20 % of patients. It is rare for patients to become completely blind in both eyes.
• Polymyalgia rheumatica, which is characterized by pain in the shoulders and hips, is closely linked to GCA, occurring in about 40-50 % of patients.
  

Investigations

• ESR – elevated in most patients with GCA.
• Temporal artery biopsy

Suggested in all cases of suspected GCA even if the diagnosis may appear "classic".

The biopsy is of low risk, causes very little pain, and often leaves little or no scar.

After the use of a topical numbing medication (the same one used by a dentist), a small part of the temporal artery from under the scalp is removed.

• Other ways to diagnose GCA include: ultrasonography, angiographic examination, CT scanning and MR angiography, high resolution MRI and position emission tomography (PET).

Management

• Although there's no cure for giant cell arteritis, immediate treatment with corticosteroid medications usually relieves symptoms and prevents loss of vision.
• Glucocorticoid treatment should be instituted immediately once the diagnosis of GCA is established.
• Daily dosing is more effective than alternate day dosing. The response usually occurs within two to four weeks after the institution of therapy.
• The diagnosis should be reevaluated in patients who are resistant to adequate steroid therapy.
• Steroid withdrawal can begin once clinical remission has been induced.
• Relapses are seen more frequently in the first year or two of the disease.
• Relapses often necessitate increased dosage or prolonged steroid treatment. Some researchers have suggested that the addition of methotrexate may be steroid-sparing while others have not demonstrated any benefit. However the routine addition of methotrexate to glucocorticoid therapy for GCA is not recommended. The efficacy of other cytotoxic drugs, dapsone, antimalarials, etanercept, and penicillamine has not been studied adequately although they have been reported to be helpful in some case reports.
• The finding of an increased risk of visual loss in patients with GCA and thrombocytosis (increase of the number of platelets in the blood), has led some to suggest the addition of drugs like aspirin for patients with high platelet counts, but there is not a lot of data to prove that this may reduce brain/skull problems.

References:

• “Giant cell arteritis”, mayoclinic.com, http://www.mayoclinic.com/health/giant-cell-arteritis/DS00440
• “Giant Cell Arteritis (Temporal Arteritis)”, Vasculitis Foundation, http://www.vasculitisfoundation.org/giantcellarteritis

Tests for hearing loss

Rinne test

Normal hearing = POSITIVE. Air conduction is louder than bone conduction.
Conductive hearing loss = NEGATIVE. Bone conduction is better than air conduction.
Sensorineural hearing loss = POSITIVE because both bone air and bone conduction are equally reduced (NB: may need to mask normal ear to avoid a false negative from the opposite side).

Weber test

Normal hearing = sound comes from middle of forehead.
Unilateral conductive hearing loss = sound is loudest in AFFECTED ear because the ambient noise is picked up by the normal ear, masking the sound of the tuning fork on that side.
Unilateral sensorineural hearing loss = sound is loudest in UNAFFECTED (normal) ear.

References

• http://en.wikipedia.org/wiki/Weber_test
• "C:\Tam's docs\uni\Admin\year2\OSCE\Clinical skills summaries\ProcSkills\Procedural Skills.doc"
  

Difference between a twitch and a tremor

A twitch is a jerky or spasmodic movement.

A tremor is an involuntary, rhythmical, alternating movement.

Pars defect

Spondylolysis is a condition in which the there is a defect in a portion of the spine called the pars interarticularis (a small segment of bone joining the facet joints in the back of the spine). The pars interarticularis defect can be on one side of the spine only (unilateral) or both sides (bilateral). The most common level it is found is at L5-S1, although spondylolisthesis can occur at L4-5 and rarely at a higher level.

Spondylolysis is the most common cause of isthmic spondylolisthesis, in which one vertebral body is slipped forward over another.

References:

• http://www.spine-health.com/topics/cd/spondy/spondy01.html
• http://www.chirogeek.com/005_Spondylo-Slide-Show.htm