Friday, June 29, 2012

Thiamine Deficiency

 This morning we discussed a case of thiamine deficiency. Thiamine, or Vitamin B1, is a water soluble vitamin, found largely yeast, legumes, pork, rice, and cereals.

Two major thiamine deficiency disorders have been described in adults.

  1. Beriberi: hallmark of adult beriberi is symmetrical peripheral neuropathy. Wet beriberi also involved cardiomyopathy and CHF.
  2. Wernicke-Korsakoff syndrome: Wernicke is an acute presentation of nystagmus, opthamoplegia, ataxia and confusion. Korsakoff syndrome is the chronic condition that involves impaired short-term memory and confabulation with otherwise grossly normal cognition.
 Uptodate have a good review article on Water soluble vitamin deficiencies.

I like to point you toward a really good review about determinant of healthy eating among low-income Canadians. As we care for our patients, it is very important that we appreciate the socio-economic context of their illness.

Wednesday, June 27, 2012

Diabetic Foot Ulcers

We discussed diabetic foot ulcers this morning. The best way to prevent these ulcers is early detection of diabetic neuropathy, which is best done with a brief history and screening with Semmes-Weinstein monofilament.

Use the monofilament in 8-10 anatomic sites recommended (see above picture). However, even testing 4 plantar sites on the forefoot identifies 90% of the patients with an insensate site. Monofilament testing is fairly sensitive (66-91% ) and has a very good NPV 94-95%.

Here is review article on preventing diabetic foot ulcers. 

Monday, June 25, 2012

Extended Light's Criteria

This morning we discussed an approach to pleural effusion.
One concept we discussed was the possibility of transforming transudative pleural fluid in patients receiving diuretic therapy to an exudate.

In such cases we can use the “extended Light’s criteria”, which is to calculate the total protein gradient (serum minus pleural fluid). The fluid is a transudate if the total protein gradient is greater than 31g/L.

Here is a previous post about the Light’s criteria with a review article by Dr. Light himself!

Friday, June 22, 2012

Bacterial Meningitis

This morning we talked about a case of bacterial meningitis.  This is a disease that is rare but has significant mortality and morbidity, so it is important to be familiar with how to diagnose and treat it. Here are a few key point we discussed this morning.

  1. Do not delay antibiotics for procedures such as CT head or LP
  2. Antibiotic doses of meningitis are different (and much higher) 
  3. Even if the CSFcultures are sterilized by prior antibiotics, other clues such as degree of neutrophillia, CSF glucose level, or the gram stain can point toward bacterial meningitis
  4. No everyone needs a CT head
  5. IDSA recommendation for CT prior to lumbar puncture is below:
    1. Immunocompromised state
    2. History of CNS disease Mass lesion, stroke, or focal infection
    3. New onset seizure Within 1 week of presentation;
    4. Papilledema
    5. Abnormal level of consciousness …
    6. Focal neurologic deficit
    7. fields, gaze palsy, arm or leg drift
 Here is a review from Lance on management of bacterial meningitis. 

**Gram stain CSF: GPC in pairs and short chains suggestive of Streptococcus pneumoniae

Thursday, June 21, 2012


Given the extreme heat in Toronto recently, I want to bring your attention to a post I did about a year ago about heat stroke, when we were hit with a heat wave and increased admissions. This extreme weather causes no only heat stokes, but also exacerbations of many chronic cardiopulmonary disease.

Tuesday, June 19, 2012

ABCDE rule

Early recognition of melanoma is an important prognostic factor. To distinguish early melanoma from other forms of benign pigmented lesions, we can use the ABCDE rule.
  • Asymmetry (if a lesion is bisected, one half is not identical to the other half)
  • Border irregularities
  • Color variegation (brown, red, black or blue/gray, and white)
  • Diameter ≥6 mm
  • Evolving: a lesion that is changing in size, shape, or color, or a new lesion
The diagnostic accuracy of the ABCD vary in different studies. In a retrospective study of 1140 lesions including 460 melanomas, the sensitivity in identifying a lesion as a melanoma was 97 percent when using a single criterion and 43 percent when using all five criteria jointly. By contrast, specificity was 36 percent for a single criterion and 100 percent for all five criteria.

Monday, June 18, 2012


This morning we discussed a case of delirium.  Although a common diagnosis, it is sometimes challenging to diagnose delirium, especially in patients with underlying dementia or depression. The Confusion Assessment Method (CAM) is a validated tool to help you identify delirium. 

The diagnosis of delirium by CAM requires the presence of features 1 AND 2 plus either 3 OR 4.
1. Acute onset and fluctuating course
2. Inattention
3. Disorganized thinking
4. Altered level of consciousness 

For admitted medical and surgical patients, the CAM has a sensitivity of 94-100% and a specificity of 90-95% for diagnosing delirium.

Here is a detailed explanation of Confusion Assessment Method (CAM).

Thursday, June 7, 2012


RS3PE syndrome stands for remitting seronegative symmetrical synovitis with pitting edema.

This syndrome has many similar features to PMR. Patienst are often over the age of 50 and are seronegative. However, unlike PMR, many patients with RS3PE have sudden onset of polyarthritis, usually more prominent distally.

Patients with this disorder respond to low-dose glucocorticoids.

RS3PE also has been described as a paraneoplastic disorder that is associated with solid tumors and hematologic disorders.

Here is a good review article on PMR.

* Areas of pain in PMR

Wednesday, June 6, 2012

Doctor, my legs are so puffy!

This morning we discussed a case of new onset bilateral leg edema. 

Approach to is to think about one or more of the following etiologies: 1. increased capillary hydrostatic pressure (e.g. CHF) 2. decreased capillary oncotic pressure (e.g. nephrotic syndrome) 3. increased capillary permeability (e.g. inflammation)

As we discussed, focus your history on cardiac, hepatic, or renal disease, or drugs that affect any of those systems.

 Physical examination should focus on the pattern of edema. Is the JVP elevated? Is there pulmonary edema? Is there ascites? Is the edema localized or generalized? Is it pitting or non-pitting? Is it acute or chronic? Pattern of edema will help you narrow down your differential diagnosis.

  Here is a reference on the topic.