Q: Which vitamin deficiency may cause life threatening lactic acidosis?



Answer: Thiamine (Vitamin B1) deficiency

Thiamine is part of the pyruvate-dehydrogenase (PDH) complex. Its deficiency inhibits pyruvate entry into mitochondria.

Clinical implication: It is important to add Thiamine on patients requring long term parentral nutrition (TPN).


Reference: Click to get references

1. Thiamine deficiency as a cause of life threatening lactic acidosis in total parenteral nutrition - Klin Wochenschr. 1991;69 Suppl 26:193-5.

2. Metabolic acidosis and thiamine deficiency - Mayo clinic Proceedings, March 1999 vol. 74 no. 3 259-263

3. Severe Lactic Acidosis Related to Acute Thiamine Deficiency - Journal of Parenteral and Enteral Nutrition, Vol. 15, No. 1, 105-109 (1991)

Q: Despite being an old player Sucralfate is still very well indicated in stress ulcer prophylaxis. What is the mechanism of action of sucralfate?

Answer: Sucralfate act by multiple mechanisms

1. Sucralfate acting locally that in an acidic environment , reacts with hydrochloric acid in the stomach to form a cross-linking, viscous, paste-like material capable of acting as an acid buffer for as long as 6 to 8 hours after a single dose.

2. It also attaches to proteins on the surface of ulcers, such as albumin and fibrinogen, to form stable insoluble complexes. These complexes serve as protective barriers at the ulcer surface, preventing further damage from acid, pepsin, and bile.

3. It prevents back diffusion of hydrogen ions.

4. It adsorbs both pepsin and bile acids.

5. Sucralfate also stimulates the increase of prostaglandin E₂, epidermal growth factors (EGF), bFGF, and gastric mucus.

Q: How Dexilant (Dexlansoprazole) is different from other PPIs (Proton Pump Inhibitors)?


Answer: Dexilant has a DUAL DELAYED RELEASE mechanism. It contains two different types of granules for two releases of medicine. Dexilant works by releasing one shift of medicine within an hour of taking it to decrease the amount of acid in stomach. Around 4–5 hours later, Dexilant releases a second shift of medicine.

How much advantage does it provide over other PPIs has yet to be determine in independent studies.

Thursday August 5, 2010


Q: What is the difference between available synthetic thyroid hormone replacement and natural thyroid hormone replacement in market?


Answer: Synthetic thyroid hormone contains T4 only and is therefore largely ineffective for patients unable to convert T4 to T3. Also some patients may develop allergy to synthetic thyroid hormone.

Natural thyroid treatments hormones are still available. Armour Thyroid is the most popular brand available and is a natural, porcine-derived thyroid replacement containing both T4 and T3. The ratio of Thyroid T4 to T3 is 4.22:1.

Armour thyroid is available in strengts as grains (1/4, 1/2, 1 grains).

1 grain of Armour is approximately equal to 100 mcg of levothyroxine.

Q: Why Prealbumin is called Prealbumin?


Answer: Prealbumin is called prealbumin because it ran faster than albumins on electrophoresis gels in contrast to general belief that its a precursor of albumin. It should not be confused with albumin.

The right name for Prealbumin is Transthyretin (TTR). TTR is a serum and cerebrospinal fluid carrier of the thyroid hormone thyroxine (T4) and retinol. This is how transthyretin gained its name, transports thyroxine and retinol.

Nutritional status can be assessed by measuring concentrations of prealbumin in the blood. Prealbumin is preferred because of its shorter half-life, although this means that its concentration more closely reflects recent dietary intake rather than overall nutritional status.

Q: In human body for measurement , each 1 g/dL decrease of albumin will raise the serum Calcium by what level?

Answer: Each 1 g/dL decrease of albumin raises the serum calcium (Ca) level by 0.8 mg/dL in human body. Remember the formula for calcium correction from internship days?

Corrected calcium (mg/dL) = measured total Ca (mg/dL) + 0.8 (4.0 - serum albumin [g/dL])

Pleural calcification in asbestos exposure

Pleural calcification occurs in about 50% with asbestos-related disease, especially along the diaphragmatic pleura. (White arrow)The overall appearance of the plaque has been likened to a holly leaf. (Black arrows) point to many of the calcified pleural plaques.

Q: 78 year old male presented with severe abdominal pain. Patient is taking huge amount of over the counter NSAIDs and you suspect perforated peptic ulcer. As an initial workup you ordered upright KUB. Looking at portable screen of technician you didn't see any free air. What should be your next step?


Answer: Take a left lateral decubitus film.

Plain x-rays of the abdomen with the patient in the upright position have been used in diagnosing perforated ulcer. However, in 30% to 50% of patients, the x-ray may be negative for free air, particularly in the elderly. A left lateral decubitus film has been shown to be most sensitive in detecting pneumoperitoneum. Placing the patient in the upright or left lateral decubitus position for 10 minutes before taking the x-ray may help detect the condition. Similarly, use of water-soluble contrast medium with an upper gastrointestinal tract series or computed tomography scan may increase the diagnostic yield.