July 2nd, 2011
A 62 year old man presents with a swollen right calf 3 weeks after undergoing a total left hip replacement. He is known to have rheumatoid arthritis.
An Emergency Department doctor tells you that he feels the patient can be discharged. He tells you this because he shows you the D-Dimer result, which is “negative”. The result is shown below.
| D-Dimer 0.08 (Normal range 0-0.18) |
Which of the following statements is true about D-Dimer testing in general patients with a suspected DVT?
a. Following a clinical assessment, clinicians should not rely on the test as a basis to ‘discharge’ or ‘investigate’
b. It is of no use in patients who have had recent surgery (e.g. within the last 12 weeks)
c. It is of no clinical use in patients with malignancy and secondary metastases
d. It can be used to discharge patients based on their underlying estimated clinical risk score
e. None of the listed answers are correct.
Leave a comment; answer in a few days!
January 29th, 2011
We asked you a question on symptoms of hypoadrenalism here.
The answer is of course: e. Skin Pigmentation
Most of the symptoms of adrenal insufficiency (e.g. hypotension, weight loss) result from low cortisol levels and therefore do not distinguish between adrenal or pituitary failure.
This question tests your understanding of the hypothalamic-pituitary-adrenal axis. This is another example where negative feedback is used to control hormone release.
ACTH is released from the pituitary gland. It acts on the adrenal glands stimulating cortisol release.
In primary adrenal failure (Addison’s disease), there is destruction of the adrenal glands and therefore they do not produce cortisol. In an attempt to stimulate the failed adrenal glands, the pituitary gland secretes high levels of ACTH.
ACTH is synthesised within the anterior pituitary gland from pro-opiomelanocortin (POMC). The cleavage of the POMC molecule results in the production of ACTH as well as a number of molecules including forms of MSH (melanocyte stimulating hormone). In fact, alpha-MSH is identical to the start of the ACTH molecule.
High levels of circulating ACTH act as MSH causing increased pigmentation.
Look in the buccal mucosa and at the palmar creases.
If the cause of hypoadrenalism is from pituitary failure, neither ACTH nor MSH will be released, hence there’s no increase in pigmentation.
Check out more free questions with our free trial!
e. Skin Pigmentation
Most of the symptoms of adrenal insufficiency (e.g. hypotension, weight loss) result from low cortisol levels and therefore do not distinguish between adrenal or pituitary failure.
This question tests your understanding of the hypothalamic-pituitary-adrenal axis. This is another example where negative feedback is used to control hormone release.
ACTH is released from the pituitary gland. It acts on the adrenal glands stimulating cortisol release.
In primary adrenal failure (Addison’s disease), there is destruction of the adrenal glands and therefore they do not produce cortisol. In an attempt to stimulate the failed adrenal glands, the pituitary gland secretes high levels of ACTH.
ACTH is synthesised within the anterior pituitary gland from pro-opiomelanocortin (POMC). The cleavage of the POMC molecule results in the production of ACTH as well as a number of molecules including forms of MSH (melanocyte stimulating hormone). In fact, alpha-MSH is identical to the start of the ACTH molecule.
High levels of circulating ACTH act as MSH causing increased pigmentation.
Look in the buccal mucosa and at the palmar creases.
If the cause of hypoadrenalism is from pituitary failure, neither ACTH nor MSH will be released, hence there’s no increase in pigmentation.
January 9th, 2011
Let’s test your endocrinology knowledge with this teaser. As ever, leave your answer as a comment. Answer will be given in a few days.
Which of these symptoms of hypoadrenalism will distinguish between primary adrenal failure and secondary (pituitary) adrenal insufficiency?
a. Postural Hypotension
b. Weight Loss
c. Fatigue
d. Hypoglycaemia
e. Skin Pigmentation
July 22nd, 2010
Those of you who guessed B as the answer to our question of the day on hepatitis C were correct!
The chances of transmission are as follows:
| Condition |
Notes |
| HIV/AIDS 0.3% |
Risk assessment needed prior to administering post exposure prophylaxis |
| Hep C 3%[1] |
PCR testing for Hep C virus will give most accurate and reliable indication of transmission |
| Hep B 30% |
Consider repeat Hep B booster/ IvIG (local policies) |
| The rule of 3′s |
The risk is higher with hollow bore needles than with normal needles (e.g. suturing). This data varies widely across specialities. Individuals vaccinated against Hepatitis B have a lower risk of transmission following a needle stick.
The prevalence of needle stick injuries has been estimated to be as high as 33% in a 6 month period for healthcare workers.[2] A good review on needle stick injuries can be read from Bandolier here.
Hep B is the most transmissible of all 3 conditions. As a healthcare professional with a transmittable disease it may preclude you from working in certain specialities e.g. some surgical specialities.
Remember the prevalence of Hepatitis B, HIV and Hepatitis C in the UK is still low (<1% for each).
[1] The risk of Hep C transmission rate varies from 3-5%. If a person is exposed, the usual practice is to PCR the blood for the hepatits C virus .
MS Sulkowski et al. Needlestick transmission of hepatitis C. JAMA 2002 287: 2406-2413.
[2] A study of 75 medical students and interns in New York
F Resnic, MA Noerdlinger. Occupational exposure among medical students and house staff at a New York City medical center. Archives of Internal Medicine 1995 155: 75-80.
Remember, loads more MCQs are available in the members area – its free to join.
May 23rd, 2010
A medical student sustains a needlestick injury from an intravenous drug user. Unfortunately this user is Hepatitis C positive.
Regarding Hepatitis C which of the following statements is true?
a. Vaccination to hepatitis C is routinely available to healthcare professionals and confers some protection
b. The chance of transmission of hepatitis C is around 3%
c. The chance of transmission is around 0.3%
d. Hepatitis C if transmitted will lead to liver failure in that individual
e. The chance of transmission is around 30%
…answer in a few days!
