Which of the following is not true regarding B-type natriuretic peptide?
Correct Answer C:
BNP - actions:
B-type natriuretic peptide:
B-type natriuretic peptide (BNP) is a hormone produced mainly by the left ventricular myocardium in response to strain.
Whilst heart failure is the most obvious cause of raised BNP levels any cause of left ventricular dysfunction such as myocardial ischaemia or valvular disease may raise levels. Raised levels may also be seen due to reduced excretion in patients with chronic kidney disease. Factors which reduce BNP levels include treatment with ACE inhibitors, angiotensin-2 receptor blockers and diuretics.
Effects of BNP:
Clinical uses of BNP:
1- Diagnosing patients with acute dyspnoea:
2- Prognosis in patients with chronic heart failure:
3- Guiding treatment in patients with chronic heart failure:
4- Screening for cardiac dysfunction:
You are a ST1 doctor in medicine doing a night shift. An elderly patient with colorectal cancer has been admitted to the Emergency Department with suspected bowel obstruction. The Emergency Department F2 doctor has tried to refer the patient to the surgeons but was told that as no surgical intervention is likely the patient should be admitted to the medics. The F2 doctor therefore phones yourself and asks you to accept the patient.
What is the most appropriate response?
Correct Answer D:
Scenarios similar to this occur on an almost daily basis for admitting medical teams. The priority in all of this has to be the patient. It may be the case if the patient is end-stage then medical admission is more appropriate. If they are Duke's A and awaiting an operation then clearly they are surgical. Until you review the patient yourself you will not have all the facts and this is therefore the best option.
Discussing the matter with the surgical team will help to clarify their opinion about the patient and is the next best option. Accepting the patient without review risks placing a patient with an acute surgical problem on a medical ward. This may delay or compromise care.
Getting into an argument with the surgical registrar is not constructive and is a poor choice, as is simply refusing to see the patient as this indicates a disregard for the patient.
A new adjuvant treatment for women with breast cancer is investigated. The study looks at the recurrence rate after 5 years. The following data is obtained:
What is the relative risk reduction?
Correct Answer B:
Relative risk reduction = (EER - CER) / CER
Relative risk:
Relative risk (RR) is the ratio of risk in the experimental group (experimental event rate, EER) to risk in the control group (control event rate, CER). The term relative risk ratio is sometimes used instead of relative risk. To recap:
For example, if we look at a trial comparing the use of paracetamol for dysmenorrhoea compared to placebo we may get the following results:
If the risk ratio is > 1 then the rate of an event (in this case experiencing significant pain relief) is increased compared to controls. It is therefore appropriate to calculate the relative risk increase if necessary (see below).
If the risk ratio is < 1 then the rate of an event is decreased compared to controls. The relative risk reduction should therefore be calculated (see below).
Relative risk reduction (RRR) or relative risk increase (RRI) is calculated by dividing the absolute risk change by the control event rate Using the above data, RRI = (EER - CER) / CER = (0.6 - 0.25) / 0.25 = 1.4 = 140%
A couple present for genetic counselling. The male partner has haemophilia whilst the female partner has been screened and shown to be a carrier of the gene causing haemophilia.
What is the chance that a future child would have haemophilia?
This question asks about the unusual situation of an affected male having children with a heterozygous (carrier) female. In this situation 50% of all children will be affected.
X-linked recessive:
In X-linked recessive inheritance only males are affected. An exception to this seen in examinations are patients with Turner's syndrome, who are affected due to only having one X chromosome. X linked recessive disorders are transmitted by heterozygote females (carriers) and male-to-male transmission is not seen. Affected males can only have unaffected sons and carrier daughters.
Each male child of a heterozygous female carrier has a 50% chance of being affected whilst each female child of a heterozygous female carrier has a 50% chance of being a carrier.
The possibility of an affected father having children with a heterozygous female carrier is generally speaking extremely rare. However, in certain Afro-Caribbean communities G6PD deficiency is relatively common and homozygous females with clinical manifestations of the enzyme defect are seen.
Which one of the following is not a risk factor for the development of pre-eclampsia?
There is some evidence to suggest that pre-eclampsia is actually less common in smokers.
Pre-eclampsia:
Pre-eclampsia is a condition seen after 20 weeks gestation characterized by pregnancy-induced hypertension in association with proteinuria (> 0.3g / 24 hours). Oedema used to be third element of the classic triad but is now often not included in the definition as it is not specific.
Pre-eclampsia is important as it predisposes to the following problems:
Risk factors:
Features of severe pre-eclampsia:
Management:
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