Question 1 of 2077
Which one of the following statements regarding metformin is true?ia
A.A Should be stopped in a patient admitted with a myocardial infarctionia
B.A Hypoglycaemia is a recognised adverse effectia
C.A May cause a metabolic alkalosisia
D.A May aggravate necrobiosis lipoidica diabeticorumia
E.A Increases vitamin B12 absorptionia
Metformin should be stopped following a myocardial infarction due to the risk of lactic
acidosis. It may be introduced at a later date. Diabetic control may be achieved through
the use of a insulin/dextrose infusion (e.g. the DIGAMI regime)
Metformin
sqweqwesf erwrewfsdfs adasd dhe
Metformin is a biguanide used mainly in the treatment of type 2 diabetes mellitus. It has a
number of actions which improves glucose tolerance (see below). Unlike sulphonylureas
it does not cause hypoglycaemia and weight gain and is therefore first-line if the patient
is overweight. Metformin is also used in polycystic ovarian syndrome and non-alcoholic
fatty liver disease
Mechanism of action
increases insulin sensitivity
decreases hepatic gluconeogenesis
may also reduce gastrointestinal absorption of carbohydrates
Adverse effects
gastrointestinal upsets are common (nausea, anorexia, diarrhoea), intolerable in
20%
reduced vitamin B12 absorption - rarely a clinical problem
lactic acidosis* with severe liver disease or renal failure
Contraindications**
chronic kidney disease: NICE recommend reviewing metformin if the creatinine
is > 130 µmol/l and stopping metformin if > 150 µmol/l
do not use during suspected episodes of tissue hypoxia (e.g. Recent MI, sepsis)
alcohol abuse is a relative contraindication
stop 2 days before general anaesthetic, restart when renal function normal
stop prior to IV contrast e.g. Angiography, restart when renal function normal
*it is now increasingly recognised that lactic acidosis secondary to metformin is rare,
although it remains important in the context of exams
,**metformin is now sometimes used in pregnancy, for example in women with
polycystic ovarian syndrome
Question 2 of 2077
Which one of the following would cause a metabolic acidosis with a normal anion gap?ia
A.A Renal tubular acidosisia
B.A Acute renal failureia
C.A Diabetic ketoacidosisia
D.A Mesenteric ischaemiaia
E.A Aspirin overdoseia
Renal tubular acidosis causes a normal anion gap
Renal tubular acidosis is the correct answer as all the other four possible options cause a
metabolic acidosis with a raised anion gap
Metabolic acidosis
sqweqwesf erwrewfsdfs adasd dhe
Metabolic acidosis is commonly classified according to the anion gap. This can be
calculated by: (Na+ + K+) - (Cl- + HCO-3). If a question supplies the chloride level then
this is often a clue that the anion gap should be calculated. The normal range = 10-18
mmol/L
Normal anion gap ( = hyperchloraemic metabolic acidosis)
gastrointestinal bicarbonate loss: diarrhoea, ureterosigmoidostomy, fistula
renal tubular acidosis
drugs: e.g. acetazolamide
ammonium chloride injection
Addison's disease
Raised anion gap
lactate: shock, hypoxia
ketones: diabetic ketoacidosis, alcohol
urate: renal failure
acid poisoning: salicylates, methanol
Metabolic acidosis secondary to high lactate levels may be subdivided into two types:
lactic acidosis type A: shock, hypoxia, burns
lactic acidosis type B: metformin
Question 3 of 2077
,A 47-year-old man with a history of chronic sinusitis presents with shortness of breath to
the Emergency Department. Initial investigations reveal:
Hb 10.4g/dl
Platelets 477 * 109/l
WCC 14.3 * 109/l
ESR 92 mm/h
Urea 20 mmol/l
Creatinine 198 µmol/l
Urine dipstick blood +++
What is the most likely diagnosis?ia
A.A Mixed cryoglobulinaemiaia
B.A Churg-Strauss syndromeia
C.A Wegener's granulomatosisia
D.A Haemolytic uraemic syndromeia
E.A Henoch-Schonlein purpuraia
The combination of pulmonary and renal involvement combined with a history of chronic
sinusitis points towards a diagnosis of Wegener's granulomatosis
Wegener's granulomatosis
sqweqwesf erwrewfsdfs adasd dhe
Wegener's granulomatosis is an autoimmune condition associated with a necrotizing
granulomatous vasculitis, affecting both the upper and lower respiratory tract as well as
the kidneys
Features
upper respiratory tract: epistaxis, sinusitis, nasal crusting
lower respiratory tract: dyspnoea, haemoptysis
glomerulonephritis ('pauci-immune', 80% of patients)
saddle-shape nose deformity
also: vasculitic rash, eye involvement (e.g. proptosis), cranial nerve lesions
Investigations
cANCA positive in > 90%, pANCA positive in 25%
chest x-ray: wide variety of presentations, including cavitating lesions
renal biopsy: crescentic glomerulonephritis
, Management
steroids
cyclophosphamide (90% response)
plasma exchange
median survival = 8-9 years
Question 4 of 2077
A 34-year-old woman is admitted to the Emergency Department following a collapse. An
ECG shows a polymorphic ventricular tachycardia. Which one of the following is not
associated with an increased risk of developing torsade de pointes?ia
A.A Tricyclic antidepressantsia
B.A Subarachnoid haemorrhageia
C.A Hypercalcaemiaia
D.A Romano-Ward syndromeia
E.A Hypothermiaia
Hypocalcaemia, not hypercalcaemia, causes prolongation of the QT interval and hence
may predispose to the development of torsade de pointes
Long QT syndrome
sqweqwesf erwrewfsdfs adasd dhe
Long QT syndrome (LQTS) is an inherited condition associated with delayed
repolarization of the ventricles. It is important to recognise as it may lead to ventricular
tachycardia and can therefore cause collapse/sudden death. The most common variants of
LQTS (LQT1 & LQT2) are caused by defects in the alpha subunit of the slow delayed
rectifier potassium channel. A normal corrected QT is less than 440 ms in males and 450
ms in females.
Causes of a prolonged QT interval
Congenital Drugs Other
Jervell-Lange-Nielsen amiodarone, sotalol, electrolyte:
syndrome (includes class 1a hypocalcaemia,
deafness and is due to antiarrhythmic drugs hypokalaemia,
an abnormal tricyclic hypomagnesaemia
potassium channel) antidepressants, acute myocardial
Romano-Ward fluoxetine infarction
syndrome (no chloroquine myocarditis
deafness) terfenadine* hypothermia
erythromycin subarachnoid
haemorrhage
Features
Which one of the following statements regarding metformin is true?ia
A.A Should be stopped in a patient admitted with a myocardial infarctionia
B.A Hypoglycaemia is a recognised adverse effectia
C.A May cause a metabolic alkalosisia
D.A May aggravate necrobiosis lipoidica diabeticorumia
E.A Increases vitamin B12 absorptionia
Metformin should be stopped following a myocardial infarction due to the risk of lactic
acidosis. It may be introduced at a later date. Diabetic control may be achieved through
the use of a insulin/dextrose infusion (e.g. the DIGAMI regime)
Metformin
sqweqwesf erwrewfsdfs adasd dhe
Metformin is a biguanide used mainly in the treatment of type 2 diabetes mellitus. It has a
number of actions which improves glucose tolerance (see below). Unlike sulphonylureas
it does not cause hypoglycaemia and weight gain and is therefore first-line if the patient
is overweight. Metformin is also used in polycystic ovarian syndrome and non-alcoholic
fatty liver disease
Mechanism of action
increases insulin sensitivity
decreases hepatic gluconeogenesis
may also reduce gastrointestinal absorption of carbohydrates
Adverse effects
gastrointestinal upsets are common (nausea, anorexia, diarrhoea), intolerable in
20%
reduced vitamin B12 absorption - rarely a clinical problem
lactic acidosis* with severe liver disease or renal failure
Contraindications**
chronic kidney disease: NICE recommend reviewing metformin if the creatinine
is > 130 µmol/l and stopping metformin if > 150 µmol/l
do not use during suspected episodes of tissue hypoxia (e.g. Recent MI, sepsis)
alcohol abuse is a relative contraindication
stop 2 days before general anaesthetic, restart when renal function normal
stop prior to IV contrast e.g. Angiography, restart when renal function normal
*it is now increasingly recognised that lactic acidosis secondary to metformin is rare,
although it remains important in the context of exams
,**metformin is now sometimes used in pregnancy, for example in women with
polycystic ovarian syndrome
Question 2 of 2077
Which one of the following would cause a metabolic acidosis with a normal anion gap?ia
A.A Renal tubular acidosisia
B.A Acute renal failureia
C.A Diabetic ketoacidosisia
D.A Mesenteric ischaemiaia
E.A Aspirin overdoseia
Renal tubular acidosis causes a normal anion gap
Renal tubular acidosis is the correct answer as all the other four possible options cause a
metabolic acidosis with a raised anion gap
Metabolic acidosis
sqweqwesf erwrewfsdfs adasd dhe
Metabolic acidosis is commonly classified according to the anion gap. This can be
calculated by: (Na+ + K+) - (Cl- + HCO-3). If a question supplies the chloride level then
this is often a clue that the anion gap should be calculated. The normal range = 10-18
mmol/L
Normal anion gap ( = hyperchloraemic metabolic acidosis)
gastrointestinal bicarbonate loss: diarrhoea, ureterosigmoidostomy, fistula
renal tubular acidosis
drugs: e.g. acetazolamide
ammonium chloride injection
Addison's disease
Raised anion gap
lactate: shock, hypoxia
ketones: diabetic ketoacidosis, alcohol
urate: renal failure
acid poisoning: salicylates, methanol
Metabolic acidosis secondary to high lactate levels may be subdivided into two types:
lactic acidosis type A: shock, hypoxia, burns
lactic acidosis type B: metformin
Question 3 of 2077
,A 47-year-old man with a history of chronic sinusitis presents with shortness of breath to
the Emergency Department. Initial investigations reveal:
Hb 10.4g/dl
Platelets 477 * 109/l
WCC 14.3 * 109/l
ESR 92 mm/h
Urea 20 mmol/l
Creatinine 198 µmol/l
Urine dipstick blood +++
What is the most likely diagnosis?ia
A.A Mixed cryoglobulinaemiaia
B.A Churg-Strauss syndromeia
C.A Wegener's granulomatosisia
D.A Haemolytic uraemic syndromeia
E.A Henoch-Schonlein purpuraia
The combination of pulmonary and renal involvement combined with a history of chronic
sinusitis points towards a diagnosis of Wegener's granulomatosis
Wegener's granulomatosis
sqweqwesf erwrewfsdfs adasd dhe
Wegener's granulomatosis is an autoimmune condition associated with a necrotizing
granulomatous vasculitis, affecting both the upper and lower respiratory tract as well as
the kidneys
Features
upper respiratory tract: epistaxis, sinusitis, nasal crusting
lower respiratory tract: dyspnoea, haemoptysis
glomerulonephritis ('pauci-immune', 80% of patients)
saddle-shape nose deformity
also: vasculitic rash, eye involvement (e.g. proptosis), cranial nerve lesions
Investigations
cANCA positive in > 90%, pANCA positive in 25%
chest x-ray: wide variety of presentations, including cavitating lesions
renal biopsy: crescentic glomerulonephritis
, Management
steroids
cyclophosphamide (90% response)
plasma exchange
median survival = 8-9 years
Question 4 of 2077
A 34-year-old woman is admitted to the Emergency Department following a collapse. An
ECG shows a polymorphic ventricular tachycardia. Which one of the following is not
associated with an increased risk of developing torsade de pointes?ia
A.A Tricyclic antidepressantsia
B.A Subarachnoid haemorrhageia
C.A Hypercalcaemiaia
D.A Romano-Ward syndromeia
E.A Hypothermiaia
Hypocalcaemia, not hypercalcaemia, causes prolongation of the QT interval and hence
may predispose to the development of torsade de pointes
Long QT syndrome
sqweqwesf erwrewfsdfs adasd dhe
Long QT syndrome (LQTS) is an inherited condition associated with delayed
repolarization of the ventricles. It is important to recognise as it may lead to ventricular
tachycardia and can therefore cause collapse/sudden death. The most common variants of
LQTS (LQT1 & LQT2) are caused by defects in the alpha subunit of the slow delayed
rectifier potassium channel. A normal corrected QT is less than 440 ms in males and 450
ms in females.
Causes of a prolonged QT interval
Congenital Drugs Other
Jervell-Lange-Nielsen amiodarone, sotalol, electrolyte:
syndrome (includes class 1a hypocalcaemia,
deafness and is due to antiarrhythmic drugs hypokalaemia,
an abnormal tricyclic hypomagnesaemia
potassium channel) antidepressants, acute myocardial
Romano-Ward fluoxetine infarction
syndrome (no chloroquine myocarditis
deafness) terfenadine* hypothermia
erythromycin subarachnoid
haemorrhage
Features
