An 86-year-old woman presented to the emergency department complaining of a 2-day
history of difficulty weight bearing and pain in the right knee. She is known to have atrial
fibrillation, for which she is currently anticoagulated with warfarin. Her INR 2 weeks ago was
seen to be 4.4, and she subsequently had her warfarin dose adjusted. On examination, you
note that her right knee is red, hot and tender with a fluctuant effusion.
What is the next most appropriate step?
A. Intravenous flucloxacillin 8%
B. 5mg oral vitamin K 10%
C. Commence colchicine 1%
D. Aspirate the joint 80%
E. Discharge the patient with advice to rest, ice, compress and elevate 1%
the leg.
Synovial fluid sampling is the key investigation in patients with suspected septic arthritis
The red, hot, tender joint is an important presentation in acute rheumatology. The three
classic differentials for this presentation are septic arthritis, gout and pseudogout. In this
lady, in view of the previously high INR, joint haematoma is also an important consideration.
It is not possible to differentiate these conditions clinically, so joint aspiration is the most
important next step. Culture will enable a positive diagnosis of septic arthritis, whilst
microscopy and gross appearance the diagnosis of crystal arthropathy.
If there is a high clinical index of suspicion of septic arthritis, the patient should be
commenced on IV antibiotics. However, this should be done after joint aspiration so that
more targetted therapy can be performed subsequently.
Warfarin reversal is not necessary in this case due to the low-risk nature of joint aspiration
and the fact that her previous INR was only 4.4 with a subsequent reduction in dose.
Colchicine is a useful medication in the acute management of gout, but the diagnosis is yet
to be established. Discharging the patient at this point is premature.
Septic arthritis in adults
Pathophysiology
● most common organism overall is Staphylococcus aureus
○ in young adults who are sexually active, Neisseria gonorrhoeae is the most
common organism (disseminated gonococcal infection)
● the most common cause is hematogenous spread
○ this may be from distant bacterial infections e.g. abscesses
● in adults, the most common location is the knee
,Features
● acute, swollen joint
○ restricted movement in 80% of patients
○ examination findings: warm to touch/fluctuant
● fever: present in the majority of patients
Investigations
● synovial fluid sampling is obligatory
○ this should be done prior to the administration of antibiotics if necessary
○ may need to be done under radiographic guidance
○ shows a leucocytosis with neutrophil predominance
○ gram staining is negative in around 30-50% of cases
○ fluid culture is positive in patients with non-gonococcal septic arthritis
● blood cultures: the most common cause of septic arthritis is hematogenous spread
● joint imaging
Management
● intravenous antibiotics which cover Gram-positive cocci are indicated. The BNF
currently recommends flucloxacillin or clindamycin if penicillin allergic
○ antibiotic treatment is normally be given for several weeks (BNF states 4-6
weeks)
○ patients are typically switched to oral antibiotics after 2 weeks
● needle aspiration should be used to decompress the joint
● arthroscopic lavage may be required
●
A 24-year-old female with a history of type 1 diabetes mellitus presents to the Emergency
Department with vomiting and abdominal pain. Finger-prick testing estimates the blood
sugar to be 25 mmol/l. Arterial blood gases record a pH of 7.22. On examination the patient
is dehydrated and weighs 80 kg. An intravenous line is sited and bloods are sent. One litre of
0.9% saline is infused and an intravenous insulin pump is set-up.
What rate should insulin be initially given?
A. 10 unit / hour 6%
B. 1 unit / hour 11%
C. 2 unit / hour 2%
D. 6 unit / hour 7%
, E. 8 unit / hour 74%
Diabetic ketoacidosis: the IV insulin infusion should be started at 0.1 unit/kg/hour
The Joint British Diabetes Societies produced guidelines in 2010 recommending starting the
insulin infusion at a rate of 0.1 unit/kg/hour.
Diabetic ketoacidosis
Diabetic ketoacidosis (DKA) may be a complication of existing type 1 diabetes mellitus or be
the first presentation, accounting for around 6% of cases. Rarely, under conditions of
extreme stress, patients with type 2 diabetes mellitus may also develop DKA.
Whilst DKA remains a serious condition mortality rates have decreased from 8% to under
1% in the past 20 years.
Pathophysiology
● DKA is caused by uncontrolled lipolysis (not proteolysis) which results in an excess
of free fatty acids that are ultimately converted to ketone bodies
The most common precipitating factors of DKA are infection, missed insulin doses and
myocardial infarction.
Features
● abdominal pain
● polyuria, polydipsia, dehydration
● Kussmaul respiration (deep hyperventilation)
● Acetone-smelling breath ('pear drops' smell)
Diagnostic criteria
American Diabetes Association Joint British Diabetes Societies (2013)
(2009)
, Key points Key points
● glucose > 13.8 mmol/l ● glucose > 11 mmol/l or known diabetes
● pH < 7.30 mellitus
● serum bicarbonate <18 mmol/l ● pH < 7.3
● anion gap > 10 ● bicarbonate < 15 mmol/l
● ketonaemia ● ketones > 3 mmol/l or urine ketones ++ on
dipstick
A 31-year-old woman is investigated for lethargy, arthralgia and cough. Over the past few
weeks she has also developed painful erythematous nodules on both shins. Respiratory
examination is normal. A chest x-ray is performed which is reported as follows:
Bilateral mediastinal nodal enlargement. No evidence of lung parenchymal disease. Normal
cardiac size.
Given the likely diagnosis, what is the most appropriate course of action?
A. Inhaled corticosteroids 0%
B. Oral cyclophosphamide 1%
C. Oral corticosteroids 20%
D. Oral methotrexate 1%
E. Observation 79%
Indications for corticosteroid treatment for sarcoidosis are: parenchymal lung disease,
uveitis, hypercalcaemia and neurological or cardiac involvement
This patient has sarcoidosis as evidenced by the erythema nodosum and bilateral hilar
lymphadenopathy. The chest x-ray is consistent with stage 1 changes. There are no
indications here for steroid therapy so observation is the most appropriate action.
history of difficulty weight bearing and pain in the right knee. She is known to have atrial
fibrillation, for which she is currently anticoagulated with warfarin. Her INR 2 weeks ago was
seen to be 4.4, and she subsequently had her warfarin dose adjusted. On examination, you
note that her right knee is red, hot and tender with a fluctuant effusion.
What is the next most appropriate step?
A. Intravenous flucloxacillin 8%
B. 5mg oral vitamin K 10%
C. Commence colchicine 1%
D. Aspirate the joint 80%
E. Discharge the patient with advice to rest, ice, compress and elevate 1%
the leg.
Synovial fluid sampling is the key investigation in patients with suspected septic arthritis
The red, hot, tender joint is an important presentation in acute rheumatology. The three
classic differentials for this presentation are septic arthritis, gout and pseudogout. In this
lady, in view of the previously high INR, joint haematoma is also an important consideration.
It is not possible to differentiate these conditions clinically, so joint aspiration is the most
important next step. Culture will enable a positive diagnosis of septic arthritis, whilst
microscopy and gross appearance the diagnosis of crystal arthropathy.
If there is a high clinical index of suspicion of septic arthritis, the patient should be
commenced on IV antibiotics. However, this should be done after joint aspiration so that
more targetted therapy can be performed subsequently.
Warfarin reversal is not necessary in this case due to the low-risk nature of joint aspiration
and the fact that her previous INR was only 4.4 with a subsequent reduction in dose.
Colchicine is a useful medication in the acute management of gout, but the diagnosis is yet
to be established. Discharging the patient at this point is premature.
Septic arthritis in adults
Pathophysiology
● most common organism overall is Staphylococcus aureus
○ in young adults who are sexually active, Neisseria gonorrhoeae is the most
common organism (disseminated gonococcal infection)
● the most common cause is hematogenous spread
○ this may be from distant bacterial infections e.g. abscesses
● in adults, the most common location is the knee
,Features
● acute, swollen joint
○ restricted movement in 80% of patients
○ examination findings: warm to touch/fluctuant
● fever: present in the majority of patients
Investigations
● synovial fluid sampling is obligatory
○ this should be done prior to the administration of antibiotics if necessary
○ may need to be done under radiographic guidance
○ shows a leucocytosis with neutrophil predominance
○ gram staining is negative in around 30-50% of cases
○ fluid culture is positive in patients with non-gonococcal septic arthritis
● blood cultures: the most common cause of septic arthritis is hematogenous spread
● joint imaging
Management
● intravenous antibiotics which cover Gram-positive cocci are indicated. The BNF
currently recommends flucloxacillin or clindamycin if penicillin allergic
○ antibiotic treatment is normally be given for several weeks (BNF states 4-6
weeks)
○ patients are typically switched to oral antibiotics after 2 weeks
● needle aspiration should be used to decompress the joint
● arthroscopic lavage may be required
●
A 24-year-old female with a history of type 1 diabetes mellitus presents to the Emergency
Department with vomiting and abdominal pain. Finger-prick testing estimates the blood
sugar to be 25 mmol/l. Arterial blood gases record a pH of 7.22. On examination the patient
is dehydrated and weighs 80 kg. An intravenous line is sited and bloods are sent. One litre of
0.9% saline is infused and an intravenous insulin pump is set-up.
What rate should insulin be initially given?
A. 10 unit / hour 6%
B. 1 unit / hour 11%
C. 2 unit / hour 2%
D. 6 unit / hour 7%
, E. 8 unit / hour 74%
Diabetic ketoacidosis: the IV insulin infusion should be started at 0.1 unit/kg/hour
The Joint British Diabetes Societies produced guidelines in 2010 recommending starting the
insulin infusion at a rate of 0.1 unit/kg/hour.
Diabetic ketoacidosis
Diabetic ketoacidosis (DKA) may be a complication of existing type 1 diabetes mellitus or be
the first presentation, accounting for around 6% of cases. Rarely, under conditions of
extreme stress, patients with type 2 diabetes mellitus may also develop DKA.
Whilst DKA remains a serious condition mortality rates have decreased from 8% to under
1% in the past 20 years.
Pathophysiology
● DKA is caused by uncontrolled lipolysis (not proteolysis) which results in an excess
of free fatty acids that are ultimately converted to ketone bodies
The most common precipitating factors of DKA are infection, missed insulin doses and
myocardial infarction.
Features
● abdominal pain
● polyuria, polydipsia, dehydration
● Kussmaul respiration (deep hyperventilation)
● Acetone-smelling breath ('pear drops' smell)
Diagnostic criteria
American Diabetes Association Joint British Diabetes Societies (2013)
(2009)
, Key points Key points
● glucose > 13.8 mmol/l ● glucose > 11 mmol/l or known diabetes
● pH < 7.30 mellitus
● serum bicarbonate <18 mmol/l ● pH < 7.3
● anion gap > 10 ● bicarbonate < 15 mmol/l
● ketonaemia ● ketones > 3 mmol/l or urine ketones ++ on
dipstick
A 31-year-old woman is investigated for lethargy, arthralgia and cough. Over the past few
weeks she has also developed painful erythematous nodules on both shins. Respiratory
examination is normal. A chest x-ray is performed which is reported as follows:
Bilateral mediastinal nodal enlargement. No evidence of lung parenchymal disease. Normal
cardiac size.
Given the likely diagnosis, what is the most appropriate course of action?
A. Inhaled corticosteroids 0%
B. Oral cyclophosphamide 1%
C. Oral corticosteroids 20%
D. Oral methotrexate 1%
E. Observation 79%
Indications for corticosteroid treatment for sarcoidosis are: parenchymal lung disease,
uveitis, hypercalcaemia and neurological or cardiac involvement
This patient has sarcoidosis as evidenced by the erythema nodosum and bilateral hilar
lymphadenopathy. The chest x-ray is consistent with stage 1 changes. There are no
indications here for steroid therapy so observation is the most appropriate action.
