137 Gout Flashcards
Name some types of non-inflammatory arthritis
OA
Neuropathic
Osteochondritis dissecans
Name 4 types of inflammatory arthritis
RA
Gout
Juvenile Chronic arthritis
Psoriatic arthritis
What are the signs and symptoms of monoarthritis?
Pain
Swelling of joint
Erythema of overlying skin
Decreased range of movement
Which organism is the most likely cause of septic arthritis?
Staph aureus
What is not present in the serum of sero-negative arthritis and which surface antigen is present?
Rheumatoid factor = not
HLA-B27
Which joints are affected mostly in psoriatic arthritis
Smaller joints ie distal interphalangeal joints
What can be seen on xray in psoriatic arthritis?
Erosion of the central joint
What is used to treat severe psoriatic arthritis?
Methotrexate
Ciclosporin
anti TNF-alpha agents
Which drugs should be avoided when treating psoriatic arthritis?
NSAIDs - could exacerbate the skin lesions
Which 2 groups of patients are most likely to develop haemoarthrosis?
Haemophiliacs
Warfarin users
Which crystals form in pseudogout and where do they usually accumulate?
pyrophosphate crystals –> in the knees
What is the treatment of pseudogout?
analgesia
steroid injection
joint replacement
Name some predisposing factors for septic arthritis?
prosthetic joint immunosuppression elderly DM RA existing joint damage IV drugs
What are the risks of leaving septic arthritis untreated?
Rapid joint destruction
Sinus/abscess formation
Septicaemia
Death
Name the 4 things observed on an x-ray of a septic arthritic joint
- Loss of joint space
- Subchondral bone erosion
- Sclerosis of femoral head
- Osteonecrosis/collapse of femoral head
What investigations are needed to diagnose septic arthritis?
MC&S of the aspirate
Blood cultures
CRP
What is the antibiotic of choice for the treatment of septic arthritis? Duration?
IV Flucloxacillin 1 - 2g + fusidic acid
IV 2/52 , followed by 4/52 PO
Should the joint be immobilised/mobilised following washout of septic arthritis?
Immobilised
What is gout?
Inflammatory response to monosodium urate monohydrate crystals in hyperuricaemia
Which enzyme is deficient in gout and which synthesis pathway does this occur in?
Urate oxidase in purine synthesis
Which group are most likely to develop gout?
Middle aged men
What effects do high and low dose aspirin have on the excretion of urate?
High = increases excretion Low = decreases excretion
What effect can renal impairment have on the excretion of urate?
Reduced excretion
What investigations should be performed when suspecting gout?
Joint fluid microscopy Serum urate (>600 = raised) U&EC CRP Urinalysis
What other factors would influence you giving urate reducing agents like allopurinol in a primary acute gout?
Other comorbidities Complications associated with the acute gout Impaired renal function Frequency Age
When should gout patients be given urate reducing agents?
Post 2nd attack
Renal impairment/stones
Tophi/tissue damage
When should urate reducing agents not be given to gout pts? What should be given in the meantime?
During an acute attack + 1 month after
Should give NSAIDs 4/52 prior to allopurinol
Name 2 xanthine oxidase inhibitors
Allopurinol
Feboxustat
Which 2 drugs does allopurinol interact with?
Warfarin
Azathiopine
Which class of drugs are sulphinpyrazone, probenecid and benzobromarone?
Uricosuric agents
What is the MOA of uricosuric agents?
Increase excretion of uric acid - inhibits resorption of UA at the proximal convoluted tubule
What is the main function of calcium homeostasis?
To maintain serum calcium levels
Why is calcium important in the body? (7 listed)
Formation of calcified tissues
Normal nerve and muscle activity
NT release, hormonal and glandular secretion
Excitation coupling of cardiac and SM
Integrity and permeability of cell membranes
Cell adhesion
Blood clotting
What converts 7-dehydroxy cholesterol into vitamin D3 and where does this occur?
UV light in the skin
Which enzyme involved with vitamin D synthesis is stimulated by PTH?
1 alpha- hydroxylase
What is the effect of viatmin D3 in the intestines?
Increases Ca absorption by stimulating espression of Ca2+ transport proteins
What is the effects of vitaminD3 on bone mineralisation?
Increases bone mineralisation by inducing terminal differentiation of osteoclasts and increasing serum calcium directly via osteoblasts
Name 3 ways in which VitD3 affects a tumour microenvironment
- inhibits - proliferation
- inhibits angiogenesis
- Induces differentiation
Which cells produce PTH?
Chief cells of the parathyroid glands
Name 3 ways in which PTH increases serum calcium
Stimulates bone resorption
Increases tubular resorption in kidneys
Stimulates 1alpha hydroxylase to hydroxylate Vit D3
Which hormone is synthesised in the parafollicular cells of the thyroid?
Calcitonin
What are the main functions of calcitonin?
Vit D regulation
Inhibits bone resorption
Satiety
What is the main cause of hypercalcaemia?
Primary hyperparathyroidism
What is the main cause of hypocalcaemia?
Renal failure
What is the gross effect of hypercalcaemia on the body?
Causes supression of activity as it blocks sodium channels
What are the effects of hypercalcaemia on the CNS?
5 listed
Depression Lethargy Decreased alertness Confusion Coma
What are the effects of Hypercalcaemia on the GIT?
3 listed
Anorexia
Constipation
N&V
Why are there more #s in hypercalcaemia?
Increased bone resorption (see Ca2+ homeastasis)
What is the gross effect of hypocalcaemia on the body?
Mainly causes increased activity as lowers threshold for depolarisation
What is Trousseu’s sign?
Inflate BP to systolic pressure and after 3 mins, fingers and wrist will spasm tetanically
What is Chvostek’s sign?
Tap on CN VII –> twitching of facial muscles on ipsilateral side
What is pseudohypoparathyroidism?
Individual is resistant to PTH so high PTH levels in serum.
Why is an osteochondral lesion ‘better’ than a chondral lesion?
Better healing as bleeding is stimulated of the underlying subchondral bone –>chondroprogenitor cells induce the healing
What is the Tx for advanced OA of the knee?
TKR
Which 2 enzymes are used in the culture expansion of autologous chondrocytes in ACI?
Collagenase and pronase
Which antibiotic is added to the culture medium in ACI?
Gentamycin
What is used in MACI as a scaffold?
Porcine collagen
