List I - Act Core Conditions Flashcards
(33 cards)
What is septic arthritis?
- Refers to the infection of a joint
* Requires a high index of suspicion and can affect both native and prosthetic joints
What are the risk factors for septic arthritis?
- Age >80 yrs
- Any pre-existing joint disease e.g. RA
- Diabetes mellitus
- Chronic renal failure
Hip or knee joint prosthesis - IV drug use
What are the main causative organisms that can lead to septic arthritis?
- Staphylococcus aureus
- Streptococcus
- Gonorrhoea (in sexually active patients)
- Salmonella (especially in sickle cell)
- MRSA
- Staphylococcus epidermis
How does septic arthritis happen?
- Bacteria will seed to the joint from:
- Bacteraemia e.g. recent cellulitis, UTI, chest infection
- Direct inoculation
- Spreading from adjacent osteomyelitis
What are the presenting features of septic arthritis?
- Single swollen joint causing severe pain (although absence of pain does not rule it out)
- Examination will reveal a red, hot swollen joint causing pain on active and passive movements
- Effusion may be present
- Often the joint is rigid and the patient will not tolerate any passive movement at all, and will be unable to weight bear
- Symptoms are more florid and obvious in native joint injection, in prosthetic joint infections, the features can be more subtle
What are the differential diagnoses for septic arthritis?
- Flare of osteoarthritis
- Haemarthrosis
- Crystal arthropathies (gout and pseudogout)
- Rheumatoid arthritis and other inflammatory arthropathies
- Reactive arthritis
- Lyme disease (infection with Borrella burgdoferi)
What investigations need to be done for septic arthritis?
- FBC
- CRP
- ESR
- Urate levels
- Blood cultures (at least two separate samples) especially those with evidence of sepsis
- Joint aspiration is essential and needs to be done before antibiotics are given (for patients with a prosthetic joint, this should be done in the operating room
- Joint fluid analysis should also be sent for Gram stain, leucocyte count, polarising microscopy and fluid culture
- Cell count with WBC > 50, 000 is considered diagnostic for septic arthritis, however lower counts may still indicate infection
- Prosthetic joint with WBC >1100 is considered septic
Which imaging is useful in the management and investigation of septic arthritis?
- Plain radiograph - may be normal in early stages but may progress to demonstrate capsule and soft tissue swelling, fat pad shift, or joint space widening
- USS can be useful to guide joint aspiration and for drainage particularly at the hip
- CT/MRI imaging is sensitive for assessing joint damage, therefore typically used if there is uncertainty in the diagnosis
What are the risk factors for septic arthritis?
- Age >80 years
- Diabetes
- Rheumatoid arthritis
- Cirrhosis
- HIV
- History of crystal arthropathy
- Endocarditis or recent bacteraemia
- IVDU
- Recent joint surgery
What is the definitive treatment and management for septic arthritis?
Considered an orthopaedic emergency
- IV antibiotics, operative irrigation and drainage of the joint
- Initiate empirical therapy prior to definitive cultures based on patient age and or risk factors (usually flucloxacillin or clindamycin if penicillin allergic)
- Transition to organism specific antibiotic therapy based once culture sensitivities are obtained
- Treatment can be monitored by following serum WBC, ESR and CRP levels during treatment
How is irrigation and drainage of the joint performed in a patient with septic arthritis?
- Approach - can be performed open or arthroscopically (joint dependent)
- Irrigation - remove all purulent fluid and irrigate joint
- Debridement - synovectomy can be performed as needed
- Cultures - obtain joint fluid and tissue for culture
Which location is most common for septic arthritis (in adults)?
- Knee
Which criteria are used for the diagnosis of septic arthritis?
- Kocher criteria - used for diagnosis
- Fever >38.5 c
- Non-weight bearing
- Raised ESR
- Raised WCC
Paediatrics only
What is temporal arteritis?
- AKA giant cell arteritis
- Systemic granulomatous arteritis that usually affects large and medium sized vessels
- Females > Males
- Temporal arteritis is commonest type
- Granulomatous lesions may be seen on biopsy (although 50% are normal)
How common is temporal arteritis?
- 20/100,000 in the UK per year
- Rare before the age of 50 years
- Highest incidence aged 70-79 years
- x 7 more common in white people than in black people and it is particularly common in Scandinavian people, with annual incidence of approximately 30 / 100, 000 people in Norway
- 2-3 times more common in women than in men
What are the complications of temporal arteritis?
Complications are largely prevented by treatment with adequate doses of corticosteroids, however may include:
- Vision loss - including amaurosis fugax and diplopia
- Large artery complications including aortic aneurysm, aortic dissection, large artery stenosis, and aortic regurgitation
- Cardiovascular disease - such as MI, heart failure, stroke and peripheral vascular arterial disease
- Others complications include:
- Peripheral neuropathy
- Depression
- Confusion and encephalopathy
- Deafness
- Complications of long term corticosteroid therapy - weight gain, bruising, osteoporosis and fractures and diabetes
What is the prognosis of temporal arteritis?
- Relapses are common and can occur if corticosteroid treatment is reduced or withdrawn too quickly
- 30-50% of people have spontaneous exacerbations of disease, especially during the first 2 years (independent of the corticosteroid regime)
When should a diagnosis of temporal arteritis be suspected?
- If the person is aged over 50 years or older with at least one of the following:
- New onset of localised headache that is usually unilateral, in the temporal area, but is occasionally diffuse or bilateral
- Temporal artery abnormality, such as tenderness, thickening, or nodularity (present in 45-75% of people)
- Occasionally the overlying skin is red, and pulsation may be reduced or absent
What other symptoms in a patient would support a diagnosis of temporal arteritis?
- Systemic features
- Fever (usually low grade), fatigue, anorexia, weight loss and depression
- Features of polymyalgia rheumatica
- Bilateral upper arm stiffness, aching, and tenderness and pelvic girdle pain (present in around 40%)
- Scalp tenderness in about 50% of people especially over the temporal and occipital arteries
- Intermittent jaw claudication - occurs in nearly half of people with GCA, causing pain in the jaw muscles while eating
- Visual disturbances - permanent or complete loss of vision in one or both eyes occurs in up to 20% of people and is a common early symptom
- Typically it is described as a feeling of a shade covering one eye which can progress to total blindness - the eye is not painful
- Double visions, visual field defects, changes to colour vision may occur, on fundoscopy there may be pallor and oedema of the optic disc and cotton wool patches and less uncommonly small haemorrhages in the retina - untreated the second eye is likely to become affected within 1-2 weeks (although it can be affected within 24 hours)
- Neurological features - occur in about 30% of people and include
- Mono neuropathy or polyneuropathy of arms or legs
- Transient ischaemic attack or stroke in the distribution of the carotid or vertebrobasilar arteries
- Upper cranial nerve palsies
- Peripheral artheritis and distal swelling with pitting oedema - occurs in about 25% of people - swelling is most prominent in the dorsum of the hands and wrists, the ankles and the tops of the feet
- Respiratory tract symptoms - cough, sore throat and hoarseness (present in about 10% of people)
What are the differential diagnoses for temporal arteritis?
- Herpes zoster
- Cluster headache or migraine
- Acute angle closure glaucoma
- Retinal transient ischaemic attacks and embolic visual deficits
- Temporomandibular joint pain, sinus disease and ear problems
- Cervical spondylosis or other upper cervical spine disease
- Ankylosing spondylitis
- Myeloma
- Serious intracranial pathology
- Connective tissue disease
What is the initial management for someone with suspected temporal arteritis?
- Temporal arteritis is a medical emergency
- Urgently refer all people with suspected temporal arteritis (GCA) using a local GCA pathway for specialist evaluation (usually by a rheumatologist) on the same working day if possible and in all cases within 3 working days
- If there is visual loss (transient or permanent) - arrange an urgent (same day) assessment by an ophthalmologist
- Immediately treat people with suspected GCA with oral prednisolone
- People with visual symptoms - 60-100 mg as a one off dose (they should be seen by an ophthalmologist the same day)
- People WITHOUT visual symptoms - 40-60 mg daily (minimum 0.75 mg/kg)
- Document the persons symptoms, signs and level of function both before and after the onset of the condition to use as a baseline to compare response to treatment
- Assess the persons response after
Which tests and investigations should be done for a person with suspected temporal arteritis to help establish a diagnosis?
- Liver function tests
- 1/3 have mild elevated LFTs
- Full blood count
- Normochromic normocytic anaemia and an elevated platelet count are common
- C-reactive protein
- CRP level is typically elevated and may be a more sensitive indicator of inflammation in some people with GCA
- ESR - often greater than 50 mm/hour
What advice should be given to someone with suspected temporal arteritis (GCA)?
- Advise the person:
- Seek urgent (same day) medical attention if they develop any visual disturbances (such as vision loss, double vision, or visual field defects)
- That the dose of prednisolone is normally reduced very slowly over several months - treatment is often required for 1-2 years but people may require low doses of corticosteroids for several years
- Relapses are common whilst the dose is being reduced
- Frequent follow up visits are required to monitor for relapses and adverse effects of corticosteroids
How should diagnosis of temporal arteritis be made in secondary care?
- All people with suspected temporal arteritis should have at least one of the following confirmatory diagnostic tests:
- Temporal and axillary artery USS or
- Temporal artery biopsy