Rheumatoid arthritis (RA) is a chronic, systemic, inflammatory autoimmune disease. It primarily affects the joints but there is a high incidence or extra-articular features. The etiology is unknown but rheumatoid factor, an anti-immunoglobulin antibody, is present in 90% of cases.
The prevalence is around 1% of the population. It is around 3 times more common in females. Onset is usually between the ages of 30 and 50 years. Around 90% of patients will have rheumatoid factor (RF). Approximately 70% are the HLA-DR4 subtype. RF is also present in other conditions though e.g. SLE.
RA appears to be the result of a mix of genetic and environmental factors. Risk factors include:
Family history of RA
Heavy metal exposure
High birth weight
There may be a specific ‘stress’ trigger factor that precipitates the disease in a susceptible individual:
Extremes of temperature
Arthritis The classic features of the arthritis are:
Typically small joints of hands and feet initially.
The condition can affect any synovial joint, with increasing numbers (usually larger) involved with disease progression. Clinically the joints will have signs of inflammation:
Stiffness (particularly in the morning)
Extra-articular features Initially, generalised constitutional symptoms are common:
Hepatomegaly and splenomegaly may be features of the disease. Felty’s syndrome is a combination of splenomegaly and leukopenia. It may be associated with anaemia and thrombocytopenia.
Progression of the arthritis can lead to destruction of the synovial joint and periarticular tissue. Adverse features of long standing RA may include:
Swan neck deformity
Cervical instability is of particular concern for anaesthetists. Destruction of the transverse ligament of C1 (the main cause in 80%) can result in atlanto-axial subluxation, occurring in about 25% of patients with severe disease. This can result in cervical cord injury with movement. This can be viewed on a lateral plain radiograph when the movement is greater than 3mm. Flexion of the neck exacerbates the movement. Other forms of cervical instability are less common, but fixed flexion deformities because of ankylosis of the spine may occur.
Temporomandibular joint involvement may impair mouth opening. Rheumatoid nodules may be present in the larynx, impairing intubation. Cricoarytenoid joint involvement may occur, this can lead to hoarseness, and rarely stridor.
This is essentially a clinical diagnosis. A good history and examination will provide a lot of information.
Investigations may include:
CRP/ESR - often raised
LFTs - often raised
Antinuclear antibodies - present in some cases and common in similar disease e.g. SLE
Uric acid - if gout a differential
Rheumatoid factor - recommended if synovitis is found on examination
Anti-cyclic citrullinated peptide (CRP) - marker of more erosive disease. May guide treatment decisions.
Joint x-rays may be performed early in the investigative process. Findings may include:
Soft tissue swelling
Loss of joint space
There has been a notable improvement in the management of RA, with more aggressive therapy reducing the extent of the advance destructive features of the disease. Drugs that are used in the management include:
DMARDs - disease modifying anti-rheumatic drugs
Once damage has occured, management will often involve the use of aids and appliances, and at times surgery.
NICE recommend specialist referral for cases of suspected RA. The time frame of this may often be on an urgent basis to minimise the time to the initiation of DMARDs to prevent the progressive damage of the disease. Simple analgesia, including paracetamol and NSAID will often be commenced at this time. NICE recommend addition of a PPI with NSAID use.
Steroids may be used in the short term to get rapid control of symptoms. They may be part of the initial treatment plan.
DMARDs form a large part of current treatment. They are used to control symptoms and prevent progressive radiological damage. DMARDs in use include:
Methotrexate and sulfasalazine have the best toxicity/adverse effects profile so are often favoured as first line options. Combination therapy may be employed in those with a poor initial response. In new presentation RA, they will often be commenced with a corticosteroid.
Biological therapies have a role in those patients with poor responses to DMARDs. They include:
The prognosis is variable. There is often some degree of disability present after 10 years of disease duration. Delay in investigation of treatment (e.g. delayed diagnosis) can worsen this. There is an increase mortality from IHD, and the consequences of immunosuppression.
The multisystem impact of RA, as well as its range of treatments, mean that there are number of possible impacts on the provision of safe anaesthesia. Patients may present due to complications of the disease, its treatment, or unrelated.
A full careful anaesthetic history is essential. Specific enquiry should be made into the sequelae of RA for that patient, noting which extra-articular features are present.
A very careful airway assessment is essential, looking for features of RA disease:
TMJ disease impairing mouth opening
Neck movement - enquire about features of neurology and pain with this.
Neck radiographs should be performed in patients with significant neck pain and or neurological features. If there is instability, surgical management of this will often precede other elective surgical issues.
Clinical examination should also be guided by presence of symptoms that raise the possibility of extra-articular system involvement:
Investigations should include:
FBC - assessing for bone marrow suppression features e.g anaemia
U&E - to assess renal function which may be affected by management
LFTs - may be deranged. Hypoalbuminemia may be present
ECG - looking for evidence of cardiac involvement
Additional investigations should be guided by concern for organ involvement:
Pulmonary function tests
ENT review if concern for laryngeal disease
Key intraoperative issues may include:
Careful positioning is important and sometimes difficult in patients with significant disease. Neutral positioning and padding is important to ensure that pressure related complication don’t develop. Particular care must be taken with the neck, ensuring neutrality of position at all times.
Patients may be on long term steroid therapy with resulting adrenal axis suppression. Supplementation may be needed to cover the stress response.
Airway management will be affected by many other factors. In cases of intubation, manual in line stabilisation should be employed to minimise cervical disturbance. In cases of severe cervical instability, awake fibre optic intubation will be the airway management option of choice to maintain stability.
Regional anaesthesia may be difficult if there is notable spine involvement. Patients may also have difficulty with general comfort during the prolonged immobility.
The usual important postoperative considerations apply to optimise recovery. Adequate analgesia will continue to be important, taking into account:
Patients with bad hand disease may be unable to use a normal PCA button
NSAIDs can be very beneficial and should be continued if possible
The patient’s normal medications should be commenced as soon as able to minimise the impact of stopping on their disease and due to lack of clear benefit from stopping them.
Patients may have chronic pain issues, and this should be considered when formulating an analgesia plan.
Mobilisation post operatively is important and some patients may benefit from physiotherapy input.