8. Rheumatoid Arthritis Flashcards
What special considerations should be made when
anaesthetising a patient with rheumatoid arthritis?
Rheumatoid arthritis (RA)
is a multi-system disease which causes a
symmetrical deforming inflammatory polyarthropathy.
It is more common in women than men and affects approximately 2% of the population worldwide.
Its extra-articular features are extensive and some are of particular importance to us as anaesthetists.
It is easiest to consider the effects of the
disease in systems and consequences of medication.
General:
> Patients are often frail and suffer chronic pain.
> Steroid therapy causes thinning of the skin and care must be taken when moving patients or when removing sticky tape as this can tear fragile skin.
> Patients must be carefully positioned on the operating table. Ideally, they should position themselves on the table prior to the induction of
anaesthesia. Pressure areas must be closely monitored.
> If planning a regional block, ensure the patient is able to position themselves to allow for this.
> Stiffness, deformity, joint pain and lack of fine motor control may render patients unable to use devices such as patient-controlled analgesia pumps.
> Musculoskeletal:
• Temporomandibular joint
involvement may limit mouth opening
• Atlanto-axial subluxation
most commonly anterior subluxation)
occurs in up to 25% of RA patients
and may be asymptomatic.
Search for signs in the history,
e.g. tingling or weakness in the limbs
or loss of fine motor control.
Assess the patient’s range of neck
movement and ensure no movement
outside this range once they are anaesthetised.
If there is any doubt about neck stability,
cervical spine X-rays
(flexion, extension and peg views) may help.
A gap of >3 mm between the odontoid peg
and the arch of the atlas in lateral flexion
suggests the risk of anterior subluxation.
An unstable neck may need
to be surgically stabilised prior
to other elective surgery.
If there is actual or potential subluxation,
use manual in-line stabilisation when
manipulating the airway and have a low threshold to use awake fibreoptic intubation.
• Crico-arytenoid involvement can cause hoarseness and limit airflow, causing stridor in severe cases. If this is a concern, request a pre- operative nasendoscopic assessment of the larynx by the ENT surgeons.
CVS
Resp
> Cardiovascular:
• Pericardial effusions are uncommon and usually asymptomatic.
They can rarely cause tamponade.
• Valvular or myocardial involvement is rare.
Request a transthoracic echocardiogram if complications are suspected.
> Respiratory:
• Pleural effusions are the most common lung manifestation of the disease.
• Rheumatoid nodules may be up to 3 cm in diameter and can be mistaken for carcinoma.
• Lung fibrosis is a rare complication and may be caused by the disease or by treatment with methotrexate. If respiratory abnormalities
are found, consider lung function testing.
> Renal:
> Nervous system:
Haematology
eyes
> Renal:
• RA can cause amyloidosis,
which can lead to renal failure.
• Drugs may affect the kidneys but analgesic nephropathy is rare nowadays.
> Nervous system:
- Carpel tunnel syndrome can occur.
- Polyneuropathy is a rare manifestation.
- Compression of nerves at the cord or root may occur, so careful positioning is important.
> Haematology:
• Anaemia of chronic disease
• Anaemia secondary to gastrointestinal blood loss caused by NSAID use.
> Eyes:
• Keratoconjunctivitis sicca (i.e. dry eyes).
Drugs
> Steroids: Patients on steroid therapy may need steroid supplementation in the peri-operative period.
> NSAIDs: Check a baseline renal function and, unless contraindicated, continue with NSAIDs in the post-operative period to help mobilisation.
> Disease modifying anti-rheumatic drugs (DMARDs): e.g. gold, penicillamine, and methotrexate.
These can all cause immunosuppression,
which may delay wound healing and increase the risk of
infection.
Do not stop these drugs without discussion with the patient’s rheumatologist as their benefits may outweigh their risks.
Post-operative care:
> Continue rheumatoid medication if possible.
> Keep patients well hydrated and
monitor renal function.
> Give early and regular physiotherapy,
aiming for rapid return to baseline mobility.
> While immobile, patients will need DVT prophylaxis.
ATLANTO- AXIAL SUBLUXATION
What does ‘atlanto-axial subluxation’ actually mean?
The Atlas is another name for the first cervical vertebra (C1).
It is derived from Greek mythology, as the ‘Atlas’
holds up the ‘globe’ that is the skull.
The Atlas is unique in that it has no body; instead it is fused to that of C2 below it. C2 is known as ‘the Axis’.
The name ‘Axis’ comes from the Latin, meaning ‘axle’. It is so called because it forms a pivot on which C1, which carries the head, can rotate. The odontoid peg, or dens, is a protrusion from the upper anterior surface of C2 which sticks up through where the body of C1 should be to articulate with the anterior arch of C1.
This is a non-weight-bearing joint and its unique structure allows the wide range of movement
of the head on the spine.
Subluxation of any joint means partial or incomplete dislocation of that joint. In this situation, the vertebrae
of C1 and 2 move out of their correct positions relative to each other and therefore can impinge on the spinal
cord. Obviously, cord compression at this high level can be catastrophic.
Atlanto-axial subluxation occurs with increased frequency in RA because the disease causes degeneration of the bursa lying next to the transverse
ligament of the atlas,
causing it to weaken (this is a thick, strap-like ligament which is attached to each side of the anterior arch of the atlas and loops behind the odontoid peg, holding it snugly against the arch).
If this ligament becomes lax, the peg is able to move away from the anterior arch of the atlas and to move posteriorly when the neck flexes. As it does this there is a risk that it will impinge on the spinal cord. Although atlanto-axial subluxation is reasonably common on X-ray, symptoms are actually rare.
