Rheumatoid Arthritis Flashcards
What’s the definition and prevalence
**RA is a chronic, systemic inflammatory disorder, mainly involving joints, but with extra-articular effects.
*Overall prevalence in the UK is 1.5 per 100 000 in ♂, and 3.6 per 100 000 in ♀,
with a peak incidence in the 7th decade.
It also affects children as Still’s disease
**(patients are often frail, in chronic pain, and taking medications with adverse effects. Airway problems are common. there is a higher than average mortality due to both the disease itself and the presence of concurrent disorders.)))
Preoperative assessment
Articular vs Non-Articular manifestations
Articular::: ————— 1) Temporomandibular 2) cricoarytenoid 3) Atlantaxial sublaxation (AAS) 4) Subaxial subluxation (below C2) 5) Other joints
Preoperative assessment/Articular
-temporomandibular & cricoarytinoid
- Temporomandibular:assess for limited mouth opening.
- Cricoarytenoid:fixation of the cricoarytenoid joints may lead to voice changes, hoarseness, or even rarely to stridor from glottic stenosis. the larynx can also be obstructed by amyloid or rheumatoid nodules. Minimal oedema may lead to airway obstruction post-operatively
AtlantoAxial Sublaxation prevalence and types
• Atlantoaxial subluxation::occurs in ~25% of severe rheumatoid patients, but, of these, only a quarter will have neurological signs or symptoms. enquire about tingling hands or feet and neck pain, and assess the range of neck movement. excessive movement during anaesthesia may lead to cervical cord compression.
**Anterior AAS:comprises 80% of all AAS. C1 forward on C2 from destruction of the transverse ligament. Significant if there is a gap of >3mm between the odontoid and the arch of the atlas in lateral f lexion radiographs. Worsened by neck flexion.
**posterior AAS:this is rare. C1 backward on C2, resulting from destruction of the odontoid peg. Can be seen on lateral extension radiographs. Worsened by neck extension (e.g. from direct laryngoscopy).
**Vertical AAS:arises from destruction of lateral masses of C1. the odontoid moves upward through the foramen magnum to compress the cervicomedullary junction.
**Lateral AAS:uncommon. Arises from the involvement of the C1/ C2 facet joints. More than 2mm difference in the lateral alignment is significant. Causes spinal nerve compression and vertebral artery compression. Requires a frontal open mouth odontoid view to assess.
Subaxial and other jounts ?
• Subaxial subluxation (i.e. belowC2):
- *More than 2mm loss of alignment is significant.
- *Look for this particularly if the patient has undergone previous fusion at a higherlevel.
• Other joints:assess joint deformities with a view to positioning and possible anaesthetic technique (if planning an axillary block, can the patient abduct their arm?). Manual dexterity may be important if planning to use standard pCA apparatus after surgery. Special adaptations are available, e.g. trigger by blowing.
What are the Non-Articular manifestations ?
1• CVS:association with CAd. Systemic vasculitis may lead to arterial occlusion in various organs and Raynaud’s. Myocardial disease due to f ibrosis, amyloid or nodular involvement. pericarditis and pericardial effusions uncommon. Aortic incompetence and endocarditisrare.
2• Respiratory:fibrosing alveolitis (restrictive defect), frequently asymptomatic.
Acute pneumonitis “”rare””. pleural effusions and/or nodules in pleura may show on X-ray. Association with obliterative bronchiolitis. Costochondral disease gives reduced chest wall compliance
3• Anaemia:NSAId-associated blood loss. Normocytic, normochromic anaemia of chronic disease. drug-associated bone marrow depression. Felty’s syndrome is a combination of splenomegaly and neutropenia and may be associated with anaemia and thrombocytopenia.
4• Nervous system:peripheral and compression neuropathies occur. Cord compression may be atlantoaxial or subaxial. Neurological changes may be chronic or acute (trauma).
5• Infections:common both from the disease itself and drug effects
.6 • Renal and hepatic:CRF from drugs is common, as is decreased albumin, increased fibrinogen and α-1 acid glycoprotein (acute phase protein).
7• thin skin and difficult venousaccess.
Investigations
- All patients should have FBC, U&es, eCG, and CXR. Consider LFt, ABGs, and coagulation studies.
- Cervical spine radiographs:the role of preoperative cervical spine f lexion/extension views is controversial, and interpretation is difficult. the automatic reordering of radiographs in all patients is unnecessary. Flexion/extension views are mandatory in all patients with neurological symptoms or signs, and in those with persistent neck pain. Stabilization surgery may be necessary before other elective surgery is undertaken. preoperative cervical spine radiographs may help determine management, but only in association with a full clinical review. Specialist radiological advice should be sought. Unless it is certain that the cervical spine is stable, all rheumatoid patients should be treated as if they might have an unstable spine. this may involve AFOI or manual in-line stabilization when undertaking direct laryngoscopy/LMA insertion/ moving the patient. MRI and Ct may be useful in assessing cord compression.
- pFts should be carried out for patients with unexplained dyspnoea or radiological abnormalities.
- An eNt opinion should be sought, and nasendoscopy performed if there is hoarseness or symptoms/signs of respiratory obstruction.
- echocardiography is needed if there is valvular or pericardial involvement and in symptomatic cardiac disease.
Drugs in the perioperative period
- Steroid supplementation, if indicated (see E p. 165).
- NSAIds:continue, as this enables early mobilization. Stop if post-operative bleeding is a potential problem, hypotension, or deterioration in renal function.
- disease-modifying antirheumatoid drugs (dMARds):these drugs include gold, penicillamine, and immunosuppressant drugs such as methotrexate, azathioprine, cyclophosphamide, anakinra, ciclosporin, leflunomide, and sulfasalazine. Usually continue, as mobilization is important, and there is little evidence that omission reduces post-operative complications (wound infections). If leucopenic, consult with the rheumatologist.
- tumour necrosis factor (tNF)-α blockers (biologics):infliximab, certolizumab, etanercept, adalimumab—belong to the class of drugs blocking the effects of tNF-α, an inflammatory mediator. Other 2nd-line drugs directly target specific monoclonal antibodies and interleukin (IL)-6 (e.g. rituximab). there are suggestions of potential for increased rate of operative infection, but no consensus on whether to discontinue perioperatively.
- dVt prophylaxis (see E p. 11):early mobilization.
- GI agents:continue h2 antagonists and ppIs prior to, and after, surgery, especially for patients on NSAIds.
Operative considerations
- take care of the neck, and maintain in a neutral position at all times, especially on transfer and turning. Use manual in-line stabilization during airway manipulation while the patient is unconscious (unless it is certain that the spine is stable). If intubation is necessary, consider fibreoptic intubation if difficulties are anticipated (see E p. 969), particularly if there is posterior AAS (rare) and/or predicted difficulty. If direct laryngoscopy is undertaken, consider using manual in-line stabilization and a gum elastic bougie(GeB).
- ensure careful positioning and padding/protection of vulnerable areas on the operating table. Note comfortable position before induction, then try to maintain this during surgery.
- Regional techniques may be difficult. patient discomfort from prolonged immobilization may favour GA, perhaps in combination with regional techniques.
- Normothermia is especially important, as hypothermia may increase the risk of wound infections.
- Strict asepsis with invasive procedures, as increased risk of infection.
Postoperative
- Adequate pain control allows early mobilization. pCA may be impractical due to impaired hand function.
- Continue NSAIds unless contraindicated.
- physiotherapy and mobilization are important.
- Continue dVt prophylaxis until the patient is fully mobile.
- Maintain fluid intake, and monitor renal function.
- Restart dMARds to avoid exacerbation of joint immobility.
