RA- GENERAL Flashcards
Definition of RA
Autoimmune chronic systemic inflammatory polyarthropathy (CSIP) with skeletal and extra-skeletal manifestations, and involvement of small and large joints in a symmetrical manner
Pathophysiology of RA
Synovial proliferation and chronic synovitis causing periarticular erosive arthropathy (PEA)
Diagnosis of RA
American College of Rheumatology (ACR) diagnostic criteria = 7 criteria, diagnosis requires at least 4 MADRAS 1. Morning stiffness 2. Arthritis involving at least 3 joints 3. Duration at least 6 wks 4. RF positive/ rheumatoid nodules/ radiographic changes consistent with RA (PEA) 5. Arthritis involving small hand joints 6. Symmetrical arthritis
5 main radiographic features of RA
- Generalised osteopaenia
- Boggy joints = effusion and soft-tissue swelling
- Periarticular erosions
- Joint destruction and deformity
- Joint ankylosis
Felty syndrome
Triad of RNS
- RA
- Neutropenia
- Splenomegaly
MDT in RA
Always MDT approach involving
- Rheumatology
- Cardiac
- Respiratory
- Anaesthetic
- Allied health
Skeletal manifestations in RA
Axial and appendicular 1. Axial - cervical spondylitis - 3 main patterns of instability Atlantoaxial subluxation Basilar invagination Subaxial subluxation - can result in cervical myelopathy 2. Appendicular - symmetrical involvement of small and large joints
Extra-skeletal manifestations in RA
3-3-3 rule 3 local systems 1. Ocular = scleritis (red painful eyes) 2. Cardiac - pericarditis - conduction abnormalities - valve abnormalities 3. Pulmonary - nodules - fibrosis - pleural effusions 3 general systems 1. Dermatologic = rheumatoid nodules (20% cases) 2. Haematologic - anaemia of chronic disease - Felty syndrome (triad of RNS) - raised ESR 3. Vasculitis - endarteritis obliterans - Reynaud's phenomenon 3 MSK 1. Myositis = due to vasculitis and side effects of treatment (steroids, plaquenil) 2. Peripheral neuropathy = CTS most common 3. Tendons = tenosynovitis and tendon rupture
Rheumatoid factor in RA
Positive in 80% cases
anti-IgG IgM antibody against Fc portion of IgG
Can be IgG, IgA or IgE
Correlation with duration and severity of disease
Perioperative pharmacologic management in RA
- NSAIDs
- stop aspirin at least 72hrs before surgery
- ideally 7-10 days - Steroids
- low dose steroids can continue
- bolus dose at time of surgery to prevent adrenal crisis - DMARDs
- methotrexate, leflunomide, sulfasalazine, hydroxychloroquine, doxycycline
- can continue per ACR 2017 guidelines - Biologic agents
- TNF inhibitors (AEIou = Adalimumab, Etanercept, Infliximab), IL-1 inhibitors, other (Rituximab)
- 10x increased risk of infection
- stop prior to surgery (timing depends on dosing cycle)
- restart after wound healing (2wks)
5 main DMARDs used in RA
- Methotrexate
- inhibits dihydrofolate (DHF) reductase and neovascularisation
- RCTs show no difference in complication rate wrt wound healing or infection - Leflunomide
- inhibits pyrimidine synthetase
- studies show increased risk of infection but can continue per ACR 2017 guidelines - Sulfasalazine
- Hydroxychloroquine (Plaquenil)
- Doxycycline
Main biologic agents used in RA
3 main groups
- TNF-alpha inhibitors
- AEIou = Adalimumab, Etanercept, Infliximab
- Etanercept = stop 1 wk prior
- Adalimumab = stop 2 wks prior
- Infliximab = stop 4 wks prior - IL-1 inhibitors
- Other biologic agents
- Rituximab = stop 7mo prior
3 preoperative anaesthetic considerations in RA
- C-spine instability
- seen in up to 60% RA patients
- consider regional anaesthesia or fibreoptic intubation - TMJ involvement = makes intubation difficult
- Cricoarytenoid involvement = makes intubation difficult
3 surgical goals in RA
- To relieve pain
- To correct deformity
- To restore function
Principles of surgical management in RA
- Address lower limb > upper limb
- order for LL = forefoot then hip and knee then hindfoot and ankle - Address proximal joints > distal joints
- shoulder and elbow before wrist and hand
- wrist before digits
- fingers before thumb - Perform predictable/ reliable/ winner operations
- Stage operations
- wrist and digits separately
- MP and IP joints simultaneously
- avoid both hands simultaneously
