Rheumatoid Arthritis:
A common, autoimmune connective
tissue disease, primarily involving joints, but with widespread systemic effects.
There is hypergammaglobulinemia, and rheumatoid factors, which are
autoantibodies of IgE, IgA, and IgM classes, are present.
Preoperative abnormalities:
1. Articular problems:
-The joint disease involves
inflammation, formation of granulation tissue, fibrosis, joint destruction, and
deformity. Any joint may be affected. Those of particular concern to the anesthetist
is the cervical, the temporomandibular, and the cricoarytenoid joints.
-Airway obstruction can occur from
closely adducted, immobile vocal cords, or from laryngeal amyloidosis.
Rheumatoid nodules can affect the larynx.
2. Extra-articular problems: occur in more than 50% of patients.
a) Lungs. May be affected by
effusions, nodular lesions, diffuse interstitial fibrosis, or Caplan’s
syndrome. This is a form of massive pulmonary fibrosis seen in coal miners with
rheumatoid arthritis or positive rheumatoid factor, and probably represents an
abnormal tissue response to inorganic dust. There may be a restrictive lung
defect, with a contribution from reduced chest wall compliance.
b) Kidney. Twenty-five percent of
patients eventually die from renal failure. Renal damage may be related to the
disease process itself, secondary amyloid disease, or drug treatment.
c) Heart. Is involved in up to 44%
of cases. Small pericardial effusions are common but are not usually of
clinical significance. Rarely, pericarditis and tamponade may occur, usually in
seropositive patients and those with skin nodules. Other problems include
endocarditis or left ventricular failure. Occasionally heart valve lesions
occur and are of two types; rheumatoid granulomas involving the leaflets and
ring, and no granulomatous valvular inflammation with thickening and fibrosis
of the leaflets.
d) Blood vessels. A widespread
vasculitis can occur. Small arteries and arterioles are often involved,
frequently in the presence of relatively disease-free main trunk vessels.
Significant ischemia may result, in the actual effects depending on the tissue or
organ supplied.
e) Autonomic involvement.
f ) Gastrointestinal. Swallowing
problems and dysphagia were found in patients with classical rheumatoid
arthritis.
g) Peripheral neuropathy.
3. Chronic anemia, which has been
shown to respond to erythropoietin therapy, is common.
Anesthetic problems:
1. Disease of the cervical
vertebrae. Cervical involvement, and damage to the cervical spinal cord, have
been associated with neck manipulation during anesthesia and sedation.
Instability is said to occur in 25% of patients with rheumatoid arthritis. Of
these, one-quarter will have no neurological symptoms to alert the physician. The
problem of instability is not necessarily confined to those with longstanding
diseases.
The commonest lesion is that of
atlantoaxial subluxation, although subaxial subluxations may occur in addition.
Destruction of bone, and weakening of the ligaments, allow the odontoid peg to
migrate backward and upwards, compressing the spinal cord against the
posterior arch of the atlas. Thus, the main danger lies in cervical flexion.
The potential dangers of anesthesia
and endoscopy have been emphasized. Flexion of the head and reduction in muscle
tone may result in cervical cord damage. Dislocation of the odontoid process
and spinal cord damage were discovered in a patient undergoing postoperative
IPPV in the ITU. It was not known exactly when this had occurred.
2. Cervical instability below the
level of a fusion. Those who have previously undergone occipital cervical
fusion may develop cervical instability below the level of the original arthrodesis.
Occipital-cervical fusion is thought to generate a greater force at the lower
cervical level that in turn stresses the unfused facet joints.
3. Laryngeal problems. A constant
pattern of laryngeal and tracheal deviation is reported to occur in some patients,
particularly those with proximal migration of the odontoid peg. The larynx is
tilted forwards, displaced anteriorly and laterally to the left, and the vocal
cords are rotated clockwise. Involvement of the larynx in the rheumatoid process is
more common than was previously thought. However, fatal airway obstruction
occurred following cervical spine fusion, secondary to massive edema in the
meso- and hypopharynx.
4. The laryngeal mask airway should
not be relied upon to overcome failed tracheal intubation. It was impossible to
insert a laryngeal mask airway into a patient with a grade 4 laryngoscopic
view. Subsequent cervical X-rays with the head maximally extended showed that
the angle between the oral and pharyngeal axes at the back of the tongue was
only 70 degrees, compared with 105 degrees in five normal patients. A
simulation of different angles using an aluminium plate showed that at an angle
less than 90 degrees, the laryngeal mask airway could not be advanced without
kinking at the corner.
5. Sleep apneas. Medullary
compression associated with a major atlantoaxial subluxation may result in
nocturnal oxygen desaturation.
6. Limitation of mouth opening may
occur secondary to arthritis of the temporomandibular joints. This is a
particular problem in juvenile rheumatoid arthritis.
7. A pericardial effusion and
tamponade can be presented as an acute abdominal emergency in patients with
seropositive rheumatoid arthritis.
8. Rheumatoid aortic valve involvement
may be more rapidly progressive than aortic valve disease from other causes so
that there is little time for compensatory hypertrophy of the ventricle to
occur. Acute aortic regurgitation caused sudden cardiac failure in a young
woman and required urgent valve replacement.
9. Lung disease can result in
reduced pulmonary reserve and hypoxia.
10. An increased sensitivity to anesthetic
agents may occur.
Management:
1. Clinical assessment of neck and
jaw mobility. The Sharp and Purser test gives some indication of cervical spine
instability. The patient should be upright, relaxed, and with the neck flexed.
With a finger on the spinous process of the axis, the forehead should be
pressed backward with the other hand. Normally there is minimal movement. If
subluxation is present, the head moves backward as reduction occurs.
2. A lateral view of the cervical
spine in flexion and extension will show the distance between the odontoid peg
and the posterior border of the anterior arch of the atlas. If subluxation is
present, this distance is greater than 3 mm. Frontal views of the odontoid and
entire cervical spine have also been suggested.
3. Cervical X-rays of patients who
have previously undergone occipital spinal fusions should be carefully examined
for evidence of cervical instability at a lower level.
4. Intubation methods. Cervical
instability may be an indication of awake fiberoptic intubation with the
application of a collar or Crutchfield tongs, to maintain rigidity during
surgery. Since spinal instability is usually in flexion, some authors believe
that safe tracheal intubation can be achieved under general anesthesia by
careful extension of the head, except in the rare instances of posterior
atlantoaxial subluxation when fibreoptic intubation is indicated. Emergency
control of the airway has been described using a laryngeal mask airway in a
patient who developed acute pulmonary edema following occipital-cervical fusion.
5. Deviation of the larynx may make
fibreoptic laryngoscopy more difficult in some patients. Examination of the
orientation of the larynx by indirect laryngoscopy at preoperative assessment
may be helpful. If there is cricoarytenoid involvement, care should be taken
with the choice of tracheal tube size and tube insertion. Cricoarytenoid
arthritis may occasionally necessitate permanent tracheostomy.
6. Although the use of the laryngeal
mask airway is increasingly common, as mentioned above, it cannot always be
relied on in patients with severe flexion deformities of the neck.
7. Assessment of pulmonary function
and reserve.
8. Examination for other significant
complications, such as valvular disease, or pericardial effusion.
9. Extreme caution should be observed
if epidural or caudal anesthesia is to be undertaken in patients in whom
intubation difficulties are anticipated. Even after a test dose to exclude an
accidental spinal, or vascular penetration, the block should only be
established very gradually.
10. The use of cervical epidural
analgesia for the treatment of digital vasculitis has been reported.
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