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Print version ISSN 0034-7094
Rev. Bras. Anestesiol. vol.57 no.2 Campinas Mar./Apr. 2007
Ankylosing spondylitis and anesthesia*
Espondilitis anquilosante y anestesia
Carlos Rogério Degrandi Oliveira, TSA
Co-Responsável do CET em Anestesiologia da Santa Casa de Santos; Membro da Comissão Científica da Sociedade de Anestesiologia do Estado de São Paulo; Membro do Núcleo de Via Aérea Difícil da Sociedade de Anestesiologia do Estado de São Paulo; Membro da Comissão de Normas Técnicas e Segurança em Anestesia da Sociedade Brasileira de Anestesiologia
OBJECTIVES: Ankylosing spondylitis (AS) is a chronic inflammatory disease
of the joints, included in the group of seronegative spondyloarthropathies.
Its main characteristic is the fusion of the bones in the spine, which causes
loss of flexibility of the back and neck. Other large articulations and connective
tissues can be affected by the inflammatory process. It affects mainly men between
the ages of 20 and 40; it is rare after the age of 50. Women represent a minority
of patients. There is little information about AS in the anesthetic literature.
The objective of this article was to review the characteristics of AS pertaining
anesthesiology for an adequate perioperative handling.
CONTENTS: The clinical characteristics of ankylosing spondylitis pertaining to the anesthetic conduct are reviewed.
CONCLUSIONS: Patients with chronic diseases of the spine represent specific challenges to the anesthesiologist. Handling of the airways and the access to the neuroaxis can be difficult. Most anesthesiologists prefer to use general anesthesia, avoiding the neuroaxis, in those patients, despite the presence of difficult airways. The degree of spine involvement will determine how difficult the tracheal intubation might be. Special care should be taken to avoid excessive manipulation of the neck, which could cause trauma to the spinal cord.
Key Words: ANESTHESIA, general; DISEASES: ankylosing spondylitis.
JUSTIFICATIVA Y OBJETIVOS:
La espondilitis anquilosante (EA) es una enfermedad inflamatoria crónica
de las articulaciones, incluida en el grupo de las espondiloartropatías
soronegativas. La característica principal de esa enfermedad es la fusión
ósea de la columna vertebral que conlleva a la pérdida permanente
de la flexibilidad del dorso y del cuello. Otras grandes articulaciones y tejidos
conectivos podrán estar afectados por el proceso inflamatorio. La EA
acomete principalmente a hombres entre los 20 y 40 años; es rara después
de los 50 años. Las mujeres corresponden solamente a la minoría
de pacientes. Existe poca información sobre la EA en la literatura anestésica.
El objetivo de este artículo fue revisar aspectos de la EA de interés
para el anestesiólogo, permitiendo un adecuado manoseo perioperatorio.
CONTENIDO: Están definidas las características de la espondilitis anquilosante en cuanto a la clínica y la conducta anestésica.
CONCLUSIONES: Los pacientes con enfermedades crónicas de la columna vertebral presentan desafíos específicos para el anestesiólogo. El manoseo de la vía aérea y el acceso al neuro-eje podrán ser difíciles. La preferencia ha sido dada a la anestesia general, incluso con la vía aérea de difícil acceso, evitando la anestesia en el neuro-eje. El grado de involucración de la columna cervical determinará cuanto podrá ser difícil la intubación traqueal. Un cuidado especial debe tenerse para evitar la manipulación excesiva de la columna cervical, lo que podría conllevar al trauma de la médula espinal.
Ankylosing spondylitis (AS) is a chronic inflammatory disease included in the group of seronegative spondyloarthropathies that affects mainly the spine, with progressive rigidity and functional limitation. It usually begins between the 2nd to the 4th decades of life, affecting mainly males (5:1) and HLA-B27 positive 1 individuals.
It is more common in white populations in which the prevalence of HLA-B27 is significantly higher. The incidence of this antigen in patients with AS is approximately 90%, being higher in northern European populations with a low rate of interracial crossing 2.
Since HLA-B27 is extremely rare in black African populations, the disease is not frequent in black people; in Brazil, a country with a high rate of interracial crossing, the disease, as well as other spondyloarthropathies, is found in mulattos due to the influence of the white genetic ascendance, but it is very rare in non-interracially mixed African-Brazilian 2.
The determination of the HLA-B27 status can predict the risk of transmitting the disease to the descendants. An increase in the incidence of the HLA-B27 antigen has been reported in Reiter syndrome, anterior uveitis, reactive arthritis, and psoriatic arthritis. This antigen does not indicate the presence of the disease, since it is present in 10% of normal individuals. The result should take into consideration the clinical and radiological data suggestive of this disease 1.
The objective of this article was to review aspects of AS pertaining to anesthesiology, contributing to the adequate perioperative handling.
Ankylosing spondylitis affects young adults. Its initial symptoms include inflammatory lumbar pain, rigidity in the morning, and a predominance of axial symptoms during its evolution.
The juvenile disease, which starts before 16 years of age, begins with arthritis and peripheral entesopathies (inflammation of the insertion of tendons and/or ligaments in the bones) evolving, after a few years, to the characteristic inflammatory lumbar pain. The juvenile disease is usually diagnosed later, and many of those patients may be diagnosed initially as juvenile rheumatoid arthritis. The hip is affected more often in the child than in the adult, which determines a worse prognosis due to the need of total hip prosthesis in many patients 3.
The modified New York criteria, which combine clinical and radiological data, are used to confirm the diagnosis of AS. The clinical criteria are: lumbar pain lasting more that three months, which improves with exercise and does not improve with rest; limitation of the movements of the lumbar spine in the frontal and sagittal planes; and decreased thoracic expansibility. The radiological criteria are: grade 2, 3, or 4 bilateral sacroiliitis; grade 3 or 4 unilateral sacroiliitis. It is necessary the presence of one clinical and one radiological criterion for the diagnosis 4.
Initially, the patient with AS complains of low lumbar pain, which improves with movement and worsens with rest, and prolonged rigidity in the morning. Its evolves upwardly, affecting, progressively, the dorsal and cervical spine, contributing to the development of the "skier" posture, characterized by straightening of the lumbar lordosis, accentuation of the dorsal kyphosis, and straightening of the cervical lordosis, with projection of the head forward. The inflammatory process may begin in the sacroiliac joints and evolve upwardly in the spine and costovertebral articulations. The interspinal ligaments calcify, forming bony bridges between the lumbar vertebrae, creating the characteristic radiological aspect of "bamboo" spine (Figure 1). The involvement of the cervical spine varies from a limitation of neck movements to complete ankylosis 3.
Patients with advanced disease have a higher risk of vertebral fractures. Mild traumas, especially the extension types, can cause fractures through the ossified intervertebral disks spaces, sectioning the spinal cord directly 5. Every potential movement on the calcified spine is concentrated in the site of the fracture.
Massive epidural hemorrhages are frequent, contributing for a high incidence of neurological deficits and mortality 6. These patients should be stabilized in flexion because neutral immobilization increases the symptoms and the neurological lesion 5.
A cervical spine immobile and in flexion, along with its predisposition for fractures secondary to traumas caused by mild extension, frequently associated with limitation of mouth opening due to changes in the temporomandibular joint, are responsible for a difficult tracheal intubation 7.
Disease of the peripheral joints is characterized by the presence of oligoarthritis and entesopathies. Oligoarthritis affects primarily large joints of the lower limbs, such as ankles, knees, and hip. The joints in the upper limbs can also be affected, as well as the sternoclavicular and costochondral joints, causing pain and limiting the thoracic expansibility. Entesopathies are usually early manifestations of juvenile AS, affecting mainly the insertion of the Achilles tendon and plantar fascia 1.
Recurring, unilateral, acute, anterior uveitis is the most frequent extra-articular manifestation, affecting up to 40% of the patients, it is usually associated with the presence of HLA-B27, and rarely causes deficits 1.
Symptoms like fever, fatigue, weight loss, and elevated erythrocyte sedimentation rate are common. Mild normocytic, normochromic anemia may be present, and alkaline phosphatase may be elevated in advanced disease. Immunoglobulin A is frequently elevated 1.
Cardiovascular complications are present in up to 3.5% of the patients after fifteen years of disease, and in up to 10% of those after 30 years of disease 8. Cicatrization of the adventitia and fibrous proliferation of the intima of the aorta and heart valves cause aortitis and aortic insufficiency, and mitral valve involvement may occasionally be present. Involvement of Purkinje fibers can cause conduction defects 8.
Fibrosis of the upper lobe of the lung, sometimes mimicking tuberculosis, is the most common pulmonary complication. The severity of the pulmonary lesion is aggravated by the limitation of the thoracic expansibility due to the involvement of intervertebral and costovertebral joints, which can decrease pulmonary complacency and be associated with decreased vital capacity.
The most important neurological disorders include spinal cord compression (especially of the cervical spinal cord due to vertebral fractures), cauda equina syndrome, focal epilepsy, vertebrobasilar insufficiency, and lesion of peripheral nerves 8.
ANESTHETIC IMPLICATIONS OF ANKYLOSING SPONDYLITIS
The anesthesiologist should base the anesthetic conduct on the extension of the disease, centered in four main aspects: degree of upper airways involvement, presence of pulmonary restriction, degree of cardiac involvement, and access to the neuroaxis.
When evaluating a patient with AS, one should pay attention to the degree of residual cervical mobility. Patients in the initial stages or with non-progressive disease may have good mobility.
Cervical involvement, with limited movements and in flexion, hinders tracheal intubation. One should avoid forcing the neck, even in the presence of neuromuscular blockade, due to the risk of fractures and possibility of vertebrobasilar insufficiency 9.
Evaluation of neck mobility is mandatory during the preoperative examination, which includes X-rays of the cervical spine, lateral and in maximal extension. The criteria that predict difficult airways should be reviewed, such as the Mallampati test, Wilson index, thyromental distance, sternomental distance, the degree of head and neck movements, and mouth opening 10.
Once the difficulties for tracheal intubation are determined, the anesthesiologist should choose a method of intubation. Fibroscope guided intubation with mild sedation of the patient and anesthesia of the mucous membranes is the method of choice in patients with advanced deformity of the cervical spine 10,11. Other safe options include awake intubation, intubation with moderate sedation of the patient, with instillation of local anesthetic in the oropharyngeal mucous membrane, infiltration of the superior laryngeal nerves, and transcricothyroid instillation using direct laryngoscopy, if possible 12,13; one can also choose blind nasal or oral intubation with the aid of a light probe, and retrograde intubation 14-18.
There are reports of the successful use of laryngeal mask in patients with AS 19,20.
The involvement of the temporomandibular joint limits mouth opening in up to 40% of the patients, which can evolve to complete ankylosis 7.
Although rare, cricoarytenoid arthritis with dyspnea, stridor, and fixation of the vocal cords may be present 8.
Cervical support should be used during the procedure, especially if symptoms of vertebrobasilar insufficiency are present.
Chest X-ray can show restrictive changes and, in the majority of the cases, pulmonary function tests should be requested. Respiratory insufficiency and the limitation of chest expansion increase the incidence of pulmonary complications and the need for postoperative mechanical ventilation in the ICU, especially in major surgeries 3.
Cardiologic evaluation (electrocardiogram and echocardiogram) is essential to determine the cardiovascular risk. Involvement of the heart valves, especially the aortic valve, may be present, with associated conduction defects. The sudden and intense variation in systemic vascular resistance caused by the spinal anesthesia is not tolerated by patients with defects in the aortic valve. External cardiac massage in the presence of a rigid thoracic wall may be ineffective 3.
X-ray of the lumbar spine may be useful to evaluate the possibility of spinal anesthesia. However, neuroaxis blocks are technically difficult, and usually impossible, due to the limited articular mobility and obliteration of the interspinal spaces 21-23.
Technical difficulties can also increase the risk of complications. Cases of spinal cord hematomas after epidural anesthesia have been reported 24-27, as well as a case of seizures after accidental intraosseous injection in caudal anesthesia 28.
Peripheral blocks are also difficult to perform due to the impossibility to position the patient adequately 3.
Patients with AS often take several drugs, increasing the risk of drug interactions. Special attention should be given to gastric protection due to the routine use of non-steroidal anti-inflammatory drugs (NSAIDS) 3.
Although pregnant women with AS carry the pregnancy to term and have normal delivery, several disease manifestations can interfere with pregnancy and labor. The physiological changes of pregnancy associated with disease manifestations make preanesthetic conduct even more difficult. Those patients should have preanesthetic evaluation to help the anesthesiologist and obstetrician to plan the best conduct.
Ankylosing spondylitis is a relative contra-indication for videolaparoscopic surgery. A recent report described the difficulties that the anesthetic-surgical team faced in a patient with accentuated kyphoscoliosis and rigidity who underwent videolaparoscopic cholecystectomy 31.
The psychosocial impact of this disease on the patient and his relatives is as important as the anesthetic-surgical aspects, since these patients may need frequent surgeries. Disease progression imposes several limitations on activities of daily living, demanding a high degree of attention and care provided by family members.
Total hip arthroplasty is the most frequent surgery in patients with AS 52, followed by knee prosthesis 33,34. However, some patients may need surgical correction of the spinal deformities (vertebral osteotomies) that demand specific anesthetic planning because they present an important challenge to the anesthesiologist: difficult airways, monitoring of neurological function by evoked potentials, positioning, and bleeding 35-39.
Physical therapy, especially supervised exercise programs, should be systematic in every stage of the disease 1.
Non-steroidal anti-inflammatory drugs are used since the beginning of treatment; there are no studies showing whether one NSAID is superior to the others on direct comparison, although there is a consensus in medical practice that indomethacin seem to have better results 40. Modern anti-inflammatories that inhibit COX-2 specifically seem to be a good choice for patients at risk for gastrointestinal toxicity or those that do not tolerate conventional NSAIDs 41.
Corticosteroids are reserved for specific cases. In patients with persistent peripheral arthritis, prednisone or methylprednisolone may be used intermittently, whenever the disease is active 42. Intra-articular corticosteroids can be an alternative in cases of persistent arthritis or refractory sacroiliitis. The infiltration should be guided by CT scan or MRI 43.
Long acting drugs should be administered to patients that do not respond to chronic NSAIDs. Sulfasalazine 44, methotrexate 45, thalidomide 46, and pamidronate 47 have shown promising results.
A new class of drugs has become available in the last few years. Biological agents, such as infliximabe and etanercept 48-51, seem to be very effective in patients refractory to the conventional treatment.
Although a specific treatment for AS is not available, it is important to know that the therapeutic resources allow, in general, an adequate control of the disease. When needed, the physician should request psychological support or the administration of antidepressants.
Patients with chronic spinal diseases present specific challenges to the anesthesiologist. Handling of the airways and access to the neuroaxis can be very difficult. General anesthesia has been the technique of choice, even with difficult airways. The degree of cervical spine involvement will determine how difficult the tracheal intubation might be. One should avoid excessive handling of the neck, which could cause trauma to the spinal cord 3.
Thus, individualized preanesthetic evaluation is fundamental, as well as the indication of the right anesthetic technique to minimize morbidity when these patients undergo surgical or diagnostic procedures.
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Dr. Carlos Rogério Degrandi Oliveira
Praça Dr. Hipólito do Rego, 7/11
11045-310 Santos, SP
Submitted em 29
de março de 2006
Accepted para publicação em 06 de dezembro de 2006
* Received from Irmandade da Santa Casa de Misericórdia de Santos, Santos, SP