Anesthesia for a severe ankylosing spondylitis patient whose posture had been restricted to only sitting for over 20 years

A 42-year-old woman with an Arnold-Chiari abnormality was scheduled for cervical spine surgery. She had severe ankylosing spondylitis, and all her joints from ankles to occipitocervical joint were fixed except hip joints, which had been replaced with artificial joints 20 years before. She could bend her upper body only in a range from -20 to 70 degree from the sitting position. Her posture had been restricted to only sitting for over 20 years, and she complained vertigo when positioned in supine position. The trachea was intubated with an aid of bronchofiberscopy under sedation in sitting position, and then anesthesia was induced with propofol and fentanyl. When she was turned to prone position, nasal bleeding was noticed and the surgery was performed in a modified sitting position. The intra- and post-operative course was uneventful. The present case indicates that long-term restriction only to sitting position modulates circulatory control in response to changing postures, and that preoperative evaluation for appropriate posture for surgery is mandatory.