[Gas leakage from an anesthetic circuit caused by mis-installation of a canister].

We report a case of gas leakage from an anesthetic circuit, due to mis-installation of a different but very similar canister. A 56-year-old woman was scheduled for a pylogastrectomy. We planned to use a Mera MD757XLV anesthesia machine. At preoperative checking of the anesthetic machine, there was a gas leak from the anesthesia circuit without apparent reasons. We therefore had to use another anesthetic machine, MD705XL, which showed no gas leakage and was used without problems during anesthesia. Closed examination after the operation showed that the gas leakage from the MD757XLV machine occurred, because one of two canisters was wrongly replaced by a canister of MD705XL. The shapes of canisters of these two anesthesia machines look very similar, but there are crucial differences in their specifications, but even the manufacturer did not notice. These unnoticeable differences led to mis-installation of canisters, and one machine provided an airtight seal whereas the other did not. Both manufacturer and users should be aware of this danger.

[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.