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A study of the time and motion of the anaesthetists' routine activities was made using conventional equipment. Films of manual and visual movements were studied in detail and the expectations of certain consultant anaesthetists regarding apparatus were recorded. Models of apparatus were used to test their acceptability. A modular system appeared preferable to a work station or to adaptation of present designs. More work and the construction of prototypes are indicated if the anaesthetic machine is to be modernized.

Internal jugular vein cannulation is reputed to be a safe procedure. The only neurological complication reported after it is a Homer's syndrome (Parikh, 1972). We report a case in which lesions of the left cervical sympathetic nerve; the ninth, tenth, eleventh, and twelfth cranial nerves; and the anterior branches of the second, third, and fourth cervical nerves occurred aftter left internal jugular cannulation. Case ReportA 64-year-old man with an anaplastic carcinoma of the bladder was admitted to hospital for cystectomy. Preoperative examination of the patient showed no neurological abnormality.As heavy blood loss was expected during the operation an arterial line was inserted into his left radial artery, an intravenous infusion into his right arm, and a central venous line into his left internal jugular vein. The latter consisted of a 16-gauge Medicut needle placed in the left internal jugular vein by the elective method described by English et al. (1969). This was then attached to a central venous pressure recording line containing 5 % dextrose solution.During the operation severe haemorrhage occurred, and eight litres of a mixture of blood, plasma, and dextran were given through the arm. Also 100 ml of 8-4% sodium bicarbonate and 10 ml of 20 % calcium chloride were given through the jugular vein, which was used for the rest of the operation to monitor central venous pressure (Briscoe, 1973).The transfusion in the neck was continued until the next day when a large swelling was noticed and the cannula was therefore removed. Intravenous tetracycline and 200 ml of 10% mannitol were given during this period but it is not certain through which line.The patient's postoperative progress was marred by an ileus during the first week, and he was not given fluids by mouth for 10 days. He was then found to have some difficulty in swallowing and it was noticed that he had a left Horner's syndrome.More neurological abnormalities appeared during the next week.A barium swallow in the third week showed obstruction at the level of the pyriform fossa and some spill of the barium into the trachea. There was no evidence (that damage had been caused directly by insertion of the needle. It appeared, therefore, that injury had been due to pressure from a haema.toma or extravasated fluid, or ito chemical damage from this fluid and ithe drugs contained in it.Haema'tomata occasionally may produce peripheral nerve palsies, and recovery may be delayed for days or weeks after subsidence of the iswelling (Parkes, 1945), presumably because of reversible structural damage tothe compressed nerve fibres (Fowler et al., 1972). Nevertheless, in -this case the delay in onset of the neurological abnormalities and the absence of iron deposits in the neck suggest that compression by a haematoma was not a major factor.The most importanit contribution to the damage was probably a direct chemical action of 'the drugs and fluids on the nerves. The swelling in the neck suggests ithat the cannula became at least partially dislodged from ithe vein, and t...

A closed-circle absorber system incorporating an in-circle Goldman vaporizer was used to administer halothane or enflurane in oxygen to adult patients. The attained inspired and end-tidal concentrations of volatile agent after a period of stabilization at each vaporizer setting were measured by mass spectrometry. During spontaneous respiration under halothane the ranges of inspired concentrations at settings 1, 11/2 and 2 were respectively 0.5-0.9%, 1.4-2.4% and 3.3-4.5%. corresponding inspired enflurane concentrations at the same settings were 0.8-1.4%, 1.9-2.8% and 3.7-5.0%. IPPV to 5% end-tidal carbon dioxide, although increasing the inspired concentrations slightly, produced considerable increases in end-tidal concentrations. Minimal pre-oxygenation was used to assess the problem of nitrogen accumulation within the circuit. The maximum nitrogen concentration was 56%.