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PNEUMATIC BANDAGE FOR USE IN THE STRIPPING OF VARICOSE VEINS
415
have given reasons for believing that the release of noradrenaline from the postganglionic fibre by the sympathetic impulse also involves the action of acetylcholine. They suggest that the sympathetic impulse releases acetylcholine, and this in turn releases noradrenaline. The action of mecamylamine and of pempidine in the postganglionic fibre would on this view be the same as their action on ganglia; it would be a block of the action of acetylcholine. Our interpretation is supported by the evidence that both bretylium and mecamylamine comby eserine pletely block the rise of blood-pressure caused 4 in the rat, whereas hexamethonium does not. J. H. BURN M.D. Cantab., F.R.S. Department of Pharmacology, W. R. GIBBONS Washington University School of Medicine, B.SC. Washington St. Louis, Missouri, U.S.A.
New Inventions PNEUMATIC BANDAGE FOR USE IN THE STRIPPING OF VARICOSE VEINS HIGH (juxtafemoral) ligation and stripping is a common method of treating varicosity of the long saphenous venous system; yet this relatively minor operation may make heavy demands upon bed space, usually on account of the associated venous extravasation. The usual practice is to ligate the long saphenous vein flush at its junction with the femoral vein, together with ligation and division of all the tributaries converainr on that area. The long saphenous trunk is then exposed immediately above the medial malleolus, the stripper is passed up to the groin, and the lower two or three inches of the long saphenous vein are stripped. The lower incision is then closed, and the upper wound loosely sutured around the stripper; crepe bandages are firmly applied to the limb, and extirpation of the vein is then completed. The upper wound is closed, and after some two or three days the crepe bandages are removed. For the past six months we have made use of a pneumatic bandage to achieve better
and
more even
compression throughout
the length of the limb. When the stripper has been passed up the vein and the lower wound closed, the transparent plastic bandage (see figure) is applied and inflated with carbon dioxide to a pressure of 20-30 mm. Hg, measured with a sphygmomanometer. The vein is stripped out, and the bandage is removed after six hours. Next day the patient is encouraged to walk without any
supporting dressings.
stripping was carried simultaneously on both legs, the pneumatic bandage being applied to one limb and crepe bandages to the other. Invariably In bilateral cases,
Pneumatic bandage showing zipn fastener on upper surface.
out
the patient stated that discomfort was less in the leg on which the pneumatic bandage was used. Experience has shown that the pneumatic bandage consider-
ably
reduces extravasation and bruising. Many patients to go home 48 hours after operation. The pneumatic bandage has the following advantages:
are
thus able
1. It is relatively inexpensive and can be re-used many times. 2. It is transparent, thus enabling skin colour to be noted. 3. The application of sustained and even pressure throughout the lennh of the limb considerably reduces extravasation, thus allowing Mriy ambulation and discharge of the patient from hospital. We wish to thank Mrs. Pnscilla Miles for the illustration. 4.
Gokhale, S. D., Gulati, 0. D., Joshi, N. 273.
Y.
Br. 7. Pharpracol. 1963,21,
The pneumatic bandage is manufactured by the Jobst Institute, Inc., 1803, Jefferson Avenue, Toledo 2, Ohio, U.S.A., and is distributed in the U.K. by Mine Safety Appliances Co. Ltd., Queenslie Industrial Estate, Glassow. E.3. DONALD B. BROWN M.B.
Varicose Vein Clinic, Western Infirmary,
Glasgow
Glasg., F.R.C.S.
IAN F. KERR M.B.
Glasg., F.R.C.S.E.
PORTABLE AIR PURIFIER SMOKE fogs as long lasting and as dense as those of December, 1952, and December, 1962, are fortunately uncommon, but air pollution severe enough to reduce visibility and to give the winter air an acrid smell are not. In these conditions many bronchitic and asthmatic patients become distressed, and Waller and Lawther 12 have shown that the subjective state of these patients varies closely with the degree of pollution. A portable air purifier seemed likely to benefit such patients, particularly if used as a recirculator to obviate the need for
altering existing heating and ventilating systems. Existing commercial air purifiers incorporate either a cellulose-asbestos matt filter to remove smoke, or activated carbon to remove gases such as sulphur dioxide. Though these effectively remove particles between 0-11 and 0°5 u in size, they are usually not portable or convenient in hospitals. The present unit was designed and manufactured by Vokes Ltd., Guildford. Mounted in a steel frame it is 3 ft. high, 18 in. square, and resembles a hospital bedside table. It is divided into two compartments by a horizontal partition. The upper one contains an electric fan which draws air through a removable filter occupying the lower compartment. Filtered air is discharged through a grille and two tubular side-ports at 160 c.ft. per minute, 30 c.ft. per minute issuing from each sideport. Provision is made for sealing off the grille and leading the efli-uent air into one or two tents by means of plastic hose attached to the side-ports. The unit can thus be used to serve in a main ward. Two alternative filters are available-a paper-filter for removing particulate matter, and a pack of activated carbon for removing sulphur dioxide. The paper filter is formed by blending cellulose and asbestos fibres and folding the sheet into deep corrugations to provide a large surface area. The filter will remove not only smoke particles but also bacteria, pollens, and spores. The carbon pack contains 2-4 kg. of activated carbon packed into the four walls, each 1 cm. thick, of a box-shaped filter. This will absorb 910 litres of sulphur tents
dioxide3
Though varying with the granularity of the carbon and competilion from other gases, the effective life of the pack in extracting sulphur dioxide is long, about a year under normal running conditions. When run in a severe " smog " the filter absorbs 1-4 litres of sulphur dioxide daily-i.e., 1/600th of its total capacity. The efficiency of the air purifier was tested by noting its effect on the natural and artificially created sulphur dioxide levels in a room of 2000 c.ft., care being taken to check the constancy of the test-room conditions and to measure its natural ventilation-rate. A room of similar size was used as a control. The natural levels of sulphur dioxide were noted and compared with the levels when the air purifier was running. Artificially high concentrations of sulphur dioxide to simulate " smoglevels were then created, and again the natural attenuation-rate was noted and compared with the rate when the
purifier was in use (see figure). Each experiment was repeated six times, and constant results were obtained. Similar sampling was carried out while ducting the whole outflow from the purifier into an 80 c.ft. plastic tent. The results indicate that sulphur dioxide is removed from proportional to its concentration in the Between 4000 and 55°o of the sulphur dioxide present is extracted in each single passage of air through the filter, the room reaching a state of equilibrium in 45-50 minutes. In a
the
test-room at a rate
room.
1. 2. 3.
Waller, R. E., Lawther, P. J. Brit. med. J. 1955, ii, 1356. Waller, R. E., Lawther, P. J. ibid. 1957, ii, 1473. Hendrickson, E. R. Air Pollution; vol. I, p. 419. New York and London.
have given reasons for believing that the release of noradrenaline from the postganglionic fibre by the sympathetic impulse also involves the action of acetylcholine. They suggest that the sympathetic impulse releases acetylcholine, and this in turn releases noradrenaline. The action of mecamylamine and of pempidine in the postganglionic fibre would on this view be the same as their action on ganglia; it would be a block of the action of acetylcholine. Our interpretation is supported by the evidence that both bretylium and mecamylamine comby eserine pletely block the rise of blood-pressure caused 4 in the rat, whereas hexamethonium does not. J. H. BURN M.D. Cantab., F.R.S. Department of Pharmacology, W. R. GIBBONS Washington University School of Medicine, B.SC. Washington St. Louis, Missouri, U.S.A.
New Inventions PNEUMATIC BANDAGE FOR USE IN THE STRIPPING OF VARICOSE VEINS HIGH (juxtafemoral) ligation and stripping is a common method of treating varicosity of the long saphenous venous system; yet this relatively minor operation may make heavy demands upon bed space, usually on account of the associated venous extravasation. The usual practice is to ligate the long saphenous vein flush at its junction with the femoral vein, together with ligation and division of all the tributaries converainr on that area. The long saphenous trunk is then exposed immediately above the medial malleolus, the stripper is passed up to the groin, and the lower two or three inches of the long saphenous vein are stripped. The lower incision is then closed, and the upper wound loosely sutured around the stripper; crepe bandages are firmly applied to the limb, and extirpation of the vein is then completed. The upper wound is closed, and after some two or three days the crepe bandages are removed. For the past six months we have made use of a pneumatic bandage to achieve better
and
more even
compression throughout
the length of the limb. When the stripper has been passed up the vein and the lower wound closed, the transparent plastic bandage (see figure) is applied and inflated with carbon dioxide to a pressure of 20-30 mm. Hg, measured with a sphygmomanometer. The vein is stripped out, and the bandage is removed after six hours. Next day the patient is encouraged to walk without any
supporting dressings.
stripping was carried simultaneously on both legs, the pneumatic bandage being applied to one limb and crepe bandages to the other. Invariably In bilateral cases,
Pneumatic bandage showing zipn fastener on upper surface.
out
the patient stated that discomfort was less in the leg on which the pneumatic bandage was used. Experience has shown that the pneumatic bandage consider-
ably
reduces extravasation and bruising. Many patients to go home 48 hours after operation. The pneumatic bandage has the following advantages:
are
thus able
1. It is relatively inexpensive and can be re-used many times. 2. It is transparent, thus enabling skin colour to be noted. 3. The application of sustained and even pressure throughout the lennh of the limb considerably reduces extravasation, thus allowing Mriy ambulation and discharge of the patient from hospital. We wish to thank Mrs. Pnscilla Miles for the illustration. 4.
Gokhale, S. D., Gulati, 0. D., Joshi, N. 273.
Y.
Br. 7. Pharpracol. 1963,21,
The pneumatic bandage is manufactured by the Jobst Institute, Inc., 1803, Jefferson Avenue, Toledo 2, Ohio, U.S.A., and is distributed in the U.K. by Mine Safety Appliances Co. Ltd., Queenslie Industrial Estate, Glassow. E.3. DONALD B. BROWN M.B.
Varicose Vein Clinic, Western Infirmary,
Glasgow
Glasg., F.R.C.S.
IAN F. KERR M.B.
Glasg., F.R.C.S.E.
PORTABLE AIR PURIFIER SMOKE fogs as long lasting and as dense as those of December, 1952, and December, 1962, are fortunately uncommon, but air pollution severe enough to reduce visibility and to give the winter air an acrid smell are not. In these conditions many bronchitic and asthmatic patients become distressed, and Waller and Lawther 12 have shown that the subjective state of these patients varies closely with the degree of pollution. A portable air purifier seemed likely to benefit such patients, particularly if used as a recirculator to obviate the need for
altering existing heating and ventilating systems. Existing commercial air purifiers incorporate either a cellulose-asbestos matt filter to remove smoke, or activated carbon to remove gases such as sulphur dioxide. Though these effectively remove particles between 0-11 and 0°5 u in size, they are usually not portable or convenient in hospitals. The present unit was designed and manufactured by Vokes Ltd., Guildford. Mounted in a steel frame it is 3 ft. high, 18 in. square, and resembles a hospital bedside table. It is divided into two compartments by a horizontal partition. The upper one contains an electric fan which draws air through a removable filter occupying the lower compartment. Filtered air is discharged through a grille and two tubular side-ports at 160 c.ft. per minute, 30 c.ft. per minute issuing from each sideport. Provision is made for sealing off the grille and leading the efli-uent air into one or two tents by means of plastic hose attached to the side-ports. The unit can thus be used to serve in a main ward. Two alternative filters are available-a paper-filter for removing particulate matter, and a pack of activated carbon for removing sulphur dioxide. The paper filter is formed by blending cellulose and asbestos fibres and folding the sheet into deep corrugations to provide a large surface area. The filter will remove not only smoke particles but also bacteria, pollens, and spores. The carbon pack contains 2-4 kg. of activated carbon packed into the four walls, each 1 cm. thick, of a box-shaped filter. This will absorb 910 litres of sulphur tents
dioxide3
Though varying with the granularity of the carbon and competilion from other gases, the effective life of the pack in extracting sulphur dioxide is long, about a year under normal running conditions. When run in a severe " smog " the filter absorbs 1-4 litres of sulphur dioxide daily-i.e., 1/600th of its total capacity. The efficiency of the air purifier was tested by noting its effect on the natural and artificially created sulphur dioxide levels in a room of 2000 c.ft., care being taken to check the constancy of the test-room conditions and to measure its natural ventilation-rate. A room of similar size was used as a control. The natural levels of sulphur dioxide were noted and compared with the levels when the air purifier was running. Artificially high concentrations of sulphur dioxide to simulate " smoglevels were then created, and again the natural attenuation-rate was noted and compared with the rate when the
purifier was in use (see figure). Each experiment was repeated six times, and constant results were obtained. Similar sampling was carried out while ducting the whole outflow from the purifier into an 80 c.ft. plastic tent. The results indicate that sulphur dioxide is removed from proportional to its concentration in the Between 4000 and 55°o of the sulphur dioxide present is extracted in each single passage of air through the filter, the room reaching a state of equilibrium in 45-50 minutes. In a
the
test-room at a rate
room.
1. 2. 3.
Waller, R. E., Lawther, P. J. Brit. med. J. 1955, ii, 1356. Waller, R. E., Lawther, P. J. ibid. 1957, ii, 1473. Hendrickson, E. R. Air Pollution; vol. I, p. 419. New York and London.