- Email: [email protected]
OPERATING-THEATRES
240
Only one of the five theatres in which I work has positive-pressure ventilation-i.e., a system whereby the
Special Articles OPERATING-THEATRES An Anæsthetist’s
Thoughts
ANDREW TINDAL M.B. Glasg., F.F.A. R.C.S. LECTURER IN
FOR years
now
ANÆSTHESIA,
UNIVERSITY OF GLASGOW
I have spent my
waking hours
as an
anaesthetist. During this period of sitting and supplying the sedation for surgical practice there have inevitably been opportunities for thinking. Some of these I have devoted to reflections on the
general unsuitability of operating-theatres for the work that is done within them. As long ago as 1941 I added some experimental observations to these reflections and wrote a paper (Tindal 1941) in which I drew attention to the work of Paul Bert. In 1878 Bert put forward the idea that if operations were done under increased pressure the required degree of anaesthesia would be more easily secured with smaller quantities of less toxic agents, particularly nitrous oxide. In my experiments I found that at a pressure of about 2 atmospheres (15 to 20 lb. per sq. in. over atmospheric pressure) laboratory animals and humans showed no ill effects, required less anaesthetic agent than at atmospheric pressure, and recovered more quickly. In a small chamber constructed to my design I carried out dental extractions under nitrous-oxide anaesthesia with satisfactory results. All this has relevance to the problems of how we ought to design the operating-theatres of the hospitals which will be built during the next decade. A full discussion by Heating and Ventilating Engineers (1959) does not encourage the idea that the problems have been solved-or even fully grasped by those concerned. For these reasons I am tempted to set out briefly an account of what I believe might be the kind of theatre we need; and of how the aseptic discipline (intelligently reinforced by antisepsis) might come to have more success than it appears to enjoy in our present era of hospital infection.
air is blown into the theatre. And in this theatre the air is sucked through a hole in the wall from the septic clinic. The fan is situated directly above the dressings steriliser. It is obvious that there is no reliable liaison between bacteriologists and surgeons. There is no authoritative work to guide the architects or engineers. In fact there has been little advance in asepsis, or in applying modern science to the problem of infection in what should be clean operations, since immediately after Lister’s epochmaking demonstrations. Why has so little use been made of modern science ? The results of applying Lister’s methods and theories were so astonishingly good that perhaps it seemed that no further effort was necessary; no doubt complacency set in. The same attitude followed the discovery of anxsthesia which spread all over the civilised world in a matter of weeks, after which there But now, was little advancement for nearly 90 years. there no is mercifully, longer complacency. Surgeons all over the country are disturbed by the increase in the number of their clean cases that go septic. Very few reliable figures are available for postoperative sepsis in clean " stitch abscesses ", cases, partly because postoperative " infected hxmatomas ", and burst wounds " are not always noted. "
One of the things that strikes me about all this is the changed status of the surgeon, who is no longer undisputed master of the theatre and of the theatre personnel. This diminution of responsibility militates against meticulous attention to detail in aseptic techniques. For instance, it is very difficult to dismiss a theatre orderly unless there is abundant evidence of gross neglect. But faults short of gross neglect may be very serious if all sorts of breaches of technique are made quietly behind the scenes. Overlong hours of working of the theatre nurses and surgeons, because of long waiting-lists, undoubtedly contributes something to our problem. It is noticeable that after four hours in theatre there is a general slacking off of concentration. Conversation, which at first was sparse, becomes general. Many of the older surgeons insisted on silence during operations, and until such time The Present Position as an efficient method of dealing with conversational An operating-theatre should contain as few bacteria spray can be devised it might be a good thing to follow In other words it should be clean-clean as possible. their example and have as little talk as possible while both as regards bacteria and ordinary dirt. Nearly a wounds are exposed. century after Lister one would expect this to be the case; but this is not so. For various reasons the operatingSources of the Bacteria that Cause Wound Sepsis theatre may be one of the dirtiest places in a hospital. You 1. The patient’s skin, hair, oral sepsis, local skin lesions. cannot imagine it to be so ? Look under the operating2. The patient’s clothes (often removed from a previous table, which is never sterilised from the day of its manu- patient)-e.g., woollen stockings. facture until it is thrown out as junk. Inspect the grids of 3. The patient’s coverings-often actual blankets. the elaborate but useless ventilating system, and collect 4. Trolleys and stretcher cloths. the black dust that issues therefrom during a gale. Watch 5. Airborne and dustborne bacteria from the ventilation a patient being transported to the operating-table on a system.
stretcher cloth that may well be stained with
traces
of
6. Airborne and dustborne bacteria tossed into the air
by
blood, faeces, and vomitus from previous patients. He may be clothed in a shirt that he has worn in bed, and it
heating appliances acting
may be likewise stained. The barrow itself often bears the
boots, nurses’ skirts and petticoats, and the long skirts of
stains of human discomfort. In one theatre my anxsthetic routine is diversified every summer by a housefly and bluebottle hunt. Using chloroform in a 20 ml. syringe I have shot down more than twenty insects in one morning. That this should be possible is almost unbelievable in modern times.
as convectors.
7. Air and dustborne bacteria from the
flip-flap
of theatre
sterile gowns. 8. Flies. 9.
Dressings and instruments
not
sterilised
by
an
adequate
method. 10.
Dressings and instruments adequately sterilised but later by dust.
contaminated
241
11. Dressings and instruments contaminated by surgeons and staff. 12. Condensation of water on the ceiling causing drops to fall on the field of operation. 13. Porous walls of bricks and
plaster.
Hair
plaster
is
particularly dangerous. peeling paint often seen above sterilisers. 15. Droplets from the nose and lips of theatre staff, especially those who talk or cough. 16. Overheated theatres which cause sweating of patient and surgeon and thus bring organisms to the surface from sweat and sebaceous glands. 17. Punctured rubber gloves.-Owing to overheating, lack of evaporation, and excitement the inside of rubber gloves often contains visible sweat. When released by accidental puncture such fluid inoculates the wound with a high concentration of bacteria. Theatre sisters tell me that a high proportion of used gloves show punctures, of which the surgeon was unaware during the operation. 14. Dust from
It will be noted in many of the sources mentioned that the organisms are airborne and come from the theatre structure and its contents. Hence any improvement in aseptic techniques must include a change in the structure and design of operating-theatres.
To protect the patients from the above contaminants, it is necessary to design a theatre with so great a positive pressure that outside air can be completely excluded, despite extreme vagaries of weather. Furthermore, the only feasible method of sterilising everything in the theatre, including the structure itself, is by heating; and this is most easily done by steam pressure, of which there is plenty to spare during the night in most
hospitals. Such a theatre would be an airtight windowless room in the form of an upright cylinder with domed ends; or, better still, it could be globular. It would be constructed of steel, if possible of stainless steel. Admission would be by an airlock-preferably two, an ingoing and an outgoing. This airlock would serve an important purpose besides compression and decompression; it would serve as an absolute barrier between the ordinary air of the hospital and the sterile air of the theatre. The air in the airlocks would be initially sterile. Time spent in the airlocks would be used to change from hospital clothes into next-to-skin theatre garments which would be sterilised to begin with, though they would not remain sterile. Showers should be provided in the airlock, because it is at least as important to bathe before an operation as it is desirable to do so after an operating session. Thus, on entering the theatre, the surgeon and his assistants would bring in a minimum of contaminants.
During the night the theatre suite could be evacuated of air by a steam-ejector pump. Excess steam-usually available at night from the main hospital boilers-could then be fed into the theatre and airlocks, at a pressure of say 5 lb. per sq. in., which would decontaminate (if not sterilise) everything in situ-garments, footwear, furniture, drapes, operating-table, dressings, instruments, theatre trolleys, and stretchers. When the steam had been applied for the necessary time it could be forced out and the theatre would remain at vacuum pressure until all the contents were dry, after which clean sterile air would be admitted.
Using
a
Sterilisation of Theatre Air compressor of 12:1 compression ratio at each
stroke of the piston, the adiabatic compression will raise the temperature of the air momentarily to around 1000°F, at which temperature all living elements will be killed. By adjusting the cam of the exhaust valve so that the air in the cylinder is almost re-expanded, most of the energy of compression will be regained by the flywheel, which could compress the next charge of air, making the air sterilisation almost costless. Adjustment of this cam will also control the temperature of the incoming air to the theatre. Ventilating and Heating of Theatre Ventilating and heating of the theatre is done by recirculation of the air in three or four large ducts. The intakes of these ducts are directly above the operating-table, so that any spray droplets that escape the surgeon’s mask are immediately borne upwards away from the operation field. In the ascending part of the duct immediately above the operator’s head is an electrically heated wire grid which sterilises the air, and by convection accelerates the air upwards. The radiated heat from this grid is prevented from reaching the surgeon by inclined slats. At the upper end of the downward limb of the duct is a cooling coil to condense excess humidity and to accelerate the air downwards in the duct. The coolant could be liquid oxygen, which is cheap and would adequately replace the oxygen used up by theatre workers. The duct then turns upwards and has an electrically heated wire grid which, being thermostatically controlled, finally heats the air to the required temperature, and re-sterilises all air which passes through.
The outlet directs the air horizontally, tangentially, and anticlockwise so that the air movement in the theatre is in the form of a natural vortex. This would be a very economical method of heating and regulating the humidity of the theatre, and at the same time the air would be continuously sterilised. Air at knee level and below, in the centre of the room, would be least disturbed. In ordinary theatres it is at this level that the bacterial count is highest. This is the level where clumsy, hot, rubber theatre boots belch forth their dubious contents, derived more often than not from outdoor socks. This is also the level where skirts and petticoats (usually personal property) flip and flap, sending out clouds of bacteria-laden dust and fluff.
242 Sterilisation of Instruments We might borrow from industry here, and pass the steel instruments-with the possible exception of knivesthrough an induction furnace. In two seconds the whole instrument-every molecule of the instrument-would simultaneously reach the required sterilisation temperature. The conveyor belt would then carry the instrument into a cooling fluid so that it would be completely sterile and cool within ten seconds. Such a steriliser could be in continuous use alongside the operating-table and yet not radiate any perceptible heat or steam. This would each advance the aseptic ideal-that instrument is used but once, then discarded. In a slightly pressurised theatre the basin steriliser could be heated to some degrees above 100°C without boiling, thus preventing excess water vapour being discharged into the theatre.
Asepsis
of
Antisepsis of Personnel personnel is impossible, but
should be made to keep the theatre atmosphere.
every effort
organisms from being shed
1. All theatre workers could have
a
into
spray in the airlock to
desquamated skin. 2. After drying, a complete rub over with a cloth damped with a mildly antiseptic oil-to prevent further shedding of epithelium and to cover the body with an antiseptic film. 3. It has been shown that carpenters working with hard wood
corporeal blood pumps and oxygenation, and it is more likely that blood substitutes will be used for oxygen carriage, in which case pressurised theatres will be a necessity (Boerema 1961, Boerema et al. 1960). Existing than
theatres cannot be modified for pressure, so that pres. surised theatres in future would have to be specially built.
With prefabrication and standard design, it is possible that a steel theatre would entail less capital expenditure. It would be more durable than stone or lime and plaster. If clean wound sepsis were reduced even by half, the shorter stay in hospital of patients would easily outweigh
capital expenditure. I am Western
grateful to Prof. J. W. Howie, Bacteriologist, Glasgow Infirmary, for advice and encouragement; and to William
Gallacher for his excellent
drawing. REFERENCES
Bert, P. (1878) C.R. Acad. Sci. 87, 782. Boerema, I. (1961) Surgery, 49, 291. Meyne, N. G., Brummelkamp, W. K., Bouma, S., Mensch, M. H., Kamermans, F., Stern Hanf, M., Aalderen, W. van (1960) J. Cardiov. Surg. 1, 133. Davey, O. G. (1959) Discovery, 216, 469. J. Inst. Hyg. Vent. Engrs (1959) 26, 257. Tindal, A. (1941) Surgo, 7, 33. —
remove
have sterile hands. Resins and oils in wood may account for this. If bare hands, well washed before an application of antiseptic resin or oil, were used at operation rather than rubber gloves (which tend to cause sweating and concentration of organisms) there would be less likelihood of tissues being inoculated with an infectious concentration of microorganisms. When a glove is punctured the resultant spillage is a highly concentrated bacterial emulsion, which the tissues are less likely to resist than the continual shedding of small numbers of microorganisms from the bare hand.
Theatre Garments Theatre fashions tend to protect the wearer rather than the patient. Long loose skirts blow the wearer’s desquamated epithelium about in clouds at every movement, while floppy, clumsy, rubber theatre-boots are hot to wear, cause sweating, and puff out foot dust at every step. To lessen the effect of flapping clothes, suitable theatre dress might be drainpipe slacks (fitting closely at the ankle), close-fitting singlet with short sleeves, socks and ballet shoes, or sandshoes. Sterile dress: short, closefitting, elastic jerkin with long sleeves tight at the wrist, tying at the back, with elastic round the trochanters. At present, because of voluminous garments, surgeons and nurses often touch non-sterile objects without being aware
of
doing
so.
All the above may seem too fantastic and unrealistic, but researchers went to far greater lengths to produce sterile rats (Davey 1959), and in I.C.I. laboratories a more exacting. aseptic ceremonial is enforced even to see these
disease-free
rats.
Conclusions To be successful the technique of
asepsis
must
be
approach perfection. more
and
more
THE Medical Research Council had its beginnings in the world of fifty years ago in which the value of scientific research was suspect. Now that the need for such research is taken for granted, the Council’s role has changed. Its latest annual report1 discusses the present functions of a central research organisation. The Council sees itself as the coordinator of resources on a national scale. Working in partnership with other establishments, it supports judiciously selected research projects. In making this selection, it must bear in mind the country’s probable future needs; but it must never allow this direction of aim to become so rigid that individual workers are unable to act on their own initiative. The Council’s status as an independent body, advised by a widely experienced board, fits it to provide opinions which can be trusted by Government and public alike. Some of the work in the report.
supported by the Council is reviewed
Brain Mechanisms A technique for injecting drugs painlessly into the cerebral ventricles of unanxsthetised animals is being used to explore the physiological basis of some of the physical symptoms of mental disorder. Some drugs-e.g., adrenaline, noradrenaline, and calcium chloride-which have an excitatory effect when given systemically are depressants when introduced directly into the cerebrospinal fluid: the animal shows a disturbance of consciousness similar to sleep or anaesthesia. Some established narcotics (chloral, chloralose, and magnesium chloride) have the same effect when given intraventricularly in very small doses. Sleep is sometimes preceded by compulsive eating, the animal often falling asleep at the dish of food. This is believed to be due to the drugs’ effect on the hypothalamic centres
controlling appetite.
highly efficient. This is impossible with modern operating-theatre design, ventilation, and discipline; and, unless the technique is beyond criticism, it might be safer to In a theatre suite as outlined, an revert to antisepsis. aseptic technique could be practised that would at least Further advances will
MEDICAL RESEARCH
depend
on extra-
Catatonia or hallucinations reminiscent of schizophrenia follow the introduction of acetylcholine or diisopropylfluorophosphonate (D.F.P.) into the ventricles: the animal maintains unnatural postures, although it is not paralysed, for, when
disturbed, attacks of
it
can
move
normally.
D.F.P.
produces
acute
in schizophrenics; but the disease is not due to the necessarily persistence of acetylcholine at some brain locus. All that can be concluded is that such persistence, 1.
psychosis
Report of the Medical Research Council for the H.M. Stationery Office.
year
1960-1961.
Only one of the five theatres in which I work has positive-pressure ventilation-i.e., a system whereby the
Special Articles OPERATING-THEATRES An Anæsthetist’s
Thoughts
ANDREW TINDAL M.B. Glasg., F.F.A. R.C.S. LECTURER IN
FOR years
now
ANÆSTHESIA,
UNIVERSITY OF GLASGOW
I have spent my
waking hours
as an
anaesthetist. During this period of sitting and supplying the sedation for surgical practice there have inevitably been opportunities for thinking. Some of these I have devoted to reflections on the
general unsuitability of operating-theatres for the work that is done within them. As long ago as 1941 I added some experimental observations to these reflections and wrote a paper (Tindal 1941) in which I drew attention to the work of Paul Bert. In 1878 Bert put forward the idea that if operations were done under increased pressure the required degree of anaesthesia would be more easily secured with smaller quantities of less toxic agents, particularly nitrous oxide. In my experiments I found that at a pressure of about 2 atmospheres (15 to 20 lb. per sq. in. over atmospheric pressure) laboratory animals and humans showed no ill effects, required less anaesthetic agent than at atmospheric pressure, and recovered more quickly. In a small chamber constructed to my design I carried out dental extractions under nitrous-oxide anaesthesia with satisfactory results. All this has relevance to the problems of how we ought to design the operating-theatres of the hospitals which will be built during the next decade. A full discussion by Heating and Ventilating Engineers (1959) does not encourage the idea that the problems have been solved-or even fully grasped by those concerned. For these reasons I am tempted to set out briefly an account of what I believe might be the kind of theatre we need; and of how the aseptic discipline (intelligently reinforced by antisepsis) might come to have more success than it appears to enjoy in our present era of hospital infection.
air is blown into the theatre. And in this theatre the air is sucked through a hole in the wall from the septic clinic. The fan is situated directly above the dressings steriliser. It is obvious that there is no reliable liaison between bacteriologists and surgeons. There is no authoritative work to guide the architects or engineers. In fact there has been little advance in asepsis, or in applying modern science to the problem of infection in what should be clean operations, since immediately after Lister’s epochmaking demonstrations. Why has so little use been made of modern science ? The results of applying Lister’s methods and theories were so astonishingly good that perhaps it seemed that no further effort was necessary; no doubt complacency set in. The same attitude followed the discovery of anxsthesia which spread all over the civilised world in a matter of weeks, after which there But now, was little advancement for nearly 90 years. there no is mercifully, longer complacency. Surgeons all over the country are disturbed by the increase in the number of their clean cases that go septic. Very few reliable figures are available for postoperative sepsis in clean " stitch abscesses ", cases, partly because postoperative " infected hxmatomas ", and burst wounds " are not always noted. "
One of the things that strikes me about all this is the changed status of the surgeon, who is no longer undisputed master of the theatre and of the theatre personnel. This diminution of responsibility militates against meticulous attention to detail in aseptic techniques. For instance, it is very difficult to dismiss a theatre orderly unless there is abundant evidence of gross neglect. But faults short of gross neglect may be very serious if all sorts of breaches of technique are made quietly behind the scenes. Overlong hours of working of the theatre nurses and surgeons, because of long waiting-lists, undoubtedly contributes something to our problem. It is noticeable that after four hours in theatre there is a general slacking off of concentration. Conversation, which at first was sparse, becomes general. Many of the older surgeons insisted on silence during operations, and until such time The Present Position as an efficient method of dealing with conversational An operating-theatre should contain as few bacteria spray can be devised it might be a good thing to follow In other words it should be clean-clean as possible. their example and have as little talk as possible while both as regards bacteria and ordinary dirt. Nearly a wounds are exposed. century after Lister one would expect this to be the case; but this is not so. For various reasons the operatingSources of the Bacteria that Cause Wound Sepsis theatre may be one of the dirtiest places in a hospital. You 1. The patient’s skin, hair, oral sepsis, local skin lesions. cannot imagine it to be so ? Look under the operating2. The patient’s clothes (often removed from a previous table, which is never sterilised from the day of its manu- patient)-e.g., woollen stockings. facture until it is thrown out as junk. Inspect the grids of 3. The patient’s coverings-often actual blankets. the elaborate but useless ventilating system, and collect 4. Trolleys and stretcher cloths. the black dust that issues therefrom during a gale. Watch 5. Airborne and dustborne bacteria from the ventilation a patient being transported to the operating-table on a system.
stretcher cloth that may well be stained with
traces
of
6. Airborne and dustborne bacteria tossed into the air
by
blood, faeces, and vomitus from previous patients. He may be clothed in a shirt that he has worn in bed, and it
heating appliances acting
may be likewise stained. The barrow itself often bears the
boots, nurses’ skirts and petticoats, and the long skirts of
stains of human discomfort. In one theatre my anxsthetic routine is diversified every summer by a housefly and bluebottle hunt. Using chloroform in a 20 ml. syringe I have shot down more than twenty insects in one morning. That this should be possible is almost unbelievable in modern times.
as convectors.
7. Air and dustborne bacteria from the
flip-flap
of theatre
sterile gowns. 8. Flies. 9.
Dressings and instruments
not
sterilised
by
an
adequate
method. 10.
Dressings and instruments adequately sterilised but later by dust.
contaminated
241
11. Dressings and instruments contaminated by surgeons and staff. 12. Condensation of water on the ceiling causing drops to fall on the field of operation. 13. Porous walls of bricks and
plaster.
Hair
plaster
is
particularly dangerous. peeling paint often seen above sterilisers. 15. Droplets from the nose and lips of theatre staff, especially those who talk or cough. 16. Overheated theatres which cause sweating of patient and surgeon and thus bring organisms to the surface from sweat and sebaceous glands. 17. Punctured rubber gloves.-Owing to overheating, lack of evaporation, and excitement the inside of rubber gloves often contains visible sweat. When released by accidental puncture such fluid inoculates the wound with a high concentration of bacteria. Theatre sisters tell me that a high proportion of used gloves show punctures, of which the surgeon was unaware during the operation. 14. Dust from
It will be noted in many of the sources mentioned that the organisms are airborne and come from the theatre structure and its contents. Hence any improvement in aseptic techniques must include a change in the structure and design of operating-theatres.
To protect the patients from the above contaminants, it is necessary to design a theatre with so great a positive pressure that outside air can be completely excluded, despite extreme vagaries of weather. Furthermore, the only feasible method of sterilising everything in the theatre, including the structure itself, is by heating; and this is most easily done by steam pressure, of which there is plenty to spare during the night in most
hospitals. Such a theatre would be an airtight windowless room in the form of an upright cylinder with domed ends; or, better still, it could be globular. It would be constructed of steel, if possible of stainless steel. Admission would be by an airlock-preferably two, an ingoing and an outgoing. This airlock would serve an important purpose besides compression and decompression; it would serve as an absolute barrier between the ordinary air of the hospital and the sterile air of the theatre. The air in the airlocks would be initially sterile. Time spent in the airlocks would be used to change from hospital clothes into next-to-skin theatre garments which would be sterilised to begin with, though they would not remain sterile. Showers should be provided in the airlock, because it is at least as important to bathe before an operation as it is desirable to do so after an operating session. Thus, on entering the theatre, the surgeon and his assistants would bring in a minimum of contaminants.
During the night the theatre suite could be evacuated of air by a steam-ejector pump. Excess steam-usually available at night from the main hospital boilers-could then be fed into the theatre and airlocks, at a pressure of say 5 lb. per sq. in., which would decontaminate (if not sterilise) everything in situ-garments, footwear, furniture, drapes, operating-table, dressings, instruments, theatre trolleys, and stretchers. When the steam had been applied for the necessary time it could be forced out and the theatre would remain at vacuum pressure until all the contents were dry, after which clean sterile air would be admitted.
Using
a
Sterilisation of Theatre Air compressor of 12:1 compression ratio at each
stroke of the piston, the adiabatic compression will raise the temperature of the air momentarily to around 1000°F, at which temperature all living elements will be killed. By adjusting the cam of the exhaust valve so that the air in the cylinder is almost re-expanded, most of the energy of compression will be regained by the flywheel, which could compress the next charge of air, making the air sterilisation almost costless. Adjustment of this cam will also control the temperature of the incoming air to the theatre. Ventilating and Heating of Theatre Ventilating and heating of the theatre is done by recirculation of the air in three or four large ducts. The intakes of these ducts are directly above the operating-table, so that any spray droplets that escape the surgeon’s mask are immediately borne upwards away from the operation field. In the ascending part of the duct immediately above the operator’s head is an electrically heated wire grid which sterilises the air, and by convection accelerates the air upwards. The radiated heat from this grid is prevented from reaching the surgeon by inclined slats. At the upper end of the downward limb of the duct is a cooling coil to condense excess humidity and to accelerate the air downwards in the duct. The coolant could be liquid oxygen, which is cheap and would adequately replace the oxygen used up by theatre workers. The duct then turns upwards and has an electrically heated wire grid which, being thermostatically controlled, finally heats the air to the required temperature, and re-sterilises all air which passes through.
The outlet directs the air horizontally, tangentially, and anticlockwise so that the air movement in the theatre is in the form of a natural vortex. This would be a very economical method of heating and regulating the humidity of the theatre, and at the same time the air would be continuously sterilised. Air at knee level and below, in the centre of the room, would be least disturbed. In ordinary theatres it is at this level that the bacterial count is highest. This is the level where clumsy, hot, rubber theatre boots belch forth their dubious contents, derived more often than not from outdoor socks. This is also the level where skirts and petticoats (usually personal property) flip and flap, sending out clouds of bacteria-laden dust and fluff.
242 Sterilisation of Instruments We might borrow from industry here, and pass the steel instruments-with the possible exception of knivesthrough an induction furnace. In two seconds the whole instrument-every molecule of the instrument-would simultaneously reach the required sterilisation temperature. The conveyor belt would then carry the instrument into a cooling fluid so that it would be completely sterile and cool within ten seconds. Such a steriliser could be in continuous use alongside the operating-table and yet not radiate any perceptible heat or steam. This would each advance the aseptic ideal-that instrument is used but once, then discarded. In a slightly pressurised theatre the basin steriliser could be heated to some degrees above 100°C without boiling, thus preventing excess water vapour being discharged into the theatre.
Asepsis
of
Antisepsis of Personnel personnel is impossible, but
should be made to keep the theatre atmosphere.
every effort
organisms from being shed
1. All theatre workers could have
a
into
spray in the airlock to
desquamated skin. 2. After drying, a complete rub over with a cloth damped with a mildly antiseptic oil-to prevent further shedding of epithelium and to cover the body with an antiseptic film. 3. It has been shown that carpenters working with hard wood
corporeal blood pumps and oxygenation, and it is more likely that blood substitutes will be used for oxygen carriage, in which case pressurised theatres will be a necessity (Boerema 1961, Boerema et al. 1960). Existing than
theatres cannot be modified for pressure, so that pres. surised theatres in future would have to be specially built.
With prefabrication and standard design, it is possible that a steel theatre would entail less capital expenditure. It would be more durable than stone or lime and plaster. If clean wound sepsis were reduced even by half, the shorter stay in hospital of patients would easily outweigh
capital expenditure. I am Western
grateful to Prof. J. W. Howie, Bacteriologist, Glasgow Infirmary, for advice and encouragement; and to William
Gallacher for his excellent
drawing. REFERENCES
Bert, P. (1878) C.R. Acad. Sci. 87, 782. Boerema, I. (1961) Surgery, 49, 291. Meyne, N. G., Brummelkamp, W. K., Bouma, S., Mensch, M. H., Kamermans, F., Stern Hanf, M., Aalderen, W. van (1960) J. Cardiov. Surg. 1, 133. Davey, O. G. (1959) Discovery, 216, 469. J. Inst. Hyg. Vent. Engrs (1959) 26, 257. Tindal, A. (1941) Surgo, 7, 33. —
remove
have sterile hands. Resins and oils in wood may account for this. If bare hands, well washed before an application of antiseptic resin or oil, were used at operation rather than rubber gloves (which tend to cause sweating and concentration of organisms) there would be less likelihood of tissues being inoculated with an infectious concentration of microorganisms. When a glove is punctured the resultant spillage is a highly concentrated bacterial emulsion, which the tissues are less likely to resist than the continual shedding of small numbers of microorganisms from the bare hand.
Theatre Garments Theatre fashions tend to protect the wearer rather than the patient. Long loose skirts blow the wearer’s desquamated epithelium about in clouds at every movement, while floppy, clumsy, rubber theatre-boots are hot to wear, cause sweating, and puff out foot dust at every step. To lessen the effect of flapping clothes, suitable theatre dress might be drainpipe slacks (fitting closely at the ankle), close-fitting singlet with short sleeves, socks and ballet shoes, or sandshoes. Sterile dress: short, closefitting, elastic jerkin with long sleeves tight at the wrist, tying at the back, with elastic round the trochanters. At present, because of voluminous garments, surgeons and nurses often touch non-sterile objects without being aware
of
doing
so.
All the above may seem too fantastic and unrealistic, but researchers went to far greater lengths to produce sterile rats (Davey 1959), and in I.C.I. laboratories a more exacting. aseptic ceremonial is enforced even to see these
disease-free
rats.
Conclusions To be successful the technique of
asepsis
must
be
approach perfection. more
and
more
THE Medical Research Council had its beginnings in the world of fifty years ago in which the value of scientific research was suspect. Now that the need for such research is taken for granted, the Council’s role has changed. Its latest annual report1 discusses the present functions of a central research organisation. The Council sees itself as the coordinator of resources on a national scale. Working in partnership with other establishments, it supports judiciously selected research projects. In making this selection, it must bear in mind the country’s probable future needs; but it must never allow this direction of aim to become so rigid that individual workers are unable to act on their own initiative. The Council’s status as an independent body, advised by a widely experienced board, fits it to provide opinions which can be trusted by Government and public alike. Some of the work in the report.
supported by the Council is reviewed
Brain Mechanisms A technique for injecting drugs painlessly into the cerebral ventricles of unanxsthetised animals is being used to explore the physiological basis of some of the physical symptoms of mental disorder. Some drugs-e.g., adrenaline, noradrenaline, and calcium chloride-which have an excitatory effect when given systemically are depressants when introduced directly into the cerebrospinal fluid: the animal shows a disturbance of consciousness similar to sleep or anaesthesia. Some established narcotics (chloral, chloralose, and magnesium chloride) have the same effect when given intraventricularly in very small doses. Sleep is sometimes preceded by compulsive eating, the animal often falling asleep at the dish of food. This is believed to be due to the drugs’ effect on the hypothalamic centres
controlling appetite.
highly efficient. This is impossible with modern operating-theatre design, ventilation, and discipline; and, unless the technique is beyond criticism, it might be safer to In a theatre suite as outlined, an revert to antisepsis. aseptic technique could be practised that would at least Further advances will
MEDICAL RESEARCH
depend
on extra-
Catatonia or hallucinations reminiscent of schizophrenia follow the introduction of acetylcholine or diisopropylfluorophosphonate (D.F.P.) into the ventricles: the animal maintains unnatural postures, although it is not paralysed, for, when
disturbed, attacks of
it
can
move
normally.
D.F.P.
produces
acute
in schizophrenics; but the disease is not due to the necessarily persistence of acetylcholine at some brain locus. All that can be concluded is that such persistence, 1.
psychosis
Report of the Medical Research Council for the H.M. Stationery Office.
year
1960-1961.