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NOTIFICATION OF INFECTIVE HEPATITIS
945 than by a more famous institution an away from their homes by tube or bus. The local dermatologist probably works single-handed, also he has a greater so that continuity is ensured ; both from the viewpoint of local difficulties, appreciation of the patient and practitioner, and in proportion to the patients seen, he may have more skin beds at his disposal One further point-I am than the teaching hospital. sure some London practitioners could make more use of the domiciliary consultation service to the advantage of their skin patients. PATRICK HALL-SMITH. Hove, Sussex. CARELESS DEATH CERTIFICATES SIR,—While I am in almost complete agreement with your note published last week under the heading of Medicine and the Law, I submit that you have misinterpreted in one respect the provisions of the Consolidated Regulations of the Registrar-General. By these the duty of refusing registration and notifying the coroner is placed upon the registrar when (inter alia) it appears from the death certificate that the practitioner has seen his patient neither within fourteen days of death It would seem that either condition nor after death. the satisfy may registrar ; in practice, however, when the interval between the last attendance and death exceeds fourteen days the death is usually reported either by the practitioner or the registrar. When this is the case the existence of a certificate, possibly initialled by the practitioner in space " A " on the reverse, may enable the coroner to conclude his inquiry without post-mortem or inquest. I can envisage that such a situation might arise when a practitioner has been on holiday leaving a locum tenens in charge of a patient with known inonerable carcinoma. R. IAN MILNE
district
hour
hospital
or more
H.M. Coroner,
Southern
District, County of London.
NOTIFICATION OF INFECTIVE HEPATITIS SIR,—While agreeing with Admiral (Oct. 27)
Rainsford
in
advocating compulsory notification of homologousserum jaundice, I disagree with certain points raised in his letter. for the incidence of jaundice are These should have read 0’12% following smallpool plasma and 0-16% following whole-blood transfusions. (2) Storage of liquid plasma at room-temperature, as advocated by Garrott Alien, 1 appears to inactivate the agent in plasma responsible for homologous-serum jaundice. My own experience has convinced me of the correctness of this view, while Hoxworth and Haesler2 state that such plasma may be used without concern about the transmission of
(1) The figures quoted
incorrect.
hepatitis. (3) Dextran is undoubtedly an effective and valuable plasma-volume expander, but it is not as harmless as Admiral Rainsford implies. Apart from allergic reactions, it may haemostatic defects. Admiral Rainsford claims that plasma is expensive and dextran inexpensive. I can only state that the cost of producing the liquid plasma to which I refer is considerably lower than the price at which commercial dextran is sold to
cause
(4)
hospitals.
I have no desire to obscure the real issue, which is the notification of infective hepatitis and homologous-serum jaundice, by starting a discussion on the relative merits of plasma and dextran. Both are valuable in the treatment of
oligsemic shock,
and it would be unfortunate
if the views expressed by Admiral Rainsford resulted in the disuse of plasma. Most cases of homologous-serum jaundice in this country at the present time follow the transfusion of whole blood or of concentrated red cells. Compulsory 1. Allen, J.
2.
G., Enerson, D. M., Barron, E. S. G., Sykes, C. J. Amer. med. Ass. 1954, 154, 103. Hoxworth, P. I., Haesler, W. E. 6th Congress of the International Society of Blood Transfusion, Boston, Mass., September, 1956 (in the press).
notification of the disease would help in the detection of the " dangerous " blood-donor who is harbouring the icterogenic agent in his blood. Glasgow and West of Scotland Blood Transfusion Service, Glasgow, C.1.
JOHN WALLACE Regional Director.
OPERATING-THEATRE STERILISERS
SIR,—Some of the statements made by Mr. Barrington Brock (Oct. 13) may cause misunderstanding. In their most valuable contribution to the prevention of theatre infections (Sept. 29) Professor Howie and Dr. Timbury included their discovery that the contents of individual packages in porous loads could be recontaminated during a vacuum-drying period in a dressing steriliser with defective air filtration. make it clear that an adequate air filter dressing sterilisers where packaged goods are dried by the most rapid and least damaging technique available at present-i.e., with steam in jacket, a negative pressure is applied at one end of the chamber drawing dried and warmed but not hot air inwards through a bacteriologically adequate filter fitted opposite at the other end of the chamber, establishing a balance of about 5 in. Hg negative pressure for up to 30 minutes depending upon the nature of the load. " It is also clear that the technique of cracking " the door, and at the same time applying a negative pressure to chamber, must now be abandoned owing to the risk of recontaminating even a properly wrapped package. The third but relatively slow method for drying porous loads-i.e., merely reducing chamber pressure to gauge zero, leaving jacket at pressure and " cracking " door-is surely not " absurd." Since, in this technique, the vapour current within each package is from within outwards throughout intelligently conducted drying periods, is it not still theoretically a bacteriologically safe procedure ? In a properly designed and operated apparatus it is certainly effective as far as drying is concerned. That hot air and superheated steam is far more damaging to heat-sensitive surgical equipment than steam on the phase boundary at much higher temperatures, is now well established through universalexperience. Pumping hot dry air at say 250°F through a load of fabrics in order to dry it is surely therefore definitely contra-indicated. In order to avoid heating the air too much, an effective practice is to attach the chamber filter with minimum length of piping. During sterilisation at 250-254°F and 15-17 lb. per sq. in., a load of fabrics gains weight over normal hydrated weight at room-temperature to the extent of about 6%. This gain represents the weight of the infinitely thin film of condensate clinging to the entire surface of each constituent fibre at the end of the period of sterilisation. During drying with steam injacket for up to 30 minutes by either of the two techniques now acceptable, this 6%" gain falls to about 1-5% which is later lost by sweating while the load-still above 212°F on removal from the hot chamber-cools to room-temperature on slatted or wire-netting shelves. Considering the total amount of condensate to be evaporated during drying and cooling to room-temperature as 100%, only 4% can be accounted for by the sensible heat of the load itself becoming available during the fall in pressure to that of outside pressure at 212°F-i.e., (218-180)100÷971. 25% is accounted for " by sweating " after the load is removed from the chamber. The remaining 71% is evaporated by sensible heat acquired from the steam jacket during the drying period. On these grounds -it may be stated that a steam jacket at about the same temperature as the steam previously used for sterilisation and a current of air to entrain evaporated load condensate are absolutely essential in drying porous loads if time and minimal damage is to be entertained. A vacuum and an effective air drying, warming, and filtering system accelerates the process.
Their
findings
must be fitted to
"
If surgical-instrument and utensil boilers are to be called " sterilisers " and dressing-sterilisers " autoclaves," aeroplanes might reasonably be referred to as " is best automobiles." I think the term " autoclave limited to its original use indicating apparatus designed before the development of balanced pressure steam traps (1920s) and having no gravity discharge operating "
automatically-e.g., (a) unjacketed pressure-cooker types of steriliser (1880s), Papins digester (1680), and copper
district
hour
hospital
or more
H.M. Coroner,
Southern
District, County of London.
NOTIFICATION OF INFECTIVE HEPATITIS SIR,—While agreeing with Admiral (Oct. 27)
Rainsford
in
advocating compulsory notification of homologousserum jaundice, I disagree with certain points raised in his letter. for the incidence of jaundice are These should have read 0’12% following smallpool plasma and 0-16% following whole-blood transfusions. (2) Storage of liquid plasma at room-temperature, as advocated by Garrott Alien, 1 appears to inactivate the agent in plasma responsible for homologous-serum jaundice. My own experience has convinced me of the correctness of this view, while Hoxworth and Haesler2 state that such plasma may be used without concern about the transmission of
(1) The figures quoted
incorrect.
hepatitis. (3) Dextran is undoubtedly an effective and valuable plasma-volume expander, but it is not as harmless as Admiral Rainsford implies. Apart from allergic reactions, it may haemostatic defects. Admiral Rainsford claims that plasma is expensive and dextran inexpensive. I can only state that the cost of producing the liquid plasma to which I refer is considerably lower than the price at which commercial dextran is sold to
cause
(4)
hospitals.
I have no desire to obscure the real issue, which is the notification of infective hepatitis and homologous-serum jaundice, by starting a discussion on the relative merits of plasma and dextran. Both are valuable in the treatment of
oligsemic shock,
and it would be unfortunate
if the views expressed by Admiral Rainsford resulted in the disuse of plasma. Most cases of homologous-serum jaundice in this country at the present time follow the transfusion of whole blood or of concentrated red cells. Compulsory 1. Allen, J.
2.
G., Enerson, D. M., Barron, E. S. G., Sykes, C. J. Amer. med. Ass. 1954, 154, 103. Hoxworth, P. I., Haesler, W. E. 6th Congress of the International Society of Blood Transfusion, Boston, Mass., September, 1956 (in the press).
notification of the disease would help in the detection of the " dangerous " blood-donor who is harbouring the icterogenic agent in his blood. Glasgow and West of Scotland Blood Transfusion Service, Glasgow, C.1.
JOHN WALLACE Regional Director.
OPERATING-THEATRE STERILISERS
SIR,—Some of the statements made by Mr. Barrington Brock (Oct. 13) may cause misunderstanding. In their most valuable contribution to the prevention of theatre infections (Sept. 29) Professor Howie and Dr. Timbury included their discovery that the contents of individual packages in porous loads could be recontaminated during a vacuum-drying period in a dressing steriliser with defective air filtration. make it clear that an adequate air filter dressing sterilisers where packaged goods are dried by the most rapid and least damaging technique available at present-i.e., with steam in jacket, a negative pressure is applied at one end of the chamber drawing dried and warmed but not hot air inwards through a bacteriologically adequate filter fitted opposite at the other end of the chamber, establishing a balance of about 5 in. Hg negative pressure for up to 30 minutes depending upon the nature of the load. " It is also clear that the technique of cracking " the door, and at the same time applying a negative pressure to chamber, must now be abandoned owing to the risk of recontaminating even a properly wrapped package. The third but relatively slow method for drying porous loads-i.e., merely reducing chamber pressure to gauge zero, leaving jacket at pressure and " cracking " door-is surely not " absurd." Since, in this technique, the vapour current within each package is from within outwards throughout intelligently conducted drying periods, is it not still theoretically a bacteriologically safe procedure ? In a properly designed and operated apparatus it is certainly effective as far as drying is concerned. That hot air and superheated steam is far more damaging to heat-sensitive surgical equipment than steam on the phase boundary at much higher temperatures, is now well established through universalexperience. Pumping hot dry air at say 250°F through a load of fabrics in order to dry it is surely therefore definitely contra-indicated. In order to avoid heating the air too much, an effective practice is to attach the chamber filter with minimum length of piping. During sterilisation at 250-254°F and 15-17 lb. per sq. in., a load of fabrics gains weight over normal hydrated weight at room-temperature to the extent of about 6%. This gain represents the weight of the infinitely thin film of condensate clinging to the entire surface of each constituent fibre at the end of the period of sterilisation. During drying with steam injacket for up to 30 minutes by either of the two techniques now acceptable, this 6%" gain falls to about 1-5% which is later lost by sweating while the load-still above 212°F on removal from the hot chamber-cools to room-temperature on slatted or wire-netting shelves. Considering the total amount of condensate to be evaporated during drying and cooling to room-temperature as 100%, only 4% can be accounted for by the sensible heat of the load itself becoming available during the fall in pressure to that of outside pressure at 212°F-i.e., (218-180)100÷971. 25% is accounted for " by sweating " after the load is removed from the chamber. The remaining 71% is evaporated by sensible heat acquired from the steam jacket during the drying period. On these grounds -it may be stated that a steam jacket at about the same temperature as the steam previously used for sterilisation and a current of air to entrain evaporated load condensate are absolutely essential in drying porous loads if time and minimal damage is to be entertained. A vacuum and an effective air drying, warming, and filtering system accelerates the process.
Their
findings
must be fitted to
"
If surgical-instrument and utensil boilers are to be called " sterilisers " and dressing-sterilisers " autoclaves," aeroplanes might reasonably be referred to as " is best automobiles." I think the term " autoclave limited to its original use indicating apparatus designed before the development of balanced pressure steam traps (1920s) and having no gravity discharge operating "
automatically-e.g., (a) unjacketed pressure-cooker types of steriliser (1880s), Papins digester (1680), and copper