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The Tainted Thermometer
559
LEADING ARTICLES
THE LANCET LONDON:
SATURDAY, SEPT. 15, 1956
The Tainted Thermometer IT is remarkable that every patient in hospital has his temperature taken at least twice a day. Other instruments of diagnosis are used only if they provide information relevant to the patient’s illness ; but this discrimination is seldom applied to the taking of temperatures. It is a pity, therefore, that in many hospitals the hygiene of temperature-taking is less efficient than it might be. A busy nurse in a ward of 30 patients may use no more than half a dozen thermometers, each of them spending only a few moments in a pink fluid before passing from one patient to another. The Medical ResearchI Council committee on cross-infection in hospitals recommended that each patient should have a separate thermometer. Few nurses or doctors and still fewer patients will disagree with this advice, yet GOODALL,2 ni 1932, found that of 19 wards he visited only 3 provided individual thermometers. Bacteriological objections to the communal thermometer are that it may convey such infections as tuberculosis, diphtheria. scarlet fever, poliomyelitis, " sore throat," influenza, and the common cold. It may help to disseminate the hospital strains of antibiotic-resistant staphylococci that now inhabit the respiratory tracts of so many patients. Bacteriology apart, there is a strong aesthetic objection to poking into one’s mouth an instrument which, a few moments ago, was sticking out of someone else’s. Objections to the communal thermometer would be less forcible if it was effectively cleaned and sterilised after use ; but the speed at which a thermometer round is conducted makes this almost impossible to achieve. Many of the fluids in which thermometers are traditionally immersed have only feeble disinfecting powers. Glycerinum thymolis co. is one of the most popular thermometer disinfectants, but GREEx and PENFOLD 3 have shown that bacteria can survive in it for twenty-four hours. Phenolic fluids are possibly more effective, but they are less popular because inaccurately dispensed solutions, if not property washed from the thermometer, may be dangerous. They also have the inconvenient property of removing the ink markings from the engraved - Ttduations. 1 in 1000 biniodide of mercury is widely used and MIRVISHhas lately examined communal thermometers kept in this solution. After four hours’ immersion—a much longer period than is possible during a ward temperature round-bacteria were own from 28 out of 51 oral thermometers and from 35 out of .58 rectal thermometers. Most of the organisms were non-pathogens, but Staphylococcus - ru.> and hæmolytic streptococci were also isolated. It seems possible that other pathogens would have been found if the wards had happened to contain patients harbouring them and if suitable culture The control of Cross-infection in Hospital. Medical Research War memorandum no. 11. H.M. Stationery Office 194 . Revised edition, 1951. J. W. D. Lancet, 1952, i. 807. 3. Green, J. B. M., Penfold, J. B. Ibid, 1947, ii. 89. 4. Mirvish, I. S. Afr. med. J. 1956, 30, 413. 1.
Council.
Goodall,
2.
methods had been used. MIRVISH does not give full details of his bacteriological methods, but it seems he did not use those suitable for the growth of tubercle bacilli and viruses. But the precise organisms isolated are relatively unimportant compared with the finding that sterilisation was inadequate. It can be argued that the need is for individual thermometers or rapid efficient disinfection, and that to provide both is not necessary. This may be true, but there is much to be said for taking the double precaution. The selection of a fluid for disinfecting thermometers is usually made by a clinician or a ward sister, and it is time that they were given reliable bacteriological guidance in making this choice. Unfortunately many disinfection experiments in. the past have been invalid because precautions were not taken to neutralise the disinfectant before making the This precaution was not overlooked by cultures. FROBISHER et al.,5 who made cultures for tubercle bacilli and other organisms (though not viruses) from thermometers that had been artificially contaminated with infected sputum. They found that 1 in 1000 alcoholic solutions of quaternary ammonium compounds and 0-5% tincture of iodine gave complete sterilisation after ten minutes’ immersion, and that the performances of all disinfectants in the trial were improved if the thermometers were wiped with a piece of soapy cotton-wool before being put into the fluid. Although alcohol itself was unreliable, disinfectants dissolved in 70% spirit were more effective than aqueous solutions, and for this purpose the cheaper isopropyl alcohol was just as effective as ethyl alcohol. At the other extreme, formalin gave particularly bad results. Iodine is expensive and some people are sensitive to it ; but MIRVISH finds that two quaternary ammonium compounds, cetrimide and benzalkonium chloride, are non-irritant. Their ability to do all that is needed in this field is still unproven, but they deserve a proper trial. Meanwhile, there is no justification. for further delay in providing each hospital patient with a separate clinical thermometer.
Cigarette
Tar
IF cigarette smoking is a cause of lung cancer, as the statistical evidence indicates,what is the substance in cigarette smoke which makes it dangerous ? To answer this question the products of smoking-tar and particles-must be collected by the artificial smoking of cigarettes under conditions which simulate the human habit so far as possible. For this reason continued efforts are being made to determine these conditions more precisely. Since we last referred7 to this work, some further progress has been made. ERMALA and HOLSTI,8g using a silver-constantan thermocouple, found that the temperature in the combustion zone of a cigarette averaged 650°C (the range was 470-812°C), whereas in the relatively harmless pipe it was 500°C (range 380-620°C). With an iron-constantan thermocouple LYONS 9 found that the range in normal quiet cigarette puffing was 580-650°C; drawing on the cigarette at intervals of
5. Frobisher, M., Sommermeyer, L., Blackwell, M. J. Appl. Microbiol. 1953, 1, 187. 6. See Lancet, 1956, i, 678. 7. Ibid, 1956, p. 1004. 8. Ermala, P., Holsti, L. R. Cancer Res. 1956, 16, 490. 23rd annual British Empire Cancer Campaign. 9. Lyons, M. J. report, 1955.
LEADING ARTICLES
THE LANCET LONDON:
SATURDAY, SEPT. 15, 1956
The Tainted Thermometer IT is remarkable that every patient in hospital has his temperature taken at least twice a day. Other instruments of diagnosis are used only if they provide information relevant to the patient’s illness ; but this discrimination is seldom applied to the taking of temperatures. It is a pity, therefore, that in many hospitals the hygiene of temperature-taking is less efficient than it might be. A busy nurse in a ward of 30 patients may use no more than half a dozen thermometers, each of them spending only a few moments in a pink fluid before passing from one patient to another. The Medical ResearchI Council committee on cross-infection in hospitals recommended that each patient should have a separate thermometer. Few nurses or doctors and still fewer patients will disagree with this advice, yet GOODALL,2 ni 1932, found that of 19 wards he visited only 3 provided individual thermometers. Bacteriological objections to the communal thermometer are that it may convey such infections as tuberculosis, diphtheria. scarlet fever, poliomyelitis, " sore throat," influenza, and the common cold. It may help to disseminate the hospital strains of antibiotic-resistant staphylococci that now inhabit the respiratory tracts of so many patients. Bacteriology apart, there is a strong aesthetic objection to poking into one’s mouth an instrument which, a few moments ago, was sticking out of someone else’s. Objections to the communal thermometer would be less forcible if it was effectively cleaned and sterilised after use ; but the speed at which a thermometer round is conducted makes this almost impossible to achieve. Many of the fluids in which thermometers are traditionally immersed have only feeble disinfecting powers. Glycerinum thymolis co. is one of the most popular thermometer disinfectants, but GREEx and PENFOLD 3 have shown that bacteria can survive in it for twenty-four hours. Phenolic fluids are possibly more effective, but they are less popular because inaccurately dispensed solutions, if not property washed from the thermometer, may be dangerous. They also have the inconvenient property of removing the ink markings from the engraved - Ttduations. 1 in 1000 biniodide of mercury is widely used and MIRVISHhas lately examined communal thermometers kept in this solution. After four hours’ immersion—a much longer period than is possible during a ward temperature round-bacteria were own from 28 out of 51 oral thermometers and from 35 out of .58 rectal thermometers. Most of the organisms were non-pathogens, but Staphylococcus - ru.> and hæmolytic streptococci were also isolated. It seems possible that other pathogens would have been found if the wards had happened to contain patients harbouring them and if suitable culture The control of Cross-infection in Hospital. Medical Research War memorandum no. 11. H.M. Stationery Office 194 . Revised edition, 1951. J. W. D. Lancet, 1952, i. 807. 3. Green, J. B. M., Penfold, J. B. Ibid, 1947, ii. 89. 4. Mirvish, I. S. Afr. med. J. 1956, 30, 413. 1.
Council.
Goodall,
2.
methods had been used. MIRVISH does not give full details of his bacteriological methods, but it seems he did not use those suitable for the growth of tubercle bacilli and viruses. But the precise organisms isolated are relatively unimportant compared with the finding that sterilisation was inadequate. It can be argued that the need is for individual thermometers or rapid efficient disinfection, and that to provide both is not necessary. This may be true, but there is much to be said for taking the double precaution. The selection of a fluid for disinfecting thermometers is usually made by a clinician or a ward sister, and it is time that they were given reliable bacteriological guidance in making this choice. Unfortunately many disinfection experiments in. the past have been invalid because precautions were not taken to neutralise the disinfectant before making the This precaution was not overlooked by cultures. FROBISHER et al.,5 who made cultures for tubercle bacilli and other organisms (though not viruses) from thermometers that had been artificially contaminated with infected sputum. They found that 1 in 1000 alcoholic solutions of quaternary ammonium compounds and 0-5% tincture of iodine gave complete sterilisation after ten minutes’ immersion, and that the performances of all disinfectants in the trial were improved if the thermometers were wiped with a piece of soapy cotton-wool before being put into the fluid. Although alcohol itself was unreliable, disinfectants dissolved in 70% spirit were more effective than aqueous solutions, and for this purpose the cheaper isopropyl alcohol was just as effective as ethyl alcohol. At the other extreme, formalin gave particularly bad results. Iodine is expensive and some people are sensitive to it ; but MIRVISH finds that two quaternary ammonium compounds, cetrimide and benzalkonium chloride, are non-irritant. Their ability to do all that is needed in this field is still unproven, but they deserve a proper trial. Meanwhile, there is no justification. for further delay in providing each hospital patient with a separate clinical thermometer.
Cigarette
Tar
IF cigarette smoking is a cause of lung cancer, as the statistical evidence indicates,what is the substance in cigarette smoke which makes it dangerous ? To answer this question the products of smoking-tar and particles-must be collected by the artificial smoking of cigarettes under conditions which simulate the human habit so far as possible. For this reason continued efforts are being made to determine these conditions more precisely. Since we last referred7 to this work, some further progress has been made. ERMALA and HOLSTI,8g using a silver-constantan thermocouple, found that the temperature in the combustion zone of a cigarette averaged 650°C (the range was 470-812°C), whereas in the relatively harmless pipe it was 500°C (range 380-620°C). With an iron-constantan thermocouple LYONS 9 found that the range in normal quiet cigarette puffing was 580-650°C; drawing on the cigarette at intervals of
5. Frobisher, M., Sommermeyer, L., Blackwell, M. J. Appl. Microbiol. 1953, 1, 187. 6. See Lancet, 1956, i, 678. 7. Ibid, 1956, p. 1004. 8. Ermala, P., Holsti, L. R. Cancer Res. 1956, 16, 490. 23rd annual British Empire Cancer Campaign. 9. Lyons, M. J. report, 1955.