235 abnormal in all 8 patients who were examined by this technique, with non-visualisation of the entire pancreas in 2 cases with lesions in the pancreatic head, localised decreased uptake in 3 (2 pancreatic head, 1 other site), and diffusely irregular uptake in 3 (1 pancreatic head, 2 other sites). Pancreatic arteriograms were consistent of pancreatic carcinoma in 2 of 6 cases tumour size to results of ACTA scanning was analysed. With lesions greater than 10 cm in diameter, as described at surgery, the ACTA scan was positive in 5 of 7 cases, whereas in cases with tumour masses less than 10 cm in diameter the scan was abnormal in 2 of 6.
with
a
diagnosis
examined. The relation of
so
DISCUSSION
This initial
study of computerised axial tomography carcinoma demonstrates that this procedpancreatic ure can detect the pesence of an abnormal pancreatic mass. The ACTA scan compared favourably with other non-invasive techniques for detecting pancreatic malignancies, however further refinement in its resolution is needed. Further adaptations are planned. Resolution should be significantly improved by increasing the speed of scanning from the present 5 min. This will eliminate respiratory motion and overcome artefacts resulting from bowel activity. Future studies will include the administration of antispasmodics such as propantheline bromide to decrease bowel activity, and the use of organspecific contrast materials. It is hoped that with further in
ATMOSPHERIC DERIVATIVES OF ANÆSTHETIC GASES AS A POSSIBLE HAZARD TO OPERATING-ROOM PERSONNEL BERNARD D. GOLDSTEIN JACOB PAZ EDWARD D. PALMES JOSEPH G. GIUFFRIDA EDWARD F. FERRAND
Departments of Environmental Medicine and Medicine, New York University Medical Center; Department of Anesthesiology, Metropolitan Hospital Center, New York; Department of Anesthesiology, New York Medical College; and New York City Department of Air Resources
During surgical procèdures in which nitrous oxide (N2O) anæsthesia was administered there was an increased concentration of both nitric oxide (NO) and nitrogen dioxide (NO2) in operating-room air. Preliminary studies suggest that the use of certain devices (e.g., electric cauteries, X-ray machines) capable of releasing energy in the operatingroom produce the oxidation of nitrous oxide. Further evaluation of gas phase reactions of anæsthetic agents within the operating-room appear warranted, particularly in relation to the occupational risks of operating-
Summary
room
personnel. INTRODUCTION
IN recent years epidemiological studies have provided relatively convincing evidence that female personnel who work in surgical operating-rooms have a higher risk of spontaneous abortion.1-s There is also suggestive but
less clearcut evidence that female anaesthetists are more likely to have congenitally malformed infants and to be infertile, and that anaesthetists have a higher risk of
and technical improvements such as these, the in addition to identifying mass lesions, will also provide an objective measurement of treatment response or progression of primary disease. A further application of this new technique will be in the design of accurate radiation ports, which would reduce the extent of radiation injury to the kidneys and small intestine.
study
ACTA scan,
The work
supported by grant N.I.H. lR26-CA19379-01. Requests for reprints should be addressed to P. S. S., Division of Medical Oncology, Georgetown University Hospital, 3800 Reservoir Road N.W., Washington, D.C. 20007, U.S.A. was
REFERENCES 1. Third National Cancer Survey Advanced Three-Year Report, (Excluding Carcinoma in Situ), Bethesda, Maryland, 1969-1971. D.H.E.W. publication no. (N.I.H.) 74-637. 2. Moertel, C. G. in Cancer Medicine (edited by J. F. Holland and E. Frei); p. 1559. Philadelphia, 1973. 3. Rösch, J. J. surg. Oncol. 1975, 1, 121. 4. Potsaid, M. S. in Radiology of the Pancreas and Duodenum (edited by S. B. Eaton, Jr. and J. T. Ferrucci, Jr.); p. 203. Philadelphia, 1973. 5. McCarthy, D., Brown, P., Melmed, R., Agnew, J., Bouchler, I. Gut, 1972, 6. 7. 8.
13, 75. Engelhart, G., Blauenstein, U. W. ibid. 1970, 11, 443. Filly, R. A., Freimanis, A. K. Radiology, 1970, 96, 575. Baum, S., Athanasoulis, C. A. in Radiology of the Pancreas and Duodenum (edited by S. B. Eaton, Jr. and J. T. Ferrucci, Jr.); p. 227. Philadelphia,
9.
Rösch, J., Holman, D. C. in Efficiency and Limits of Radiologic Examination
10.
Silvis, S. E., Rohrmann, C. A., Vennes, J. A. Ann. intern. Med. 1976, 84,
11.
Ledley,
1973. of the Pancreas
(edited by H. Anacker); p. 159. Stuttgart,
1975.
438.
12.
R. S., DiChiro, G., Leussenhop, A. J., Twigg, H. L. Science, 1974, 186, 206. Schellinger, D., DiChiro, G., Axelbaum, S. P., Twigg, H., Ledley, R. S. Radiology, 1975, 114, 757.
cancer. 4-8 In addition, an increased rate of congenital abnormalities and spontaneous malformations in the wives of male anaesthetists has been both claimed and disputed.2 S9 These findings have sparked further investigation of the possible mutagenic and teratogenic effects of individual anaesthetic gases used in the operat-
ing-room. Studies of this problem have focused on individual anaesthetic gases used in the operating-room, or on their metabolites within the body. The supposition that it is one of these agents that is directly responsible for the observed effects in part assumes that no new compounds are formed in operating-room air. To the best of our knowledge the possibility that anaesthetic gases may be chemically modified within the atmosphere of the operating-room, and that the resultant derivatives may be responsible for reported adverse effects, has not previously been considered. We report here preliminary evidence suggesting that energy-releasing devices used during surgical procedures, including electric cauteries and portable X-ray machines, result in the oxidation of nitrous oxide in operating-room air. Nitrous oxide (N20) is a commonly used inducing agent administered to the patient at concentrations frequently in the range of 60 to 70%. It has long been considered to be inert at low concentrations and precautions against its release into operating-room air have not been stringent. Accordingly, exposure of operating-room personnel to N20 concentrations of up to 7 000 p.p.m. has been reported. 10 Chemically, N20 is an oxide of nitrogen whose properties have little in common with the more reactive higher oxides of nitrogen such as nitric oxide (NO) and nitrogen dioxide (N02). Nitric oxide is formed as a result of combustion or other energetic processes oc-
236
curring in atmospheres containing nitrogen and oxygen. Subsequent oxidation converts NO to N02 and higher oxides of nitrogen. The fact that N20 is far more readily oxidised to these higher oxides of nitrogen than is nitrogen has special significance to our hypothesis. METHODS AND RESULTS
In order to evaluate whether NO and N02 were formed within the operating-room atmosphere, we utilised a chemiluminescent monitor which continuously measures these two gases as well as total oxides of
nitrogen NOx), not including N20. During operative procedures in which N20 was the inducing agent a definite rise in NO and, to a lesser extent, N02 levels was observed in conjunction with the use of energy-releasing devices; specifically electric cauteries and portable X-ray machines. With the probe of the chemiluminescent device located about 3 metres on a perpendicular line from the middle of the operating-table, concentrations of NO of about 0-60 p.p.m. and levels of N02 of about 0. 15 p.p.m. were often recorded during these operations, with higher peaks occurring in conjunction with more intensive use of these devices. Following the end of surgery NO and NO, levels generally fell within thirty minutes to presurgical baseline values of approximately 0.04 p.p.m. for each. Becauseonly one chemiluminescent monitor was available it was impossible to simultaneously obtain continuous recordings of NO and N02 in control areas of the surgical suite. To determine whether extraneous
of oxides of nitrogen (e.g., cigarette smoke, autotraffic) might be contributing to these observations, personal N02 monitors were affixed to the clothing of operating-room and control personnel or placed in various locations throughout the surgical suite and adjoining areas on three separate days for a total of twelve operations in which N20 was the inducing agent. These pencil-size monitors provide a time-weighted average of N02 concentrations for the period they are in use." The average N02 level in the operating-room during the 11 procedures in which energy-releasing devices were utilised was 0-114 p.p.m.+0-007 (S.E.), and in control areas was 0-057 p. p.m. + 0. 00 3. The difference is statistically significant at p1 1 p.p.m. NOx. In each case appropriate controls in the absence of added N20 produced far lower levels of NOx. sources
mobile
U.S.A.
DISCUSSION
These levels of NO and
N02
are not
to be hazardous, although there is some evidence to suggest that inhalation of N02 may enhance the effects of chemical carcinogens.’ The recorded operating-room concentrations are far below the acceptable American industrial hygiene limit levels of 25 p.p.m. for NO and 5 p.p.m. for N02, but the observed N02 concentrations do exceed the primary U.S. air quality standard of 0.05 p.p.m. (annual average). However, the major importance of the present findings is the clear indication that operating-room atmospheres are not inert. In addition to the oxidation of N20, it is quite conceivable that energy-releasing devices used during surgery may also act to alter halogenated hydrocarbon anuesthetic gases present in the operating-room environment. While any discussion of the possible chemical alterations is still speculative, it is of interest that halogenated hydrocarbon anaesthetics are chemically somewhat similar to the fluorocarbons used as propellants in aerosol spray cans. The chemistry of these compounds has been under intense study because of the possibility that solar ultraviolet energy produces activated fluorocarbon intermediates, including free radical forms, which result in depletion of stratospheric ozone. The postulated fluorocarbon derivatives, including molecules stripped of halogen atoms and free radical compounds, are similar to the hypothesised products of microsomal mixed-function oxidase metabolism of halogenated hydrocarbon anxsthetics. 13 14 There is some evidence to suggest that these metabolites are responsible for deleterious effects.15 Furthermore, it is also possible that, in an atmosphere containing both N20 and halogenated hydrocarbon anaesthetics, the use of energy-releasing devices may lead to the formation of other toxic intermediates-e.g., nitroso compounds. The possibility that occupational hazards to operating-room personnel result from inhalation of compounds produced by the atmospheric action of energy-releasing devices on anaesthetic agents has potential practical implications. Replacement or appropriate modification of energy-releasing surgical accessories might be far preferable to replacing currently used anaesthetic gases which are relatively safe and reliable for the patient. Alternatively, it may be possible to restrict use of energy-releasing devices to operating-rooms specially equipped to minimise release of anxsthetic gases into the work area. Such devices may include cardiac defibrillation and pacing equipment, laser beams, and ultraviolet-light sources, as well as cauteries and X-ray machines. In addition to the compounds discussed above, other unexpected hazardous intermediates might be present in operating-room air. For instance, both formaldehyde and hydrochloric acid are occasionally introduced into the surgical suite. These two compounds may react together in air to produce bis(chloromethyl)ether, a mutagenic agent suspected of having caused human cancer.16 On the basis of the present results, we believe that a careful assessment of operating-room air during actual surgical procedures is warranted as part of the evaluation of occupational hazards to operating-room personnel. Requests for reprints should be addressed to B.D.G., New York University Medical Center, 550 First Avenue, New York, N.Y. 10016,
expected
by
themselves
237 models for the care of patients with cancer and coronary heartdisease. Neither of these efforts are mentioned. Similarly in France, work is underway in Nancy on organisational and other aspects of general practice. These omissions raise doubts about the validity of the conclusions drawn. None of the collaborators in this work, apart from Professor Blanpain, were medically qualified; the major omission in most of the descriptions is that of epidemiologically or medically oriented studies on health care, and the book gives too thin a view of work going on in these areas. This may be due to advice received by the authors from the United States where much medical-care research is considered respectable only if it is carried out by economists and sociologists. Perhaps the main lesson to be drawn from this study is how little European doctors seem to care for medical-care research and how much more needs to be done to further their education and broaden their outlook in this respect.
Reviews of Books Community Health Investment in Belgium, France, Health Services Research ;M federal German Prance, Federal and the Netherlands. JAN BLANPAIN and LUK DELESIE. London: Oxford University Press, for the Nuffield Provincial Hospitals Trust. 1976. Pp. 474. /;8.SO.
Republic,
THIS volume is designed to provide an overview of healthservices research in four countries in Europe. The Nuffield Provincial Hospitals Trust commissioned this study in view of the U.K.’s entry into the European Economic Community, to try to determine what is happening in health services research in Europe today and to assess possible methods of control and development. The inquiry was undertaken by Professor Blanpain and his group from the department of hospital administration and medical care organisation at the University of Leuven in Belgium. The book gives a fascinating account of health-services research in Europe and provides a remarkable landmark of reference. It complements Portfolio for Health 1 and 2 by the Nuffield Provincial Hospitals Trust which portray British work. The book lists work being undertaken in four E.E.C. countries and attempts to distinguish different research strategies. There is an outline of expenditure and a description of the research settings. Finally comes a list of projects with brief details of the participants and objectives. The authors some differences in strategy: thus the Netherlands and Belgium seem to favour university-related research while Germany and France tend more towards specific research institutions. Only in the Netherlands is a significant proportion of research expenditure devoted to health services research. Expenditure in the other three countries is pitifully small compared with that on biomedical and other technological subjects. The authors classify the research projects into population based, health-care consumers, health manpower, medical specialists (including general practitioners and nurses), organi sational arrangements, hospital studies, management, physical improvement and operational studies, and financing (including cost accounting). They also look at planning studies. Healthservices research is defined as organised and rigorous inquiry into the efficacy of medical care, including preventive, diagnostic, curative, rehabilitative, supportive, and terminal care. Postal methods of inquiry were mainly used, with some site visits. This book will serve as a useful catalogue and reference work for identifying areas of interest in different countries. However, there are some remarkable omissions. In Hanover, for example, work has been done on the outcome and methods of treatment of acute appendicitis in Germany compared with other countries and on theoretical models for measurement of quality of care. Investigators in Heidelberg are looking at
Health Care
Report of W.H.O.lInternational Collaborative Study of Medical Care Utilisation. Edited by ROBERT KOHN and KERR L. WHITE. London: Oxford University Press. 1976. Pp. 592. £10.
suggest
1. Vaisman, A I. Eksp. Khir Anest. 1967, 3, 44. 2. Askrog, V. F., Harvold, B. Nord. Med. 1970, 83, 498. 3 Cohen, E. N., Bellvill, J. W., Brown, B. W. Anesthesiology, 1971, 35, 343 4 Knill-Jones, R. P., Moir, D. B., Rodrigues, L. V., Spence, A. A. Lancet, 1972, i, 1326 5 Report of an Ad Hoc Committee on the Effects of Trace Anesthetics on thee Health of Operating Room Personnel. Anesthesiology, 1974, 41, 321. 6 Corbett, T. H., Cornell, R. G., Endres, J. L., Lieding, K. ibid. p. 341. 7. Bruce, D L., Eide, K. A., Linde, H. W., Eckenhoff, J. E. ibid. 1968, 29, 565. 8. Corbett, T. H., Cornell, R. G., Lieding, K., Endres, J. L. ibid. 1973, 38, 260 9. Knill-Jones, R. P., Newman, B. J., Spence, A. A. Lancet, 1975, ii, 807. 10. Askrog, V , Petersen, R. Saert Nord. Med. 1970, 83, 501. 11. Palmes, E. D., Gunnison, A. F. Am. ind. Hyg. Ass. J. 1973, 34, 78. 12. Katz, G., Laskin, S., Sellakumar, A., Kuschner, M. Proc. Am. ind. Hyg. Ass _
,
.
1976 (abstract 33). 13. Cohen, E. N., Trudell,
J. R., Edmunds, H. N., Watson, E. Anesthesiology’’ 1975, 43, 392. 14. Van Dyke, R. A., Wood, C. L Drug Metab. Disp. 1974, 3, 51. 15 Blake, D A., Cascorbi, H. F, Rozman, R. S., Meyer, F. J. Toxicol. appl. Pharmac. 1969, 15, 83 16. Albert, R E., Pasternack, B. S., Shore, R. E., Lippmann, M., Nelson, N. Ferris, B. Envir. Hlth Perspect. 1975, 11, 209.
’
TWELVE years ago a group was set up to compare the use of health-care systems in various countries, or at least those parts of health care which lent themselves to measurement. The fieldwork, gathered by household interviews, was done in 1968-69, and this is the final report. In the meantime, there has been a major reorganisation of the health services in the U.K., the United States has extended the scope of Medicare and Medicaid, and we have begun to question the socially distorting effects of overintrusive health-service systems. But even those who would wish for a decrease in the professional expropriation of health care, would agree that this study is most valuable for its objective assessments of the extent of the process under differing political structures. This ambitious collaborative investigation with its carefully planned approach based on information gathered from population samples rather than service records, makes an important contribution to epidemiological as well as social research in health services. The twelve study populations are representative of over 15 million people in seven industrialised countries. Six are in North America, one in South America, four in continental Europe, and one (Liverpool) in the United Kingdom. The structured questionnaire, including background on demographic as well as social factors, deals with a basic two-week previous period of recall. It is not claimed that each area is typical of the rest of its country: Liverpool, for example, has a hardly representative surplus of hospital beds compared with the rest of the U.K. But, despite contrasting social philosophies, there turns out to be an impressive ability of similar health care philosophies to impose comparable patterns of behaviour. For example, there was remarkably little dissatisfaction expressed with dental services in any of the study areas-surely an indication more of a lack of awareness of dental problems among the populations than of the true adequacy of the care provided. Measures of the levels of health also did not, by themselves, explain the variation in the rates of physician use. About half of all persons with specific health problems did not want a contact with a physician, with a less than twofold variation round the median rate. The focus is on perceived and reported morbidity as an indicator of need and a major determinant of potential demand for health services. Extensive tabulations display both recognised illness and the availability, as well as the accessibility, of human and material resources for care. There
are
chapters
on
morbidity
and health resources, the
use
of physician services, hospitals, medicines, and dental, optical and other non-physician health-care personnel such as nurses. The literature reviews are extensive and the discussions not limited to a rigid statistical framework. But anyone looking for insights into the efficiency, efficacy, or simply satisfaction to the individual, of care in these regions will not find it in this
with
a
diagnosis
examined. The relation of
so
DISCUSSION
This initial
study of computerised axial tomography carcinoma demonstrates that this procedpancreatic ure can detect the pesence of an abnormal pancreatic mass. The ACTA scan compared favourably with other non-invasive techniques for detecting pancreatic malignancies, however further refinement in its resolution is needed. Further adaptations are planned. Resolution should be significantly improved by increasing the speed of scanning from the present 5 min. This will eliminate respiratory motion and overcome artefacts resulting from bowel activity. Future studies will include the administration of antispasmodics such as propantheline bromide to decrease bowel activity, and the use of organspecific contrast materials. It is hoped that with further in
ATMOSPHERIC DERIVATIVES OF ANÆSTHETIC GASES AS A POSSIBLE HAZARD TO OPERATING-ROOM PERSONNEL BERNARD D. GOLDSTEIN JACOB PAZ EDWARD D. PALMES JOSEPH G. GIUFFRIDA EDWARD F. FERRAND
Departments of Environmental Medicine and Medicine, New York University Medical Center; Department of Anesthesiology, Metropolitan Hospital Center, New York; Department of Anesthesiology, New York Medical College; and New York City Department of Air Resources
During surgical procèdures in which nitrous oxide (N2O) anæsthesia was administered there was an increased concentration of both nitric oxide (NO) and nitrogen dioxide (NO2) in operating-room air. Preliminary studies suggest that the use of certain devices (e.g., electric cauteries, X-ray machines) capable of releasing energy in the operatingroom produce the oxidation of nitrous oxide. Further evaluation of gas phase reactions of anæsthetic agents within the operating-room appear warranted, particularly in relation to the occupational risks of operating-
Summary
room
personnel. INTRODUCTION
IN recent years epidemiological studies have provided relatively convincing evidence that female personnel who work in surgical operating-rooms have a higher risk of spontaneous abortion.1-s There is also suggestive but
less clearcut evidence that female anaesthetists are more likely to have congenitally malformed infants and to be infertile, and that anaesthetists have a higher risk of
and technical improvements such as these, the in addition to identifying mass lesions, will also provide an objective measurement of treatment response or progression of primary disease. A further application of this new technique will be in the design of accurate radiation ports, which would reduce the extent of radiation injury to the kidneys and small intestine.
study
ACTA scan,
The work
supported by grant N.I.H. lR26-CA19379-01. Requests for reprints should be addressed to P. S. S., Division of Medical Oncology, Georgetown University Hospital, 3800 Reservoir Road N.W., Washington, D.C. 20007, U.S.A. was
REFERENCES 1. Third National Cancer Survey Advanced Three-Year Report, (Excluding Carcinoma in Situ), Bethesda, Maryland, 1969-1971. D.H.E.W. publication no. (N.I.H.) 74-637. 2. Moertel, C. G. in Cancer Medicine (edited by J. F. Holland and E. Frei); p. 1559. Philadelphia, 1973. 3. Rösch, J. J. surg. Oncol. 1975, 1, 121. 4. Potsaid, M. S. in Radiology of the Pancreas and Duodenum (edited by S. B. Eaton, Jr. and J. T. Ferrucci, Jr.); p. 203. Philadelphia, 1973. 5. McCarthy, D., Brown, P., Melmed, R., Agnew, J., Bouchler, I. Gut, 1972, 6. 7. 8.
13, 75. Engelhart, G., Blauenstein, U. W. ibid. 1970, 11, 443. Filly, R. A., Freimanis, A. K. Radiology, 1970, 96, 575. Baum, S., Athanasoulis, C. A. in Radiology of the Pancreas and Duodenum (edited by S. B. Eaton, Jr. and J. T. Ferrucci, Jr.); p. 227. Philadelphia,
9.
Rösch, J., Holman, D. C. in Efficiency and Limits of Radiologic Examination
10.
Silvis, S. E., Rohrmann, C. A., Vennes, J. A. Ann. intern. Med. 1976, 84,
11.
Ledley,
1973. of the Pancreas
(edited by H. Anacker); p. 159. Stuttgart,
1975.
438.
12.
R. S., DiChiro, G., Leussenhop, A. J., Twigg, H. L. Science, 1974, 186, 206. Schellinger, D., DiChiro, G., Axelbaum, S. P., Twigg, H., Ledley, R. S. Radiology, 1975, 114, 757.
cancer. 4-8 In addition, an increased rate of congenital abnormalities and spontaneous malformations in the wives of male anaesthetists has been both claimed and disputed.2 S9 These findings have sparked further investigation of the possible mutagenic and teratogenic effects of individual anaesthetic gases used in the operat-
ing-room. Studies of this problem have focused on individual anaesthetic gases used in the operating-room, or on their metabolites within the body. The supposition that it is one of these agents that is directly responsible for the observed effects in part assumes that no new compounds are formed in operating-room air. To the best of our knowledge the possibility that anaesthetic gases may be chemically modified within the atmosphere of the operating-room, and that the resultant derivatives may be responsible for reported adverse effects, has not previously been considered. We report here preliminary evidence suggesting that energy-releasing devices used during surgical procedures, including electric cauteries and portable X-ray machines, result in the oxidation of nitrous oxide in operating-room air. Nitrous oxide (N20) is a commonly used inducing agent administered to the patient at concentrations frequently in the range of 60 to 70%. It has long been considered to be inert at low concentrations and precautions against its release into operating-room air have not been stringent. Accordingly, exposure of operating-room personnel to N20 concentrations of up to 7 000 p.p.m. has been reported. 10 Chemically, N20 is an oxide of nitrogen whose properties have little in common with the more reactive higher oxides of nitrogen such as nitric oxide (NO) and nitrogen dioxide (N02). Nitric oxide is formed as a result of combustion or other energetic processes oc-
236
curring in atmospheres containing nitrogen and oxygen. Subsequent oxidation converts NO to N02 and higher oxides of nitrogen. The fact that N20 is far more readily oxidised to these higher oxides of nitrogen than is nitrogen has special significance to our hypothesis. METHODS AND RESULTS
In order to evaluate whether NO and N02 were formed within the operating-room atmosphere, we utilised a chemiluminescent monitor which continuously measures these two gases as well as total oxides of
nitrogen NOx), not including N20. During operative procedures in which N20 was the inducing agent a definite rise in NO and, to a lesser extent, N02 levels was observed in conjunction with the use of energy-releasing devices; specifically electric cauteries and portable X-ray machines. With the probe of the chemiluminescent device located about 3 metres on a perpendicular line from the middle of the operating-table, concentrations of NO of about 0-60 p.p.m. and levels of N02 of about 0. 15 p.p.m. were often recorded during these operations, with higher peaks occurring in conjunction with more intensive use of these devices. Following the end of surgery NO and NO, levels generally fell within thirty minutes to presurgical baseline values of approximately 0.04 p.p.m. for each. Becauseonly one chemiluminescent monitor was available it was impossible to simultaneously obtain continuous recordings of NO and N02 in control areas of the surgical suite. To determine whether extraneous
of oxides of nitrogen (e.g., cigarette smoke, autotraffic) might be contributing to these observations, personal N02 monitors were affixed to the clothing of operating-room and control personnel or placed in various locations throughout the surgical suite and adjoining areas on three separate days for a total of twelve operations in which N20 was the inducing agent. These pencil-size monitors provide a time-weighted average of N02 concentrations for the period they are in use." The average N02 level in the operating-room during the 11 procedures in which energy-releasing devices were utilised was 0-114 p.p.m.+0-007 (S.E.), and in control areas was 0-057 p. p.m. + 0. 00 3. The difference is statistically significant at p1 1 p.p.m. NOx. In each case appropriate controls in the absence of added N20 produced far lower levels of NOx. sources
mobile
U.S.A.
DISCUSSION
These levels of NO and
N02
are not
to be hazardous, although there is some evidence to suggest that inhalation of N02 may enhance the effects of chemical carcinogens.’ The recorded operating-room concentrations are far below the acceptable American industrial hygiene limit levels of 25 p.p.m. for NO and 5 p.p.m. for N02, but the observed N02 concentrations do exceed the primary U.S. air quality standard of 0.05 p.p.m. (annual average). However, the major importance of the present findings is the clear indication that operating-room atmospheres are not inert. In addition to the oxidation of N20, it is quite conceivable that energy-releasing devices used during surgery may also act to alter halogenated hydrocarbon anuesthetic gases present in the operating-room environment. While any discussion of the possible chemical alterations is still speculative, it is of interest that halogenated hydrocarbon anaesthetics are chemically somewhat similar to the fluorocarbons used as propellants in aerosol spray cans. The chemistry of these compounds has been under intense study because of the possibility that solar ultraviolet energy produces activated fluorocarbon intermediates, including free radical forms, which result in depletion of stratospheric ozone. The postulated fluorocarbon derivatives, including molecules stripped of halogen atoms and free radical compounds, are similar to the hypothesised products of microsomal mixed-function oxidase metabolism of halogenated hydrocarbon anxsthetics. 13 14 There is some evidence to suggest that these metabolites are responsible for deleterious effects.15 Furthermore, it is also possible that, in an atmosphere containing both N20 and halogenated hydrocarbon anaesthetics, the use of energy-releasing devices may lead to the formation of other toxic intermediates-e.g., nitroso compounds. The possibility that occupational hazards to operating-room personnel result from inhalation of compounds produced by the atmospheric action of energy-releasing devices on anaesthetic agents has potential practical implications. Replacement or appropriate modification of energy-releasing surgical accessories might be far preferable to replacing currently used anaesthetic gases which are relatively safe and reliable for the patient. Alternatively, it may be possible to restrict use of energy-releasing devices to operating-rooms specially equipped to minimise release of anxsthetic gases into the work area. Such devices may include cardiac defibrillation and pacing equipment, laser beams, and ultraviolet-light sources, as well as cauteries and X-ray machines. In addition to the compounds discussed above, other unexpected hazardous intermediates might be present in operating-room air. For instance, both formaldehyde and hydrochloric acid are occasionally introduced into the surgical suite. These two compounds may react together in air to produce bis(chloromethyl)ether, a mutagenic agent suspected of having caused human cancer.16 On the basis of the present results, we believe that a careful assessment of operating-room air during actual surgical procedures is warranted as part of the evaluation of occupational hazards to operating-room personnel. Requests for reprints should be addressed to B.D.G., New York University Medical Center, 550 First Avenue, New York, N.Y. 10016,
expected
by
themselves
237 models for the care of patients with cancer and coronary heartdisease. Neither of these efforts are mentioned. Similarly in France, work is underway in Nancy on organisational and other aspects of general practice. These omissions raise doubts about the validity of the conclusions drawn. None of the collaborators in this work, apart from Professor Blanpain, were medically qualified; the major omission in most of the descriptions is that of epidemiologically or medically oriented studies on health care, and the book gives too thin a view of work going on in these areas. This may be due to advice received by the authors from the United States where much medical-care research is considered respectable only if it is carried out by economists and sociologists. Perhaps the main lesson to be drawn from this study is how little European doctors seem to care for medical-care research and how much more needs to be done to further their education and broaden their outlook in this respect.
Reviews of Books Community Health Investment in Belgium, France, Health Services Research ;M federal German Prance, Federal and the Netherlands. JAN BLANPAIN and LUK DELESIE. London: Oxford University Press, for the Nuffield Provincial Hospitals Trust. 1976. Pp. 474. /;8.SO.
Republic,
THIS volume is designed to provide an overview of healthservices research in four countries in Europe. The Nuffield Provincial Hospitals Trust commissioned this study in view of the U.K.’s entry into the European Economic Community, to try to determine what is happening in health services research in Europe today and to assess possible methods of control and development. The inquiry was undertaken by Professor Blanpain and his group from the department of hospital administration and medical care organisation at the University of Leuven in Belgium. The book gives a fascinating account of health-services research in Europe and provides a remarkable landmark of reference. It complements Portfolio for Health 1 and 2 by the Nuffield Provincial Hospitals Trust which portray British work. The book lists work being undertaken in four E.E.C. countries and attempts to distinguish different research strategies. There is an outline of expenditure and a description of the research settings. Finally comes a list of projects with brief details of the participants and objectives. The authors some differences in strategy: thus the Netherlands and Belgium seem to favour university-related research while Germany and France tend more towards specific research institutions. Only in the Netherlands is a significant proportion of research expenditure devoted to health services research. Expenditure in the other three countries is pitifully small compared with that on biomedical and other technological subjects. The authors classify the research projects into population based, health-care consumers, health manpower, medical specialists (including general practitioners and nurses), organi sational arrangements, hospital studies, management, physical improvement and operational studies, and financing (including cost accounting). They also look at planning studies. Healthservices research is defined as organised and rigorous inquiry into the efficacy of medical care, including preventive, diagnostic, curative, rehabilitative, supportive, and terminal care. Postal methods of inquiry were mainly used, with some site visits. This book will serve as a useful catalogue and reference work for identifying areas of interest in different countries. However, there are some remarkable omissions. In Hanover, for example, work has been done on the outcome and methods of treatment of acute appendicitis in Germany compared with other countries and on theoretical models for measurement of quality of care. Investigators in Heidelberg are looking at
Health Care
Report of W.H.O.lInternational Collaborative Study of Medical Care Utilisation. Edited by ROBERT KOHN and KERR L. WHITE. London: Oxford University Press. 1976. Pp. 592. £10.
suggest
1. Vaisman, A I. Eksp. Khir Anest. 1967, 3, 44. 2. Askrog, V. F., Harvold, B. Nord. Med. 1970, 83, 498. 3 Cohen, E. N., Bellvill, J. W., Brown, B. W. Anesthesiology, 1971, 35, 343 4 Knill-Jones, R. P., Moir, D. B., Rodrigues, L. V., Spence, A. A. Lancet, 1972, i, 1326 5 Report of an Ad Hoc Committee on the Effects of Trace Anesthetics on thee Health of Operating Room Personnel. Anesthesiology, 1974, 41, 321. 6 Corbett, T. H., Cornell, R. G., Endres, J. L., Lieding, K. ibid. p. 341. 7. Bruce, D L., Eide, K. A., Linde, H. W., Eckenhoff, J. E. ibid. 1968, 29, 565. 8. Corbett, T. H., Cornell, R. G., Lieding, K., Endres, J. L. ibid. 1973, 38, 260 9. Knill-Jones, R. P., Newman, B. J., Spence, A. A. Lancet, 1975, ii, 807. 10. Askrog, V , Petersen, R. Saert Nord. Med. 1970, 83, 501. 11. Palmes, E. D., Gunnison, A. F. Am. ind. Hyg. Ass. J. 1973, 34, 78. 12. Katz, G., Laskin, S., Sellakumar, A., Kuschner, M. Proc. Am. ind. Hyg. Ass _
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1976 (abstract 33). 13. Cohen, E. N., Trudell,
J. R., Edmunds, H. N., Watson, E. Anesthesiology’’ 1975, 43, 392. 14. Van Dyke, R. A., Wood, C. L Drug Metab. Disp. 1974, 3, 51. 15 Blake, D A., Cascorbi, H. F, Rozman, R. S., Meyer, F. J. Toxicol. appl. Pharmac. 1969, 15, 83 16. Albert, R E., Pasternack, B. S., Shore, R. E., Lippmann, M., Nelson, N. Ferris, B. Envir. Hlth Perspect. 1975, 11, 209.
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TWELVE years ago a group was set up to compare the use of health-care systems in various countries, or at least those parts of health care which lent themselves to measurement. The fieldwork, gathered by household interviews, was done in 1968-69, and this is the final report. In the meantime, there has been a major reorganisation of the health services in the U.K., the United States has extended the scope of Medicare and Medicaid, and we have begun to question the socially distorting effects of overintrusive health-service systems. But even those who would wish for a decrease in the professional expropriation of health care, would agree that this study is most valuable for its objective assessments of the extent of the process under differing political structures. This ambitious collaborative investigation with its carefully planned approach based on information gathered from population samples rather than service records, makes an important contribution to epidemiological as well as social research in health services. The twelve study populations are representative of over 15 million people in seven industrialised countries. Six are in North America, one in South America, four in continental Europe, and one (Liverpool) in the United Kingdom. The structured questionnaire, including background on demographic as well as social factors, deals with a basic two-week previous period of recall. It is not claimed that each area is typical of the rest of its country: Liverpool, for example, has a hardly representative surplus of hospital beds compared with the rest of the U.K. But, despite contrasting social philosophies, there turns out to be an impressive ability of similar health care philosophies to impose comparable patterns of behaviour. For example, there was remarkably little dissatisfaction expressed with dental services in any of the study areas-surely an indication more of a lack of awareness of dental problems among the populations than of the true adequacy of the care provided. Measures of the levels of health also did not, by themselves, explain the variation in the rates of physician use. About half of all persons with specific health problems did not want a contact with a physician, with a less than twofold variation round the median rate. The focus is on perceived and reported morbidity as an indicator of need and a major determinant of potential demand for health services. Extensive tabulations display both recognised illness and the availability, as well as the accessibility, of human and material resources for care. There
are
chapters
on
morbidity
and health resources, the
use
of physician services, hospitals, medicines, and dental, optical and other non-physician health-care personnel such as nurses. The literature reviews are extensive and the discussions not limited to a rigid statistical framework. But anyone looking for insights into the efficiency, efficacy, or simply satisfaction to the individual, of care in these regions will not find it in this
