EDITORIAL
478
large differences in past years in the exposure intensities of various jobs, work settings, and activities. Insulators and pipe coverers, whether working in shipbuilding or construction, had intense exposures. So did many workers who manufactured asbestos products. Studying other trades and settings, one encounters a greater range of individual exposures. Boilermakers and pipefitters who did ripout and repair of old insulated equipment probably had heavier exposures than those installing new equipment. The same exposure diversity can be inferred from the histories of shipyard welders and machinists, some of whom, working in shops on shore, rarely set foot on board vessels. There are other trades that have widespread potential for some exposure but in which asbestosis rarely occurs such as carpenters, electricians, marine, and operating engineers, as well as the generality of shipbuilding and industrial construction workers. Unfortunately, these considerations provide only rough guidelines for deciding what constitutes an adequate exposure history. The trade or job, length of career, setting (outdoors or indoors, confined or spacious), and activity mix of production-construction-maintenance-repair-demolition can all provide useful information. Questions about
these items, which should be within the knowledge of the worker and are often documentable, tend to elicit accurate answers. Given the pervasive influence of litigation, questions about the perceived dustiness of working conditions usually elicit exaggerations. But if it cannot preciselydefine an adequate history, the present report stands squarely against the temptation to categorize asbestos exposure as simply present or absent or yes or no, to deal only with length of exposure and ignore differences in intensity. Many authors have resorted to this simplistic scheme, especially in reports of radiologic surveys or retrospective mortality studies. It is at least defensible when studying pleural plaques or mesotheliomas, which can result from exposures far below those that cause asbestosis. In the epidemiologic study or the clinical diagnosis of asbestosis, both intensity and duration of exposure must be taken into account. The clinician, though lacking a precise definition of the adequate exposure history, should nonetheless be able to identifya history so weak that it fails to satisfy the exposure criterion just as he or she should be able to identify an array of response data that fails to establish a probability of DIPF. Either of these deficiencies, or the presence of a potential con-
founder, precludes a sound clinical diagnosis of asbestosis. At that point, asbestosis is a strictly pathologic diagnosis. ROBERT N. JONES, M.D. Tulane University School of Medicine New Orleans, Louisiana
References .1. Gaensler EA, Jederlinic PJ, Churg A. Idiopathic pulmonary fibrosis in asbestos-exposed workers. Am Rev Respir Dis 1991; 144:689-96. 2. American Thoracic Society. The diagnosis of nonmalignant diseases related to asbestos. Am Rev Respir Dis 1986; 134:363-8. 3. International Labour Office. Encyclopedia of occupational health and safety.3rd ed. Geneva: ILO, 1983; 187-91. 4. Lusted LB. Introduction to medical decision making. Springfield, IL: Chas. C. Thomas, 1968; 114-7. 5. McNeil BJ, Keeler E, Adelstein SJ. Primer on certain elements of medical decision making. N Engl J Med 1975; 293:211-5. 6. Schwartz WB, Wolfe HJ, Pauker SG. Pathology and probabilities. N Engl J Med 1981; 305: 917-23. 7. American College of Radiology, Asbestos Working Group. Asbestos related diseases. Chicago: ACR, 1983; 45, 47. 8. College of American Pathologists and National Institute of Occupational Safety and Health, Pneumoconiosis Committee. The pathology of asbestosassociated diseases of the lungs and pleural cavities: diagnostic criteria and proposed grading schema. Arch Pathol Lab Med 1982; 106:544-96.
Is Sleep-disordered Respiration Part of Pulmonary Medicine?
Since the original descriptions of the sleep apnea syndrome in the early 1970s, there has been an increasing recognition of the widespread prevalence of this disease. Many new diagnostic facilities such as sleep laboratories have been developed. New treatments for the disease like nasal continuous positive airway pressure (CPAP) have been described and widely applied. Increasingly, pulmonologists have become involved in this aspect of medicine, both from the point of view of clinical care of patients, as well as basic and clinical research. Issues related to sleep apnea and other sleep disorders have receivedincreasing public attention. Currently, there is a National Commission on Sleep Disorders Research that will
shortly report to Congress. The Commission invites input from all interested parties. This latest event provides an opportunity to reflect on the present status of this field and consider the different views that are emerging as to the future of this aspect of medicine. The purpose of this editorial is to layout some of these issues. In some ways, the debate is similar to that which took place in critical care medicine within the last decade. Sleep Disorders: A Multidisciplinary Area
Within the American Thoracic Society (ATS)the viewof various committees has been that management of patients with a variety of sleep disorders requires a mul-
tidisciplinaryapproach. Pulmonologists with special interest and training in sleeprelated respiratory disorders, neurologists with an interest in movement disorders during sleep and narcolepsy, and psychiatrists with interest and expertise in insomnia and disorders of circadian rhythm are needed. Thus sleep disorders is seen as what has been termed a "horizontal" area of medicine that cuts across the "vertical" boundaries of existing subspecialties (1). Because sleep apnea is the most common reason for patients seeking help at sleep disorders centers, pulmonologists will playa major role. Currently, 44010 of the physicians sitting the professional accreditation examination in sleep disorders medicine are AM REV RESPIR DIS 1991; 144:478-480
479
EDITORIAL
pulmonologists, and this percentage is growing. The number of trained psychiatrists (16%) and neurologists (30070) sitting the examination is less. One argument that has been put forward to support this multidisciplinary view is that the field of sleep disorders is strengthened by maintaining its roots in these disciplines. These roots provide intellectual support and knowledge. Certainly one could argue that in the last decade the "pulmonary root" provided a new method of treatment of patients with obstructive sleep apnea (nasal CPAP) and nocturnal ventilation of patients with neuromuscular disease and obesity hypoventilation syndrome. These roots should also provide a steady flow of young clinicians and investigators to move the field forward. Others would point out that this multidisciplinary approach has some potential problems. First, if pulmonologists become the dominant group involved in this aspect of medicine, will patients with nonpulmonary sleep disorders be less wellserved? Patient groups are concerned that pulmonologists running sleep disorders centers may not be sufficiently knowledgeable or interested in management of patients with other sleep disorders such as narcolepsy. This concern is heightened by the knowledge that narcolepsy is a chronic disease that usually presents in adolescence and young adulthood and is more prevalent than multiple sclerosis. A second potential problem, albeit related, is whether pulmonary programs will provide the appropriate clinical training for the next generation of practitioners in this field. Finally, there are concerns about whether, with the current emphasis on molecular biological approaches to intrinsic lung disease, the pulmonary academic community has the breadth of vision to support development of the novel research programs that this area needs. In short, will the "pulmonary root" control the future of the field but not be sufficiently committed to its future development? An Alternative Model: "Doctors of the Night"
Given these legitimate concerns, others have proposed that sleep disorders has reached a stage of development that it is now a truly separate specialty. The field has the following: special area of basic knowledge (mechanisms controlling sleep); a group of investigators interested in this; a journal committed to the area (Sleep), a separate Board (Board of Sleep
Medicine); and a complete textbook (Principles and Practice of Sleep Medicine) (2). Thus, others would argue that it has all that it needs to separate from its roots and develop independently. The obvious difficulties with this approach are whether the field, as it currently stands, is sufficient in scope to be a separate discipline and whether it is sufficiently strong to be self supporting. Will the tree flourish if the roots are cut? Particular concerns relate to the number of young people, both clinicians and investigators, who might enter such a new field. Current signs are not positive in this regard. Currently, there are only six certified programs offering a total of 10 positions for 1 yr of training in sleep disorders medicine. Moreover, the number of investigators in the field of basic sleep mechanisms is small. Despite the growing clinical importance 0 f the area, there has been a decline in the number of manuscripts published on this important topic although quality manuscripts continue to be published in journals such as Science (J. Siegel, personal communication). The Cardiopulmonary Sleep Center: Another Separatist Viewpoint
If sleep disorders itself is not strong enough to become an independent entity, what about its component parts? Some would argue that there should be specific clinical entities related to diagnosis and management of patients with sleep disordered respiration, such as the Cardiopulmonary Sleep Laboratory. Guidelines for such clinical service entities have been proposed (3), and accreditation of such specialty laboratories is done by the American Sleep Disorders Association. Having tried originally to establish this type of laboratory, I appreciate the difficulties of this approach. The fundamental problem is that patients do not present with sleep disordered respiration; they present with complaints. The major complaints are excessive daytime sleepiness and nocturnal awakenings, among other complaints. Although many patients will ultimately have typical obstructive sleep apnea, others will have narcolepsy, nocturnal myoclonus, or neurologic diseases. Thus, one quickly realizes that running a Cardiopulmonary Sleep Center requires familiarity with the clinical features and diagnosis and management of a large variety of sleep disorders. In essence,the knowledge base is similar to that required for running a complete sleep disorders center.
Pulmonary Medicine and Sleep Disorders - the Responsibility
If, based on the high prevalence of sleep apnea syndrome and the demographics of the practitioners entering the field, pulmonologists play an important role in determining the future of this aspect of medicine, then pulmonary medicine assumes, at least in part, a responsibility. This responsibility is developing programs to train our medical students about sleep disorders and to train our postdoctoral fellows to manage patients with these diseases. The available evidence suggests that the pulmonary community is not fully aware of this responsibility. In 1988, a survey was done with respect to training in sleep disordered respiration by the new Section of Respiratory Neurobiology and Sleep of the ATS.This showed that there was a large amount of clinical activity in this area but little, if any, training. Seventy percent of pulmonary academic programs reported clinical activities related to diagnosis and management of sleep disorders. The mean number of sleep studies done per year was 229 (range, 10 to 1,000). In certain programs there are more sleep studies done than bronchoscopies. However, only 29% of programs reported a formal rotation in the sleep laboratory as part of their training program. It would be difficult to envisage a pulmonary training program without training in bronchoscopy. This paradox -large amount of clinical activity but little if any trainingraises concerns about the commitment of the pulmonary academic community to this endeavor. After this survey, a joint committee of the ATS, American College of Chest Physicians, and American Sleep Disorders Association had been formed and is developing guidelines with respect to implementation of training. The joint committee has proposed that we should consider two levels of training. The first level would be to ensure that all pulmonary fellows know about diagnosis and management of patients with sleep disordered respiration. This would be part of a normal pulmonary fellowship. The second level would be for a small subset of pulmonary fellows that aspire to be directors of sleep centers and take the examination in sleep medicine. This would require an additional period of training in other, nonpulmonary aspects of sleep disorders, and electroencephalography, among others. This component of our training programs might be analogous to the new critical care addition, with development of specific
EDITORIAL
480
tracks. Implementation of this type of program is not a welcome charge for pulmonary training directors who have just recovered from their critical care trauma. Moreover, there are issues as to how this will be financially supported. The pulmonary community needs, however, to act with dispatch. A group of neurologists, under the auspices of American Board of Psychiatry and Neurology, has been approved by the American Board of Medical Specialties to issue a certificate of added qualification in clinical neurophysiology that includes sleep medicine. The qualification of the separate Board of Sleep Medicine is not currently recognized by the American Board of Medical Specialties. One approach, advocated by committees of the ATS, is to ask the American Board of Internal Medicine to develop a certificate of special competence in sleep medicine. It will be important, however, to ensure collaboration between these various boards to prevent "balkanization" of this area of medicine and avoid the critical care outcome. -Pulmonary Medicine and Sleep Disorders- the Opportunity
Sleep disorders represent, however, not only a responsibility but also a great opportunity for the pulmonary community. Epidemiologic data that is being gathered indicate the high prevalence of sleepdisordered respiration in the community. It seems unlikely that all such patients can be studied at a full sleep disorders center. New technologies are being developed to allow in-home studies, i.e., unattended monitoring of sleep. The role of these technologies in the diagnosis of sleep disordered respiration remains to be determined as does the most costeffective way to practice this aspect of medicine. Much research and development needs to be done to develop optimal diagnostic strategies. The pulmonary community can contribute to this exciting development. At present we have an effective but
cumbersome treatment for sleep apnea syndrome (nasal CPAP). Currently, pharmacologic approaches are essentially unhelpful. Such pharmacologic approaches might be directed at reducing the hypotonia of upper airway dilator muscles during sleep. This raises interesting questions about the neural mechanisms and neuropharmacology of upper airway motor control and how this is affected by sleep. Modern neuroscience provides many techniques to address these questions. There is a need to investigate the coupling of neurons that regulate sleep/wake state with those neurons that control cardiorespiratory activity. Uncovering of these interactions will,moreover, contribute to unravelling the fundamental nature of sleep, how it is affected by disease, and how disease may disrupt normal sleep. As an alternative therapeutic strategy, we might plan to ameliorate the resultant excessivedaytime sleepiness, that is, the main clinical consequence of the disease. The latter raises important questions about the fundamental nature of sleepiness about which we know little; this is one of the largest uncharted areas in modern biology. But is this a pulmonary question? Some would see this as being too far removed from the lung. On the other hand, if sleep apnea is seen as a pulmonary disease, and as such is one of the most common, should we not be concerned with investigating the fundamental basis of its major clinical consequence? The pulmonary community is involved, for good reason, in many other aspects of modern biology, e.g., immunology, smooth muscle, ion channels, gene transfer, and muscle biology. It would seem to be an artificial boundary to exclude neural mechanisms underlying sleepiness from our scope. Conclusion
In this brief outline, I have reviewedsome of the differing viewpoints about where the diagnosis and management of sleep disorders should be headed. This debate
is, in essence, an age old one because it reflects a territorial approach versus an ecumenical one (1). The outcome of this debate will, at least in part, depend on how the pulmonary community views this area and whether it is willing to play a leadership role. There is an important void with respect to organized training for practitioners and in many areas of both clinical and basic research. This void represents an opportunity for the pulmonary community to make important contributions. These opportunities will be laid out in the upcoming report to the Congress from the National Commission on Sleep Disorders Research that the pulmonary community will be able to assess. The issue ultimately reduces to whether the pulmonary community has the vision, energy, and commitment to playa leadership role in this exciting, developing aspect of our discipline. If we do assume a leadership role and collaborate with others, we can potentially avoid fragmentation of this aspect of medicine to the eventual benefit of all our patients. I. PACK, M.B., CH.B., PH.D., FRCP Center for Sleep and Respiratory Neurobiology University of Pennsylvania Medical Center Philadelphia, Pennsylvania ALLAN
Acknowledgment The writer is grateful to Norman Edelman, Jim Kiley, John Remmers,Wolfgang SchmidtNowara, Philip Smith, Kingman Strohl, and Philip Westbrook for comments and information. References 1. King EG, Sibbald WJ. The territorial imperative. Chest 1988; 93:1121-2.
2.' Kryger MH, Roth T, Dement WC, eds. Principles and practice of sleep medicine. Philadelphia: W.B. Saunders ce, 1989. 3. Martin RJ, Block AJ, Cohn MA, et al. Indications and standards for cardiopulmonary sleep studies. Sleep 1985; 8:371-9.
478
large differences in past years in the exposure intensities of various jobs, work settings, and activities. Insulators and pipe coverers, whether working in shipbuilding or construction, had intense exposures. So did many workers who manufactured asbestos products. Studying other trades and settings, one encounters a greater range of individual exposures. Boilermakers and pipefitters who did ripout and repair of old insulated equipment probably had heavier exposures than those installing new equipment. The same exposure diversity can be inferred from the histories of shipyard welders and machinists, some of whom, working in shops on shore, rarely set foot on board vessels. There are other trades that have widespread potential for some exposure but in which asbestosis rarely occurs such as carpenters, electricians, marine, and operating engineers, as well as the generality of shipbuilding and industrial construction workers. Unfortunately, these considerations provide only rough guidelines for deciding what constitutes an adequate exposure history. The trade or job, length of career, setting (outdoors or indoors, confined or spacious), and activity mix of production-construction-maintenance-repair-demolition can all provide useful information. Questions about
these items, which should be within the knowledge of the worker and are often documentable, tend to elicit accurate answers. Given the pervasive influence of litigation, questions about the perceived dustiness of working conditions usually elicit exaggerations. But if it cannot preciselydefine an adequate history, the present report stands squarely against the temptation to categorize asbestos exposure as simply present or absent or yes or no, to deal only with length of exposure and ignore differences in intensity. Many authors have resorted to this simplistic scheme, especially in reports of radiologic surveys or retrospective mortality studies. It is at least defensible when studying pleural plaques or mesotheliomas, which can result from exposures far below those that cause asbestosis. In the epidemiologic study or the clinical diagnosis of asbestosis, both intensity and duration of exposure must be taken into account. The clinician, though lacking a precise definition of the adequate exposure history, should nonetheless be able to identifya history so weak that it fails to satisfy the exposure criterion just as he or she should be able to identify an array of response data that fails to establish a probability of DIPF. Either of these deficiencies, or the presence of a potential con-
founder, precludes a sound clinical diagnosis of asbestosis. At that point, asbestosis is a strictly pathologic diagnosis. ROBERT N. JONES, M.D. Tulane University School of Medicine New Orleans, Louisiana
References .1. Gaensler EA, Jederlinic PJ, Churg A. Idiopathic pulmonary fibrosis in asbestos-exposed workers. Am Rev Respir Dis 1991; 144:689-96. 2. American Thoracic Society. The diagnosis of nonmalignant diseases related to asbestos. Am Rev Respir Dis 1986; 134:363-8. 3. International Labour Office. Encyclopedia of occupational health and safety.3rd ed. Geneva: ILO, 1983; 187-91. 4. Lusted LB. Introduction to medical decision making. Springfield, IL: Chas. C. Thomas, 1968; 114-7. 5. McNeil BJ, Keeler E, Adelstein SJ. Primer on certain elements of medical decision making. N Engl J Med 1975; 293:211-5. 6. Schwartz WB, Wolfe HJ, Pauker SG. Pathology and probabilities. N Engl J Med 1981; 305: 917-23. 7. American College of Radiology, Asbestos Working Group. Asbestos related diseases. Chicago: ACR, 1983; 45, 47. 8. College of American Pathologists and National Institute of Occupational Safety and Health, Pneumoconiosis Committee. The pathology of asbestosassociated diseases of the lungs and pleural cavities: diagnostic criteria and proposed grading schema. Arch Pathol Lab Med 1982; 106:544-96.
Is Sleep-disordered Respiration Part of Pulmonary Medicine?
Since the original descriptions of the sleep apnea syndrome in the early 1970s, there has been an increasing recognition of the widespread prevalence of this disease. Many new diagnostic facilities such as sleep laboratories have been developed. New treatments for the disease like nasal continuous positive airway pressure (CPAP) have been described and widely applied. Increasingly, pulmonologists have become involved in this aspect of medicine, both from the point of view of clinical care of patients, as well as basic and clinical research. Issues related to sleep apnea and other sleep disorders have receivedincreasing public attention. Currently, there is a National Commission on Sleep Disorders Research that will
shortly report to Congress. The Commission invites input from all interested parties. This latest event provides an opportunity to reflect on the present status of this field and consider the different views that are emerging as to the future of this aspect of medicine. The purpose of this editorial is to layout some of these issues. In some ways, the debate is similar to that which took place in critical care medicine within the last decade. Sleep Disorders: A Multidisciplinary Area
Within the American Thoracic Society (ATS)the viewof various committees has been that management of patients with a variety of sleep disorders requires a mul-
tidisciplinaryapproach. Pulmonologists with special interest and training in sleeprelated respiratory disorders, neurologists with an interest in movement disorders during sleep and narcolepsy, and psychiatrists with interest and expertise in insomnia and disorders of circadian rhythm are needed. Thus sleep disorders is seen as what has been termed a "horizontal" area of medicine that cuts across the "vertical" boundaries of existing subspecialties (1). Because sleep apnea is the most common reason for patients seeking help at sleep disorders centers, pulmonologists will playa major role. Currently, 44010 of the physicians sitting the professional accreditation examination in sleep disorders medicine are AM REV RESPIR DIS 1991; 144:478-480
479
EDITORIAL
pulmonologists, and this percentage is growing. The number of trained psychiatrists (16%) and neurologists (30070) sitting the examination is less. One argument that has been put forward to support this multidisciplinary view is that the field of sleep disorders is strengthened by maintaining its roots in these disciplines. These roots provide intellectual support and knowledge. Certainly one could argue that in the last decade the "pulmonary root" provided a new method of treatment of patients with obstructive sleep apnea (nasal CPAP) and nocturnal ventilation of patients with neuromuscular disease and obesity hypoventilation syndrome. These roots should also provide a steady flow of young clinicians and investigators to move the field forward. Others would point out that this multidisciplinary approach has some potential problems. First, if pulmonologists become the dominant group involved in this aspect of medicine, will patients with nonpulmonary sleep disorders be less wellserved? Patient groups are concerned that pulmonologists running sleep disorders centers may not be sufficiently knowledgeable or interested in management of patients with other sleep disorders such as narcolepsy. This concern is heightened by the knowledge that narcolepsy is a chronic disease that usually presents in adolescence and young adulthood and is more prevalent than multiple sclerosis. A second potential problem, albeit related, is whether pulmonary programs will provide the appropriate clinical training for the next generation of practitioners in this field. Finally, there are concerns about whether, with the current emphasis on molecular biological approaches to intrinsic lung disease, the pulmonary academic community has the breadth of vision to support development of the novel research programs that this area needs. In short, will the "pulmonary root" control the future of the field but not be sufficiently committed to its future development? An Alternative Model: "Doctors of the Night"
Given these legitimate concerns, others have proposed that sleep disorders has reached a stage of development that it is now a truly separate specialty. The field has the following: special area of basic knowledge (mechanisms controlling sleep); a group of investigators interested in this; a journal committed to the area (Sleep), a separate Board (Board of Sleep
Medicine); and a complete textbook (Principles and Practice of Sleep Medicine) (2). Thus, others would argue that it has all that it needs to separate from its roots and develop independently. The obvious difficulties with this approach are whether the field, as it currently stands, is sufficient in scope to be a separate discipline and whether it is sufficiently strong to be self supporting. Will the tree flourish if the roots are cut? Particular concerns relate to the number of young people, both clinicians and investigators, who might enter such a new field. Current signs are not positive in this regard. Currently, there are only six certified programs offering a total of 10 positions for 1 yr of training in sleep disorders medicine. Moreover, the number of investigators in the field of basic sleep mechanisms is small. Despite the growing clinical importance 0 f the area, there has been a decline in the number of manuscripts published on this important topic although quality manuscripts continue to be published in journals such as Science (J. Siegel, personal communication). The Cardiopulmonary Sleep Center: Another Separatist Viewpoint
If sleep disorders itself is not strong enough to become an independent entity, what about its component parts? Some would argue that there should be specific clinical entities related to diagnosis and management of patients with sleep disordered respiration, such as the Cardiopulmonary Sleep Laboratory. Guidelines for such clinical service entities have been proposed (3), and accreditation of such specialty laboratories is done by the American Sleep Disorders Association. Having tried originally to establish this type of laboratory, I appreciate the difficulties of this approach. The fundamental problem is that patients do not present with sleep disordered respiration; they present with complaints. The major complaints are excessive daytime sleepiness and nocturnal awakenings, among other complaints. Although many patients will ultimately have typical obstructive sleep apnea, others will have narcolepsy, nocturnal myoclonus, or neurologic diseases. Thus, one quickly realizes that running a Cardiopulmonary Sleep Center requires familiarity with the clinical features and diagnosis and management of a large variety of sleep disorders. In essence,the knowledge base is similar to that required for running a complete sleep disorders center.
Pulmonary Medicine and Sleep Disorders - the Responsibility
If, based on the high prevalence of sleep apnea syndrome and the demographics of the practitioners entering the field, pulmonologists play an important role in determining the future of this aspect of medicine, then pulmonary medicine assumes, at least in part, a responsibility. This responsibility is developing programs to train our medical students about sleep disorders and to train our postdoctoral fellows to manage patients with these diseases. The available evidence suggests that the pulmonary community is not fully aware of this responsibility. In 1988, a survey was done with respect to training in sleep disordered respiration by the new Section of Respiratory Neurobiology and Sleep of the ATS.This showed that there was a large amount of clinical activity in this area but little, if any, training. Seventy percent of pulmonary academic programs reported clinical activities related to diagnosis and management of sleep disorders. The mean number of sleep studies done per year was 229 (range, 10 to 1,000). In certain programs there are more sleep studies done than bronchoscopies. However, only 29% of programs reported a formal rotation in the sleep laboratory as part of their training program. It would be difficult to envisage a pulmonary training program without training in bronchoscopy. This paradox -large amount of clinical activity but little if any trainingraises concerns about the commitment of the pulmonary academic community to this endeavor. After this survey, a joint committee of the ATS, American College of Chest Physicians, and American Sleep Disorders Association had been formed and is developing guidelines with respect to implementation of training. The joint committee has proposed that we should consider two levels of training. The first level would be to ensure that all pulmonary fellows know about diagnosis and management of patients with sleep disordered respiration. This would be part of a normal pulmonary fellowship. The second level would be for a small subset of pulmonary fellows that aspire to be directors of sleep centers and take the examination in sleep medicine. This would require an additional period of training in other, nonpulmonary aspects of sleep disorders, and electroencephalography, among others. This component of our training programs might be analogous to the new critical care addition, with development of specific
EDITORIAL
480
tracks. Implementation of this type of program is not a welcome charge for pulmonary training directors who have just recovered from their critical care trauma. Moreover, there are issues as to how this will be financially supported. The pulmonary community needs, however, to act with dispatch. A group of neurologists, under the auspices of American Board of Psychiatry and Neurology, has been approved by the American Board of Medical Specialties to issue a certificate of added qualification in clinical neurophysiology that includes sleep medicine. The qualification of the separate Board of Sleep Medicine is not currently recognized by the American Board of Medical Specialties. One approach, advocated by committees of the ATS, is to ask the American Board of Internal Medicine to develop a certificate of special competence in sleep medicine. It will be important, however, to ensure collaboration between these various boards to prevent "balkanization" of this area of medicine and avoid the critical care outcome. -Pulmonary Medicine and Sleep Disorders- the Opportunity
Sleep disorders represent, however, not only a responsibility but also a great opportunity for the pulmonary community. Epidemiologic data that is being gathered indicate the high prevalence of sleepdisordered respiration in the community. It seems unlikely that all such patients can be studied at a full sleep disorders center. New technologies are being developed to allow in-home studies, i.e., unattended monitoring of sleep. The role of these technologies in the diagnosis of sleep disordered respiration remains to be determined as does the most costeffective way to practice this aspect of medicine. Much research and development needs to be done to develop optimal diagnostic strategies. The pulmonary community can contribute to this exciting development. At present we have an effective but
cumbersome treatment for sleep apnea syndrome (nasal CPAP). Currently, pharmacologic approaches are essentially unhelpful. Such pharmacologic approaches might be directed at reducing the hypotonia of upper airway dilator muscles during sleep. This raises interesting questions about the neural mechanisms and neuropharmacology of upper airway motor control and how this is affected by sleep. Modern neuroscience provides many techniques to address these questions. There is a need to investigate the coupling of neurons that regulate sleep/wake state with those neurons that control cardiorespiratory activity. Uncovering of these interactions will,moreover, contribute to unravelling the fundamental nature of sleep, how it is affected by disease, and how disease may disrupt normal sleep. As an alternative therapeutic strategy, we might plan to ameliorate the resultant excessivedaytime sleepiness, that is, the main clinical consequence of the disease. The latter raises important questions about the fundamental nature of sleepiness about which we know little; this is one of the largest uncharted areas in modern biology. But is this a pulmonary question? Some would see this as being too far removed from the lung. On the other hand, if sleep apnea is seen as a pulmonary disease, and as such is one of the most common, should we not be concerned with investigating the fundamental basis of its major clinical consequence? The pulmonary community is involved, for good reason, in many other aspects of modern biology, e.g., immunology, smooth muscle, ion channels, gene transfer, and muscle biology. It would seem to be an artificial boundary to exclude neural mechanisms underlying sleepiness from our scope. Conclusion
In this brief outline, I have reviewedsome of the differing viewpoints about where the diagnosis and management of sleep disorders should be headed. This debate
is, in essence, an age old one because it reflects a territorial approach versus an ecumenical one (1). The outcome of this debate will, at least in part, depend on how the pulmonary community views this area and whether it is willing to play a leadership role. There is an important void with respect to organized training for practitioners and in many areas of both clinical and basic research. This void represents an opportunity for the pulmonary community to make important contributions. These opportunities will be laid out in the upcoming report to the Congress from the National Commission on Sleep Disorders Research that the pulmonary community will be able to assess. The issue ultimately reduces to whether the pulmonary community has the vision, energy, and commitment to playa leadership role in this exciting, developing aspect of our discipline. If we do assume a leadership role and collaborate with others, we can potentially avoid fragmentation of this aspect of medicine to the eventual benefit of all our patients. I. PACK, M.B., CH.B., PH.D., FRCP Center for Sleep and Respiratory Neurobiology University of Pennsylvania Medical Center Philadelphia, Pennsylvania ALLAN
Acknowledgment The writer is grateful to Norman Edelman, Jim Kiley, John Remmers,Wolfgang SchmidtNowara, Philip Smith, Kingman Strohl, and Philip Westbrook for comments and information. References 1. King EG, Sibbald WJ. The territorial imperative. Chest 1988; 93:1121-2.
2.' Kryger MH, Roth T, Dement WC, eds. Principles and practice of sleep medicine. Philadelphia: W.B. Saunders ce, 1989. 3. Martin RJ, Block AJ, Cohn MA, et al. Indications and standards for cardiopulmonary sleep studies. Sleep 1985; 8:371-9.
