International Psychogeriatrics, Vol. 3, No. 2,1991 0 1991 Springer Publishing Company
The Impact of Care Delivery Setting and Patient Selection in Shaping Research Questions and Results
Psychosocial and Management Aspects of Delirium Peter V. Rabins, M.D. Department of Psychiatry and Behavioral Sciences Johns Hopkins University School of Medicine Baltimore, Maryland, U.S.A. ABSTRACT: Data to demonstrate that psychosocial factors, sensory deprivation, or sleep deprivation alone can cause delirium are few. Nonetheless, these factors or conditions may contribute to the development or symptom presentation of a delirium when other metabolic or toxic etiologiesare present. There is likewise little research on the appropriate treatment of the delirious patient. Clinical experiencesuggests that attention to the patient’s psychological state through frequent orientation,emotional support,and frequentexplanation can hcip. Low-dose neuroleptic drugs are occasionally useful and necessary.
In the 195Os, 1960s, and 1970s many researchers focused on environmental and psychosocial etiologies of the major mental illnesses (Linn, 1965; Ziskind, 1965). Over a decade ago Lipowski (1980) examined this literature in relationship to delirium, and his work remains a thorough and excellent review of the extant literature. As he notes, studies in this field have been beset by the difficulties which have plagued the field of delirium in general: the lack of a clear definition of delirium and the lack of a reliable “marker” for delirium.
SENSORY DEPRIVATION Sensory dcprivation is an environmental stressor that has been proposed as a model system for studying the development of delirium (e.g., Zubek, 1969). Some studies report the development of misinterpretarions, illusions, and hallucinations in occasional subjects who undergo days of constant stimuli or who are deprived of sensory input or sleep, but no study of sensory deprivation has used specific criteria to determine if delirium developed. The case summaries published along with these studies likewise provide few convincing descriptions of subjects experiencing a state that fulfills current criteria for delirium. Even in studies that determined level 319
320
P. V . Rabins
of consciousness or degree of inattention, data demonstrating changes that suggest delirium are few (e.g., Zubek & MacNeill, 1966; Marjerisson & Keough, 1967). Heron, Tait, and Smith (1972), however, did use the electroencephalogram (EEG) to determine whether sensory deprivations could be etiologic for delirium. They observed eight subjects who spent four or seven days wearing gloves, cardboard cuffs, and a translucent mask. The subjects lay in bed in a soundproofed room listening to “white noise.” They experienced these conditions for 21 out of 24 hours, leaving the room only to eat or to use achemical toilet. One of the subjects who experienced “vivid hallucinatory activity” had “a sharp increase in [EEG] frequency on Day 4 of isolation.” In the other subjects the EEG slowed during the deprivation period compared to each subject’s baseline. (A decrease in frequency is expected in most deliria except for alcohol and sedative withdrawal.) Thc EEG returned to baseline after several days. The authors report that these abnormalities existed during both the wake and sleep periods. This study is more convincing of a causal cffect of sensory deprivation than arc studies of sleep deprivation, which also show EEG changes (Dement, 1960,1972). Since slowing of the EEG is a sign of the first stages of sleep, any individual deprivedof sleep for significant periods of time might show slowing as the first sign of sleep deprivation. The “black-patch” psychosis that occurs after covering the eyes (Weisman & Hackett, 1958) is an unsatisfactory model for determining the outcome of sensory deprivation. Many patients who undergo eye surgery receive anticholinergic drugs or other medications (including eye drops) concurrenty with patching. Since delirium can be caused by drops with anticholinergic and beta-blocking activity, these drugs arc a more plausible etiology of the delirium, hallucinations, and delusions seen in individuals with one or both eyes patched than is the patching. One of the classic papers published on sensory deprivation as an etiology of delirium illuminates the problems in experimental design and in relating research findings to delirium.In the well-known study of intensive care units, Wilson & El Dorado (1972) suggested that lack of external visual cues might cause delirium. He compared intensive care units in two hospitals; one unit had windows while the other did not. Data were collected by a retrospective chart review. The chart reviewers were apparently not blind, either to the hypothesis being tested or to the unit on which patients were hospitalized. The same surgeons practiced on both units, and the types of surgical proccdurcs the patients had experienced were similar. No data are presented comparing types of anesthesia or medications administered. Delirium was defined as “an acute brain syndrome charactcrizcd by impairmcnt of orientation, memory, intellectual function, andjudgment, with lability of affect.” The rate of delirium in the unit without windows was 40%, while on the unit with windows the rate was 18% (p < -05).Among those in the windowless unit, the rate of delirium was higher in individuals who were anemic or who had elevated BUNS. This suggested that the delirium was caused by an interaction between sensory deprivation and an underlying metabolic abnormality.
Psychosocial and Management Aspects of Delirium
321
This study has serious methodological limitations: The diagnosis of delirium was made retrospectively from charts. It is likely that patients with a “quiet” delirium would be unrecognized. In delineation of delirium, researchers were not blind to knowledge of which ICU unit the patient was being tested on, and it is not clear if medication exposure was similar in both groups. “Sundowning,” the worsening of behavior that occurs late in the day in elderly individuals, might also be considered an environmentally induced form of delirium. The Cameron study (1941) of this phenomenon is notable because the author stated a hypothesis and devised a protocol to test the hypothesis. Further, he compared fatigue to decreased sensory input as the etiology of the sundowning behaviors. Cameron’s study involved blindfolding elderly subjects early and late in the day. Many of them had an underlying dementia. Following the blindfolding, behavior deteriorated, no matter what time of day the study was carried out. Cameron concluded that it was the decrease in visual input which led to the bchavioral deterioration. While it is somewhat unfair to apply modern methodological standards to a 50-year-old study, the methodology does have a major bearing on whether the study was an adequate test of the hypothesis. Cameron reported changes in behavior, including increases in restlessness and agitation, but a decrease in level of consciousness or attentiveness or a decline in cognitive ability was not reported. It thus appears that Cameron demonstrated that blindfolding elderly demented individuals leads to changes in behavior that include worsening disorientation, but there is little to suggest the patients became delirious. The finding that blindfolding demented patients leads to disorientation now appears inconsequential, and the study cannot be used to support the contention that decreased sensory input causes sundowning or delirium. It does demonstrate that decreasing sensory cues can cause behavioral deterioration in the brain-injured. In summary, Lipowski’s (1980) conclusion a decade ago that “there is insufficient evidence that sensory deprivation alone can cause delirium (p. 141)” still applies today. Nonetheless, some evidence can be mustered to support the “hypothesis that reduction of sensory input and/or sensory monitoring facilitate the development of delirium” (p. 141).
MANAGEMENT OF THE DELIRIOUS PATIENT Although delirium is a prevalent problem and its associations with environmental changes have long been noted, data addressing the management and treatment of delirium are few. Obviously, a major effort must be made toward identifying the underlying etiology or etiologies of the delirium (Cutting, 1980). Treating an identifiable cause is clearly the Cornerstoneto any management scheme. However, even when an etiology is identified, correction of the abnormality may be slow. Sometimes a specific etiology is not identified, or multiple etiologies are identified (Cutting, 1980). Even when it is unclear exactly what specific steps must be taken
322
P.V. Rabinr
to correct the medical abnormalities, careful supportive care is of major importance. Many authors and clinical experience suggest that several broad actions can be taken to improve management of the person with delirium. 1. Provide a predictable, orienting environment. The disorientation, visual misinterpretations, hallucinations, and paranoid ideation that are common in delirium are quite frightening to patients. Frequent verbal orientation, easyto-read calendars and clocks, adequate but not overwhelming lighting, and frequent contact with staff are important general interventions. They help remind a delirious patient where he or she is, and why. Staff should be particularly encouraged to have frequent interactions, to identify themselves, and to mention casually such things as day or time of year, place, and the patient’s current physical condition. Many patients seem to be calmed by k i n g told directly that they are disoriented or confused and that they are hallucinating. Explaining that this is a manifestation of their underlying condition or is a known side effect and allowing them to express their fears and discomfort is usually supportive. Because memory impairment is a central feature of the cognitive disorder of delirium, these supportive, reorienting, empathic interventions need to be repeated frequently. 2. Somatic therapies and restraints. Phanacotherapy and physical restraints should be avoided if possible. These often make patients more frightened or agitated. Many psychoactivedrugs, as well as many compounds not generally considered psychoactive, can worsen the delirium; it is thus a cardinal rule to try to minimize all pharmacological interventions. However, some patients are so frightened, deluded, and/or restless that pharmacotherapy or physical restraints are necessary to prevent self-injury or harm to others. Many authorities recommend low-dose haloperidol; while other agents are mentioned as well, there are no good controlled studies that demonstrate which agent, if any, is effective. 3. Interventions with family and other care providers. One of the important effects of properly diagnosing delirium is that the diagnosis can be used to explain unusual behavior to both professional and family care providers. It is important to acknowledge the meaningful content of some patient’s delirium, but it is equally important to emphasize that thc bulk of symptoms arises directly from the underlying metabolic or structural abnormality or intoxication. Families often nccd to be instructed not to repeatedly correct the ill person, to remain calm, to frequently reorient their loved onc, to use physical touch if this is reassuring to the individual, and to remember that the person may not remember after several minutes what they have just been told. If at all possible, important decisions requiring the delirious person’s input should be delayed until the patient is recovered. When this is not possible, remember that delirious individuals can be given a number of facts and may be able to keep them in mind for several minutes; thus they can participate in
Psychosocial and Managemew Aspects of Delirium
323
a decision, even though they may not remember doing so later. In such an instance, it might be advisable to have several witnesses to the discussion. 4. Psychiatricconsultationand psychiatric treatment. In some situations the psychiatrist is uniquely qualified to integrate an appreciation of the patient’s frightened, suspicious state and the complex medical issues which are being treated. The ability to combine an appreciation of these elements with the provision of support to the caregivers justifies a consultation in many cases. Occasionally, patients may be better managed on a psychiatric service, but this should be considered only when it is medically safe and when a patient’s ability to ambulate freely might be of major benefit.
SUMMARY Delirium might be taken as the paradigm of the unique contributions of psychiatry to medicine. The fact that it is clearly an“organic disorder,” and yet has prominent mental symptoms and experiences, supports the involvement of psychiatrists and other mental health practitioners in the care of such patients. One must never lose sight that a search for the primary etiology and correction, when possible, is the hallmark of treatment, but the management of symptoms can be of great benefit to patient and staff alike.
REFERENCES Cameron, D. E. (1941). Studiesin senilenocturnal delirium. Psychiatric Quarferly,15,4753. Cutting,J. (1980). Physical illness and psychosis. British Journal of Psychiatry, 136,109119. Dement, W. C . (1960). The effect of dream deprivation. Science, 131, 1705-1707. Dement, W. C., (1972). “Sleep deprivation and the organization of the behavioral states.” In Z. J. Lipowski (Ed.), Delirium: Acute bruin failure in man. 1980. Springfield: Charles C Thomas. Erkinjuntti, T., Wikstrom, J., Parlo, J.. & Autio, L (1986). Dementia among medical inpatients:Evaluation of 2000consecutiveadmissions.Archives ofInternal Medicine, 146,1923-1926. Heron, W., Taft, G., & Smith, G. K. (1972). Effects of prolonged perceptual isolation on the human electroencephalogram. Brain Research, 43,28-284. Koponen, H., Stenback, U., Matilla,E., Soininen, H., Reinikainen, K., & Rickkinen, P.J. (1989). Delirium among elderly persons admittcd to a psychiatric hospital: Clinical courseduring theacute stageandone-yearfoilow-up.Acta PsychiatricaScandinavica, 79,579-585. Linn, L. (1965). Psychiatric reactions complicating cataract surgery. Inlernational Ophthalmology Clinics, 5 , 143-1 54. Lipowski, Z . J. (1967). Delirium, clouding of consciousness and confusion. Journal of Nervous and Mental Disease, 145,227-255.
324
P . V . Rabim
Lipowski, Z. J. (1980). Delirium: Acute brain failure in man. Springfield: Charles C Thomas. Marjemson, G., & Keough, R. P. (1967). Electroencephalographicchanges during brief periods of perceptual deprivation. Perceptual and Motor Skills, 24,611-615. Rabins, P., Lucas, M. J., Teitelbaum, M., Mark,S.R., & Folstein, M. (1983). Utilization of psychiatric consultation for elderly patients. Journal of the American Geriatrics Society, 31,581-585. Robinson,J. R. (1989). The natural history of mental disorder in old age: A long-term study. British Journal of Psychiatry, 154,783-789. Roth, M. (1955). The natural history of mental disorder in old age. Journal of Mental Science, 101,281-301. Ruskin, P. E. (1985). Gempsychiatric consultation in a university hospital: A report on 67 referrals. American Journal of Psychiatry, 142,333-336. Simon, A., & Cahan, R. B. (1963). The acute brain syndrome in geriatric patients. Psychiatric Research Reports, 168-21. Weisman, A. D., & Hackett, T. P. (1958). Psychosis after eye surgery. New England Journal of Medicine, 2.58, 1284-1289. Wilson, L. M., & El Dorado, A. (1972). Intensive care delirium. Archives of Internal Medicine, 30,225-226. Ziskind, E. (1965). An explanation of mental symploms found in acute sensory dcprivation: Researches 1958-1963. American Journal of Psychiatry, 121,939-946. Zubek, J. P. (Ed.) (1969). Sensory deprivation: Fifleen years of research. New York: Appleton-Century-Crofts. Zubek, J. P., & MacNeill, M. (1966). Effects of immobilization: Behavioral and EEG changes. Canadian Journal of Psychology, 20,3 16-366. ORprinfs. Requests for offprints should be sent to Dr. P. Rabins, Meyer 279, Johns Hopkins Hospital, 600 N. Wolfe St., Baltimore, MD 21205.
The Impact of Care Delivery Setting and Patient Selection in Shaping Research Questions and Results
Psychosocial and Management Aspects of Delirium Peter V. Rabins, M.D. Department of Psychiatry and Behavioral Sciences Johns Hopkins University School of Medicine Baltimore, Maryland, U.S.A. ABSTRACT: Data to demonstrate that psychosocial factors, sensory deprivation, or sleep deprivation alone can cause delirium are few. Nonetheless, these factors or conditions may contribute to the development or symptom presentation of a delirium when other metabolic or toxic etiologiesare present. There is likewise little research on the appropriate treatment of the delirious patient. Clinical experiencesuggests that attention to the patient’s psychological state through frequent orientation,emotional support,and frequentexplanation can hcip. Low-dose neuroleptic drugs are occasionally useful and necessary.
In the 195Os, 1960s, and 1970s many researchers focused on environmental and psychosocial etiologies of the major mental illnesses (Linn, 1965; Ziskind, 1965). Over a decade ago Lipowski (1980) examined this literature in relationship to delirium, and his work remains a thorough and excellent review of the extant literature. As he notes, studies in this field have been beset by the difficulties which have plagued the field of delirium in general: the lack of a clear definition of delirium and the lack of a reliable “marker” for delirium.
SENSORY DEPRIVATION Sensory dcprivation is an environmental stressor that has been proposed as a model system for studying the development of delirium (e.g., Zubek, 1969). Some studies report the development of misinterpretarions, illusions, and hallucinations in occasional subjects who undergo days of constant stimuli or who are deprived of sensory input or sleep, but no study of sensory deprivation has used specific criteria to determine if delirium developed. The case summaries published along with these studies likewise provide few convincing descriptions of subjects experiencing a state that fulfills current criteria for delirium. Even in studies that determined level 319
320
P. V . Rabins
of consciousness or degree of inattention, data demonstrating changes that suggest delirium are few (e.g., Zubek & MacNeill, 1966; Marjerisson & Keough, 1967). Heron, Tait, and Smith (1972), however, did use the electroencephalogram (EEG) to determine whether sensory deprivations could be etiologic for delirium. They observed eight subjects who spent four or seven days wearing gloves, cardboard cuffs, and a translucent mask. The subjects lay in bed in a soundproofed room listening to “white noise.” They experienced these conditions for 21 out of 24 hours, leaving the room only to eat or to use achemical toilet. One of the subjects who experienced “vivid hallucinatory activity” had “a sharp increase in [EEG] frequency on Day 4 of isolation.” In the other subjects the EEG slowed during the deprivation period compared to each subject’s baseline. (A decrease in frequency is expected in most deliria except for alcohol and sedative withdrawal.) Thc EEG returned to baseline after several days. The authors report that these abnormalities existed during both the wake and sleep periods. This study is more convincing of a causal cffect of sensory deprivation than arc studies of sleep deprivation, which also show EEG changes (Dement, 1960,1972). Since slowing of the EEG is a sign of the first stages of sleep, any individual deprivedof sleep for significant periods of time might show slowing as the first sign of sleep deprivation. The “black-patch” psychosis that occurs after covering the eyes (Weisman & Hackett, 1958) is an unsatisfactory model for determining the outcome of sensory deprivation. Many patients who undergo eye surgery receive anticholinergic drugs or other medications (including eye drops) concurrenty with patching. Since delirium can be caused by drops with anticholinergic and beta-blocking activity, these drugs arc a more plausible etiology of the delirium, hallucinations, and delusions seen in individuals with one or both eyes patched than is the patching. One of the classic papers published on sensory deprivation as an etiology of delirium illuminates the problems in experimental design and in relating research findings to delirium.In the well-known study of intensive care units, Wilson & El Dorado (1972) suggested that lack of external visual cues might cause delirium. He compared intensive care units in two hospitals; one unit had windows while the other did not. Data were collected by a retrospective chart review. The chart reviewers were apparently not blind, either to the hypothesis being tested or to the unit on which patients were hospitalized. The same surgeons practiced on both units, and the types of surgical proccdurcs the patients had experienced were similar. No data are presented comparing types of anesthesia or medications administered. Delirium was defined as “an acute brain syndrome charactcrizcd by impairmcnt of orientation, memory, intellectual function, andjudgment, with lability of affect.” The rate of delirium in the unit without windows was 40%, while on the unit with windows the rate was 18% (p < -05).Among those in the windowless unit, the rate of delirium was higher in individuals who were anemic or who had elevated BUNS. This suggested that the delirium was caused by an interaction between sensory deprivation and an underlying metabolic abnormality.
Psychosocial and Management Aspects of Delirium
321
This study has serious methodological limitations: The diagnosis of delirium was made retrospectively from charts. It is likely that patients with a “quiet” delirium would be unrecognized. In delineation of delirium, researchers were not blind to knowledge of which ICU unit the patient was being tested on, and it is not clear if medication exposure was similar in both groups. “Sundowning,” the worsening of behavior that occurs late in the day in elderly individuals, might also be considered an environmentally induced form of delirium. The Cameron study (1941) of this phenomenon is notable because the author stated a hypothesis and devised a protocol to test the hypothesis. Further, he compared fatigue to decreased sensory input as the etiology of the sundowning behaviors. Cameron’s study involved blindfolding elderly subjects early and late in the day. Many of them had an underlying dementia. Following the blindfolding, behavior deteriorated, no matter what time of day the study was carried out. Cameron concluded that it was the decrease in visual input which led to the bchavioral deterioration. While it is somewhat unfair to apply modern methodological standards to a 50-year-old study, the methodology does have a major bearing on whether the study was an adequate test of the hypothesis. Cameron reported changes in behavior, including increases in restlessness and agitation, but a decrease in level of consciousness or attentiveness or a decline in cognitive ability was not reported. It thus appears that Cameron demonstrated that blindfolding elderly demented individuals leads to changes in behavior that include worsening disorientation, but there is little to suggest the patients became delirious. The finding that blindfolding demented patients leads to disorientation now appears inconsequential, and the study cannot be used to support the contention that decreased sensory input causes sundowning or delirium. It does demonstrate that decreasing sensory cues can cause behavioral deterioration in the brain-injured. In summary, Lipowski’s (1980) conclusion a decade ago that “there is insufficient evidence that sensory deprivation alone can cause delirium (p. 141)” still applies today. Nonetheless, some evidence can be mustered to support the “hypothesis that reduction of sensory input and/or sensory monitoring facilitate the development of delirium” (p. 141).
MANAGEMENT OF THE DELIRIOUS PATIENT Although delirium is a prevalent problem and its associations with environmental changes have long been noted, data addressing the management and treatment of delirium are few. Obviously, a major effort must be made toward identifying the underlying etiology or etiologies of the delirium (Cutting, 1980). Treating an identifiable cause is clearly the Cornerstoneto any management scheme. However, even when an etiology is identified, correction of the abnormality may be slow. Sometimes a specific etiology is not identified, or multiple etiologies are identified (Cutting, 1980). Even when it is unclear exactly what specific steps must be taken
322
P.V. Rabinr
to correct the medical abnormalities, careful supportive care is of major importance. Many authors and clinical experience suggest that several broad actions can be taken to improve management of the person with delirium. 1. Provide a predictable, orienting environment. The disorientation, visual misinterpretations, hallucinations, and paranoid ideation that are common in delirium are quite frightening to patients. Frequent verbal orientation, easyto-read calendars and clocks, adequate but not overwhelming lighting, and frequent contact with staff are important general interventions. They help remind a delirious patient where he or she is, and why. Staff should be particularly encouraged to have frequent interactions, to identify themselves, and to mention casually such things as day or time of year, place, and the patient’s current physical condition. Many patients seem to be calmed by k i n g told directly that they are disoriented or confused and that they are hallucinating. Explaining that this is a manifestation of their underlying condition or is a known side effect and allowing them to express their fears and discomfort is usually supportive. Because memory impairment is a central feature of the cognitive disorder of delirium, these supportive, reorienting, empathic interventions need to be repeated frequently. 2. Somatic therapies and restraints. Phanacotherapy and physical restraints should be avoided if possible. These often make patients more frightened or agitated. Many psychoactivedrugs, as well as many compounds not generally considered psychoactive, can worsen the delirium; it is thus a cardinal rule to try to minimize all pharmacological interventions. However, some patients are so frightened, deluded, and/or restless that pharmacotherapy or physical restraints are necessary to prevent self-injury or harm to others. Many authorities recommend low-dose haloperidol; while other agents are mentioned as well, there are no good controlled studies that demonstrate which agent, if any, is effective. 3. Interventions with family and other care providers. One of the important effects of properly diagnosing delirium is that the diagnosis can be used to explain unusual behavior to both professional and family care providers. It is important to acknowledge the meaningful content of some patient’s delirium, but it is equally important to emphasize that thc bulk of symptoms arises directly from the underlying metabolic or structural abnormality or intoxication. Families often nccd to be instructed not to repeatedly correct the ill person, to remain calm, to frequently reorient their loved onc, to use physical touch if this is reassuring to the individual, and to remember that the person may not remember after several minutes what they have just been told. If at all possible, important decisions requiring the delirious person’s input should be delayed until the patient is recovered. When this is not possible, remember that delirious individuals can be given a number of facts and may be able to keep them in mind for several minutes; thus they can participate in
Psychosocial and Managemew Aspects of Delirium
323
a decision, even though they may not remember doing so later. In such an instance, it might be advisable to have several witnesses to the discussion. 4. Psychiatricconsultationand psychiatric treatment. In some situations the psychiatrist is uniquely qualified to integrate an appreciation of the patient’s frightened, suspicious state and the complex medical issues which are being treated. The ability to combine an appreciation of these elements with the provision of support to the caregivers justifies a consultation in many cases. Occasionally, patients may be better managed on a psychiatric service, but this should be considered only when it is medically safe and when a patient’s ability to ambulate freely might be of major benefit.
SUMMARY Delirium might be taken as the paradigm of the unique contributions of psychiatry to medicine. The fact that it is clearly an“organic disorder,” and yet has prominent mental symptoms and experiences, supports the involvement of psychiatrists and other mental health practitioners in the care of such patients. One must never lose sight that a search for the primary etiology and correction, when possible, is the hallmark of treatment, but the management of symptoms can be of great benefit to patient and staff alike.
REFERENCES Cameron, D. E. (1941). Studiesin senilenocturnal delirium. Psychiatric Quarferly,15,4753. Cutting,J. (1980). Physical illness and psychosis. British Journal of Psychiatry, 136,109119. Dement, W. C . (1960). The effect of dream deprivation. Science, 131, 1705-1707. Dement, W. C., (1972). “Sleep deprivation and the organization of the behavioral states.” In Z. J. Lipowski (Ed.), Delirium: Acute bruin failure in man. 1980. Springfield: Charles C Thomas. Erkinjuntti, T., Wikstrom, J., Parlo, J.. & Autio, L (1986). Dementia among medical inpatients:Evaluation of 2000consecutiveadmissions.Archives ofInternal Medicine, 146,1923-1926. Heron, W., Taft, G., & Smith, G. K. (1972). Effects of prolonged perceptual isolation on the human electroencephalogram. Brain Research, 43,28-284. Koponen, H., Stenback, U., Matilla,E., Soininen, H., Reinikainen, K., & Rickkinen, P.J. (1989). Delirium among elderly persons admittcd to a psychiatric hospital: Clinical courseduring theacute stageandone-yearfoilow-up.Acta PsychiatricaScandinavica, 79,579-585. Linn, L. (1965). Psychiatric reactions complicating cataract surgery. Inlernational Ophthalmology Clinics, 5 , 143-1 54. Lipowski, Z . J. (1967). Delirium, clouding of consciousness and confusion. Journal of Nervous and Mental Disease, 145,227-255.
324
P . V . Rabim
Lipowski, Z. J. (1980). Delirium: Acute brain failure in man. Springfield: Charles C Thomas. Marjemson, G., & Keough, R. P. (1967). Electroencephalographicchanges during brief periods of perceptual deprivation. Perceptual and Motor Skills, 24,611-615. Rabins, P., Lucas, M. J., Teitelbaum, M., Mark,S.R., & Folstein, M. (1983). Utilization of psychiatric consultation for elderly patients. Journal of the American Geriatrics Society, 31,581-585. Robinson,J. R. (1989). The natural history of mental disorder in old age: A long-term study. British Journal of Psychiatry, 154,783-789. Roth, M. (1955). The natural history of mental disorder in old age. Journal of Mental Science, 101,281-301. Ruskin, P. E. (1985). Gempsychiatric consultation in a university hospital: A report on 67 referrals. American Journal of Psychiatry, 142,333-336. Simon, A., & Cahan, R. B. (1963). The acute brain syndrome in geriatric patients. Psychiatric Research Reports, 168-21. Weisman, A. D., & Hackett, T. P. (1958). Psychosis after eye surgery. New England Journal of Medicine, 2.58, 1284-1289. Wilson, L. M., & El Dorado, A. (1972). Intensive care delirium. Archives of Internal Medicine, 30,225-226. Ziskind, E. (1965). An explanation of mental symploms found in acute sensory dcprivation: Researches 1958-1963. American Journal of Psychiatry, 121,939-946. Zubek, J. P. (Ed.) (1969). Sensory deprivation: Fifleen years of research. New York: Appleton-Century-Crofts. Zubek, J. P., & MacNeill, M. (1966). Effects of immobilization: Behavioral and EEG changes. Canadian Journal of Psychology, 20,3 16-366. ORprinfs. Requests for offprints should be sent to Dr. P. Rabins, Meyer 279, Johns Hopkins Hospital, 600 N. Wolfe St., Baltimore, MD 21205.
