CHAPTER 25 FAILURE TO THRIVE
Practice of Geriatrics
CHAPTER 25 FAILURE TO THRIVE
Roy B. Verdery, Ph.D., M.D.
Pathophysiology and Etiology
Approach to the Patient with Failure to Thrive
Social Factors and Assessment
Treatment of the Older Person with Failure to Thrive
Records and Economics
Failure to thrive in older people is a syndrome consisting of progressive loss of physical functioning, weight, and lean body mass.1,2 Failure to thrive defined in this way is a process of gradual loss of function due to various causes, both organic (systemic disease) and nonorganic (functional or psychosocial problems). The condition of being at risk for failure to thrive and the condition of impaired function have both been called “frailty.”3 Frailty is obviously closely related to failure to thrive. Another closely related condition is malnutrition. Malnutrition is generally characterized by a loss of fat mass and visceral protein that occurs when nutritional requirements exceed intake and utilization. Malnutrition can cause failure to thrive and result in frailty. Another related problem is sarcopenia,4 characterized by low muscle mass. Both malnutrition and failure to thrive can lead to sarcopenia, and sarcopenia is a direct cause of frailty because physical function depends, to some extent, on muscle mass.
Failure to thrive, sarcopenia, frailty, and malnutrition in old age have been recognized for a long time. Readers with a literary interest should read the description of the seventh age of man in Shakespeare’s As You Like It for a poetic description of this problem. In the geriatric and gerontologic literature, these processes have been referred to collectively as “predeath.”5 They have also been studied from a psychological point of view, in which the possibility that there is a “terminal drop” preceding death has been considered.6 Although the idea that there is a general decline in cognition immediately preceding death in very old people has been refuted,7 one interpretation of the data is that cognitive impairment may be a cause of failure to thrive, malnutrition, frailty, and sarcopenia, and that these systemic problems accompanying dementia lead to death.
Several recent studies have shown that the prevalence of failure to thrive in people older than 65 years is 10% to 25% in general outpatient populations.8,9 and 10 Prevalence is similar whether failure to thrive is defined as functional loss following hip fracture or weight loss in a general outpatient population. In patients older than 65 admitted to an acute care hospital, up to 50% have experienced weight loss before they entered the hospital. Among this number, hospitalization “cures” 50% to 75%.10 People with prehospital weight loss whose weight loss continues after hospitalization are at high risk of death. Seventy-five to ninety percent of people with persistent weight loss die within 1 year following hospitalization. There has been no careful look at risk factors for failure to thrive in elderly people. Anecdotal evidence suggests that dementia is a significant risk factor.
PATHOPHYSIOLOGY AND ETIOLOGY
Failure to thrive can be divided into two major categories: (1) failure to thrive caused by organic problems, many of which are diagnosable and treatable, and (2) failure to thrive due to nonorganic problems, which are commonly accompanied by starvation.11 Most nonorganic causes of failure to thrive can be diagnosed by careful functional, psychological, and social assessment, and many can be cured by direct dietary intervention. There remains a group of patients in whom failure to thrive has no clear cause. Idiopathic failure to thrive is a diagnosis of exclusion and can only be used as a diagnosis after the patient has been carefully evaluated for both organic and nonorganic problems.
Almost all chronic systemic diseases can cause failure to thrive in very old people. A list of organic causes of failure to thrive is given in Table 25-1. Although the manifestations are similar, many different mechanisms cause the functional decline, weight loss, malnutrition, sarcopenia, and frailty in these diseases. Cancer cachexia is due to a combination of hypermetabolism and central anorexia, although functional or mechanical gastrointestinal obstruction commonly plays a role. Chronic infections, such as tuberculosis, infectious endocarditis, and human immunodeficiency virus (HIV) infection, cause anorexia probably through a central action of inflammatory cytokines. In HIV infection, in addition to anorexia, malabsorption caused by drugs or opportunistic organisms is often involved. Nonetheless, the specific cause of acquired immune deficiency syndrome (AIDS) cachexia in an individual patient may not be evident. Chronic inflammatory diseases, epitomized by Crohn’s disease and rheumatoid arthritis, cause weight loss due to central anorexia produced by the systemic effects of inflammatory cytokines, and, in Crohn’s disease, malabsorption. The common endocrinologic diseases of aging—thyroid disease, diabetes, growth hormone deficiency, and deficiency of androgens and estrogens—generally cause failure to thrive, malnutrition, and sarcopenia by directly stimulating catabolism or inhibiting the anabolic response to nutrients. The mechanism behind failure to thrive caused by organ failure depends on the organ that has failed. Respiratory failure leads to failure to thrive through a combination of hypermetabolism, difficulty in eating due to hypoxemia while chewing, drug-induced anorexia, and catabolism stimulated by chronic steroid use. Cardiac cachexia appears to be cytokine mediated, at least in part.12 Cachexia due to liver failure is probably due to ineffective use of nutrients. Renal failure probably produces failure to thrive both by directly reducing hormones that stimulate cell proliferation (e.g., erythropoietin) and by the central anorectic effects of uremia.
TABLE 25-1 ORGANIC CAUSES OF FAILURE TO THRIVE
Depending on the specific drug, medications can cause failure to thrive by producing effects on nearly any system or organ.13,14 Drugs can directly inhibit appetite, the ability to eat and swallow, absorption of nutrients, the use of energy, protein, and micronutrients, and the ratio of anabolism to catabolism. Among the easiest causes of failure to thrive to treat are single drugs or polypharmacy. Table 25-2 lists groups of medications associated with weight loss and failure to thrive. Anorexia is the most common reason for failure to thrive due to medications. The second most common problem caused by medications is gastrointestinal dysfunction, which is generally a direct effect of gastric motility. A few medications directly affect metabolic rate.
TABLE 25-2 DRUGS THAT CAN CAUSE FAILURE TO THRIVE
Nonorganic causes of failure to thrive are generally associated with starvation due to inability to get food, lack of interest in food or anorexia, or inability to eat if food is available and the patient is hungry.
Table 25-3 shows the sequence of functions from the desire to eat through swallowing and demonstrates the complex interaction between the psychological, social, and functional aspects of eating. In a geriatric assessment paradigm these integrated components of eating behavior can be discussed, and separate emphases can be placed on physical function, psychological problems, and social considerations that affect food intake.
TABLE 25-3 FUNCTIONAL SEQUENCE FROM APPETITE TO ABSORPTION OF NUTRIENTS
Functional problems can be subdivided into instrumental activities of daily living (IADLs) and personal activities of daily living (ADLs). Among instrumental activities of daily living that affect failure to thrive are the ability to shop and prepare meals, and among the significant personal activities of daily living are the ability to eat, chew, and swallow. While these problems are not independent of dementia and depression or isolation and poverty, functional assessment must start with consideration of physical ability. In addition to physical problems that impair independent performance of ADLs and IADLs, progressive neurologic and rheumatologic diseases affect these necessary functions. Thus, cerebrovascular disease (stroke) and Parkinson’s disease, as well as other, less common progressive neurologic diseases (e.g., Creutzfeldt-Jakob disease, progressive supranuclear palsy, Pick’s disease, and so on), can impair independent performance of ADLs and IADLs and lead to starvation. Similarly, osteoarthritis, rheumatoid arthritis, and other diseases associated with joint or muscle inflammation and destruction can cause loss of function and consequent failure to thrive. Last, problems affecting chewing and swallowing and dental problems are often overlooked by physicians. Conversely, dentists often report weight gain following treatment of dental problems in elderly people. Table 25-4 is a list of diagnoses that can cause failure to thrive by interfering with function.
TABLE 25-4 PROBLEMS AFFECTING FUNCTION THAT CAN CAUSE FAILURE TO THRIVE
Psychological problems leading to failure to thrive are generally those that directly affect the desire for food (Table 25-5). The most common of these is depression. It has been proposed that most idiopathic failure to thrive is due to depression.15,16 A problem related to depression is intentional starvation or “chronic suicide.”17 This very vexing problem occurs not infrequently in people who have decided that they have no reason to continue living in their present condition. This problem must be very carefully separated from depression because depression is a treatable disease that may have to be addressed despite the patient’s wishes. An intentional decision not to eat may be the last autonomous decision a person makes. The moral and ethical dilemmas raised by people who decide to end their lives by not eating are profound.
TABLE 25-5 INTERACTIONS AMONG SOCIAL AND PSYCHOLOGICAL PROBLEMS CONTRIBUTING TO FAILURE TO THRIVE
As mentioned earlier, dementia can cause starvation and failure to thrive through its effect on independent performance of ADLs and IADLs. Anecdotally, it has been suggested that people with Alzheimer’s disease experience periodic drops in weight caused by decreases in food intake and increases in activity. The picture of the hyperactive, wandering patient with end-stage Alzheimer’s disease who nonetheless eats only four cans of commercial nutritional supplement is common. Such patients should be carefully assessed to be certain that medications, particularly neuroleptics or benzodiazepines, are not making this problem worse. Neuroleptics can cause akathisia characterized by increased agitation and activity and can precipitate failure to thrive. Benzodiazepines can cause anorexia and are known to predispose elderly people to falling.
Social disability also causes failure to thrive. As shown in Table 25-5, social problems are closely related to psychological problems. Older people are commonly isolated. They often have left family and friends in other states when they moved to retirement communities. Many widows and widowers live out the last years of their lives alone. Eating is a social event, and the absence of social contacts can directly lead to decreased food intake. Poverty, too, is a major contributor to failure to thrive in very old and oldest-old people. Most people have used up their retirement savings by the age of 75 to 85, and the amount of money available from public assistance programs may be inadequate to provide rent and medications as well as adequate food. The combination of isolation and poverty can lead to unusual eating behaviors and even the consumption of food that is not intended for people (e.g., cat or dog food).
Neglect and abuse are also causes of failure to thrive in the elderly. As people become more dependent on families and friends and less able to defend themselves because of physical impairment and cognitive deficits, they become more vulnerable to people who take advantage of them. People may take advantage of elderly individuals either by not feeding them as much as they should (that is, neglecting them) or by deliberately starving them for personal gain. Because of their vulnerability, failure to thrive in elderly people due to neglect or abuse is essentially indistinguishable from the effects of neglect and abuse of children and consequent childhood failure to thrive.
There is anecdotal evidence that, in addition to these well-established diagnoses, there are idiopathic or otherwise unknown causes of organic failure to thrive. One can hypothesize that immune dysfunction may cause centrally mediated anorexia and peripheral hypermetabolism even in the absence of an identifiable inflammatory stimulus.
APPROACH TO THE PATIENT WITH FAILURE TO THRIVE
The geriatric assessment paradigm (Table 25-6) is especially effective in evaluating older patients with failure to thrive. The medical portion of the geriatric assessment is specifically useful for addressing organic causes of failure to thrive. Psychological, functional, and social evaluations are especially useful in evaluating people with nonorganic failure to thrive. The group of patients in whom no clear etiology of failure to thrive emerges after a complete geriatric assessment, those with idiopathic failure to thrive, can then be identified for further observation or evaluation.
TABLE 25-6 GERIATRIC ASSESSMENT PARADIGM
Table 25-1 offers a list of common medical problems that cause failure to thrive in older people. These can be used to focus the history and physical examination. Family histories of cancer, exposure to tuberculosis and other chronic pathogens, and familial problems causing organ failure, particularly heart and kidney failure, are useful considerations with which to start the evaluation. Personal behaviors that increase risk for HIV infection, cancer, or heart disease, including sexual preference and tobacco or alcohol use, are equally important in the initial evaluation.
A complete physical evaluation, including careful examination of all major systems and organs, is invaluable. Not only should such an examination focus on possible organ failure, it should also focus on signs of systemic disease such as lymph node enlargement, signs of chronic infection such as subacute bacterial endocarditis, and evidence of chronic inflammatory processes such as inflammatory arthritis, temporal arteritis, and polymyalgia rheumatica.
Judicious use of laboratory testing based on the history and physical examination is essential for cost-effective evaluation of an elderly patient with failure to thrive. Although rare diseases can lead to failure to thrive in their end stages, indiscriminate use of laboratory tests to rule these out is not warranted without support from the history and physical examination. The most useful screening tests are a complete blood count with differential and a comprehensive chemistry panel. If the complete blood count with differential is normal, the likelihood of significant metabolic problems or problems associated with either a pleocytosis caused by inflammatory or neoplastic process or cytopenia due to chronic disease, impaired cytopoiesis, or accelerated cell destruction is decreased. The most common abnormality found on a complete blood count is anemia of chronic disease characterized by a mildly decreased red cell count and hematocrit, normal red cell indices, and decreased reticulocyte count in the absence of vitamin B12, folate, and iron deficiency. A comprehensive chemistry panel provides a rapid screen for chronic diseases affecting the kidneys or liver and for undiagnosed diabetes. The only endocrinologic test that has sufficient sensitivity and specificity to be used as a screening test in a person with failure to thrive is a thyroid function test. The simplest of these is the high-sensitivity measurement of thyroid-stimulating hormone (TSH), which can identify either hypothyroidism or hyperthyroidism. A chest radiograph is useful and cost effective because of the high prevalence of lung cancer, chronic pulmonary disease, tuberculosis, and often lung infection in this population. A screening mammogram, if one hasn’t been done recently, is probably also cost effective, although for breast cancer to cause failure to thrive it generally must be accompanied by distant metastases, which usually cause abnormalities on the physical examination or other tests. HIV testing in people with the appropriate risk factors is sometimes warranted. There is probably no reason to screen for other endocrinologic abnormalities such as growth hormone, estrogen, or testosterone levels. Other radiologic or nuclear medicine scans are also not cost effective. It is common for people with failure to thrive to have a combination of problems including anemia of chronic disease, hypoalbuminemia, hypocholesterolemia, and a mildly elevated fasting glucose level. This group of metabolic problems, however, does not help to identify a specific diagnosis since these abnormalities accompany most chronic inflammatory processes and chronic systemic diseases or organ failure.
Among the nonorganic causes of failure to thrive, one of the most important treatable problems is depression. Depression should be evaluated early in the course of evaluation for failure to thrive using either the Diagnostic and Statistical Manual, 4th edition (DSM-IV) criteria18 or the Geriatric Depression Scale.19 The Geriatric Depression Scale has been validated in both demented and nondemented patients. In the absence of an organic cause of failure to thrive and the presence of significant depression, a tentative diagnosis of depression should be entertained and treated aggressively. Untreated depression in an older person with failure to thrive can be fatal within a few weeks. Deliberate self-starvation without depression must be considered in the absence of other signs and symptoms of depression.
The second main area that has to be addressed in evaluating people for psychological problems causing failure to thrive is dementia. As mentioned previously, people with Alzheimer’s disease may show episodic decreases in weight and declines in physical function. Any of the popular screening methods for dementia should be used to evaluate a person with failure to thrive. A widely used screening tool is the Folstein minimental state examination.20 Other screens for dementia are also useful, although they may require the collection of additional information if they show that dementia may be present.
Screening for functional causes of failure to thrive can be accomplished simply and effectively. Vision that is adequate for reading is probably adequate to prevent failure to thrive unless it is causing loss of ability to perform an essential function, such as driving the car to buy food. Deafness by itself seldom causes failure to thrive, although it is sometimes accompanied by severe depression, and a deaf person who is depressed may very well have failure to thrive that can be treated simply by improving the ability to communicate.
Among the best screens for functional problems that cause failure to thrive are the Fillenbaum IADL scale21,22 and the Katz ADL scale.22,23 Dependence in IADLs often accompanies dementia, and a person who is unable to shop or prepare meals because of dementia may very well have failure to thrive because of starvation. Dependence in IADLs is often not easily addressed through the help offered by physical and occupational therapists. In contrast, dependence in ADLs recognized by the Katz ADL scale is often improved by physical and occupational therapy. Difficulty in performing ADLs can cause failure to thrive directly owing to the inability to ingest food even if it is available. Physicians should keep in mind that evaluation by a dentist is often important.
SOCIAL FACTORS AND ASSESSMENT
There are no good screening tests for social problems causing failure to thrive. Evaluation of income and poverty level is often difficult because of the patient’s reluctance to discuss finances even with a social worker. In addition, there are important regional and cultural variations in social ability and disability. For example, a person living in a city may have more social support than an isolated person living in a rural setting who must drive to get to a grocery store. One important cause of failure to thrive is the living situation of the patient. That is, does the patient live alone or with a spouse, family, or significant other? Another useful question that might be asked is, “If you were to break your leg and need some assistance for a week or two, how many people do you know who could help you?” Some people know many people who would be able to help out in the event of a medical emergency, and some people know very few. Living alone and isolation are among the most important risk factors for failure to thrive. Caregiver “burnout” or “fatigue” must also be considered.24 The physician must also consider whether an element of abuse or neglect exists.
It should be possible to evaluate an older individual efficiently for medical, psychological, functional, and social causes of weight loss and functional decline. From time to time, physicians encounter people who have idiopathic failure to thrive and have no problem that is easily identified. Anecdotal evidence suggests that even prolonged observation or an autopsy of these people is unable to pinpoint the cause of failure to thrive. Whether the diagnosis of such people should be idiopathic failure to thrive based on the negative work-up for other causes or malnutrition or depression because of the similarity in diagnostic criteria is a matter of professional judgment. Failure to thrive is an acceptable diagnosis of exclusion.
TREATMENT OF THE OLDER PERSON WITH FAILURE TO THRIVE
The mainstay of treatment of a patient with failure to thrive is a careful diagnostic work-up and specific treatment of the underlying problem. The organic causes listed in Table 25-1 can all be specifically diagnosed, and most have specific treatments. Depression is treatable with medications, counseling, or, occasionally, electroconvulsive therapy. Functional abnormalities can be addressed by referral to subspecialists or specific therapists. Social problems causing failure to thrive can be addressed specifically as well. In many cases, nonorganic causes of failure to thrive can be handled by admitting a patient to a nursing home or other long-term care situation.
Often, whether failure to thrive has a specific diagnosis or not, a common problem is inadequate food intake. Ideally, this problem is addressed directly by increasing the caloric and protein intake and prescribing a multivitamin with minerals. Among the best things to offer are high calorie food items such as desserts. One of the most calorically dense foods available is high-quality ice cream. This is generally eaten without any difficulty by most patients with failure to thrive. Other desserts, puddings, pies, and so on are also nutritionally dense. Standard nutritional supplements are also effective, although these supplements are often quite expensive and not as palatable as nutritionally dense ordinary foods. A patient with a treatable cause of failure to thrive may need enteral tube feeding. In general, such aggressive treatment should be restricted to people whose underlying problems are clearly reversible. One thing to avoid in treating a person with failure to thrive is unnecessary use of diets with limited salt, sugar, or cholesterol content. Such special diets are often aimed at preventing chronic diseases or the problems resulting from chronic diseases, which are of lower priority than reversing weight loss and functional decline. As mentioned earlier, weight loss that is not treatable commonly leads to death in over 75% of patients within the first year after it is recognized.
Failure to thrive in older patients is often recognized only immediately prior to death. No guidelines are available at this time that indicate when treatment of failure to thrive is futile. Nonetheless, advance directives must be carefully considered in diagnosing and treating failure to thrive in the elderly. Many individuals, particularly the very old, do not fear death as much as they fear disability, discomfort, and loss of dignity. Diagnostic and treatment modalities must be carefully considered with the wishes of the patient in mind. Patient autonomy, the right to make decisions about what is done to one’s own body, is one of the more salient ethical principles in this regard.
RECORDS AND ECONOMICS
Failure to thrive has its own International Classification of Diseases (ICD-9) code and can be used as a diagnosis of exclusion. Failure to thrive can also be used as a co-diagnosis when a principal diagnosis is known. Indeed, failure to thrive is one of the few geriatric syndromes that has an acceptable diagnostic code.
In the present health care climate, cost-effective diagnosis and cost-effective treatment are important considerations. A physician evaluating a patient with failure to thrive must develop a differential diagnosis list based on the history and physical examination. Screening tests not based on a defendable differential diagnosis list must be limited to those with very low cost and a high positive predictive value. The tests listed previously are the most useful ones, in the opinion of the author. Similarly, cost-effective treatment must be emphasized. To a great extent, this requirement decreases the usefulness of treating, for example, growth hormone deficiency. Although relative growth hormone deficiency is very prevalent in older people, there are no data suggesting that beginning such an expensive treatment in older people with failure to thrive produces reliable benefit. Among the most cost-effective treatments is simple dietary supplementation, particularly increasing the quantity of nutritionally dense normal foods. Of course, specific treatment of known diseases such as infective endocarditis is almost always highly cost effective.
Failure to thrive is a syndrome and a diagnosis of exclusion that occurs primarily in individuals of advanced age. It is defined by loss of function and weight loss, and, if it is not treatable, it can lead to death in a fairly short period of time. The prevalence of failure to thrive is 10% to 20% in people older than 65, and it is usually due to either organic disease or nonorganic problems: psychological, functional, or social. Failure to thrive due to diagnosable problems is treatable, although the mainstay of much treatment is nutritional supplementation. Idiopathic failure to thrive is commonly recognized and continues to vex specialists in geriatric medicine. As with other chronic diseases affecting survival near the end of life, careful attention must be paid to the risks, costs, and benefits of diagnostic tests and interventional modalities, taking into account the patient’s advance directives.
There are many unanswered questions relating to failure to thrive from both an epidemiologic point of view and a biologic point of view. The need for further research in this area is clearly evident.
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