General Considerations
Undernutrition affects substantial numbers of elderly. The degree of unintended weight loss that deserves evaluation is not agreed upon, although a reasonable threshold is loss of 5% of body weight in 1 month or 10% of body weight in 6 months.
“Frailty” is a term that may be clinically useful for describing a subgroup of patients—almost always elders—who have delicate health, are not robust, and have decreased functional reserve. Although clinicians generally agree on most of the clinical characteristics that define the frailty syndrome, there is not yet a consensus definition of frailty. Frailty may be accompanied by physiologic changes in inflammatory and neuroendocrine systems. The label of “failure to thrive” is typically applied when some triggering event—loss of social support, a bout of depression or pneumonia, the addition of a new medication—pulls a struggling elderly person below the threshold of successful independent living.
Clinical Findings
Useful laboratory and radiologic studies for the patient with weight loss include complete blood count, serum chemistries (including glucose, TSH, creatinine, calcium), urinalysis, and chest radiograph. These studies are intended to uncover an occult metabolic or neoplastic cause but are not exhaustive. Exploring the patient’s social situation, cognition, mood, and dental health are at least as important as looking for a purely medical cause of weight loss.
There is not yet a standard assessment tool for frailty. However, the most widely recognized definition of frailty requires that the patient exhibit at least three of the five following clinical criteria: (1) slow gait speed; (2) low hand grip strength; (3) exhaustion; (4) weight loss; and (5) low energy expenditure. Few physicians screen for the syndrome, since an evidence-based treatment for frailty does not yet exist. Patients who meet criteria for the frailty syndrome are at increased risk for poor clinical outcomes.
Treatment
Oral nutritional supplements of 200–1000 kcal/d can increase weight and improve outcomes in malnourished hospitalized elders. Megestrol acetate as an appetite stimulant has not been shown to increase body mass or lengthen life in the elderly population. For those who have lost the ability to feed themselves, assiduous hand feeding may allow maintenance of weight. Although artificial nutrition and hydration (“tube feeding”) may seem a more convenient alternative, it deprives the patient of the taste and texture of food as well as the social milieu typically associated with mealtime; before this option is chosen, the patient or his or her surrogate should be offered the opportunity to review the benefits and burdens of the treatment in light of overall goals of care. If the patient makes repeated attempts to pull out the tube during a trial of artificial nutrition, the treatment burden becomes substantial, and the utility of tube feeding should be reconsidered. Although commonly used, there is no evidence that tube feeding prolongs life in patients with end-stage dementia.
The ideal strategies for preventing the frailty syndrome are unknown. At present, treatment is largely supportive, multifactorial, and individualized based on patient goals, life expectancy, and comorbidities. Sometimes, transitioning a patient to a palliative approach or a hospice program is the most appropriate clinical intervention when efforts to prevent functional decline fail.
