Geriatrics stands at the intersection of three forces:
Gerontology (both basic and applied)
Chronic disease management, especially multimorbidities
Principles of gerontology can help to explain insights of geriatric care. For example, the presentation of disease is often different in older persons because the response to stress is different. A hallmark of aging is a decreased ability to respond to stress. The body's stress response is what typically generates the symptoms of an illness. Older people fail to respond as actively. Hence, they may not have spiking fevers or elevated white blood cell counts in the face of an infection. Heart disease may be silent.
Chronic disease management is difficult on its own. It is much more difficult when an older patient suffers from multiple simultaneous diseases. Basic care guidelines may not work. Indeed, they may pose a threat (Boyd et al., 2005).
Much of the emphasis in care planning is directed at containing disease and maintaining function and improving quality of life. Death is a part of old age. Geriatrics must deal with that reality and help patients and families deal with end of life, helping them to make informed decisions that reflect their goals and priorities. But geriatrics cannot focus exclusively on end-of-life care. One compromise has been the evolution of palliative care (discussed in Chapter 18). To this triad, some might also add a role for advocating reasonable preventive actions (see Chapter 5).
The care of older patients differs from that of younger patients for a number of reasons. While there continues to be a debate about the cause of these differences, it is likely that they are a combination of biological changes that occur during the course of aging, associated diseases, and attitudes and beliefs of older adults and their caregivers. Aging is defined as the time-sequential deterioration that occurs in most living beings, including weakness, increased susceptibility to disease and adverse environmental conditions, loss of mobility and agility, and age-related physiological changes (Goldsmith, 2006). At least in vitro, it is clear that the “aging clock” can be reset (reviewed in Rando and Chang, 2012). Somatic cell nuclear transfer of the nucleus of a mature somatic cell into an enucleated oocyte can give rise to mature, fertile animals.
It is important to distinguish life expectancy from life span. The former refers to what proportion of the possible maximum age a person may live. The latter suggests a biological limit to how many years a species can expect to survive. In general, geriatrics has the most to contribute to improving life expectancy, but new genetic breakthroughs may ultimately affect life span as well. Another helpful distinction is between chronological aging and gerontological aging. The latter is calculated on the basis of the risk of dying, the so-called force of mortality. Thus, two people of the same chronological age ...