Geriatric Physiological Changes and Syndromes

Physiological Changes

Geriatric patients experience predictable physiological changes across multiple organ systems, combined with increased vulnerability to geriatric syndromes, including frailty, falls, cognitive impairment, incontinence, and polypharmacy, which fundamentally alter their response to illness and injury 1, 2
Reduced glucose-induced insulin release and increased insulin resistance in peripheral tissues develop with aging 3
Abdominal obesity increases with elevated free fatty acids and inflammatory markers, further worsening insulin resistance 3
Impaired endothelial function occurs through suppressed nitric oxide formation and reduced flow-mediated dilation 3
Impaired leukocyte function, including decreased phagocytosis, bacterial killing, and chemotaxis, leads to increased infection risk 3
Activation of NF-κB pathway with production of proinflammatory cytokines and oxidative stress 3
Increased vascular permeability and mitochondrial dysfunction occur with acute stress 3
Elevated renal threshold for glycosuria masks typical hyperglycemia symptoms like polyuria and polydipsia 3
Impaired thirst mechanisms increase dehydration risk 3

Frailty is an independent mortality risk factor in elderly trauma patients, affecting approximately 25% of persons aged ≥85 years 2, 4
Falls are the most common injury mechanism, with 6% sustaining fractures and 10-30% developing polytrauma 4
Cognitive impairment/dementia is a permanent cognitive decline affecting treatment decisions and medication adherence 5
Delirium is an acute cognitive impairment often precipitated by illness or medications 1
Polypharmacy is a significant concern, with older adults accounting for >700,000 emergency visits annually for adverse drug events, and insulin and warfarin being leading causes 3
Depression commonly co-occurs with cognitive decline and affects treatment adherence 1, 5

Inadequate caloric intake is the primary cause of malnutrition, not the underlying illness itself 2
Unintended weight loss >5% in 6 months or >10% beyond 6 months defines malnutrition in older adults 2
Vitamin D deficiency increases osteoporosis and fracture risk 5
Increased infection rates and pressure ulcers are clinical consequences of malnutrition 2
Prolonged hospital stays and convalescence are associated with malnutrition 2
Higher mortality rates directly correlate with malnutrition 2

Social isolation is a significant predictor of mortality in older adults 5
Living conditions, caregiver presence, and financial status directly impact treatment feasibility 5
Multicomplexity, the intersection of multiple chronic conditions with social determinants, fundamentally alters care management 1
Activities of daily living (ADL) independence is jeopardized by acute illness combined with age-related changes 2
Autonomy and quality of life are the primary goals of geriatric medicine, not disease cure 2
Reduced capacity for rehabilitation means many patients cannot return to baseline function 2

Attributing symptoms to "old age" requires investigation, not dismissal 3
Missing atypical presentations, as elderly patients often lack typical symptoms, is a common pitfall 3
Overlooking medication burden and systematically reviewing all medications for appropriateness and deprescribing opportunities is crucial 1, 5
Ignoring cognitive status, as cognitive impairment affects informed consent, medication adherence, and self-care abilities, is a significant concern 1, 5
Failing to assess frailty, as frailty predicts outcomes better than chronological age alone, is a critical oversight 4, 6, 7