Homeostasis in Geriatrics PDF

The tendency toward a stable equilibrium between interdependent elements, especially as maintained by physiological processes HOMEOSTASIS 1 April 2024 Volker Homeostasis 1 Homeostasis Altered Homeostasis in Geriatrics refers to the process of change brought on by the normal aging process and its eff...

The tendency toward a stable equilibrium between interdependent elements, especially as maintained by physiological processes HOMEOSTASIS 1 April 2024 Volker Homeostasis 1 Homeostasis Altered Homeostasis in Geriatrics refers to the process of change brought on by the normal aging process and its effect on illness and injury. As we study the aging process, it is very important for clinicians to understand what changes are normal in the aging process, what changes are brought about because of disease or disuse, and how these two processes interact to produce risk, morbidity and loss of function, and mortality. 1 April 2024 Volker Homeostasis 2 Homeostasis in Aging Physiologic reserves are diminished in each individual body system Diminished feedback systems Loss of integrated physiologic homeostasis Leading to diminished total-body reserves Crisis in one system induces loss of regulation in others This is an interrelated, interdependent problem 1 April 2024 Volker Homeostasis 3 Homeostasis Norm a l age- relate d declin e Crisis Crisis 1 April 2024 Volker Homeostasis 4 Homeostenosis Norm a l age- relate d declin e Crisis Physiologic Reserve or Resilience Crisis Death ses a e r c n I eficit D e v r e c Res i g o l o i s Phy 1 April 2024 Volker Homeostasis 5 Homeostenosis As we age we have less reserve As we age sudden illness results in crisis and recovery does not usually return to baseline Result: mild/moderate illness & injury → prolonged recovery (loss of function) Serious illness & injury → significantly increased risk of death 1 April 2024 Volker Homeostasis 6 Today we will… Try to differentiate between normal aging and pathologic aging Focus on normal changes in the geriatric patient due to aging Explore abnormal responses to aging by organ system 1 April 2024 Volker Homeostasis 7 Principles Homeostatic balance will be less optimal, and reached more slowly, with age Decreased cellular function (rate and efficiency) secondary to accumulation of lipofuscin, secondary lysosomes and other inter- and intracellular detritus (clinker theory) Drug distribution and homeostatic mechanisms change with change in body composition, particularly a decrease in total body water 1 April 2024 Volker Homeostasis 8 Endocrine System Aging Physiology Decreased T3 Gradual pancreatic β-cell senescence and increased tissue resistance to insulin Marked decrease in DHEA Sex hormone decrease 1 April 2024 Clinical Presentation Occult hypothyroidism Increased fasting glucose and glucose intolerance Osteoporosis, decreased libido, decreased corticosteroid reserve Volker Homeostasis 9 Endocrine System Aging Physiology Clinical Presentation Decreased plasma renin and Predisposition to aldosterone hyperkalemia Increased norepinephrine, Impaired extracellular vasopressin, atrial volume regulation and natriuretic peptide, and electrolyte homeostasis parathormone Normal resting heart rate but diminished maximal Decreased responsiveness to β-adrenergic stimulation heart rate 1 April 2024 Volker Homeostasis 10 Cardiovascular System Aging Physiology Decreased baroreceptor response Increased collagen deposition and cross-linking → increased arterial stiffness Decreased cardiocytes and increased fibroblasts 1 April 2024 Clinical Presentation Increased risk of orthostatic hypotension (falls) Increased SBP (stiff pipes) and afterload Impaired LV relaxation (diastolic dysfunction) Increased reliance on atrial kick (lacking in Afib) Volker Homeostasis 11 Cardiovascular System Aging Physiology Marked dropout of pacemaker cells in SA node Deterioration of conductive cells in SA/AV/His/Purkinje system 1 April 2024 Clinical Presentation Increased risk of atrial fibrillation Decreased maximal heart rate Increased risk of heart block Volker Homeostasis 12 Pulmonary System Aging Physiology Increased collagen deposition and cross-linking → increased arterial stiffness; fibrosis Accumulated effects of oxidative stress/free radical damage Reduced diaphragmatic strength (sarcopenia) 1 April 2024 Clinical Presentation Decreased lung elasticity, decreased FVC and FEV1 Loss of alveoli and total alveolar surface area, and thus maximal oxygen uptake (emphysematous change) Reduced tidal volume, V/Q mismatch Volker Homeostasis 13 Gastrointestinal System Aging Physiology Dental caries Slowed colonic transit time Increased hepatocyte accumulation of lipofuscin and secondary lysosomes 1 April 2024 Clinical Presentation Decreased appetite, infection, ?CVD Constipation Reduced metabolism, clearance of drugs Volker Homeostasis 14 Renal/urinary System Aging Physiology Decreased renal mass, GFR, renal tubular secretion and concentrating ability, and bladder capacity Gradual hypertrophy of prostate 2° to lifelong testosterone exposure 1 April 2024 Clinical Presentation Decreased creatinine clearance (~8% per decade) Decreased drug clearance Obstruction due to BPH Carcinoma of Prostate risk Volker Homeostasis 15 Musculoskeletal System Aging Physiology Mechanical wear and tear of articular cartilage Gradual lengthening of tendons, ligaments, and fascia 1 April 2024 Clinical Presentation Arthritic pain, loss of ROM and stability Increased laxity of joints Flattening of arch of feet Why aren’t we all walking around on pancake feet? Volker Homeostasis 16 Musculoskeletal System Aging Physiology Decreased muscle mass and lean body mass Negative calcium balance in both sexes, decreased bone mass 1 April 2024 Clinical Presentation Sarcopenia, weakness, increased fall risk Osteoporosis, loss of height, increased curvature of spine (kyphosis), decreased muscle strength for breathing, and gait impairment Volker Homeostasis 17 Skin Aging Physiology Decreased vascularity of dermis, decreased total body water Crosslinking and deterioration of collagen and elastin Altered epidermal turnover time Decreased melanocytes Low dermis density, reduced subcutaneous adipose and eccrine function Hair loss 1 April 2024 Clinical Presentation Dry skin, greater risk of tearing and injury Prolonged wound healing Uneven tanning Poor insulation, decreased sweating response Decreased self-esteem Volker Homeostasis 18 Skin Tear Shearing tear along dermis/ epidermis plane 1 April 2024 Volker Homeostasis 19 Special Senses—Vision Aging Physiology Clinical Presentation Increased rigidity of iris Decreased size of anterior chamber Accumulation of yellow substance in lens Decreased elasticity and cloudiness of lens (cataracts) Decreased size of pupils, impaired adaptation to variable lighting Alteration of color perception; e.g. blue appears green-blue Significant impairment of vision in presence of glare and lowlight conditions; falls; global impairment 1 April 2024 Volker Homeostasis 20 Special Senses—Hearing Aging Physiology Loss of cochlear neurons Hearing loss for pure tones; higher frequencies more than lower frequencies 1 April 2024 Clinical Presentation Social isolation, impaired ability to learn and to keep up Volker Homeostasis 21 Special Senses—Olfactory Aging Physiology Detection reduced by 50% 1 April 2024 Clinical Presentation Reduced appetite Decreased protein/calorie intake Volker Homeostasis 22 Immune System Aging Physiology Involution of thymus with decreased new T lymphocytes, decreased capability of T lymphocytes to proliferate in response to antigens Decreased suppressor T lymphocytes, decreased humoral immunity 1 April 2024 Clinical Presentation Anergy (loss of response) to various skin tests Inadequate response to extrinsic antigens like the pneumococcal vaccine. Decreased T cell function Decreased antibody response Volker Homeostasis 23 Spiritual/Psychological Systems Aging Physiology Decreased special senses Loss of spouse and loved ones/close friends Dependency and debility Frailty 1 April 2024 Clinical Presentation Barriers to communication Grief, sense of loss, depression; social isolation Shame, loss of self-esteem and self-confidence; despair Volker Homeostasis 24 In General Aging Physiology Lifelong accumulation of trauma Environmental exposures Non-medical stressors – – – – Social Societal Cultural Financial 1 April 2024 Clinical Presentation Various disabilities Carcinogenesis Diseases of poverty, abuse, exploitation, discrimination Volker Homeostasis 25 Obtundation: Differential Dx Hyponatremia Dehydration Hypoxia MI Addisonian crisis Hyperglycemia Urinary retention Constipation 1 April 2024 Volker Homeostasis Stroke Pneumonia Urosepsis Other infection Renal failure / azotemia Intoxication Depression 26 Summary Awareness of altered homeostasis can guide the provider To recognize more efficiently the disease states more commonly found in the geriatrics age group because of that altered homeostasis To consider multimorbidity in the evaluation and treatment in the geriatric population To treatments and interventions which are less likely to stress reserves To promote lifestyle changes which minimize further risk to homeostasis and crisis states 1 April 2024 Volker Homeostasis 27 Homeostenosis Norm a l age- relate d declin e Crisis Physiologic Reserve or Resilience Crisis Death ses a e r c n I eficit D e v r e c Res i g o l o i s Phy 1 April 2024 Volker Homeostasis 28