Geriatric Nursing and Age Related Changes Age-Related Health Problems
Gerontology and Nursing Care for Age-Related Changes in Body Systems: Their Assessment, Age-Related Physiological Causes, and Nursing Education and Care
Topic Objectives
Upon completing this topic, the reader should be able to:
- Describe the structural and functional changes in multiple body systems during the normal aging process.
- Understand the clinical significance of these age-related changes concerning the health and disease risks of the older adult.
- Discuss the components of a nursing assessment for the older adult, considering the manifestations of normal aging.
- Identify care strategies to promote successful aging in older adults, considering age-related changes.
Aging as a Normal Process
The process of normal aging, independent of disease, is accompanied by various changes in body systems.
As evidenced by longitudinal studies such as the Baltimore Longitudinal Study of Aging (2010), modifications occur in both the structure and function of organs, becoming most pronounced in those aged 85 years or older (Hall, 2002).
Many of these alterations are characterized by a decline in physiological reserve. While baseline function is preserved, organ systems become progressively less capable of maintaining homeostasis when exposed to environmental stresses, disease, or medical therapies (Miller, 2009).
Age-related changes are significantly influenced by genetics and long-term lifestyle factors, including physical activity, diet, alcohol consumption, and tobacco use (Kitzman & Taffet, 2009).
Furthermore, there is significant heterogeneity among older adults; clinical manifestations of aging can range from stability to significant functional decline in specific organ systems (Beck, 1998).
Clinical Implications of Age-Related Changes
The clinical implications of these age-related changes are crucial in nursing assessment and care of the older adult for several reasons. First, changes associated with normal aging must be differentiated from pathological processes to develop appropriate interventions (Gallagher, O’Mahony, & Quigley, 2008).
Manifestations of aging can also adversely impact the health and functional capability of older adults.
Developing and Evaluating Clinical Practice Guidelines requires therapeutic strategies to correct (Matsumura & Ambrose, 2006). Age-associated changes predispose older persons to selected diseases (Kitzman & Taffet, 2009). Thus, nurses’ understanding of these risks can lead to more effective assessment and care approaches.
Finally, aging and illness may interact reciprocally, resulting in altered presentation of illness, response to treatment, and outcomes (Hall, 2002).
Cardiovascular System
Cardiac reserve declines in normal aging. This alteration does not affect cardiac function at rest; resting heart rate, ejection fraction, and cardiac output remain virtually unchanged with age.
However, under physiological stress, the older adult’s heart struggles to increase both rate and cardiac output in response to increased cardiac demand, such as during physical activity or infection (Lakatta, 2000).
This diminished functional reserve results in reduced exercise tolerance, fatigue, shortness of breath, slow recovery from tachycardia (Watters, 2002), and intolerance to volume depletion (Mick & Ackerman, 2004).
Additionally, due to the decreased maximal attainable heart rate with aging, a heart rate above 90 beats per minute (bpm) in an older adult indicates significant physiological stress (Kitzman & Taffet, 2009).
Age-dependent changes in both the vascular system and the heart contribute to the impairment in cardiac reserve. An increase in the wall thickness and stiffness of the aorta and carotid arteries results in decreased vessel compliance and greater systemic vascular resistance (Thomas & Rich, 2007).
Elevated systolic blood pressure (BP) with constant diastolic pressure follows, increasing the risk of isolated systolic hypertension and widened pulse pressure (Joint National Committee [JNC], 2004).
Strong arterial pulses, diminished peripheral pulses, and an increased potential for inflamed varicosities occur commonly with age. Reductions in capillary density restrict blood flow in the extremities, leading to cool skin (Mick & Ackerman, 2004).
As an adaptive measure to increased workload against non-compliant arteries, the left ventricle and atrium hypertrophy and become rigid.
The impairment in left ventricular relaxation during diastole places greater dependence on atrial contractions for left ventricular filling (Lakatta, 2000).
Furthermore, sympathetic response in the heart is blunted due to decreased beta-adrenergic sensitivity, resulting in reduced myocardial contractility (Thomas & Rich, 2007).
Additional age-related changes include sclerosis of the atrial and mitral valves, impairing their closure and increasing dysfunction risk. The ensuing leaky heart valves may result in aortic regurgitation or mitral stenosis, presenting on exam as heart murmurs (Kitzman & Taffet, 2009).
Loss of pacemaker and conduction cells contributes to changes in the resting electrocardiogram (ECG) of older adults. Isolated premature atrial and ventricular complexes are common arrhythmias, and the risk of atrial fibrillation is increased (Thomas & Rich, 2007).
Because of atrial contractions in diastole, S4 frequently develops as an extra heart sound (Lakatta, 2000).
Baroreceptor function, which regulates BP, is impaired with age, particularly with changes in position. Postural hypotension with orthostatic symptoms may follow, especially after prolonged bed rest, dehydration, or cardiovascular drug use, and can cause dizziness and increase the risk of falls (Mukai & Lipsitz, 2002).
Cardiac assessment of an older adult includes performing an ECG and monitoring heart rate (40-100 bpm within normal limits), rhythm (noting whether it is regular or irregular), heart sounds (S1, S2, or extra heart sounds S3 in heart disease or S4 as a common finding), and murmurs (noting location where loudest).
The apical impulse is displaced laterally. In palpating the carotid arteries, asymmetric volumes and decreased pulsations may indicate aortic stenosis and impaired left cardiac output, respectively.
Auscultation of a bruit potentially suggests occlusive arterial disease. Peripheral pulses should be assessed bilaterally at a minimum of one pulse point in each extremity.
Assessment may reveal asymmetry in pulse volume, suggesting insufficiency in arterial circulation (Docherty, 2002). The nurse should examine the lower extremities for varicose veins and note dilation or swelling. In addition, dyspnea with exertion and exercise intolerance are critical to note (Mahler, Fierro-Carrion, & Baird, 2003).
BP should be measured at least twice (Kestel, 2005) on the older adult and performed in a comfortably seated position with back support and feet flat on the floor. The BP should then be repeated after 5 minutes of rest.
Measurements in both supine and standing positions evaluate postural hypotension (Mukai & Lipsitz, 2002).
Nursing Education for Cardiac Issues
Nursing care strategies include referrals for older adults with heart rhythm irregularities and decreased or asymmetric peripheral pulses. The risk of postural hypotension emphasizes the need for safety precautions (Mukai & Lipsitz, 2002) to prevent falls.
These include avoiding prolonged recumbency or motionless standing and encouraging the older adult to rise slowly from lying or sitting positions and wait 1 to 2 minutes after a position change to stand or transfer.
Overt signs of hypotension, such as a change in sensorium or mental status, dizziness, or orthostasis, should be monitored, and fall prevention strategies should be instituted.
Sufficient fluid intake is advised to ensure adequate hydration and prevent hypovolemia for optimal cardiac functioning (Docherty, 2002; Watters, 2002).
Older adults should be encouraged to adopt lifestyle practices for cardiovascular fitness to achieve a healthy body weight (body mass index [BMI] 18.5-24.9 kg/m²; American Heart Association Nutrition Committee et al., 2006) and normal BP (JNC, 2004).
These practices involve a healthy diet (Knoops et al., 2004), physical activity appropriate for age and health status (Netz, Wu, Becker, & Tenenbaum, 2005), and elimination of the use of and exposure to tobacco products (US Department of Health and Human Services [USDHHS], 2004a).
Pulmonary System
Respiratory function slowly and progressively deteriorates with age. This decline in ventilatory capacity rarely affects breathing during rest or customary limited physical activity in healthy older adults (Zeleznik, 2003); however, with greater than usual exertional demands, pulmonary reserve against hypoxia is readily exhausted, and dyspnea occurs (Imperato & Sanchez, 2006).
Anatomical and Physiological Changes in Respiratory System
Several age-dependent anatomical and physiological changes combine to impair the functional reserve of the pulmonary system. Respiratory muscle strength and endurance deteriorate to restrict maximal ventilatory capacity (Buchman et al., 2008).
Secondary to calcification of rib cage cartilage, the chest wall becomes rigid (Imperato & Sanchez, 2006), limiting thoracic compliance. Loss of elastic fibers reduces recoil of small airways, which can collapse and cause air trapping, particularly in dependent portions of the lung.
Decreases in alveolar surface area, vascularization, and surfactant production adversely affect gaseous exchange (Zeleznik, 2003). Additional clinical consequences of aging include an increased anteroposterior chest diameter caused by skeletal changes.
An elevated respiratory rate of 12-24 breaths per minute accompanies reduced tidal volume for rapid, shallow breathing. Limited diaphragmatic excursion and chest/lung expansion can result in less effective inspiration and expiration (Buchman et al., 2008; Mick & Ackerman, 2004).
Due to decreased cough reflex effectiveness and deep breathing capacity, mucus and foreign matter clearance are restricted, predisposing to aspiration, infection, and bronchospasm (Watters, 2002).
Further, elevating the risk of infection is a decline in ciliary and macrophage activities and drying of the mucosal membranes with more difficult mucous excretion (Hrwe, Mushtaq, Robinson, Rosher, & Khardori, 2007).
With the loss of elastic recoil comes the potential for atelectasis. Due to reduced respiratory center sensitivity, ventilatory responses to hypoxia and hypercapnia are blunted (Imperato & Sanchez, 2006), putting the older adult at risk for respiratory distress with illness or narcotic administration (Zeleznik, 2003).
Changes in Ventilatory Capacity
Modifications in ventilatory capacity with age are reflected in changes in pulmonary function tests measuring lung volumes, flow rates, diffusing capacity, and gas exchange. Because total lung capacity remains constant, vital capacity is reduced, and residual volume is increased.
Reductions in all measures of respiratory flow (forced expiratory volume in 1 second [FEV1], forced vital capacity [FVC], FEV1/FVC, peak expiratory flow rate [PEFR]) quantify a decline in useful air movement (Imperato & Sanchez, 2006).
Due to impaired alveolar function, the lung’s diffusing capacity for carbon monoxide (DLCO) declines, as does pulmonary arterial oxygen tension (PaO2), indicating impaired oxygen exchange; however, arterial pH and partial pressure of arterial carbon dioxide (PaCO2) remain constant (Enright, 2009).
Reductions in arterial oxygen saturation and cardiac output restrict the amount of oxygen available for use by tissues, particularly in the supine position, although arterial blood gas seldom limits exercise in healthy subjects (Zeleznik, 2003).
Respiratory Assessment Respiratory Pattern
Respiratory assessment includes determining the breathing rate, rhythm, regularity, volume (hyperventilation/hypoventilation), depth (shallow, deep; Docherty, 2002), and effort (dyspnea; Mahler et al., 2003).
Auscultation of breath sounds throughout the lung fields may reveal decreased air exchange at the lung bases (Mick & Ackerman, 2004).
The thorax and symmetry of chest expansion should be inspected. A history of respiratory disease (tuberculosis, asthma), tobacco use (expressed as pack years), and extended exposure to environmental irritants through work or avocation is contributory (Imperato & Sanchez, 2006).
Secretions and Productive Cough
Subjective assessment of cough includes questions on quality (productive/nonproductive), sputum characteristics (note hemoptysis; purulence indicating possible infection), and frequency (during eating or drinking, suggesting dysphagia and aspiration; Smith & Connolly, 2003).
Secretions and decreased breathing rate during sedation can reduce ventilation and oxygenation (Watters, 2002). Oxygen saturation can be followed through arterial blood gases and pulse oximetry (Zeleznik, 2003), while breathing rate (greater than 24 respirations per minute), accessory muscle use, and skin color (cyanosis, pallor) should also be monitored (Docherty, 2002).
The inability to expectorate secretions, the appearance of dyspnea, and decreased saturation of oxygen (SaO2) levels suggest the need for suctioning to clear airways (Smith & Connolly, 2003).
Optimal positioning to facilitate respiration should be regularly monitored, with upright positions (Fowler’s or orthopneic position) recommended (Docherty, 2002). Pain assessment may be necessary to allow ambulation and deep breathing (Mick & Ackerman, 2004).
See Atypical Presentation of Disease section for the assessment of pneumonia, tuberculosis, and influenza.
Nursing Care Education and Strategies
Nursing care strategies useful in facilitating respiration and maintaining patent airways in the older adult include positioning to allow maximum chest expansion through the use of semi or high Fowler’s or orthopneic position (Docherty, 2002).
Additionally, frequent repositioning in bed or encouraging ambulation, if mobility permits, is advised (Watters, 2002). Analgesics may be necessary for ambulation and deep breathing (Mick & Ackerman, 2004).
Hydration is maintained through fluid intake (6-8 oz per day) and air humidification, preventing desiccation of mucous membranes and loosening secretions to facilitate expectoration (Suhayda & Walton, 2002).
Suctioning may be necessary to clear airways of secretions (Smith & Connolly, 2003), while oxygen should be provided as needed (Docherty, 2002).
Incentive spirometry, using sustained maximal inspiration devices (SMIs), can improve pulmonary ventilation, mainly inhalation, and loosen respiratory secretions, particularly in older adults unable to ambulate or declining in function (Dunn, 2004).
Deep breathing exercises, such as abdominal (diaphragmatic) and pursed-lip breathing, and controlled and huff coughing, can further facilitate respiratory function.
Techniques for healthy breathing, including sitting and standing erect, nose breathing (Dunn, 2004), and regular exercise (Netz et al., 2005), should be promoted. Education on eliminating the use of and exposure to tobacco products should be emphasized (USDHHS, 2004a).
Renal and Genitourinary Systems
In normal aging, the mass of the kidney declines with a loss of functional glomeruli and tubules and a reduction in blood flow.
Concomitantly, changes occur in the activity of regulatory hormones, vasopressin (antidiuretic hormone), atrial natriuretic hormone, and the renin-angiotensin-aldosterone system (Miller, 2009).
These alterations combine to result in a decreased glomerular filtration rate (GFR), with a 10% decrement per decade starting at age 30, and impaired electrolyte and water management (Beck, 1998).
Despite these changes, the older adult maintains the ability to regulate fluid balance under baseline conditions; however, with age, the renal system is more limited in responding to externally imposed stresses.
This reduced functional reserve increases vulnerability to disturbances in fluid homeostasis and renal complications and failure (Lerma, 2009), particularly from fluid/electrolyte overload and deficit, medications, or illness (Miller, 2009).
Medication Effects on the Urinary System
The decline in functional nephrons emphasizes the risk from nephrotoxic agents, including nonsteroidal anti-inflammatory drugs (NSAIDs), beta-lactam antibiotics, and radiocontrast dyes.
Reduced GFR impairs the older adult’s ability to excrete renally cleared medications, such as aminoglycoside antibiotics (e.g., gentamicin) and digoxin, increasing the risk of adverse drug reactions (Beyth & Shorr, 2002).
Dosages should be based on GFR, estimated by the Cockcroft-Gault equation for creatinine clearance (Péquignot et al., 2009) or the modification of diet in renal disease (MDRD), rather than by serum creatinine concentration (Miller, 2009; National Kidney Disease Education programs, 2009).
Serum creatinine levels overestimate GFR due to the parallel decrease in skeletal muscle mass, which produces creatinine and GFR for creatinine elimination, resulting in potential drug overdose (Beck, 1998).
Risk of Electrolyte Imbalance
Increased risk of electrolyte imbalances can result from age-dependent impairment in the excretion of excessive sodium loads, particularly in heart failure and with NSAID use, leading to intravascular volume overload.
Clinical indicators include weight gain (greater than 2%), intake greater than output, edema, change in mental status, tachycardia, bounding pulse, pulmonary congestion with dyspnea, increased BP, and central venous pressure (CVP), and distended neck/peripheral veins (Beck, 1998).
Conversely, sodium wasting or excess sodium excretion when maximum sodium conservation is needed, can occur with diarrhea.
Hypovolemia and dehydration may ensue (Stern, 2006), manifesting as an acute change in mental status (may be the initial symptom), weight loss (greater than 2%), decreased tissue turgor, dry oral mucosa, tachycardia, decreased BP, postural hypotension, flat neck veins, poor capillary refill.
Oliguria (less than 30 mL/hr), increased hematocrit, and specific gravity of urine, blood urea nitrogen (BUN): plasma creatinine ratio greater than 20:1, and serum osmolality greater than 300 mOsm/kg (Mentes, 2006).
Impaired potassium excretion puts the older adult at risk for hyperkalemia, particularly in heart failure and with the use of potassium supplements, potassium-sparing diuretics, NSAIDs, and angiotensin-converting enzyme (ACE) inhibitors (Mick & Ackerman, 2004).
Clinical indicators include diarrhea, change in mental status, cardiac dysrhythmias or arrest, muscle weakness and areflexia, paresthesia and numbness in extremities, ECG abnormalities, and serum potassium greater than 5.0 mEq/L (Beck, 1998).
Acidosis and Alkylosis
Limited acid excretion capability can cause metabolic acidosis during acute illness in the older adult. This condition presents as Kussmaul’s respirations, change in mental status, nausea, vomiting, arterial blood pH less than 7.35, serum bicarbonate less than 22 mEq/L, and PaCO2 less than 38 mm Hg with respiratory compensation (Beck, 1998).
Causes of abnormal water metabolism with age include diminution in maximal urinary concentrating ability, which, in concert with blunted thirst sensation and total body water, can result in hypertonic dehydration and hypernatremia (Mentes, 2006).
Often associated with insensible fluid loss from fever (Miller, 2009), hypernatremia presents with thirst; dry oral mucosa; dry, furrowed tongue; postural hypotension; weakness; lethargy; serum sodium greater than 150 mEq/L; and serum osmolality greater than 290 mOsm/kg. Disorientation, seizures, and coma occur in severe hypernatremia (Suhayda & Walton, 2002).
Impaired excretion of a water load, exacerbated by ACE inhibitors, thiazide diuretics (Miller, 2009), and selective serotonin reuptake inhibitors (SSRIs: Mentes, 2006), predisposes the older adult to water intoxication and hyponatremia (Beck, 1998).
Clinical indicators involve lethargy, nausea, muscle weakness and cramps, serum sodium less than 135 mEq/L, and serum osmolality less than 290 mOsm/kg. Confusion, coma, and seizures are seen in severe hyponatremia (Suhayda & Walton, 2002).
Lower Urinary System Changes
Changes in the lower urinary tract with age include reduced bladder elasticity and innervation, contributing to decreases in urine flow rate, voided volume, and bladder capacity, as well as increases in after void residual and involuntary bladder contractions.
A delayed or decreased perception of the signal from the bladder to void translates into urinary urgency (Kevorkian, 2004). Increased nocturnal urine flow, which results from altered regulatory hormone production, impaired ability to concentrate urine, and bladder muscle instability, can lead to nocturnal polyuria (Miller, 2009).
In older men, benign prostatic hyperplasia (BPH) can result in urinary urgency, hesitancy, and frequency. All these changes combine to increase the risk of urinary incontinence in the older adult. Further, urgency and nocturia increase the risk of falls.
Changes with age in the urinary tract’s physiology, such as increased vaginal pH and decreased antibacterial activity of urine, contribute to developing bacteriuria and potentially urinary tract infection (UTI: Htwe et al., 2007; Stern, 2006).
Renal assessment includes monitoring renal function (GFR) based on creatinine clearance, particularly in acute and chronic illness (Lerma, 2009; Miller, 2009; Péquignot et al., 2009). The choice, dose, need, and alternatives for nephrotoxic and renally excreted agents should be considered (Beyth & Shorr, 2002).
Dehydration, volume overload, and electrolyte status are assessed by screening for fluid/electrolyte imbalance risks based on the older adult’s age, medical and nutritional history, medications, cognitive and functional abilities, psychosocial status, and bowel and bladder patterns.
Data on fluid intake and output, daily weights, and vital signs, including orthostatic BP measurements, are needed. Heart rate is a less reliable indicator for dehydration in older adults due to the effects of medications and heart disease (Suhayda & Walton, 2002).
Physical assessment for fluid/electrolyte status focuses on the skin for edema and turgor. Note that turgor in older adults is a less reliable indicator for dehydration because of poor skin elasticity, and assessment over the sternum or inner thigh is recommended.
Additional assessment involves the oral mucosa for dryness and cardiovascular, respiratory, and neurologic systems. Acute changes in mental status, reasoning, memory, or attention may be initial symptoms of dehydration (Suhayda & Walton, 2002).
Pertinent laboratory tests include serum electrolytes, serum osmolality, complete blood count (CBC), urine pH and specific gravity, BUN, hematocrit (Mentes, 2006), and arterial blood gases (Beck, 1998).
Evaluations of urinary incontinence, UTI, and nocturnal polyuria using a 72-hour voiding diary are recommended. See Atypical Presentation of Diseases section for UTI.
Voiding history and rectal exam are required to diagnose BPH (see Chapter 18, Urinary Incontinence). Fall risk should be addressed when nocturnal or urgent voiding is present (see Chapter 15, Fall Prevention: Assessment, Diagnoses, and Intervention Strategies).
Ongoing care involves monitoring renal function (Lerma, 2009; Miller, 2009; Péquignot et al., 2009) and levels of nephrotoxic and renally cleared drugs (Beyth & Shorr, 2002).
Maintaining fluid/electrolyte balance is paramount (Beck, 1998). To prevent dehydration, older adults weighing between 50 and 80 kg are advised to have a minimum fluid intake of 1,500-2,500 mL/day (unless contraindicated by medical condition; Suhayda & Walton, 2002) from fluids and food sources, including fruits, vegetables, soups, and gelatin, while avoiding high salt and caffeine (Mentes, 2006; Ney, Weiss, Kind, & Robbins, 2009).
Incontinence care and exercise can help manage voiding problems, including reduced incontinence among nursing home residents (Schnelle et al., 2002).
Behavioral interventions recommended for nocturnal polyuria include limiting fluid intake in the evening, avoiding caffeine and alcohol, and prompt voiding schedule (Miller, 2009).
Safety precautions and fall prevention strategies are needed in nocturnal or urgent voiding situations (see Chapter 15, Fall Prevention: Assessment, Diagnoses, and Intervention Strategies).
Oropharyngeal and Gastrointestinal Systems
Age-specific alterations in the oral cavity can adversely affect the older adult’s nutritional status. Deterioration in the strength of muscles of mastication and the potential for tooth loss and xerostomia due to dehydration or medications may reduce food intake (Hall, 2009).
Contributing to poor appetite are altered taste perception and diminished sense of smell (see Chapter 20, Oral Health Care: Ney et al., 2009; Visvanathan & Chapman, 2009).
Changes in the esophagus with age include delayed emptying, decreased upper and lower esophageal sphincter pressures, sphincter relaxation, and peristaltic contractions.
Although these alterations rarely impair esophageal function and swallowing sufficiently to cause dysphagia or aspiration in normal aging, such conditions can develop in conjunction with disease or medication side effects in older adults (Gregersen, Pedersen, & Drewes, 2008; Ney et al., 2009).
Diminished gastric motility with delayed emptying contributes to altered oral drug passage time and absorption in the stomach; elevated risk of gastroesophageal reflux disease (GERD; Hall, 2009); and decreased postprandial hunger, leading to decreased food intake and possible malnutrition (Visvanathan & Chapman, 2009).
Reduced mucin secretion impairs the protective function of the gastric mucosal barrier and increases the incidence of NSAID-induced gastric ulcerations (Newton, 2005).
While the motility and most absorptive functions of the small intestine are preserved with age, the absorption of vitamin B12, folic acid, and carbohydrates declines (Hall, 2009). In addition, malabsorption of calcium and vitamin D contributes to the risk of osteoporosis.
Supplementation with calcium and vitamins D and B12 is now recommended for older adults (USDHHS, 2005; Visvanathan & Chapman, 2009).
Age-dependent weakening of the large intestinal wall predisposes older adults to diverticulosis and may lead to diverticulitis (Hall, 2009).
While the motility of the colon appears to be preserved with age, increased self-reports of constipation in older adults may be attributed instead to altered dietary intake, medications, inactivity, or illness.
Diminished rectal elasticity, internal anal sphincter thickening, and impaired sensation to defecate contribute to the risk of fecal incontinence in older adults (Gallagher et al., 2008), although this condition is primarily found in combination with previous bowel surgery or disease and not in normal aging (Hall, 2009).
Pancreatic exocrine output of digestive enzymes is preserved to allow normal digestive capacity with aging (Hall, 2009). Regarding endocrine function, aging changes in carbohydrate metabolism allow a genetic predisposition for diabetes to become manifest (Meneilly, 2010).
An age-related decrease in gallbladder function increases the risk of gallstone formation.
Although liver size and blood flow decline with age, reserve capacity maintains adequate hepatic function, and liver function test values remain stable; however, the liver is more susceptible to damage by stressors, including alcohol and tobacco, associated with changes in the hepatic and intestinal cytochrome P450 system (Hall, 2009). Clearance of a range of medications, including many benzodiazepines, declines, resulting in an increased potential for dose-dependent adverse reactions to these drugs (Beyth & Shorr, 2002).
Reductions in antimicrobial activity of saliva and immune response of the gastrointestinal tract with age contribute to a high risk for infectious and inflammatory diseases of this system (Htwe et al., 2007).
Further, impaired enteric neuronal function may blunt the older adult’s reaction to infection and inflammation, resulting in an atypical presentation of disease (see Atypical Presentation of Disease section: Hall, 2002). In the gastrointestinal evaluation, the abdomen and bowel sounds are assessed.
Liver size, pain reports, anorexia, nausea, vomiting, and altered bowel habits should be noted (Visvanathan & Chapman, 2009). Assessment of the oral cavity includes dentition and chewing capacity (Chapman, 2007; see Chapter 20, Oral Health Care).
Weight is monitored, with BMI calculation compared to recommended values (American Heart Association Nutrition Committee et al., 2006; Visvanathan & Chapman, 2009).
Deficiencies in diet can be identified by comparing dietary intake, using a 24- to 72-hour food intake record, with nutritional guidelines (Chapman, 2007; Roberts & Dallal, 2005; USDHHS, 2005). In addition, laboratory values of serum albumin, prealbumin, and transferrin are useful nutritional indicators.
Low albumin concentration can also affect the efficacy and potential for toxicity of selected drugs, including digoxin and warfarin (Beyth & Shorr, 2002). Several instruments for screening the nutritional status, eating habits, and appetite of older adults are available.
Signs of dysphagia, such as coughing or choking with solid or liquid food intake, should be reported for further evaluation. If aspiration from dysphagia is suspected, the lungs must be assessed for infection, typically indicated by unilateral or bilateral basilar crackles in the lungs, dyspnea, tachypnea, and cough (Imperato & Sanchez, 2006).
A decline in function or change in mental status may signal an atypical presentation of respiratory infection from aspiration (Ney et al., 2009). Evaluation of GERD is based on typical and atypical symptoms (see Atypical Presentation of Disease section; Hall, 2009).
To assess constipation or fecal incontinence, a careful history with a 2-week bowel log noting laxative use is needed. Fecal impaction is assessed by digital examination of the rectum as a hardened mass of feces, which can be palpated. The impaction may also be palpated through the abdomen (Gallagher et al., 2008).
For continuing care, referrals should be provided to a registered dietitian for poor food intake, unhealthy BMI (healthy BMI: 18.5-24.9 kg/m²; overweight: 25-29.9 kg/m²; obesity: 30 kg/m² or greater, American Heart Association Nutrition Committee et al., 2006), and unintentional weight loss of 10% or greater in 6 months (Chapman, 2007; Ney et al., 2009).
Drug levels and liver function tests are monitored if drugs are metabolized hepatically (Beyth & Shorr, 2002). Explanation of normal bowel frequency, the importance of diet and exercise, and recommended types of laxatives address constipation problems (Gallagher et al., 2008).
Mobility should be encouraged to prevent constipation, and prophylactic laxatives should be provided if constipating medications such as opiates are prescribed (Stern, 2006). Community-based food and nutrition programs (Visvanathan & Chapman, 2009) and education on healthful diets using the food pyramid for older adults may be useful in improving dietary intake (see Chapter 22, Nutrition; JNC, 2004; USDHHS, 2005).
Musculoskeletal System
Musculoskeletal tissues undergo age-associated changes that can negatively impact function in the older adult.
In sarcopenia, or the loss of muscle mass and strength, a decline in the size, number, and quality of skeletal muscle fibers occurs with aging. Lean body mass is replaced by fat and fibrous tissue (Loeser & Delbono, 2009), so that by age 75, only 15% of the total body mass is muscle compared to 30% in a young, healthy adult (Matsumura & Ambrose, 2006).
These alterations result in diminished contractile muscle force with increased weakness and fatigue and poor exercise tolerance. Age-specific physiological alterations contributing to sarcopenia include reductions in muscle innervation, insulin activity, and sex steroid (estrogen, testosterone) and growth hormone levels.
Additionally, individual factors such as weight loss, protein deficiency, and physical inactivity can accelerate the development of this condition to progress to a clinically significant problem (Jones et al., 2009).
Sarcopenia has been documented to affect function adversely in older adults by increasing the risk of disability, falls, unstable gait, and the need for assistive devices. Physical activity, particularly strength training, and adequate intake of energy and protein can prevent or reverse sarcopenia (Narici, Maffulli, & Maganaris, 2008).
Age-dependent bone loss occurs in both sexes and at all sites in the skeleton. Whereas bone mass peaks between ages 30 and 35, density decreases at a rate of 0.5% per year.
This decrement, caused by reduced osteoblast activity in the deposition of new bone, is accompanied by deterioration in bone architecture and strength. Further, from 5-7 years following menopause during estrogen decline, bone loss in women accelerates to a 3%-5% annual rate (USDHHS, 2004b).
This loss, resulting from osteoclast activation with elevated bone breakdown or resorption, occurs mainly in cancellous or trabecular bone such as the vertebral body and may develop into Type I osteoporosis in women aged 51-75 years who risk vertebral fractures.
Following this postmenopausal period, bone loss slows again in women and involves cortical bone in the long bones of the extremities. With aging, both women and men may develop Type II osteoporosis and are susceptible to hip fractures and kyphosis from vertebral compression fractures later in life (Simon, 2005).
An age-associated decline in the strength of ligaments and tendons, which are integral to normal joint function, predisposes to increased ligament and tendon injury, more limited joint range of motion (ROM), and reduced joint stability, leading to osteoarthritis (Narici et al., 2008).
Degeneration of intervertebral discs caused by dehydration and poor nutrient influx elevates the risk of spinal osteoarthritis, spondylosis, and stenosis with aging (Loeser & Delbono, 2009).
Age-related changes in articular cartilage, which covers the bone endings in joints to allow smooth movement, involve increased dehydration, stiffening, crystal formation, calcification, and roughening of the cartilage surface.
Although these alterations have a minor effect on joint function under baseline conditions, the aging joint is less capable of withstanding mechanical stress, such as obesity or excess physical activity stress, and is more susceptible to disease, including osteoarthritis (Loeser, 2010).
Age-dependent changes in stature include dorsal kyphosis, reduction in height, flexion of the hips and knees, and a backward tilt of the head to compensate for the thoracic curvature.
A shorter stride, reduced velocity, and broader base of support with feet more widely spaced characterize modifications in gait with age (Harris et al., 2008).
The musculoskeletal assessment includes inspecting posture, gait, balance, body parts symmetry, and extremities alignment. Kyphosis, bony enlargements, or other abnormalities should be noted.
The clinician should palpate bones, joints, and surrounding muscles, evaluate muscle strength on a scale of 0/5, and note symmetry and signs of atrophy of major upper and lower extremity muscle groups.
Active and passive ROM for major joints is evaluated, noting pain, limitation of ROM, and joint laxity. Joint stabilization and slow movements in ROM examinations are advised to prevent injury.
Functionality, mobility, fine and gross motor skills, balance, and fall risk should be assessed (see Chapter 6, Assessment of Physical Function, and Chapter 15, Fall Prevention: Assessment, Diagnoses, and Intervention Strategies; Harris et al., 2008).
For continuing care, referrals to physical or occupational therapy may be appropriate.
Increased physical activity, including exercises for ROM (Netz et al., 2005) and muscle strengthening and power (Narici et al., 2008), are recommended to maintain maximal function.
Interventions to promote such behavior in older adults involve health education, goal setting, and self-monitoring (Conn, Minor, Burks, Rantz, & Pomeroy, 2003).
Pain medication may be needed to enhance functionality (see Chapter 14, Pain Management; McCleane, 2008). Strategies to prevent falls and avoid physical restraints.
To prevent and treat osteoporosis, adequate daily intake of calcium (1,200 mg for women aged 50 years and older) and vitamin D (400 IU for women aged 50-70 years and 600 IU for women aged 71 years and older), physical exercise, and smoking cessation are recommended (USDHHS, 2004b).
In addition, routine bone mineral density screening for osteoporosis is advised for women aged 65 years and older and for women aged 60-64 years at increased risk for osteoporosis fractures (Agency for Healthcare Research and Quality, 2010).
Nervous Systems and Cognition
Age-related alterations in the nervous system can affect function and cognition in older adults.
Changes include a reduced number of cerebral and peripheral neurons (Hall, 2002), modifications in dendrites and glial support cells in the brain, and loss and remodeling of synapses.
Decreased neurotransmitter levels, particularly dopamine, and deficits in systems that relay signals between neurons and regulate neuronal plasticity also occur with aging (Mattson, 2009).