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PROPERTIESAllow user to leave interaction: AnytimeShow ‘Next Slide’ Button: Show alwaysCompletion Button Label: View Presentation
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Critical Care for Older Adults
Dorothy W. Bird, MD*
Lisa B. Caruso, MD, MPH†
Suresh Agarwal, MD, FACS*
Boston University Medical Center
Department of Surgery*, Department of Medicine- Geriatric Services†
™Page 3
Introduction
• Older adults (age >65yo) are the fastest growing segment of the US population (ref: 1,2)
• Almost HALF of all ICU admissions are older adults (ref: 1,2)
– Exacerbation of chronic illness
– New onset of illness or trauma
• By 2030 20% of Americans will be >65yo (ref: 1)
• By 2050 5% of Americans will be >85yo (ref: 1)
™Page 4
Introduction
• Older adults differ from their younger ICU counterparts in several ways:
– Physiology (cardiopulmonary, renal)
– Drug metabolism
– Nutritional needs
– Susceptibility to delirium
– ICU outcomes
– Closer to end of life
™Page 5
Cardiovascular Changes
• Age-related changes in collagen, elastin→loss of recoil (ref: 3)
– Increased systolic blood pressure
– Widened pulse pressure (ref: 1)
– Progressive left ventricular stiffness, thickness →Diastolic Dysfunction (ref: 1,2,3)
• Less able to tolerate atrial fibrillation
• Increased sensitivity to volume overload
• Increased susceptibility to heart failure
• Increased preload dependency
™Page 6
Cardiovascular Changes
• Fewer cardiac myocytes (ref: 2,4)
• Fibrosis/loss of autonomic tissue (ref: 2)
– Conduction abnormalities (sick sinus, a-fib, BBB)
• Diminished sensitivity to β-adrenergic stimulation (ref: 1,2,3,4)
– Stroke volume, preload more important for increasing cardiac output
– Even minor hypovolemia can cause cardiac impairment (Increased preload dependency)
– Diminished response to norepinephrine, isoproterinol, dobutamine
™Page 7
Cardiovascular Risk Factors
• Increased prevalence of coronary artery disease in older adults (ref: 1,2,3)
– May present as heart failure, pulmonary edema, arrhythmias
– Myocardial ischemia more likely to go unrecongnized
™Page 8
Pulmonary Changes
• Increased chest rigidity (ref: 1,2,3,4), kyphosis (ref: 2)
– Increased work of breathing
• Decreased forced total lung capacity, vital capacity, FEV11,3
• Decreased inspiratory, expiratory force (ref: 1,2)
• Diminished respiratory muscle strength (↓25%) (ref: 1,4)
™Page 9
Pulmonary Changes
• Premature closure of terminal airways (ref: 3)
– V-Q mismatch (ref: 2,3)
– Decrease in PaO2 controversial (ref: 3,4)
• Expected PaO2= 100 – 0.325 x age
– Increased A-a gradient (ref: 1,3)
• Expected P(A-a)O2 = (age +10) x 0.25
™Page 10
Pulmonary Changes
• Blunted Ventilatory control (ref: 2,3)
– Diminished response to hypoxia (↓50%)
– Diminished response to hypercapnia (↓40%)
• Reduced cough, mucociliary clearance (ref: 2,3)
• Impaired pulmonary immunity (ref: 2,3)
• Diminished gag (ref: 3)
• Difficulty swallowing (ref: 2,3)
– Increased risk of aspiration
™Page 11
Cardiopulmonary Summary
Cardiopulmonary BASICS:
• Decreased cardiac and respiratory reserves can lead to rapid decompensation in older adults and slower response time in correction
• Pulmonary insult (pneumonia) can trigger heart failure exacerbation
• Acute respiratory failure can result from hemodynamic shock
™Page 12
Renal Changes
• Decreased creatinine clearance (CC), decreased GFR (ref: 1,2,3)
– Cockroft-Gault Estimated CC = (140-age) x wt(kg)/72 x serum creatinine
– Adjust medication dosage based on estimated CC, not serum creatinine!
™Page 13
Renal Changes
• Concealed renal insufficiency (ref: 2)
– Reduced GFR despite NORMAL serum creatinine
– May be due to increased prevalence of hypertension, diabetes in elderly
– Present in 13.9% of elderly patients
– Associated with increased risk of adverse reaction with hydrophilic medications
™Page 14
Renal Changes
• Loss of nephrons (0.5-1%/year) (ref: 2,3)
• Reduced renal plasma flow (10%/decade) (ref:1,2,3)
• Reduced concentrating ability of medullary nephrons (ref: 1,2,3)
• Less responsive to ADH (ref: 2,3)
– More free water loss→ dehydration, electrolyte imbalance (hyperkalemia, hyponatremia)
– Thiazide-induced hyponatremia common in older adults
™Page 15
Nutrition
• Protein-calorie malnutrition is common in older adults at admission and may develop quickly during hospitization (ref: 1,2,3)
• Diminished muscle mass→ hospital malnutrition→ further weakness (ref: 2,3)
• Increased mortality in underweight older adults (ref: 3)
• Low albumin, pre-albumin associated with increased post-op mortality in older adults
™Page 16
Nutrition
• Assess nutritional status in all older adults:
– pre-albumin
– transferrin
– indirect calorimetry
– CRP: marker of inflammation, inverse relationship with pre-albumin
• Nutritional support should begin within 24h of ICU admission (ref: 2)
™Page 17
Medications
• Adverse drug reaction is the most common iatrogenic disorder in older adults (ref: 3)
• Age is an independent risk factor for adverse drug interaction2
• Increased body fat (25-50%), decreased body water in older adults (ref: 1,3)
– Hydrophilic drugs (digoxin, theophylline) have lower volume of distribution—reach higher levels faster
– Lipophilic drugs (psychotropics) have larger volume of distribution—progressive accumulation
• Impaired drug excretion (renal, hepatic) (ref: 3)
• EFFECT: increased half-life, longer duration of action of many medications (ref: 3)
™Page 18
Medications
• Reduced serum albumin→ higher free drug levels→ greater pharmacologic effect (ref: 3)
• Decreased cytochrome p450 activity→ reduced elimination (especially warfarin, theophylline) (ref: 3)
• Altered sensitivity of receptors to commonly used medications (ref: 3)
– More sensitive: warfarin, narcotics, sedatives, anticholinergics
– Less sensitive: β-adrenergic agonists/antagonists
• Polypharmacy (ref: 2,3)
– Probability of adverse drug interaction:
• 7% if on >5 medications, 24% if on >10 medications
™Page 19
Medications
• Drugs most often associated with adverse reactions (ref: 2):
– Digitalis
– ACE-I
– Hypoglycemics
• Contrast-induced nephrotoxicity- increased in older adults (ref: 2)
– Ensure preventative measures are taken when using contrast studies!
• When starting medications: Start low, go slow!
– Especially with sedatives and anti-psychotics!
™Page 20
Delirium
• Seen in 1/3-1/2 of hospitalized older adult patients (ref: 2,3)
• Up to 70% of older adults in ICU (ref: 2,3)
• Can lead to loss of mobility, atrophy, contractures, pressure ulcers, falls, thromboembolism, incontinence, anorexia, constipation, de-motivation (ref: 3)
• Associated with prolonged hospitalization, nursing home placement, increased mortality (ref: 2,3)
™Page 21
Delirium
• Predisposing factors: (ref: 2,3)
– Prior cognitive impairment: patients with dementia are 5x more likely to develop delirium!
– Structural brain disease
– Chronic illness
– Sleep deprivation
– Drug/alcohol use
– Unfamiliar surroundings/social isolation
• Use of sedatives, psychotropics, restraints can worsen symptoms, increase risk of aspiration, ulcers, etc. (ref: 3)
™Page 22
Delirium
• Indicative of diffuse brain dysfunction (ref: 3)
• Associated with four disease classes: (ref: 2,3)
– Primary cerebral disease (infection, tumor, stroke, dementia)
– Systemic illness (infection, cardiac, pulmonary, hepatic, uremia, endocrine)
– Intoxication (EtOH, drugs, toxins)
– Withdrawal (EtOH, benzodiazepine, barbiturates)
™Page 23
Delirium
• Prevention,Treatment (ref: 2,3)
– Identify underlying cause!
– Minimize offending medications
• neuroleptics, opioids, anticholinergics, sedatives, H2-blockers
– Constant observation, minimize restraints!
– Well-lighted, predictable environment
– Eyeglasses, hearing aids, dentures
– Frequent reorientation by staff and family
– Establish normal sleep-wake cycle
™Page 24
Postoperative Cognitive Dysfuntion(POCD)
• Acute, short-term disorder of cognition, memory, attention following surgery (ref: 2)
• Present in 26% non-cardiac surgery older adults at 1 week post-op, 9.9% at 3 months (ref: 2)
• Present in 80% of older adults after cardiac surgery by discharge, 50% at 6 weeks post-op (ref: 2)
• May be first sign of hypoxemia, sepsis, electrolyte imbalance! Usually idiopathic (ref: 2)
– Suspected interaction between anesthesia and age-related change in neurotransmitters (ref: 2)
™Page 25
POCD
• Prognosis
– Good: transient symptoms in most sufferers (ref: 2)
– Prolonged POCD: may last months→ years (ref: 2)
• Risk factors
– AGE! (ref: 2)
– Also: duration of anesthesia, post-op infection, respiratory complicaions (ref: 2)
– Age is the only risk factor for prolonged POCD (ref: 2)
™Page 26
Pressure Ulcers
• Associated with immobility in older adults
• 50% pressure ulcers occur in those >70yo (ref: 3)
• Sites:
– sacrum, ischial tuberosities, hip, heel, elbow, knee, ankle, occiput
• Found in 28% of those confined to bed or chair for 1 week (ref: 3)
• High mortality
– 73% mortality if develops in first 2 weeks of hospitalization (ref: 3)
– May lead to sepsis→ 60% mortality if ulcer is cause (ref: 3)
• Now considered a “never event”- no reimbursement
™Page 27
Pressure Ulcers
• Prevention
– Frequent repositioning: q2 hours (ref. 3)
– Avoid pressure on bony prominences (ref. 3)
• Rest back on pillows at 30-degree angle from bed
– Head of bed not more than 30 degrees (ref. 3)
– Do not tuck sheets at foot of bed (ref. 3)
• Allow feet to assume natural position
• Protect heels by elevating feet with pillows
– Lift patients to move, do not drag (ref. 3)
– Pat skin dry, do not rub (ref. 3)
– Reduce contact with soilage (fecal, urinary incontinence) (ref. 3)
™Page 28
Pressure Ulcers
• Prevention
– Ensure adequate nutrition, hydration, pain control (ref. 3)
– Early mobilization (ref. 3)
– Rehab service consult (ref. 3)
™Page 29
Outcomes
• Age is associated with progressive risk of ICU death2
– Mortality: 36.8% in >65yo; 14.8% <45yo (ref. 2)
– 1-year post-ICU survival: 47% in ≥65yo, 83% <35yo (ref. 2)
age ICU survival 3-mo survival
<75 80%
75-79 68% 54%
80-84 75% 56%
≥85 69% 51%
From: Somme et al. Intensive Care Med 2003: 29:2137-2143
™Page 30
Outcomes
• Octegenarian hospital survivors discharged to subacute facility have higher mortality compared to those discharged to home (31% vs. 17%) (ref. 2)
• Likelihood of discharge to subacute facility directly related to preadmission comorbidities (ref. 2)
™Page 31
Optimizing ICU Use
GOAL: Minimize misery, maximize dignity
• ICU care should provide temporary physiologic support for reversible conditions (ref. 2)
• Decision to admit older adults should be based on: patient comorbidities, acuity of illness, prior functional status, patient’s wishes (ref. 2)
• Always clarify and document advanced directives and wishes for intubation, CPR, vasoactive medication
™Page 32
References
1. Nagappan R, Parkin G. Geriatric critical care. Crit Care Clin 2003:253-270.
2. Marik, PE. Management of the critically ill geriatric patient. Crit Care Med 2006; 34(9):S176-S182.
3. Dhanani S, Norman DC. Chapter 19. Care of the elderly patient. In: Bongard FS. Current diagnosis and treatment critical care. 3rd ed. New York: McGraw-Hill;2008.
4. Delerme, A, Ray P. Acute respiratory failure in the elderly: diagnosis and prognosis. Age and Aging 2008;37:251-257.