Anaesthetic Management of Elderly Patients
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Transcript of Anaesthetic Management of Elderly Patients
Anaesthetic Management of Elderly Patients
Lt Col Md Rabiul AlamMBBS, MCPS, FCPS
Classified AnaesthesiologistDept of Anaesthesiology
Combined Military Hospital, Dhaka, Bangladesh
Scopes
• Anaesthetic definition of elderly & workload• Brief on age-related changes• Importance of good anaesthetic evaluation• Practice of functional reserve/capacity
assessment• Morbidity and Mortality• Decision of Surgery & Planning of Anaesthesia• Perioperative management
Anaesthetic Definition of ‘Elderly’
• WHO: >65 years• UN: 60+ years• AAGBI:
– >80 years = elderly – Physiological
changes/functional decline most marked after 80 years
• Chrono- vs biological age– Chronological age - poor
discriminator of individual surgical risk
– ‘old’ 60 years old vs ‘young’ 80 years old
– Heterogenecity - most consistent feature in the elderly population
Trend in percentage of elderly population in Bangladesh
Ref: http://www.bbs.gov.bd/WebTestApplication/userfiles/Image/PopMonographs/elderlyFinal.pdf
• 2015 = 12.8 Millions• 2020 = 14.0 M• 2025 = 17.2 M
Multimorbidity among Elderlyin Bangladesh
• Conducted among persons aged ≥60 years• Overall prevalence = 53.8%• Multimorbidities:
– arthritis, stroke, obesity, signs of thyroid hypofunction, obstructive pulmonary symptoms, symptoms of heart failure, impaired vision, hearing impairment, and high blood pressure
Ref: Khanam MA, Streatfield PK, Kabir ZN, Qiu C, Cornelius C, Wahlin A. Prevalence and Patterns of Multimorbidity among Elderly People in Rural Bangladesh: A Cross-sectional Study. J Health Popul Nutr 2011;29:406-14.
Size of the problem
• Increasing numbers– > 60’s – quite faster growing section of
the population– 2025- >15% of population will be 60
years and over• Increasing workload
– 50% of elderly will require anaesthesia for surgical intervention in their lifetime
– surgical/anaesthetic advances
Mechanism of Injury to Elderly
Surgery on Geriatric patients in CMH Dhaka
Brief reminder of age-related changes
Age-related cardiovascular changes
• Reduced autonomic responsiveness• SNS activity ↑; Parasympathetic ↓• Baroreceptor reflex activity ↓• β-adrenoceptor responsiveness ↓
• Decreased maximum heart rate• Frank-Starling mechanism- major
mechanism for maintaining stroke volume
Age-related cardiovascular changes
• Increased vascular stiffness– ↑ systolic BP– widening of pulse pressure
• Left ventricular wall thickening– ↓ compliance: impairment of diastolic
function• Greater dependence on atrial function for
ventricular filling– contribute up to 30% of SV
Dependence on High Filling Pressure
Young
End-Diastolic Volume
End
-Dia
stol
ic P
ress
ure
Elderly
Frank-Starling Curve
Aging and Contractility:Response to Exercise/Stress
55
60
65
70
Young
Eje
ctio
n Fr
actio
n(%
)
At Rest Maximal Exercise
Elderly
Response to Anesthesia
• Anaesthetics can:– Remove sympathetic tone
– Dramatic when baseline tone is very high– Directly depress heart, vascular smooth muscle– Diminish baroreceptor reflexes
Add to That …
• Changes in sympathetic tone from waxing and waning surgical stimulus variable depth of anesthesia
• Changes in patient’s volume status
• Results in LABILE BLOOD PRESSURE !
Age-related respiratory changes
• ↓ Vital capacity / ↑ Residual volume• ↓ strength and mobility of muscles• lung elastic recoil ↓• chest wall compliance ↓• spinal collapse (anterior wedging)
• ↑ Closing volume/capacity• ↑ V/Q abnormalities → ↓ gas exchange
Effect of age on closing capacity and FRC
Lung volume (L)
Age (years)
FRC, uprightFRC, supine
Closing
capacity
Postoperative PaO2 in the Elderly
Oxygen by Facemask
No Oxygen supplement
Postoperative PaO2 (mmHg)
Age (years)
Patients with no pre-existing pulmonary disease
Age-related respiratory changes
• ↓ hypoxic and hypercapnic reflex control• Poor upper airway tone
– snoring almost universal• Poor cough (7 fold reduction in sensitivity
of cough reflex)• ↑ risk of aspiration (silent!!)• Chest wall rigidity → more dependent on
the diaphragm
Age-related neurological changes
• ↓ Brain cell mass (10-30% by age 80)– loss of central cholinergic and
dopaminergic cells– 70-80% loss of dopaminergic function
required before symptoms seen in Parkinson’s disease
• Poor reflex control– baroreceptor, thermoregulation
Age-related neurological changes• Blindness
– cataracts, glaucoma– problem with visual analogue scales
• Deafness – problems with comprehension– may be denied by patient
• Cognitive impairment– dementia present in 22% of over 80’s– (life expectancy-50% in 5yrs)
Age-related hepatic changes
• ↓ Liver mass and blood flow– 1% loss/yr after 30 yrs– minor changes in cytochrome P450 activity– variable effect on Phase I reactions; Phase II
not affected• Reduced albumin: altered drug binding
Age-related renal changes
• Marked decline in RBF and GFR (1% loss of function/yr after 30 yrs)
• Plasma creatinine: not good guide of renal function because of reduced muscle mass
• Response to Na concn impaired; less able to excrete Na load
• Reduced ability to dilute/concentrate urine– ↓ thirst perception– fear of incontinence– locomotor problems-inability to get to fluids
Age-related musculoskeletal changes
• Osteoarthritis/Osteoporosis– Immobility → ↑ venous stagnation– Limits ability to exercise
• Poor stability/balance– ↑ risk of accidents esp. in unfamiliar
surroundings• Ligamental laxity
– cervical vertebrae slip
Airway Management:Changes with Aging
Arthritic Changes:• Decreased cervical spine and neck
mobility• Smaller mouth opening• Smaller glottic opening
– Smaller endotracheal tube
Fragile teeth
To be remembered…
• Airway management may be more difficult• Prone to airway collapse (risk of pneumonia)• Higher work of breathing (risk of hypercarbia)• Lower blood oxygen levels
(greater need for supplemental oxygen)• After leaving Recovery room, hypoxia is more
likely in PACU from residual drug/CNS effects
Pharmacology in the Elderly Patients:Increased Bolus Drug Effect
• Decreased protein binding– Higher free, unbound plasma drug levels
• Decreased volume of distribution• Slower redistribution of drug
• ALL of these INCREASE target organ levels!– Examples: Thiopental, Propofol
Bolus Drug Strategy for the Elderly:
• GO LOW !• GO SLOW !• We can always give more!
Temperature Regulation
• Elderly prone to both hypo-, hyperthermia• Lower body metabolism• Decreased ability to change skin blood flow
(less able to hold or get rid of heat)• Hypothermia
– Shivering increases metabolic demand• Increased risk of myocardial ischemia
Postoperative Delirium
• Most common form of perioperative CNS dysfunction
• Acute confusion, decreased alertness, misperception
• Patient may show agitation or withdrawal
• 10-15% of elderly surgical patients
• 30-50% if undergoing cardiac or orthopedic surgery
• Seen after general, regional and MAC anesthetics
• Results prolonged hospital stay and protract postop care
Minimising Postoperative Delirium:Try to Avoid:
• Anticholinergics - atropine and scopolamine (NOT glycopyrrolate)
• Ketamine• Benzodiazepines• Large doses of barbiturates and
Propofol• Pethidine
Common & Treatable Causes of Postoperative Delirium
• Hypoxemia• Hypercarbia• Hypotension• Pain• Sepsis• Metabolic
Morbidity&
Mortality
Highest incidence of mortality and morbidity- NCEPOD data
Traditional diagnostic approach
CNS CVS RS GI UGS Immunesystem
History of presenting illness
Medical/Surgical history
Physical examination
Investigations
Diagnosis and Mx plan
Organ-system based approach for preoperative assessment
CNS CVS RS GI UGS Immunesystem
Medical and surgical history
Activity level and quality
Physical examination
Investigations
Assessment of organ system reserve
Functional Reserve/Capacity Assessment
Integrated functional reserve
• Metabolic equivalence– attempt to quantify metabolic (O2 delivery)
capacity of the patient– estimates the likely outcome of surgery– predicts the likelihood of postoperative
complications• patients unable to reach 4 METS
Examples of metabolic equivalents (METS)Score Activity
1 Eat and dress, walk indoors around the house
2 Walk a block on the level,do light work around the house
4 Climb a flight of stairs or walk uphill, heavy domestic work, run a short distance
6 Moderate recreational activitiese.g., light jogging, golf, doubles tennis
10 Strenuous sports e.g., swimming, running
Risk factors for postop mortality in elderlyASA physical status III and IV
Surgical procedures Major and/or emergency procedures
Co‐existing diseaseCardiac, pulmonary disease, diabetes mellitus, liver, and renal impairment
Functional status <1–4 MET*
Nutritional status Poor, albumin <35%, anaemia
Place of residence Not living with familyAmbulatory status Bedridden
Cardiopulmonary Exercise Testing in elderly patients undergoing major
surgery
Optimisation preoperatively
• Multidisciplinary team approach– Geriatric medical specialist/anaesthetist
• mental state• endocrine• polypharmacy issues
– Cardiologist• murmurs (aortic stenosis)• intractable cardiac failure
– Physiotherapists, nutritionists
Outcome assessment and placement
• Inherent risk of operation– size of stress response– is it appropriate surgery?
• Matching of experience of surgeon/anaesthetist to physical status of the elderly patient
• Plan appropriate anaesthetic technique• Appropriate postop care
– ward/HDU/ICU
Decision of surgery & anaesthetic plan
• Working Party consider– ‘clinical’ & – ‘organisational themes’ that are imp throughout the
peri-op journey• Particular emphasis on interventions that
– the poorer outcomes associated with emergency surgery
• Reciprocal flow of info btw patients & doctors• S/S those require urgent review, & how to access
Decision of surgery/Anaesthesia (cont…)
• Rx plans - discussion btw Patients & Senior doctors• Proposed Mx of expected complications• Assessment & optimisation must start ASAP• Longer for elective surg, shorter for emergency surg• Opportunities to optimise the pathophysiological
condition must not be missed before surgery• Fluid resuscitation / pharmacological manipulation of
chronic co-morbidities before elective surgery
Pre-operative optimisation• Organ-specific morbidity
– diabetes, cardiorespiratory disease and anaemia• Ischaemia
– ↓O2 uptake – analgesia, thermoregulation, antibiotics
– ↑O2 delivery – O2, fluids, medication review, avoidance of hypotension and severe anaemia
• Malnutrition– Oral nutrition and supplementation– Iron, vitamin B12 and folate supplementation provided for subclinical
nutritional anaemia at least 28 days before elective ortho surgery reduces postop morbidity & mortality
– Prolonged pre-op fasting to be avoided (abdominal surgery)
Pre-operative optimisation (cont…)Proactive planning•Anaesthetists should be aware of their role in ‘prehabilitation’•Maintaining/enhancing functional reserve to facilitate postop rehabilitation & discharge back into the community
– Potential risk factors for postop morbidity – Patient info and encouragement – Enhanced recovery protocols, fluid therapy– Avoidance of ischaemia, adequate analgesia, thermoregulation– Selection of the most appropriate anaesthetic technique– Employment of postop care plan– Avoidance of certain medications
Futility
• Inappropriate procedure with no benefit in longevity– heroic surgical therapy– ‘senior’ decision to operate
• Palliative surgery must be provided for symptomatic relief
To sum up………….
Young Elderly