Basics of geriatric anesthesia

1. GERIATRIC ANAESTHESIA
(PHYSIOLOGY AND PHARMACOLOGY)
PRESENTATION BY: DR. HARSIMRAN WALIA
Moderator: Dr. A. V. Chandak

2. Objectives
1- Define the geriatric population
2- enumerate the anesthetic problems for a
Ger. Pt.
3. Physiological changes & Pharmacological
drug alterations required in Ger. pts
4- mention the different methods for avoiding
these problems
5- Categorize patients according to risk

3.  Aging is a universal and progressive physiologic phenomenon
characterized by degenerative changes in both the structure
and functional reserve of organs and tissues.
 Functional reserve is the degree to which organ function can
increase above the level necessary for basal activity.
 This provides a safety margin available to meet the additional
demands of surgery, healing and convalescence.
 Two important principles of aging are
1) progressive loss of functional reserve in all organ
system
2) The extent and onset of these changes vary from person
to person

4. MECHANISMS OF AGING
 There is increasing imbalance of homeostatic mechanisms and
increased incidence of pathological processes
 Aging is viewed as an extremely complex multi-factorial
process with interaction of various pathways to differing
degrees and effect
 The elderly (≥65 yr) population is the fastest growing part of
the population in many parts of the developed world.
 Peri-operative morbidity becomes more frequent in the elderly
with steep increases after the age of 75.

5. Concept of Frailty
 The greatest challenge facing the medical profession is to maintain
function for as long as possible.
 Our goal for successful aging is that the physical and mental abilities
remain at a level sufficient to maintain a lifestyle that is enjoyable and
productive
 Frailty refers to a loss of physiologic reserve that makes a person
more vulnerable to disability during and after stress.
 Components: Mobility, Muscle weakness, Poor exercise tolerance,
Unstable balance and Factors related to body composition like weight
loss, malnutrition, muscle wasting
 Incidence= 6.9% in people older than 65 years

6. AGE RELATED PROBLEMS
 Hypertension
 Diabetes mellitus
 Heart disease
 Malignancy
 Myocardial ischemia
 Cerebral vascular accident
 Chronic renal insufficiency, Liver dysfunction
 COPD, Pneumonia
 Dementia- Alzheimer’s disease = 6-8% older than 65 years
-Presence of cognitive deficit, agitation
-Predictor of postoperative delirium

7.  Parkinson’s disease- 3% older than 65 years
-Classic triad= tremor, muscle rigidity, brady-kinesia
-postoperative risk of aspiration
 Poly-pharmacy- Average patients takes 8 different drugs per day which are
directly proportional to adverse drug reactions with incidence of 5%-35%.
 Depression- 10% older than 65 years
 Immobility- Decreases muscle mass which influence pulmonary function
 Dehydration- Associated with hypernatremia and infection like pneumonia
 Alcoholism- Manifest as accident, postoperative pneumonia

8.  Hypothermia
 Chronic pain- Assessment of pain complicated by social,
emotional, cognitive and subjective issues. Arthritis, bone
fracture, musculoskeletal
 Thus the anesthesiologists is the only caregiver prior to
surgery to look at the patients as a whole and aware of
preoperative risk factors and probable perioperative
adverse outcomes and assist the surgical team in
handling identified outcomes.

9. PHYSIOLOGICAL CHANGES DURING
AGEING
A. Cardiovascular system and Autonomic Nervous System
1. Decline in the responsiveness of β- receptors
- plasma catecholamine level unchanged
- decrease in beta-adrenergic receptors density
- 20% decrease of maximal HR
2. Decreases in arterial compliance results in increased Systemic Vascular
Resistance
3. Progressive replacement of functional cardiac and vascular tissue by stiff,
fibrotic material
- elevated afterload
- elevated systolic BP, diastolic pressure changes little
- LV hypertrophy, hypertension

10. 4. Loss of contractile strength and efficiency, decreased
organ perfusion.
5. Heart valves become fibrotic and sclerotic resulting in
thickening and reduced flexibility.
6. Decreased cardiac output, stroke volume, ejection
fraction, decreased coronary artery blood flow
7. Impaired diastolic filling due to prolonged contraction
and a slowed relaxation
8. Decreased baroreceptor reflex lead to increased risk of
orthostatic hypotension and syncope

11. 10. Decreased compliance of vessels hinder response to
changes in intravascular volume during position changes or
third space loss
11. Cardiac conduction system becomes fibrotic lead to loss
of SA nodal cells and prone to dysrrhythmia
12. Thermoregulation affected by autonomic impairment lead
to inadequate heat production and conservation results heat
stroke and hypothermia
• These factors render the elderly patients less capable of
defending their CO and BP against the usual perioperative
challenges.

12. B. Respiratory System
Changes in Respiratory system occurs as a result of reduction in elastic
support of the airways and leads to increased collapsibility of the alveoli and
terminal conducting airways.
Changes are-
1. Decline in elasticity of the bony thorax
-Decreased tidal volume
-Increased residual volume
-Decreased vital capacity
-Increased dead space
-Ratio of RV to TLC increased
-Increased FRC
-Closing capacity increased

13. 2. Loss of muscle mass with weakening of the muscles of
respiration
-FEV1 decreases progressively with aging (30ml per year)
-Ratio of FEV to FEV1 of the elderly decreases.
-The diaphragmatic function declines with age
3. Increase in V/Q mismatch plus the increased alveolar dead
space
4. Resting PaO2 declines with age at a rate described by
PaO2=100-(0.4×age)mmHg
Mean PaO2 declines from 95 at age 20 to 73 at age 75
years
Hence Gas exchange efficiency declines with age

14. 5. Decrease in alveolar gas exchange surface
6. Decrease in central nervous system responsiveness
- Ventilatory response to hypercapnia and hypoxia is blunted in
the elderly.
Thus we need to increase FiO2 and tidal volume
7. Intra-pleural pressure increases with age
8. Costo-chondral joint calcification makes thorax more stiff and rigid
lead to decreased chest wall compliance

15.  Thorax changes shape with age.
 Kyphosis of the thoracic spine is the first change and is
due principally to osteoporotic vertebral collapse
 This causes A-P diameter of the chest to increase at the
expense of lateral diameter, leading to barrel chest
deformity with apparent increased heart
Thus respiratory system consist of combination of
restrictive and obstructive lung disease.

16. 


18. Upper Airway Protective Reflex
 Laryngeal, pharyngeal and airway reflexes are less effective in
older people due to loss of muscular pharyngeal support lead to
upper airway obstruction
 Protective reflex of coughing and swallowing are diminished due
to loss of cilia resulting in chronic pulmonary inflammation from
repeated aspirations lead to aspiration pneumonia
 Elastic support of airways decreased, become more collapsible
cause airway closure lead to mismatch of ventilation and
perfusion results arterial de-saturation.
 Increased periodic breathing during sleep results more likely to
apnea and airway obstruction .

19. C. Nervous System
1. Brain size decreased by 20% beyond 80 years
2. General loss of neuronal substance
3. Decrease in the number of peripheral neurons
4. Depletion of dopamine, norepinephrine, tyrosine, serotonin results
depression, loss of memory, motor dysfunction
5. CBF and cerebral oxygen consumption(CMRO2) is decreased in
proportion to the decrease in brain mass. Cerebral autoregulation is
well maintained in geriatric patients without prior neurological disease
6. Increased latency of sleep, increased periods of wakefulness during
night
7. Generalized increase in thresholds for all forms of perception

20. 8. Decline in number and density of motor end plate units due
to increase in atypical extrajunctional cholinergic receptors.
So dose of NMB drugs are slightly increased
 CNS is target organ for virtually every anaesthetic agent.
9. Age related diseases such as cerebral arteriosclerosis,
Alzheimer’s and Parkinson’s disease are more common
with advancing age

21. D. Renal System
1. Decreased renal mass by 30% older than 80 years mainly
in the cortex due to glomerulosclerosis results decreased
renal blood flow and GFR. This causes delay in drug
clearance and prolong the clinical effects of drugs
2. Decreased tubular function reserve
3. Reduced abilities to concentrate urine or conserve sodium
4. Renal vascularity reduced and CO is redistributed
predisposing to renal ischemia in peri-anaesthetic period

22. E. Hepatic system
1. Decrease in liver mass by 40% older than 80 years
2. There is a lack of correlation between structural and
functional data concerning the aging liver
3. Loss of hepatic tissues lead to delayed drug metabolism
and reduced hepatic drug clearance
4. Decreased plasma albumin concentration result increase
in drug action like thiopentone, diazepam, midazolam,
fentanyl, sufentanil

23. F. Changes in body composition
1.Decreased in lean body mass and total body water lead to smaller central
compartment and increased serum concentration of drug. Increased in body
fat lead to greater volume of distribution with prolong the clinical effect of
drug.
G. Musculo skeletal system
1. Fragile skin, decreased subcutaneous fat, poor skin turgor
2. Functional impairment of bones and joints, Osteoporosis
3. Frequent fractures of hip, Injury to surgical positioning
H. Haematological and Immune system
1. Reduced spleen size and bone marrow production
2. Reduced haematopoietic response to imposed anaemia lead to life
threatening infections

24. I. Endocrine System
1. Progressive impairment of insulin function, impaired glucose homeostasis
2. Decreased thyroxine clearance
3. Decreased renin, aldosterone production
4. Decreased vitamin D absorption
5. Increased plasma concentration of ADH
J. Thermoregulation
1. Diminished vasoconstriction and metabolic heat production
2. Both inhalational and intravenous like propofol, alfentanil alter the regulatory
threshold that fall body temperature by 4°C
3. Risks of intraoperative hypothermia – MI, surgical wound infection, increased
blood loss, impaired drug metabolism

25. K. Protein binding
1. Circulating level of serum protein (especially albumin) decreases in
quantity results acid drugs that bind to albumin like diazepam,
pethidine have reduced dose requirement
2. Increased alpha 1 acid glycoprotein increases the requirement of
basic drugs like lignocaine because reduces the free fraction of basic
drugs
3. Qualitative change of serum protein reduce the binding effectiveness
of the available protein.
4. This will lead to higher free drug levels and an enhanced delivery of
the drug to the brain

26. Clinical Pharmacology of Drugs
 Inhaled anaesthetic: Reduced MAC value and CO results rapid
induction and prolonged recovery due to altered ion channels,
synaptic activity or receptor sensitivity.
 Intravenous anaesthetic:
Thiopentone sodium=Administration of IV barbiturates produces the
peripheral vasodilatation with a moderate BP decrease.
-With a decreased baroreceptor reflex and increased vascular wall
rigidity, the drug may cause a dangerous drop in BP.
-In the elderly, elimination half-life is 13-25 hrs(6-12 hrs in the
young)
-The thiopental dose requirement may decrease 25-75 percent.
.

27. Etomidate= An imidazole IV hypnotic drug associated with
haemodynamic stability
-May offer advantage for induction of anaesthesia in elderly
patients specially in those with limited cardiovascular
reserve
Propofol= Propofol produces greater decrease in systemic BP
than thiopental .
-Injecting the propofol slowly with sufficient time can minimize
the effect of cardiovascular depression.
-Studies show patients older than 80 years exhibit less post-
anesthetic mental impairment with propofol than other
agents.
-Induction: using 1.2-1.7 mg/kg in the elderly (versus 2.0-2.5
mg/kg in younger patients)

28.  Benzodiazepines: Due to decreased drug clearance and
increased brain sensitivity the dose decreases to 75%.
 Opioids: Twice as potent in elderly patients, so short acting
opioids like fentanyl, sufentanil, alfentanil, remifentanil
are better choices.
1/2 the bolus dose and 1/3 the infusion rate required.

29.  Muscle relaxants:
Succinylcholine- This agent is metabolized by pseudocholinesterase
which is not affected by the aging process.
-The response of succinylcholine is unaltered with aging.
Non-depolarizing muscle relaxant
-Long-acting agents:
Metocurine, pancuronium (renal)
Doxacurium, pipecuronium (renal)
-Intermediate-acting agents
Vecuronium, rocuronium (renal)
Atracurium, cisatracurium (Hoffmann elimination)
Due to decrease in renal or hepatic reserve , the duration of action
prolonged.

30.  Other drugs: Due to decrease in vagal outflow and beta receptor
sensitivity, dose of atropine, adrenaline or other adrenergic drugs
increased.
 Neuraxial anaesthesia: the time of onset is decreased and spread is
more extensive with bupivacaine (H).Reduction in plasma clearance
lead to prolong motor and sensory blockade.

31. Preoperative assessment:
1. Check for concomitant disease states
2. Cognitive status, personality disturbances
3. Review for implanted devices- dentures, hearing aid,
spectacles
4. Assess the degree of functional reserve, pertinent organ
system and pt. as a whole, history and physical examination
5. Lab. and diagnostic studies= BUN, creatinine, glucose, Hb,
coagulation profile, nutritional status, review of ECG, chest X-
ray,2D-ECHO, PFT
6. Review Current medication regimen
7. Informed consent

32. Regional versus General anaesthesia:
 Use of RA decrease the incidence of postoperative cognitive
dysfunction compared with GA.
 RA affects the coagulation system by preventing postoperative
inhibition of fibrinolysis. Thus decrease incidence of DVT and PE.
 Haemodynamic effects of RA associated with decreased blood loss
in pelvic and lower extremity surgery and lower risk of hypoxemia
 In RA, pt. maintain their own airway and level of pulmonary function.

33. Summary

34. INTRAOPERATIVE MANAGEMENT
 Elderly patients require lower doses of premedication
 Opioid premedication may be valuable
 Anticholinergic medication rarely needed
 Pretreatment with H2 antagonist, metoclopramide may be used
 Anxiety relief by benzodiazepine
 Smaller doses are needed in comparision to young adults for induction
 Etomidate produces less hypotension than propofol.
 Hypo or hypertension or both may occur during induction, intubation or
postintubation, so performed standard technique carefully.
 α-agonist used with fluid administration in hypovolemia
 Protective gag reflex is weakened

35.  Placement of ET tube is difficult in elderly
 Facial shape is altered, TM joint dysfunction, loose teeth/without teeth with
cervical arthritis makes exposure of larynx more difficult
 Care should be taken during laryngoscopic examination to avoid over
extension of neck
 When rapid sequence intubation is performed cricoid pressure should be
applied
 ETT have adverse effects on muco-ciliary clearance and swallowing than
laryngeal mask, but ETT provide a large tidal volume and PEEP to prevent
atelectasis.

36. POSTOPERATIVE CARE
 The major goal is to good pain relief by achieving adequate analgesia.
Failure to achieve analgesia associated with adverse outcomes like sleep
deprivation, respiratory impairment, ileus, suboptimal mobilization, insulin
resistance, tachycardia and hypertension. The consequences include longer
hospitalization and increased incidence of delirium.
 Opioids is the mainstay of postoperative analgesia, but it producing same
adverse outcome like respiratory depression, sedation, delirium, ileus.
 Adjunctive drugs –NSAIDS which reduce opioids requirement and some of
its adverse effects.
 Epidural analgesia is superior than IV therapy due to improved
cardiopulmonary outcome, more rapid return of bowel function, earlier
mobilization, better nutritional status.

37.  ECG, hourly urine output, BP must be monitored .Direct intra- arterial
pressure and CVP in high risk patients.
 Arrhythmia –common in elderly patients due to metabolic
disturbances such as hyperventilation, hypokalemia,
hypomagnesemia, hypocalcemia, hypoxia, hypercarbia.
 Postoperative hypothermia common in elderly. It manifests altered
metal status, delayed recovery from anaesthesia, sluggish deep
tendon reflexes, shallow respiratory pattern.
Perioperative hypothermia aggravates surgical bleeding
due to impaired platelet function, reduced intrinsic and extinsic
clotting, increased fibrinolysis.

38.  Postoperative confusion due to neurological problems, sepsis, metabolic
disturbances- hypoxia, hypercarbia, acidosis, hypoglycemia, hyponatremia,
renal and liver dysfunction.
 Postoperative delirium= 10% after major surgery
Diagnostic and statistical manual of mental disorders (DSM-IV)
- Disturbance of consciousness
- Change in cognition that cannot be better accounted for by a preexisting
or evolving dementia
- The disturbance develops over a short time
- Evidence from the history, physical examination, lab finding that the
disturbance is caused by direct physiologic consequences of a medical
condition

39. Precipitating factors for postoperative delirium
1. Age > 65 years and male gender
2. Cognitive impairment, Functional impairment, Sensory impairment
3. Poly-pharmacy, alcoholism, sedatives, narcotics, anticholinergic
4. Co-morbidity
5. Major surgeries
6. ICU admission
7. Pain, Sleep deprivation, Immobility, dehydration
8. Metabolic and electrolyte disorders
9. Greater intra-operative blood loss, More postoperative blood transfusion

40. PERIOPERATIVE
COMPLICATIONS
 Cardiovascular- MI, cardiac arrest, AF, hypertension
 pulmonary- pneumonia, prolonged intubation, re-intubation
 central nervous system- Stroke, TIA, Postoperative cognitive
decline
 Renal dysfunction –Due to drugs such as Aminoglycosides,
ACEI , NSAIDS or hypovolemia / cardiac dysfunction
 wound infection

41. WAYS TO IMPROVE ANAESTHESIA
IN OLDER PATIENTS
1. Proper preoperative evaluation
2. Be aware of contracted volume and hypotension on induction
3. Assume diastolic dysfunction
4. Administer beta blocker pre/intra/postoperative
5. Look for renal/ hepatic function
6. Tight glucose control
7. Administer antibiotic on time
8. Use lower doses of anaesthetic agents
9. Vigilant intraoperative monitoring
10. Postoperative pain control , delirium management

42. In Conclusion

43.  Elderly patients are uniquely vulnerable and particularly sensitive to
the stress of trauma, hospitalization, surgery and anesthesia.
 Accordingly, minimizing perioperative risk in geriatric patients
requires:
 meticulous preoperative assessment of organ function and
reserve,
 meticulous intraoperative management of coexisting disorders,
 Careful drug selection & dosage titration,
 Careful fluid therapy,
 RA better than GA
 Proper psychological preparation & management
and alert postop. pain control.

44. References
 Miller’s Anesthesia – seventh edition,Vol.2
 Barash Clinical Anesthesia - sixth edition
 Anesthesia Review Course – 2009
 Morgan clinical anaesthesiology –fifth edition

45. 03-09-2013
DR. HARSIMRAN WALIA
45