This document discusses geriatric anesthesia and the age-related physiological changes that are important to consider. It notes that people over 65 are more likely to have surgery and aging results in declining organ function and reserve. It then summarizes the key age-related changes in major organ systems like cardiovascular, respiratory, renal, and neurological function that are important for anesthesiologists to be aware of when treating elderly patients. Finally, it provides recommendations for the preoperative, intraoperative, and postoperative care of geriatric patients undergoing anesthesia.

1. Geriatric Anesthesia
Dr.Mohamed Taha

2.  People over 65 years of age are 3.5 times more likely to
have surgery.
 Aging results in a progressive decline in the functional
reserve of all organs; the rate at which function
diminishes is highly variable between individuals.

3. Aging is a progressive physiologic process characterized
by :
1- Decreased end-organ reserve
2- Decreased functional capacity
3- Increasing imbalance of homeostatic mechanisms.
4- Increasing incidence of pathologic processes.

4. Pathophysiology Of Aging By System
Cardiovascular
 Decreased arterial elasticity:
• Increased afterload
• Left ventricular hypertrophy
• Increased systolic blood pressure, mean arterial
pressure, and pulse pressure
 Autonomic imbalance:
• Increased vagal tone
• Decreased sensitivity of adrenergic receptors
• Decreased baroreceptor reflex

5.  Fibrosis of the conducting system and loss of sinoatrial
node cells .
 Sclerosis calcification of valves.
 High incidence of diastolic dysfunction .

6. Cardiac adjustments to arterial stiffening during ageing

7. Cardiac response to increased flow
demand in the young and the elderly

8. Respiratory
 Decreased lung tissue elasticity (due to reorganization of collagen
and elastin):
1• Early collapse of small airways and over distension of alveoli 01/Q
mismatch).
2• Increased residual volume (total lung capacity unchanged).
3• Increased closing capacity .
4• Decreased arterial oxygen tension.
5• Loss of alveolar surface area (increased anatomic and physiologic
dead space).

9.  Increased V/Q mismatch.
 Increased chest wall rigidity leading to increased work of breathing.
 Blunted response to hypercapnia, hypoxia, and mechanical stress.
 Decreased protective reflexes (coughing and swallowing) increasing
the risk for aspiration.
 Increased pulmonary vascular resistance and pulmonary arterial
pressure.
 Blunted hypoxic pulmonary vasoconstrictive response.

10. Renal
 Decreased renal mass:
• Mostly renal cortex secondary to decreased functioning
glomeruli.
• Progressive decline in creatinine clearance.
• Increased risk of perioperative acute renal failure.
 Decreased renal blood flow:
• Decreases 10% every decade of aging.
• Serum creatinine unchanged due to loss of muscle mass.

11.  Decreased tubular function:
• Altered sodium balance, urine concentrating ability. and drug
excretion
• Increased risk for dehydration and electrolyte abnormalities.
 Decreased renin-aldosterone system resulting in impaired
potassium excretion.
S. Cr. is a poor predictor of renal function in elderly patients.

12. Neurologic
 Decreased brain mass, particularly the cerebral cortex (frontal lobes).
 Cerebral blood flow decreases lD-20%, although auto regulation stays
intact.
 Decreased neurotransmitter synthesis: GABA, serotonin, dopamine,
norepinephrine, and acetylcholine system .
 Variable degrees of cognitive function decline, especially short-term
memory.
 Decreased general anesthesia (MAQ and local anesthetic requirement.

13. Neuraxial changes
a) reduction of the area of the epidural space, increased
permeability of the Dura, and decreased volume of CSF.
b) The diameter and number of myelinated fibers in the dorsal and
ventral nerve roots are decreased. c) decreased conduction
velocity in peripheral nerves.
These changes tend to make elderly individuals more sensitive to
neuraxial and PNBs.

14.  A)Reduction of the area of the epidural space, increased
permeability of the dura , and decreased volume of CSF.
B) The diameter and number of myelinated fibers in the dorsal and
ventral nerve roots are decreased.
C) decreased conduction velocity in peripheral nerves.
These changes tend to make elderly individuals more sensitive to
neuraxial and PNBs.

15. Gastrointestinal
 Decreased liver function secondary to reduced liver mass and
hepatic blood flow:
• Reduced biotransformation .
• Decreased albumin production.
• Decreased plasma cholinesterase.
 Delayed gastric emptying .
 Increased gastric pH .

16. Musculoskeletal
 Reduced muscle mass; atrophic skin; frail veins.
 Increased body fat; total body water decreases.
 Arthritis can affect various joints that can complicate
positioning.
 Degenerative changes of the cervical spine; intubation
potentially more difficult.

17. Endocrine/metabolic
 Atrophy of endocrine glands leading to impaired hormone
function:
Insulin, thyroxine, growth hormone, testosterone.
 Blunted neuroendocrine stress response.
 Decreased heat production and alteration in hypothalamic
temperature-regulating center.
 increases risk of hypothermia.

18. Age-related pharmacologic effects
 Increased body fat and decreased total body water:
Higher plasma concentration of water-soluble drugs.
Lower plasma concentration of fat-soluble drugs.
 Reduced clearance secondary to decreased hepatic and
renal function.

19.  Altered protein binding:
Reduced albumin affects binding of acidic drugs (opioids.
barbiturates, benzodiazepines).
Increased a,-acid glycoprotein after binding of basic drugs
local anesthetics).
 Pharmacodynamics changes:
Drug effects may be intensified due to decreased number of
available receptors .
Reduced anesthetic requirement (or Mac).

20. Preoperative Evaluation
 Perform a thorough history and physical examination (based on
clinical correlate) .
 Assess optimization of preexisting conditions such as CAD,
hypertension, or diabetes .
 Review medication history as polypharmacy is common among
the elderly, increasing the risk of medication interaction .
 The decision to operate should not be based on age alone, but
should reflect an assessment of the risk-to-benefit ratio of individual
cases.

21. INTRAOPERATIVE
 Monitoring based on procedure type and underlying organ involvement
 Careful titration of anesthetic agents with cardiac- and respiratory-
depressant effects.
 Careful attention toward fluid management to avoid fluid overload; at
the same time maintain adequate hydration/tissue perfusion.
 Age-related respiratory effects as well as coexisting pulmonary disease
may necessitate vigorous preoxygenation.
 Avoid hypothermia.

22. Regional anesthesia is a reasonable choice:
Local anesthetic dose requirement is typically reduced;
reduce local anesthetic dose for spinal anesthesia by 40% .
Increased risk of hypotension from the sympathectomy
.

23. Age-related Effects On Anesthetic Agents

25. Postoperative Management
 Optimal pain management to improve respiratory effort, prevent
delirium, and promote early ambulation.
 Higher incidence of perioperative complications in the elderly due
to age-related .
 physiologic changes as well as associated comorbidities:
* Infection
* Thromboembolism
* Respiratory: most common morbidity for reasons mentioned
above

26.  Cardiovascular: MI and cardiac arrest more common in elderly.
 Stroke: risk factors are age, atrial fibrillation, and history of previous
stroke.
 Postoperative confusion, delirium, or cognitive dysfunction common
in elderly.