anesthesia concerns in geriatrics,physiological changes,dose adjustment Chronological age,Biological age Regional versus General Anesthesia

1. GERIATRIC ANAESTHESIA
PRESENTED BY
DR. M.ANEEQUE ALAM KHAN
DEPARTMENT OF ANAESTHESIA, SICU AND PAIN
MANAGEMENT
CIVIL HOSPITAL KARACHI / DOW UNIVERSITY OF
HEALTH SCIENCES
aneeque86@gmail.com

2.  Usually we refer to patients aged ≥65 yr
 Chronological age The number of years a person has lived
 Biological age refers to how old that human seems
 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
 Decreased end-organ reserve
 Decreased functional capacity
 Increasing imbalance of homeostatic
mechanisms
 Increasing incidence of pathologicprocesses.

4. Physiological changes
Nervous system
 Memory decline occurs in > 40% of individuals.
 There is a decrease in the volume of gray and white matter.
 Decreases in brain reserve are
manifested by :
 increased sensitivity to anesthetic
medications
increased risk for perioperative delirium and postoperative cognitive
dysfunction.

5.  Neuraxial changes :
a) Reduction of the area of the epidural space
b) Increased permeability of the dura
c) Decreased volume of CSF
d) Decreased conduction velocity in peripheralnerves.
• These changes tend to make elderly individuals more sensitive to neuraxial
and PNBs.
 Dementia andparkinsonism
• Cognitive deficits are associated with poorer rehabilitation outcomes and
higher surgicalmortality.
• Parkinson's patients are at increased riskfor:
Postoperative pharyngeal dysfunction
Risk of aspiration
Autonomic instability

6. Cardiovascular changes
 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

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

8. Respiratory System
 Decreased lung tissue elasticity (due to reorganization of collagen
and elastin):
 Early collapse of small airways and over distension of alveoli
(V/Q mismatch).
 Increased residual volume (total lung capacity unchanged).
Increased closing capacity .
 Decreased arterial oxygen tension.
 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. • Liver
volume decreases approximately 20% to
40% with aging.
Hepatic blood flow decreases about 10%
per decade.
There is a variable decrease in the liver's
intrinsic capacity to metabolize drugs.

13. Other problems
 Polypharmacy
 The number of medications used is directly
proportional to the likelihood of having an adverse
drug reaction
 Malnutrition
Surgical patients who are malnourished have
increased morbidity and mortality and increased
length of stay.

14.  Dehydration
 Dehydration and is often associated with
hypernatremia and accompanied by infection,
e.g. pneumonia and UTI.
 Immobility
 Bed rest leads to ventricular atrophy,
hypovolumia, and orthostatic intolerance.
Prolonged bed rest causes decreases in
muscle mass, which may influence pulmonary
function.

15. Hypothermia
contributors
 frail constitution,
 reduced metabolic rate,
 reduced subcutaneous fat layer,
 major and long operations, and
 impaired thermoregulation
 unintentional hypothermia has been associated with
myocardial ischemia, angina, and hypoxemia during the early
postoperativeperiod.

16. Pharmacological changes
 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.
 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).

17. Preoperative Evaluation
 Perform a thorough history and physical examination
 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 .

18. 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
 Avoid hypothermia.

19.  Inhaled Anesthetics
 The (MAC) decreases approximately 6% per decade for most
inhaled anesthetics.
 Intravenous Anesthetics
 Propofol, ketamine, thiopental, etomidate reduce dose
requirement
 The dose requirement of midazolam to produce sedation is
decreased approximately 75% due to increased brain
sensitivity and decreased drug clearance.

20.  Opiates
 Morphine clearance is decreased in elderly
patients.
 Sufentanil, alfentanil, remifentanil and fentanyl are
approximately twice as potent in elderly patients.
 Muscle Relaxants
 Generally, age does not significantly affect the
pharmacodynamics of muscle relaxants.
 Duration ofaction may be prolonged, however, if the
drug depends on liver or renal metabolism.

21. Regional versus General Anesthesia
 Specific effects of regional anesthesia may provide some
benefit.
decrease the incidence of DVT
decreased blood loss
regional anesthesia does not require instrumentation of the
airway and may allow patients to maintain their own airway
and level of pulmonary function.

22. Postoperative Considerations
 Optimal pain management to improve respiratory effort,
prevent delirium, and promote early ambulation.
 Infection
 Thromboembolism
 MI and cardiac arrest more common in elderly
 Stroke
 Postoperative confusion, delirium, or cognitive dysfunction
common in elderly.

23.  Chronological age is a poor predictorof physiologicage

24. THANK YOU