Principles of Anesthesiology Nursing II Anesthesia for Geriatric Patients

1
Principles of Anesthesiology Nursing
IIAnesthesia for Geriatric Patients Jeffrey
Groom, MS, CRNA, ARNPClinical Associate
ProfessorAnesthesiology Nursing ProgramSchool
of Nursing Florida International University
2
Average Life Expectancy

• 3000 BC - 18 years
• 275 BC - 26 years
• 1900 AD - 49 years
• 1980 AD - 76 years
• 2002 AD - 85 years
• 2020 AD - 90 years..

3
Patients over 65, represent 12 of Population

• Patients over 65, represent 25 of Surgical and
  Diagnostic Procedures requiring anesthesia
  service
• 33 of health care expenditures and 50 of
  federal health dollars

4
Ingunial Hernia Repair

• 1927 Age gt 50 IHR was contraindicated
• Advances in medicine, surgey and anesthesia
• 1994 31,000 pts had IHR and in-hopsital stay
• 1994 114,000 pts had IHR in Ambulatory Surgery

5
Physiologic Similarity and Difference
INFANTS
ELDERLY
Chronologic age vs. Physiologic age RealAge Test
by Michael Roizen, MD
6
Physiologic Similarity and DifferenceInfants
Elderly

• Decreased ability to increase heart rate in
  response to hypovolemia, hypotension, hypoxia
• Decreased lung compliance
• Decreased arterial oxygen tension
• Decreased renal tubular function
• Increased susceptibility to hypothermia

7
AGING

• Molecular effects
• Cellular effects
• Physiologic effects

8
CARDIOVASCULAR Normal physiologic changes

• Decreased arterial elasticity
• Elevated afterload
• Elevated systolic blood pressure
• Left ventricular hypertrophy

9
CARDIOVASCULARNormal physiologic changes

• Decreased adrenergic activity
• Decreased resting heart rate
• Decreased maximal heart rate
• Decreased baroreceptor reflex

10
CARDIOVASCULARCommon Pathophysiology

• Atherosclerosis
• Coronary artery disease
• Essential hypertension
• Congestive heart failure
• Cardiac dysrrhythmias
• Aortic stenosis

11
RESPIRATORY Normal physiologic changes

• Decreased pulmonary elasticity
• Decreased alveolar surface area
• Increased residual volume
• Increased closing capacity
• V/Q mismatching
• Decreased arterial oxygen tension

12
RESPIRATORY Normal physiologic changes

• Increased chest wall rigidity
• Decreased muscle strength
• Decreased cough
• Decreased maximal breathing capacity
• Blunted response to hypercapnia and hypoxia

13
RESPIRATORY Common Pathophysiology

• Emphysema
• Chronic bronchitis
• Reactive airway disease
• Pneumonia
• Lung cancer
• Tuberculosis

14
RENAL Normal physiologic changes

• Decreased renal blood flow
• Decreased renal plasma flow
• Decreased glomerular filtration rate
• Decreased renal mass
• Decreased renin-aldosterone responsiveness
• Impaired potassium excretion

15
RENAL Normal physiologic changes

• Decreased tubular function
• Impaired sodium handling
• Decreased concentrating ability
• Decreased diluting capacity
• Impaired fluid handling
• Decreased drug excretion

16
RENAL Normal physiologic changes

• Decreased muscle mass keeps creatinine within
  normal limits
• BUN gradually increases (0.2 mg/dL per yr gt
  30yrs)

17
RENAL Normal physiologic changes

• Decreased sodium handling, concentrating ability
  and diluting capacity
• Predioposed to dehydration or fluid overload
• Increased BUN or c

18
RENAL Common pathophysiology

• Diabetic nephropathy
• Hypertensive nephropathy
• Prostatic obstruction
• Congestive heart failure

19
MUSCULOSKELETAL Common Pathophysiology

• Decreased elasticity
• Prone to soft tissue trauma
• Frail veins
• Arthritis
• Decreased range of motion
• Difficulty in positioning
• Osteoprosis
• Increased risk for fracture

20
Neurologic Normal physiologic changes

• Decreased brain mass and cerebral blood flow
• Decreased synthesis of neurotransmitters
• Decreased neuronal mass in cerebral cortex
• Degeneration of peripheral neurons resulting in
  decreased conduction velocity and skeletal muscle
  atrophy

21
Hepato-Gastrointestional Normal physiologic
changes

• Decreased liver mass and hepatic blood flow
• Decreased rate of biotransformation, albumin
  production, and plasma cholinesterase synthesis
• Delayed gastric emptying
• Increased gastric pH

22
Age Related Pharmacologic Changes

• Age produces both PK and PD related pharmacologic
  changes
• Distribution affected by decrease in total body
  water and 2x increase in body fat
• VoD is decreased for water-sol (high plasma)
• VoD is increased for lipid-sol (low plasma)
• If VoD increased, elimination half-life
  prolonged, unless rate of clearance is also
  increased
• Renal hepatic function decline with age, so
  drug clearance may be prolonged

23
Age Related Pharmacologic Changes

• Protein binding is affected by age
• Albumin decreases
• Albumin binds acidic drugs(barbs, benzos, opioid
  agonists)
• Glycoprotein increases
• Glycoprotein binds basic drugs(local
  anesthetics)
• Major PD change is reduced anesthetic requirement
• Lower minimum alveolar concentration requirements

24
Age Related Pharmacologic Changes

• INHALATIONAL ANESTHETICS
• MAC decreases 4 per decade after age 40
• Depressed cardiac output more rapid onset
• Major V/Q abnormality more delayed onset
• Myocardial depressant effects are more pronounced
• Recovery from VAAs may be prolonged because of
• Increased VoD (increased body fat)
• Decreased hepatic function (decreased halothane
  metabolism)
• Decreased pulmonary gas exchange

25
Age Related Pharmacologic Changes

• NONVOLITALE ANESTHETIC AGENTS
• Elderly have lower dose requirements for
  barbiturates, benzos and opioid agonists
• STP Propofol induction dose for 80 yo is
  approximately half of the dose for 20 yo
• Slower distribution from central to peripheral
• Aging increases PD sensitivity to Benzos
• Accumulates in fat store, VoD large, elimination
  slower therefore half-life is prolonged
• Opioid agonists PK and PD changes
• Small initial VoD prolonged elimination
  half-life(PK)
• Increased brain sensitivity (PD)

26
Age Related Pharmacologic Changes

• MUSCLE RELAXANTS
• Onset and recovery may be prolonged
• Decreased CO and slow muscle blood flow may
  double onset time
• Decreased renal or hepatic clearance may delay
  recovery
• Decreased plasma cholinesterase levels may
  prolong SUX (M gt F)

27
Geriatric AnesthesiaThey are not just
little-er adults