Anesthesia for Geriatrics

Card Set Information

Anesthesia for Geriatrics
2014-02-23 08:41:30
BC Nurse Anesthesia Adv Princ

geri! geri! geri!
Show Answers:

  1. Elderly pt age
    > 65 yo
  2. theories describing aging mechanisms
    • protein damage- collagen becomes stiffer, elastin is replaced with collagen, CV system has more rx
    • mitochondiral deterioration- body runs out of energy b/c mitochondria are less effective due to oxidative stress, leads to decline in organ function
  3. functional reserve of organ function
    • difference between the basal (min) and max organ system function
    • safety margin to meet additional demands (increase CO, incr CO2 elim) of trauma and disease
  4. How does organ system functional reserve change with aging?
    • functional reserve decreases as we age (begins at age 40, sharp decrease after age 70)
    • decreases in functional reserve may not become apparent until the body is stressed (illness, surgery, polypharmacy)
  5. How does body composition change with aging?  (Ie muscle, fat, metabolism, metabolically active areas, CO) What effect does this have?
    • Atrophy of metabolically active areas (kidney, brain, liver)
    • Loss of lean muscle
    • Increased adipose mass
    • Prolonged drug effects
    • Decreased metabolism and heat prod
    • Decreased resting CO
  6. How does the neuro system change with aging?  What effect does this have?
    • Loss of neuronal tissue mass
    • Reduced central NT activity
    • Decreased anesthetic req
    • Impaired autonomic homeostasis
  7. How does the CV system change with aging?  What effect does this have?
    • Decreased elasticity
    • Decreased beta adrenergic responsiveness
    • Decreased cardiac and arterial compliance
    • Decreased max HR and CO
  8. How does the pulmonary system change with aging?  What effect does this have?
    • Increased intrathoracic stiffness
    • Decreased lung recoil
    • Reduced alveolar surface area
    • Reduced VC
    • Increased WOB
    • Impaired efficiency of gas exchange
  9. How do the renal and hepatic systems change with aging?  What effect does this have?
    • Decreased perfusion and vascularity
    • Loss of tissue mass
    • Decreased drug clearance
    • Inability to withstand salt or water loads
  10. How do the blood and immune systems change with aging?  What effect does this have?
    • Decreased immune competence
    • Loss of hematopoietic reserve
  11. How does TBW composition change with aging? What about adipose tissue?
    • Decrease TBW
    • Incr adipose tissue
  12. Hepatic enzyme activity is ____.  Hepatic blood flow is ____.  Drugs dependent on biotransformation in the liver have ____ clearance.
    • Unchanged
    • Decreased
    • Decreased
  13. How should renal function be assess in a geri pt?
    • Look at creatinine clearance
    • Serum creatinine is NOT accurate due to decreased skeletal muscle mass
  14. How does the concentrating ability of the kidneys change with aging?
    • Decreased
    • Decreased ability to conserve water or eliminate excess Na+
  15. T or F, the collecting ducts have increased sensitivity to ADH?
    F, decreased sensitivity, ADH levels are increased
  16. Most common lyte abn
  17. Hyponatremia value:
    mild- mod
    • Hyponatremia < 135
    • mild- moderate < 125
    • severe < 120
  18. Differentiate btw chronic and acute hyponatremia
    • Chronic- well tolerated and asymptomatic
    • Acute- dangerous, presents as CNS disorder, N/V, sz, muscle cramps
  19. Endocrine changes
    • increased rx to insulin, esp in skeletal muscle
    • decreased aldosterone secretion
  20. Heart changes
    -LV wall
    -conduction fibers
    -SA node cells
    • -decreased # myocytes
    • -increased thickness LV wall
    • -decreased density of conduction fibers
    • -decreased # SA node cells
  21. Effects of age related heart changes
    • incr stiffness
    • decr contractility
    • decr beta responsiveness
  22. T or F, the heart has less of a response to endogenous and exogenous catecholamines
  23. Vascular changes
    -elastin and collagen
    -MAP and pulse pressure
    • loss of elastin and increase in collagen causes decr arterial compliance
    • decreased compliance
    • increased MAP and pulse pressure
  24. Which is more common diastolic or systolic HTN
    systolic due to increased periph vascular rx due loss of elastin and increase in collagen
  25. ANS changes
    -SNS activity
    -beta responsiveness
    • increased SNS activity
    • decreased response to beta adrenergic activity due to decreased receptor activity and decreased signaling
  26. baroreceptor responsiveness
  27. Changes to alpha adrenergic responsiveness
  28. Net effect of decr beta VD receptor responsiveness and unchanged alpha VC responsiveness
    unopposed VC
  29. Why is end diastolic volume so important?
    • Need enough EDV to get length tension relationship for optimum contractility (Starling Law)
    • LV is stiff, so this can be difficult
  30. Why can AF be detrimental?
    • EDV is important for optimum CO
    • but filling is impaired due to stiff LV
    • thus need atrial kick to aid ventricular filling and maintain CO
  31. How are plasma levels of NE affected?
  32. By age 80, ___% of elderly have some degree of CAD and ___ % have angina.
    • 80
    • 25
  33. T or F, DM facilitates the atherosclerosis of coronary arteries
    • T
    • assoc autonomic neuropathy
    • VD of coronary arteries is impaired
  34. Why is upper airway obstruction risk increased
    Loss of collagen, elastin, and pharyngeal muscle support
  35. T or F, aspiration risk is incr?
  36. What are the effects of the anatomic changes to the respiratory system?
    • Increased anatomic dead space
    • Decreasing perfusing capacity
    • Increased CC
    • Impaired gas exchange
  37. T or F, chest wall compliance is increased?
    F, decreased due to kyphosis, vertebral collapse, and costochondral calcifications
  38. Increase or decrease in the following with aging?
    Max insp and exp force
    PA pressure
    • Decreased
    • Increased
    • Increased
    • Increased
  39. At what age does CC exceed FRC?
    ~ 60 yo
  40. T or F, HPV is unchanged with aging?
    F, it's impaired
  41. What occurs when CC > FRC?
    • Shunt
    • Decreased PaO2
  42. List reasons for impaired gas exchange
    • Decreased diffusion (loss of functional alveolar SA, increased alveolar membrane thickness)
    • Impaired V/Q matching
    • Increased A-a gradient
  43. Ventilatory responses to hypercapnea ___ by __% and ventilatory response to hypoxia ___.
    • Decreases, 50%
    • decreases
    • esp at night
  44. GA reduces FRC by ___%
    as much as 15
  45. MAC ___ by __% per decade after the age of 40.
    • decreases 
    • 6
  46. Why might an elderly pt seen pre-op (DOS) have an increased sensitivity to barbs?  How should be adjust the dose?
    • Pt hypovolemic (NPO), drug gets concentrated in a smaller central compartment, larger reserve due to increased adipose
    • 20% less
  47. SE of barbs in the elderly
    • Dose dept hypotension
    • Decreased CO by decreasing preload and contractility
  48. Pd
    What the drug does to the body, the drug's pharm effect
  49. Pk
    What the body does to the drug, absorption, metab, elim, etc
  50. Propofol dose adjustments for elderly
    • decrease by 20-60%
    • dose based on lean body mass
    • smaller central Vd and decreased clearance
  51. T or F, elderly pts are more likely to have reps depression and hypotension 2/2 propofol
  52. Etomidate dose adjustment for elderly
    • Decrease dose by 25-50%
    • Decreased clearance in elderly
  53. Pd and Pk changes of benzos in the elderly
    • Pd- increased sensitivity
    • Pk- decreased clearance
  54. Risks associated with IV diazepam in the elderly
    • increased risk of thrombophlebitis and thrombosis
    • effect of active metabolites will be more profound
  55. What sedative hypnotics have active metabolites?
    • thiopental (only signif with long inf at high doses)
    • diazepam
    • ketamine
  56. Which opioids have active metabolites?
    • Demerol
    • Morphine
    • Dilaudid
    • Fent
  57. T or F, elderly its are equally sensitive to opioids as younger pts
    F, more sensitive
  58. Why might uptake and elim of volatiles be prolonged in elderly pts?
    • V/Q mismatch
    • Alteration in CO (slowed circa time)
    •   myocardial depressant effect is increased
    •   no compensatory increase in HR
  59. T or F, elderly pts require a decreased initial dose of NMBs?
    F, initial dose is unchanged
  60. How is the onset time of NMBs changed in the elderly pt?
    Increased onset time 2/2 decreased CO and decreased muscle blood flow
  61. How is the metabolism and clearance of NMBs altered in elderly pts?
    • Prolonged 2/2 decreased hepatic blood flow and decreased GFR
    • Most NMBs are eliminated by either liver or kidney
    • Less of an issue with cis-atro or atrocurium (ester hydrolysis / Hoffman elim)
  62. Is the priming technique appropriate for an elderly pt?
    Not contraindicated but pts are at increased risk for aspiration and desat
  63. T or F, the onset to complete twitch suppression at the adductor policis is slowed in the elderly?
  64. Is brain sensitivity to the following drugs increased or decreased: volatiles, prop, midaz, morphine, sufent, remi?
  65. In general, anesthetic agent drug doses need to be decreased in the elderly pt, T or F?
  66. T or F, regional anesthesia is preferred over GA in the elderly?
    • F, no benefit
    • Positive outcomes are r/t degree of HD control, not choice of anesthetic technique
    • CNS complications are minimized only if minimal sedation is used
  67. Elderly pts are more likely to experience hypotension from a spinal, T or F?
    T, more profound sympathectomy
  68. Factors determining surgical risk in the elderly
    • age
    • ASA status
    • elective vs. urgent
    • type of surgery
  69. How can we evaluate functional reserve pre-op?
    Exercise tolerance, goal > 4 mets
  70. factors contributing to peri-op M+M in the elderly
    • decr organ system functional reserve
    • effects of age related disease and its tx
    • impaired autonomic homeostasis
    • need for medical intervention and invasive procedures
    • polypharm
    • emergency surgery
  71. T or F, the sensitivity of the cerebral cortex to respiratory depressants increases with age?
  72. T or F, no increased risk of corneal abrasion and post-op shivering in elderly pt?
    • F, increased risk
    • corneal abrasion due to decreased lacrimation
    • shivering- altered thermoreg and decr heat production
  73. Major CV complications
    MI, myocardial ischemia, arrhythmias, HTN, hypotension
  74. What types of non-CV surgeries are associated with the highest CV risk?
    Surgeries involving thorax, blood vessels, head and neck, and abdomen
  75. Most peri-op infarcts occur __ days post-op
  76. Why should tachycardia be avoided?
    Risk factor for myocardial ischemia and infarct due to increased myocardial O2 consumption and decreased O2 supply
  77. Risk factors for cognitive dysfunction in the elderly
    • Hypotension
    • Pre-op depression
    • Surgery type
    • Anesthetic technique
    • Intra-op sedation
    • Hypoxia
    • Lyte disturbances
    • Peri-op meds
  78. T or F, GA is associated with more post-op cognitive dysfunction than regional?
    F, regional is only associated with decreased cognitive dysfunction if no sedation is used
  79. Why are elderly pts at increased risk for hypothermia?
    • impaired thermoreg
    • decreased subdermal tissue
    • decreased muscle mass so less heat production
    • impaired VC and HTN
  80. Why are elderly pts at increased risk for hypoxia?
    • Atelectasis and PNA are common
    • V/Q mismatch
    • High aspiration risk
    • Increased incidence of sleep apnea
    • Supplemental O2 is essential
  81. Predictors of post-op pulmonary complications in elderly pts undergoing non cardiac surgery 
    • Post-op NGT
    • Pre-op productive cough
    • Long anesthetic (GA)
    • COPD
    • Smoking
    • ETOH use
    • Chronic steroid use
    • Impaired LOC / CVA
    • TEE (increased aspiration risk)
  82. Other risk factors
    • nutrition
    • dehydration
    • mobility
    • depression
    • ETOH
    • chronic pain
    • autonomy