Anesthesia for the Geriatric Patient Jonathan Weed, MD

All of the following are associated with the age-related changes in the kidney EXCEPT? 1.Decreased serum creatine concentration 2.Decreased number of glomeruli 3.Renal perfusion shifted to the medulla 4.Decreased glomerular filtration rate 5.Decreased overall renal tissue

Serum CR remains unchanged b/c skeletal muscle mass declines Glomeruli decrease by over 33%; overall mass about 30% Renal cortex is sensitive to loss of vascularity, but medulla is spared GFR increases slightly; compensatory mechanism resulting from shift of renal perfusion from cortex to medulla.

Which of the following statement regarding cardiovascular changes associated with aging is FALSE? 1.There is a modest decrease in resting cardiac index. 2.The maximal heart rate is age limited. 3.There is a myocardial muscle atrophy 4.There is decreased ventricular compliance. 5.There is impaired diastolic relaxation.

Heart does not atrophy w/age; heart size and myocardial tissue mass actually increases Decrease in cardiac index is not a degenerative process, but rather a result of reduced systemic requirements (decreased muscle mass and organ tissue mass) Decreased compliance and diastolic dysfunction create dependency on synchronous atrial contraction (NSR) for adequate end-diastolic filling

Which of the following statements regarding anesthetic requirments in the elderly is TRUE? 1.The median effective dose (ED50) for neuromuscular blocking agents is reduced. 2.A reduced volume of local anesthetic is required for spinal anesthesia. 3.Parenteral morphine requirments are directly related to patient age. 4.Minimum alveolar concentration (MAC) values decline >75% than in young adulthood. 5.The brain becomes more sensitive to etomidate and less sensitive to narcotics.

Despite decreased skeletal muscle mass, ED50 of NMB agents is unchanged or even slightly higher Elderly pts experience slightly higher levels of spinal anesthesia than young pts when given an equivalent dose of spinal LA Parenteral morphine requirments are inversely related to pt age, and independent of body weight. MAC values decline by up to 30 % from young adulthood to geriatric age.

Which of the following statements regarding the cardiovascular system and aging is/are true? 1.There is elastic replacement of fibrous tissue within the cardiovascular system. 2.Vascular impedance increases 3.Ventricular wall hypertrophy occurs only as a result of arterial hypertension. 4.Maximal cardiac output decreases.

Fibrotic replacement of elastic tissue can cause arterial hypertension Fibrotic vessels also cause increased vascular impedance to cardiac ejection, which Can lead to LVH, even in absence of hypertension Elderly pts have a lower limit of max CO

Which of the following statements regarding the pulmonary system in the geriatric patients is/are TRUE? 1.Pulmonary shunting increases 2.Pulmonary deadspace increases 3.Vital capacity decreases 4.Lung elasticity decreases 5.All of the above

Which of the following statements regarding the pulmonary system in elderly patients is/are TRUE? 1.Closing capacity typically becomes greater than the volume of the lung at rest. 2.Hypoxic pulmonary vasoconstriction remains intact during general anesthesia 3.Elderly patients are predisposed to acute postoperative ventilatory failure 4.The cardiovascular and ventilatory responses to hypoxia are increased onset

Emphysemal-like changes occur in elderly pts: loss of elasticity  increased compliance, increased closing capacity (loss of elastic recoil)

Residual volume increase –>vital capacity decreases Increased anatomic and alveolar dead space results from breakdown of alveolar septae and loss of total alveolar surface area GA depresses hypoxic vasoconstriction Increased work of breathing due to bone calcification and chest wall stiffness predisposes them to post-op failure Cardiopulmonary system responds more slowly to hypoxia and hypercarbia

Which of the following statements regarding an 80 year old patient compared with a 20 year old patient is/are true? 1.Liver tissue mass decreases by 40% 2.Renal blood flow decreases by 50% 3.Glomeruli decreases by 30% 4.Renal tissue mass decreases by 30 %

Which of the following statements regarding central nervous system changes in elderly patients is/are True? 1.The adult brain weight is 20% less by age 80 years 2.The cerebrospinal fluid decreases in the 80yo 3.There is a > 30% decrease of the neuronal population of the cerebral cortex 4.Cerebral blood flow in the gray matter is maintained in the elderly patient

Decrease in brain matter results in compensatory increase in CSF volume Neuronal population of the cerebral cortex decreases by 30-50% CBF in the gray matter declines 20-30%

Which of the following statements regarding the peripheral nervous system in the elderly patient is/are TRUE? 1.The postjunctional muscle membrane is thicker 2.The dose requirements for competitive neuromuscular blocking agents are not significantly reduced 3.Motor nerve conduction velocity decreases 4.The total number of acetylcholine receptors increases

Which of the following statements regarding the geriatric patients and neuromuscular blocking agents is/are TRUE? 1.The time to onset of neuromuscular blockade is decreased 2.The dose requirement decreases in parallel with age-related decline in skeletal muscle mass 3.Age is the primary determinant of the completeness of antagonism of neuromuscular block 4.The clinical duration of action of most neuromuscular blocking agents is increased

Which of the following statements regarding the nervous system in the aged is/are TRUE? 1.The contractile properties of peripheral vascular smooth muscle remain intact 2.Cortisol secretion declines at least 15% 3.Endogenous beta-blockade occurs 4.Plasma concentrations of norepinephrine are 2 to 4 times greater than in younger patients

NE concentrations are 2 to 4 times higher, but responsiveness of beta-receptors is reduced, leading to an “endogenous b-blockade” Alpha and muscarinic receptors remain largely intact, thus vascular smooth muscle contractile properties are not affected Adrenal tissue atrophy leads to 15% decline in cortisol levels