A & P & Pathophysiology

Question 1

⚡️What is the greatest challenge when providing care for the older high‐risk surgical patient?

Answer 1

⚡️The greatest challenge when providing care for older high-risk surgical patients is preventing, detecting, and managing complications. Managing older high-risk patients requires vigilance and rapid and appropriate response to potential problems. [Nagelhout, N A , Be. 2013 p1214]

Question 2

⚡️What three changes put the geriatric patient at risk for hypothermia?

Answer 2

⚡️Hypothermia is more pronounced and lasts longer in the elderly due to (1) lower metabolic rate, (2) higher ratio of body surface area to body mass, and (3) less effective peripheral vasoconstriction in response to cold. [Nagelhout, N A , Sc. 2013 p1215]

Question 3

In general, are most plasma protein levels increased, decreased, or unchanged in the elderly? What important protein is an exception?

Answer 3

In general, most plasma protein levels are unchanged, or slightly decreased. For example, albumin is slightly decreased in the geriatric population. An important exception is alpha‐1 glycoprotein (AAG) which is increased in the geriatric population. This is clinically relevant because AAG binds basic drugs, such as local anesthetics and opioids. [Barash, Clin. Anes., 4th ed. 2001, p248; Kirby, Clin. Anes. P r a c t , 2eed. 2002, p677]

Question 4

How is renal function altered in the geriatric patient?

Answer 4

Altered renal function in the older patient are characterized by progressive atrophy of the renal parenchyma (tissue), deterioration of renal vascular structures, decreased renal blood flow (RBF) and an overall decrease in renal mass. [Nagelhout, N A , 5c. 2013 p1218]

Question 5

What is the best indicator of drug clearance in the geriatric individual?

Answer 5

Creatinine clearance is the best indicator of drug clearance in the geriatric individual. [Nagelhout, N A , 5e. 2013 p1219]

Question 6

⚡️The older patient with renal impairment is at risk for what four (4) physiologic alterations or challenges?

Answer 6

⚡️The older patient with renal impairment is at risk for (1) fluid overload, (2) accumulation of metabolites of drugs that are excreted by the kidneys, (3) decreased drug elimination, which can prolong the effects of a wide range of anesthetic drugs and adjuncts, and (4) electrolyte imbalances, which can lead to arrhythmias by affecting cardiac conduction. [Nagelhout, N A , Se. 2013 p1219]

Question 7

What happens to residual volume with aging?

Answer 7

Residual volume increases with age. [Nagelhout, N A , 5e. 2013 p1217]

Question 8

What changes occur in total lung capacity (TLC) with age?

Answer 8

Specific (height‐adjusted) total lung capacity does not change with age. The key is “specific (height-adjusted)” TLC . Absolute TLC decreases slightly with age. [Nagelhout, N A , 5e. 2013 p1217]

Question 9

How do functional residual capacity (FRC) and vital capacity (VC) change in the elderly?

Answer 9

FRC usually only increases slightly (10%) with age. Vital capacity is significantly decreased with age. [Nagelhout, N A , 5e. 2013 p1217]

Question 10

How is vital capacity (VC) altered in the older adult? What accounts for this change?

Answer 10

Vital capacity decreases in the older adult due a progressive increase in residual volume (RV). Since TLC is relatively unchanged in the older adult, the increasing RV takes volume away from TLC. [Authors;Nagelhout,NA, 56. 2013 p1217]

Question 11

What changes occur to closing volume and closing capacity in the older adult?

Answer 11

Closing volume and closing capacity both increase progressively with age. (Recall CC= CV + RV). [Nagelhout, N A , Se. 2013 p1217; Authors]

Question 12

How do closing capacity and functional residual capacity compare when the 44-year-old patient is in the supine position?

Answer 12

Closing capacity and functional residual capacity are about equal (CC ≈ FRC) when the 44-year-old patient is in the supine position. [Nagelhout, N A , Be. 2013 p1217]

Question 13

At approximately what age does closing capacity equal or exceed functional residual capacity in the awake, upright individual?

Answer 13

By age 65, closing capacity equals or exceeds functional residual capacity in the upright position in most individuals. [Nagelhout, N A , Sc. 2013 p1217]

Question 14

Give an equation to estimate closing volume in the young, healthy adult? What is the equation to estimate closing volume in a 70-year-old?

Answer 14

Closing volume is 30% of total lung capacity in the 20 year old and increases to about 55% of total lung capacity at age 70 years. [Nagelhout, N A , 5e. 2013 p599]

Question 15

What happens to FEV1 with age?

Answer 15

FEV1 decreases with age due to loss of elastic recoil, decrease in small airway diameter, and airway collapse with forced expiration. [Nagelhout, N A , 5e. 2013 p1217]

Question 16

What signs of pulmonary disease are exhibited by elderly patients?

Answer 16

Elderly patients have signs of both obstructive and restrictive disease. The chest wall exhibits decreased compliance, consistent with restrictive disease, whereas the lung parenchyma is more compliant, leading to obstructive disease signs and symptoms. [Authors]

Question 17

How do Pa02 and PaCO2 change with age?

Answer 17

Pa02 decreases steadily with age, reaching normal values of ～80 mm‐Hg by age 70. The progressive decline in Pa02 is due to the ventilation:perfusion mismatch (specifically shunting) caused by closing capacity encroaching upon and eventually exceeding FRC. PaCO2 remains relatively constant with age. [Millen Anes., 76. 2009 p7l‐2t; Nagelhout, N A , 5e. 2013 p1217]

Question 18

Write an equation that shows how the Pa02 can beestimated for agiven age. Predict the Pa02 of a 78-year-old patient.

Answer 18

PaO2 = 102-Age/3. Pa02 = 102‐78/3 = 102‐26 = 76 mmHg for a 78-year‐old. [Morgan and Mikhail, Clin. Aries, 1996,p429]

Question 19

How does the arterial blood-alveolar partial pressure CO2 difference (PaCO2 - PACO2) change with age? Why?

Answer 19

The PaCO2‐PACO2 gradient increases with age because there is a progressive increase in ventilation:perfusion (V/Q) mismatching (e.g., shunting) with age. [Stoelting and Miller, Basics, 1994, p397]

Question 20

Does the VD/VT ratio generally increase, decrease, or remain the same in the geriatric population?

Answer 20

With advancing age dead space increases (increased VD), therefore the VD/ VT ratio will also increase. Recall that VD/VT is given by the Bohr equation. Normal VD/VT = 150 ml/450 ml 2 0.33 (33%). In other words, in the geriatric person, the fraction of tidal volume that is dead space increases. Clinical relevance: increased VD requires increased minute ventilation (VE) and increased work of breathing to maintain alveolar ventilation (VA). [Morgan, Mikhail, and Murray, Clin. Anes, 3eed. 2002, pp490‐492, 492t; Kirby, Clin. Anes. P r a c t , 2eed. 2002, p888]

Question 21

How does the ventilatory response

to hypoxemia or hypercapnia in the elderly compare to that seen in younger patients?

Answer 21

In the elderly, the ventilatory response to hypoxemia and hypercarbia is decreased by 50% or more, predisposing them to increased episodes of apnea. [Nagelhout, N A , 5e. 2013 p1217-1218; Miller and Pardo, Basics , 6th. 2011 pChp35]

Question 22

How does chest wall compliance and pulmonary (lung) compliance differ in the elderly compared with the young healthy adult?

Answer 22

In the elderly, chest wall compliance is decreased and pulmonary compliance is increased. This means the chest wall is more difficult to distend (it is more rigid) but the lung distends easier (it is less rigid). [Morgan and Mikhail, Clin. Anes., 1996, p744]

Question 23

Identify seven (7) cardiovascular changes that occur with aging.

Answer 23

Seven age-related cardiovascular changes are (1) myocardial hypertrophy, (2) myocardial stiffening, (3) reduced LV relaxation (reduced lusitropy), (4) reduced B-receptor responsiveness, (5) conduction system abnormalities, (6) stiff arteries (reduced compliance), and (7) stiff veins. [Nagelhout, N A , Sc. 2013 p1216t;]

Question 24

How do cardiac output and stroke volume in the elderly compare with cardiac output and stroke volume in the young adult?

Answer 24

Cardiac output decreases with age, but stroke volume does not change with age. [Stoelting and Miller, Basics, 1994]

Question 25

What population—other than persons with atrial fibrillation, atrial flutter, or junctional rhythms—are particularly dependent upon atrial contraction to achieve adequate ventricular filling?

Answer 25

Geriatric and elderly individuals are particularly dependent on atrial contraction to achieve adequate ventricular filling due to age‐associated diastolic dysfunction (reduced ventricular filling). [Nagelhout, N A , Be. 2013 p1215]

Question 26

What physiologic change places the geriatric person at risk for aspiration?

Answer 26

Geriatric persons are at risk for aspiration due to decreased laryngeal reflexes. [Barash, Clin. Anes., 4th ed. 2001, p1208]

Question 27

How are autonomic reflex responses affected in the elderly?

Answer 27

Autonomic responses that maintain cardiovascular and metabolic homeostasis are progressively impaired in the elderly. Anesthesia usually produces arterial hypotension in the elderly, which requires treatment. This hypotension results from autonomic dysfunction. [Barash, Clin. Anes., p1132]

Question 28

An elderly patient becomes hypotensive and tachycardic when going from supine to upright position. Why?

Answer 28

Autonomic dysfunction (viz., baroreceptor reflexes are impaired). [Barash, Clin. Anes., 1997, p1132]

Question 29

Elderly patients have changes in autonomic function referred to as physiologic beta blockade. Identify two cellular changes that explain the blunted B-receptor response in the geriatric patient. What two cardiovascular responses are altered due to the blunted B-receptor response?

Answer 29

Decreased B-receptor responsiveness is secondary to both decreased receptor affinity and alterations in signal transduction (specifically, decreased intracellular cyclic AMP). Decreased B-receptor responsiveness assumes functional importance when increased flow demands are placed on the heart. Normally, B-receptor-mediated mechanisms act to increase the heart rate, venous return, and systolic arterial pressure while preserving preload reserve. In contrast, the attenuated B-receptor response in the elderly during exercise/ stress is associated with (1) decreased maximal heart rate and (2) decreased peak ejection fraction. Such decreases cause the increased peripheral flow demand to be met primarily by preload reserve, thereby making the heart more susceptible to cardiac failure. [Millen Anes., 6e. 2005 p2436‐2437; Duke, Secrets, 3e. 2005 p409]

Question 30

What two important changes in the autonomic nervous system (ANS) take place with aging?

Answer 30

The two most important changes in the autonomic nervous system with aging are a decrease in response to B‐receptor stimulation and an increase in sympathetic nervous system activity. [Miller, A n e s , 6e. 2005 p2436; Barash, Clinical Anes, 5e. 2006 p1224]

Question 31

Why do geriatric patients have a decreased response to beta antagonists?

Answer 31

In the geriatric patient, the beta receptor has a reduced affinity for beta-adrenergic receptors antagonists. Beta‐adrenergic receptor agonists also show a reduced affinity for the beta-adrenergic receptor in the elderly. [Miller, Anes, 2000, pp2146‐2147; Duke and Rosenberg, Secrets, 1995, p413]

Question 32

An elderly patient is supine. This position changes to sitting or standing. Blood pressure decreases but heart rate remains unchanged. Why?

Answer 32

Gravity causes blood to pool in dependent extremities when going from the recumbent to the sitting or standing position. Heart rate does not change because autonomic responses that maintain cardiovascular and metabolic homeostasis are progressively impaired in the elderly. This impairment is referred to as autonomic dysfunction. [Barash, Clin. Anes , 1997, p1132]