Frailty Flashcards
Persons aged 65 and older are prescribed the highest proportion of medications in relation to their percentage of the U.S. population
Now, 13% of total population buy ____of all prescription drugs
• By 2040, 25% of total population will buy ___ of all prescription drugs
33%
50%
• Nearly 1 in 3 acutely hospitalized older patients
Adverse drug reactions are the most common iatrogenic illness
Results are
functional losses and increased costs
Describe:
overused
underused
misused
overused: no indications: about 7-37% of drugs in this category
Unused: not prescribed when indicated; few indicated
Misused: inidation present, but wrong dose, duration or freqeuncy
Problems associated with medicatiosn and the elderly
inapp use causes hospital admits
hip fxr 2x more likely under influence of drug
1/1,000 elderly die of drug side effect
Mrs. J is an 89 year old woman with hypothyroidism. She is on replacement with Synthroid 0.20 mg qd. She recently had a hip fracture which was repaired. She has noted weight loss, jittery feelings, and malaise.
What might explain her symptoms?
What age related physiologic change might affect the pharmacokinetics of Synthroid?
Factors affecting drug dispotinon and response in the elderly:
body composition, reduced total body water, reduced lean body mass, body weight, increased body fat, protein binding, reduced serum albumin
What happens to body fat, plasma voluem and total body water as you age?
Body fat to total body wt will increase 35%
Plasma volume will decrease by 8%
Total body water will decrease by 17%
Functions of the kidney
Excretion of metabolic waste products and foreign chemicals
Regulation of water and electrolyte balances
Regulation of body fluid osmolality and electrolyte concentrations
Regulation of arterial pressure
Regulation of acid-base balance
Secretion, metabolism, and excretion of hormones Gluconeogenesis
Estimate the interstitial fluid volume of a healthy individual with a body mass of 60 kg.
9 Liters:
water is 2/3 of total body weight thus 40 L
of that 40 L, 1/3 is extracellular fluid about 13 L
of Extracellular fluid 2/3 is Interstital fluid thus
9L
By weight, the body is composed of 50-70% water. We’ll use the value of 60%. Lean subjects have _______than obese individuals.
greater water content
Intracellular Fluid (ICF) =
2/3 Total Body Water (40% of body weight)
Extracellular Fluid (ECF) =
1/3 Total Body Water (20% of body weight)
The average 70 kg man with ~42 liters of TBW would then have ~______in the ICF and ~______in the ECF.
28 liters (42 liters x 2/3)
14 liters (42 liters x 1/3)
The barrier between ICF and ECF is the
The barrier between the plasma and Interstitla fluid two compartments is
cell membrane.
the capillary wall
CALCULATE THE NORMAL BLOOD VOLUME
Plasma volume is ~3 liters and the hematocrit (packed red blood cell fraction of blood) averages 0.38-0.42.
So the average individual will have a blood volume of ~5 liters:
Plasma Volume / (1-Hct),
i.e., 3 liters / (1-0.4).
An individual of normal body composition (plasma osmolarity = 280 mOsm/l) ingests 1 liter of a solution containing 200 mmole/liter NaCl. After equilibration of body fluids, and before any renal excretion has occurred, which statement will be true?
His intracellular fluid osmolarity will be increased compared to initial conditions.
Capillary wall is highly permeable to _________, but not to ______
water, electrolytes, and other small molecules
proteins
Plasma ≈ ______, except for more proteins in plasma
Interstitial fluid
The cell membrane is highly permeable to___, but not to______
water
most electrolytes or proteins
Which compatment is High in Na+, Cl-, HCO3-
ECF:
Which compartment is High in K+, PO43- and organic anions, protein
ICF
What maintains the balance of Na+ and K between the ECF and ICF?
The Na/K ATPase pump
The______ is the barrier betwee the ECF and ICF and is goverend by the ______
cell membrane
osmotic forces
is a function of the total number of particles in solution, independent of mass, charge, or chemical composition.
Osmolarity
Dissolved particles in biological solutions are expressed in terms of milliosmoles (mOsm). Osmolarity is the concentration of
osmotically active particles in total solution and is expressed in terms of mOsm/liter of water.
How do you account for osmoles in a substance like glucose vs NaCl?
For substances that do not dissociate into smaller particles when dissolved (e.g., urea, glucose, inulin, etc.), 1 mole = 1 osmole and 1 mmole = 1 mOsm.
For substances that dissolve into two particles (NaCl) or three particles (CaCl2), the osmolarity will be double or triple the molarity (1 mmole NaCl = 2 mOsm).
the movement of water across a semi-permeable membrane due to differences in osmolarity (an osmotic pressure gradient). A 1 mOsm/l difference in osmolarity can exert an osmotic pressure equivalent to 19.3 mmHg.
Osmosis
What is the Influence of Adding Isotonic NaCl Solutions to the ECF on Total Body Water (TBW), Extracellular (ECFV) and Intracellular Fluid Volume (ICFV)?
TBW: Increase
ECV: Increase
ICFV: No change
Steady state osmolarity: Stays same
What is the Influence of Adding Hypertonic NaCl Solutions to the ECF on Total Body Water (TBW), Extracellular (ECFV) and Intracellular Fluid Volume (ICFV)?
TBW: Increase
ECFV: Increase
ICFV: Decrease
Steady State Osmolatiry: Increase
What is the Influence of Adding Hypotonic NaCl Solutions to the ECF on Total Body Water (TBW), Extracellular (ECFV) and Intracellular Fluid Volume (ICFV)?
TBW: Increase
ECFV: increase
ICFV: Increase
Steady State Osomolatiry: Decrease