Lecture 4: Deconditioning

Question 1

What are some major implications resulting from DC?

Answer 1

1. decreased endurance
2. increased CV/P response to low levels of exercise
3. inability to perform work tasks due to SOB

Question 2

What are major reasons for rise in DC?

Answer 2

1. sedentary US lifestyle
2. increasing number of bed rests pts
3. increasing number of cancer/chronic illness survivors

Question 3

What is major CV effect from bed rest/ DC?

Answer 3

decreased VO2 max or uptake of O2 by body

happens primarily bc of CV system

Question 4

What causes this lack up O2 uptake?

Answer 4

1. decrease in blood volume- within 1-3 days there is significant diuresis effect

Question 5

How much % of extracellular fluid is lost in this 1-3 day span?

Answer 5

15-20% is lost from 2nd space of (IV), this leads to a decrease in central venous pressure

Question 6

What increases due to autonomic changes in CV system due to DC/BR?

Answer 6

1. increasing resting HR (1-3 days)
2. increased max HR (4-7 days)
3. increased EF, 1-3 days (more efficient not fighting gravity)
4. exaggerated submax exercise response at any workload 1-3 days

Question 7

What decreases due to autonomic changes in CV system due to DC/BR?

Answer 7

1. decreases stroke volume
2. decreased peripheral vascular tone and response to position change (TPR)- due to dilation of arteries and veins

since you are not fighting gravity there is no contraction

Question 8

What happens to CO equation during BR?

Answer 8

HR needs to increase to offset decreasing stroke volume

this increase in HR also leads to less diastolic filling time further decreasing SV

Question 9

What happens to SBP during BR?

Answer 9

decreases due to decreasing CO and TPR

Question 10

What factors lead to Orthostasis?

Answer 10

1. blood pooling in legs
2. decreased blood volume
3. decreased venomotor tone

Question 11

What is definition of Orthostasis?

Answer 11

drop in systolic BP greater than 20 or drop more than 10 with DBP with positional changes

OR rises in HR 20 bpm with positional change

Question 12

Along with vitals what else must you look for in pts with orthostasis?

Answer 12

symptoms: LH, dizzy, diaphoretic

Question 13

What is one important way to resolve OTN?

Answer 13

activate skeletal muscle pump with feet on ground and some type of movement

also compression stockings and meds( last resort)

Question 14

What is worst thing you can do for a patient suffering from constant OTN?

Answer 14

more bed rest

Question 15

What is biggest pulmonary effect from BR?

Answer 15

atelectasis- due to lack of expansion of alveoli

dangerous bc pt could get pneumonia due to trapped infection

Question 16

How long does it take for respiratory reserve volumes to be affected when on BR?

Answer 16

around 30 days, mostly due to resp muscle atrophy(diaphragm)

Question 17

Why is functional mobility so important for BR pts?

Answer 17

increase Vt and re expand the gas exchange vessels, only if pts are breathing with exercise

Question 18

When using an incentive spirometer what is a good way for pts to increase Vt?

Answer 18

holding breath to allow pores of Kohn to open nearby collapsed alveoli

Question 19

What are two major MS effects due to BR?

Answer 19

1. muscle atrophy

2. decalcification of bone

Question 20

What happens to postural muscles on BR?

Answer 20

don’t need to work when not fighting gravity

1/8 of strength is lost within 1 week so may be hard to even sit up

Question 21

What happens to skeletal muscles during BR?

Answer 21

more loss of LE muscles, 15-20 % strength and endurance lost in knee extensors after 1 month

Question 22

What is the window for initial muscle atrophy?

Answer 22

24-48 hours

Question 23

What can a pt get due to loss of bone calcification?

Answer 23

increased chance of renal calculi or renal stones due to increased calcium b/c of bone reabsorption and no bone production

Question 24

What are the benefits of aerobic exercise in pts with DC?

Answer 24

1. decreased risk of OTN (increased venomotor tone and pumps)
2. increase plasma fluid levels
3. improve peripheral conditioning

Question 25

When prescribing exercise for Dc pts what should frequency be?

Answer 25

less duration but increased frequency