Hazards of Bed Rest Flashcards
What are some outcomes of bed rest?
-loss of LE strength
-loss of aerobic capacity
-decreased SPPB performance
-decreased PPT performance
-decreased stair climbing power performance
Aerobic capacity drops _____ per year in adults 50-70 years, how much is the loss of aerobic capacity after 10 days of bed rest?
1.5%
12.2%–> almost a decade of decline
Functional Decline During Hospitalization:
-decline in ADLs is common among hospital patients at hospital discharge
-at 3 months post hospitalization: 40% of survivors reported new ADL/IADL disabilities compared with pre-admission
-older ppl who develop new functional deficits during hospitalization are less likely to recover lost function
What is the leading complication of hospitalization for the elderly?
functional decline
(34-50% of hospitalized older adults)
-may occur as early as day 2 of hospitalization
–> many patients will end up requiring post-acute care (SNF, IRF, LTACH)
Detraining: Reversibility of Training:
-gains that are made with aerobic and strength training are reversible through detraining
-don’t have to be completely sedentary- simply a decline in usual activity
**it’s very important to match the exercise to what the patient is already doing at home–> make it harder than that!
Some of the hazards of bed rest and physiologic changes:
-decreased muscle mass
-decreased strength/endurance
-decreased plasma volume/dehydration
-decreased HR/SV/CO
-decreased aerobic capacity
-accelerated bone loss
-osteopenia/ osteoporosis
-dec. lung volumes and gas exchange
-increased WOB decreased paO2 and SpO2
-sensory deprivation/isolation –> an lead to changes in mental state
-altered MS/delirium/agitation/
confusion
VO2 equation with CO and a-v O2 difference included:
VO2 = CO x (a-v O 2 difference)
What happened to the cardiac output of college aged subjects that underwent bedrest for 3 weeks, following the 3 week period ?
-significant decline in CO 3 weeks after bedrest for every subject
-heart rate increases at submaximal intensities
-SV decreases at submaximal intensities
What happens to blood composition during bed rest?
-decreased plasma volume
-increased blood viscosity
–> hypovolemic state occurs very quickly
-decrease in plasma volume causes a decrease in VO2max
What is Virchow’s triad?
-venous stasis
-blood vessel damage
-hyper-coagulability
- DVT
What happens to the CV system during bed rest?
- Cardiac output decreases
- Stroke volume decreases
- HRrest increases–> limits HR reserve
- Decreased plasma volume
- Orthostatic hypotension (decreased blood volume)
- VTE (DVT & PE)
–> decreased cardiac reserve and aerobic capacity
– predispose patient to progressive disability
Neurologic changes associated with bed rest
-decreased PNS activity
-increased sympathetic activity –> compensation technique
-results in increased plasma NE
-inadequate increase in sympathetic output in individuals susceptible to orthostatic intolerance
Baroreceptors and bed rest:
-prolonged bed rest leads to loss of baroreceptor sensitivity
–> decreased HR response in some subjects, which led to syncope upon standing
-lack of HR response after 5 minutes of standing
What is orthostatic intolerance?
Orthostatic intolerance (OI) is a group of symptoms that develop when standing upright and are relieved by lying down. It can be a subcategory of dysautonomia, a disorder of the autonomic nervous system that occurs when an individual stands up. OI is common in young people, and initial OI is a normal, short-lived form.
What are the 3 types of orthostatic syndromes?
Orthostatic hypotension:
-decrease SBP > 20 mmHg
-decrease DBP> 10
Postural Tachycardia:
-increased HR > 30 degrees first 10 seconds standing
-no decrease in BP
Reflex Syncope:
-sudden drop in BP and HR
