Bed, Rest, Deconditioning & Hospital Acquired Weakness Flashcards
how is the CV system affected by bed rest/immobility
- reduced VO2max
- increased resting HR
- decreased CO
- reduced cardiac vagal tone
- increased norepiniphrine
- enhanced beta-adrenergic receptor sensitivity
- hypovolemia
- venous pooling
orthostatic hypotension
- a drop in BP during a change in position
- decreased upright position tolerance
- drop in 20 in systolic
- and 10 in diastolic
when can OH occur
within 3 wks of bed rest, sooner for elderly
what is a main complication that occurs with OH that has to do with circulation
excessive pooling of blood in LEs –>
decreased circulating blood volume –>
rapid HR = diminished diastolic ventricular filling and decline in cerebral perfusion
treatment for OH
exercises in bed before sitting them up early mobilization LE exercises to increase blood circulation compression stocking tilt table
how is the hematologic system affected by bed rest
- RBC mass reduction by 5% to 25%
- decreased total blood volume, red blood cell mass and plasma volume
you can also have elevated HCT due to bed rest, what can this lead to
increased risk for DVT
you have decreased blood plasma and increased RBC = dehydration
reduced capillarization of peripheral muscle beds is a complication of the hemtologic system due to bed rest, why do we need to know this as a PT
you have reduced blood flow to exercising muscles which will decrease exercise tolerance
what is a venous thromboembolism and what are the 3 things involved
- virchow triad
- venous stasis
- hypercoagulability
- blood vessel damage
primary site for venous thromboembolism
calf and soleus sinus
what is directly related to frequency of DVT
length of bed rest
what pharmacology will decrease blood coagulability
unfractioned heparin (UFH) low molecular weight heparin (LMWH)
what are the key elements of bed rest contributing to MSK changes
lack of LE WB forces
decreased number/magnitude of muscle contractions
when does adaptations to decreased loading of muscles occur
within days
where does atrophy occur greatest
in antigravity muscles (quads) than antagonist muscles (hamstrings)
what muscle fibers are affected the most
type IIB (fast twitch) more than type 1 and type IIA
if a pt is immobilized in the shortened position what happens
enhances atrophy
if a pt is immobilized in the lengthened/stretched position what happens
decrease loss of muscle fiber proteins
disuse osteoporosis is due to what
bone loss due to not enough stress placed on the bone
what two things can result from immobilization
hypercalciuria and negative calcium balance results
what happens to calcium balance within one week of bedrest
negative calcium balance
pathogenesis of a pressure injury
pressure causes ischemia, compresses capillaries and occludes blood flow –> excessive pressure can lead to tissue necrosis
stage 1 decubitus ulcers
skin intact
non-blanchable
stage 2 decubitus ulcers
broken skin
top epidermis
