Effects of Immobilization and Deconditioning

William McKinley MD

Case: PM&R Consult• 47 yo male, T-3 ASIA A• MVA, DOI 6 weeks ago

• ROS: – Pain, poor sleep, bowel

accidents, night-time bladder incont, dizzy when OOB

• Bladder Rx: IC + 2000cc/day

• Meds: perc, SQ hep, docusate, supp’s prn

• EXAM:• Ht 5’6”, weight 105lbs• VS: 90/55, 100.9, 105, 26• Labile, tearful, NAD• Basilar rales• Tachy• Rt hand numbness • Leg atrophy w/ swelling Lt

thigh, Rt knee• Dec ROM bil. ADF, + Thomas

test• Sacral pressure ulcer (stage 3)

Problem list and management strategies?

“Anyone who lives a sedentary life and does not exercise, even if he eats good foods and takes care

of himself according to proper medical principles, all his days

will be painful ones and his strength shall wane”

Immobilization & Deconditioning

• Immobilization – physical restriction of movement to body or a body segment

• Deconditioning – decreased functional capacity of multiple organ systems– Severity is dependent on degree & duration of immobility

• Disuse causes:– Impairment (organ system)– Disability (decline of function)

• The goal of rehabilitation is to restore & maximize function!

Clinical Immobility

• 20% of rehab admissions are 2nd to “deconditioning”

• Patients & Situations at risk for prolonged immobilization / bed rest:– Chronically ill, aged, disabled

– Paralysis (SCI, Stroke, BI/coma, NMD)

– LBP

– Post operatively / complications

– Polytrauma, CAD, Obstetrical comp’s

Organs Systems affected with prolonged debilitation

(Space program – “effects of immobilization and weightlessness”)

• Cardiovascular• Respiratory• Muscular • Skeletal• Joint & CTD• Gastrointestinal

• Genitourinary• Integumentary• Endocrine• Neurological• Psychological

Cardiovascular areas affected

• Heart

• Blood vessels (tone)

• Fluid balance

• Venous thrombosis

CV: Heart

• Increased heart rate (resting tachycardia)– HR rises 0.5 bpm/day over first several weeks– Exaggerated with exercise (even trivial exertion)– Angina, decreased LV-EDV

• Decreased stroke volume – 15% in 2 weeks– Cardiac Output remains largely unchanged

• Cardiac muscle mass may decrease

CV: Blood Vessels

• Blood pools in the legs– Blood vessels may lose their ability to constrict in

response to postural change– Decreased

• venous return• Stroke volume• Blood pressure

– ORTHOSTASIS!

• Rx: early mobilization, isometric LE exercise, positioning/gradual tilting, TEDs, fluids, meds

CV: Fluid Balance

• Prolonged recumbence leads to volume loss– Shifts 700cc to thorax, increased CO by 25%– Gradual diuresis (protein loss)– Decreased plasma volume –10-15%, Hct may

increase, then fall as RBC mass decreases

CV: Venous Thrombosis (DVT)

• “Virchow’s Triad” – stasis, hypercoagulability, vessel trauma (risk factors for Thrombosis)

• “high risk” patients – see next slides

– Venous stasis 2nd to decreased blood flow, Inc viscosity– hypercoagulability, increased blood fibrinogen

• Location: calf veins highest risk, 20% propagate to popliteal, 50% of popliteal will embolize (PE)

• Rx: SCD’s, ambulation, TED, SQ prophylaxis

Identifying High Risk for DVT

• Standardized Risk assessment (See next slide)

• Then stratify as follows: – Low Risk: < 2 factors – Moderate Risk: 2-4 risk factors – High Risk: > 5 risk factors OR TKR/THR OR Fracture

of hip, femur, or tib-fib

• Age 40-60 years – Age > 60 (count as 2 factors)

• History of DVT or PE – (count as 5 factors)

• Malignancy• Obesity (>120 % of IBW)• Immobilization (>72hrs)• Major Surgery• Paralysis • Trauma

• Severe COPD• Pregnancy, or post partum < 1

month• Severe sepsis• Hypercoagulable state• Nephrotic Syndrome• Leg ulcers, edema, or stasis • History of MI, CHF, Stroke, IBD

Risk Factors:

Respiratory

• Potential decrease in lung volumes (2nd to muscle weakness, positioning/restriction)

• Vital capacity• TLC• Residual volume• Expiratory reserve • Functional residual capacity

• A-V shunting• Increased respiratory rate

Resp (cont)

• Dec cough (abdominal weakness, decreased ciliary action)

• Pneumonia, Atelectasis– Hypostatic (posterior, LLL)– Aspiration (RLL)

• Rx: early mob, position changes, chest PT, incentive spirometry, asst cough, fluids, meds

Muscle

• Progressive decrease in muscle strength / endurance– Strength declines

• 1-3%/day• 10-20% per week (plateaus at 25-40% in 3-5 wks)• Greater in antigravity muscles (quadriceps, back extensors,

plantarflexors)• Type 1 (slow twitch, oxidative) muscles

• Fatigability– Decreased ATP & glucose stores and ability to use fatty

acids

Muscle (cont)

• Decrease in muscle mass & tension– Decreased fiber diameter (decreased myofibrils & xsec

area)– Muscle atrophy / wasting 2nd to decreased muscle

synthesis– 3%/day (decreased fiber size, not #)

• Body Composition changes– Decreased lean body mass (up to 3%)– Increased body fat (up to 12%)

Muscle (cont)

• Prevention/Treatment– daily isometric contractions can prevent deterioration– Note: it may take 2-3 times longer to “regain” lost

muscle mass & strength

• 20-30% of maximal contraction for several seconds

• 50% maximal contraction for 1 second• FES

Soft Tissues

• Contracture – decreased PROM of joint (2nd to joint, Conn Tissue or muscle shortening)– one of the “most” function-limiting complications

• With immobility, collagen develops CROSS-LINKS and becomes less flexible– Joint – synovial tightening– Conn tissue - Loose turns to dense– Muscle - decreased sarcomeres

• muscles (especially 2-joint), tendons, ligaments may become involved

Contractures

• Risk factors for contractures:– Positioning– Pain

• Local trauma, DJD• Infection, Poor circulation• Edema• Amputation (BKA: knee & hip, AKA: hip)

– Muscle imbalance• Paralysis/weakness (esp 2 joint muscles)• Spasticity

• Muscles most affected: hip flexors, hands, gastroc, shoulder abd/IR’s

Contractures (cont)

• Contracture prevention– Bed positioning

• Ext of neck, hips, knee…, ankle neutral, ”functional” hand position

– BID range of motion exercises (terminal, sustained)• Standing, early mob & ambulation• CPM for TKA

– Splinting – static, serial casts– Heat (40-43 degrees)– Surgery (capsular release, tenotomy, tendon transfer /

lengthening)– Nerve & MP blocks

Ligaments and Tendons

• The PARRALEL arrangement of type 1 collagen is crucial for their function

• With immobility (and lack of “stress”), new fibers may be laid down OBLIQELY causing decreased strength and elasticity

• Water and GAG content of the tissues decreased with disuse

• Rx: periodic longitudinal stress can prevent deterioration

Bone• “Wolff’s Law” – buildup or breakdown of bone is proportionate to

the forces being applied (weight-bearing, muscle forces, gravity)– When forces are not applied - it rapidly resorbs

• Osteoporosis! – peaks at 4-6 weeks• Bone density decreases 40% after 12 weeks (accelerated in SCI)• (xray not sensitive until 35-50% bone loss)

– Increased osteoclastic activity– Decreased rate of bone formation – The WEIGHT_BEARING bones are the first to lose mass (first few days)– Vertebral columns lose up to 50%

• Can lead to fracture, even with minor trauma• Prevention: weight-bearing & muscle contractions

Bone (cont)

• Immobility Hypercalcemia may occur 2-4 weeks after onset– Symptoms: N/V, abd pain, lethargy, muscle weakness

– Treatment: hydration and lasix diuresis, mobilization

• Heterotopic Ossification– In either neurological, osseous or muscular trauma

Joints

• Cartilage degeneration (proteoglycan diminishes)– Synovial atrophy & fatty infiltrate

– Underlying bone degeneration

• Benign joint effusions may occur spontaneously in SCI

• Contractures

Gastrointestinal

• Decreased fluid intake, appetite• Increased transit time in esophagus, stomach• Reduced small bowel motility (2nd to increased

adrenergic activity)• Constipation

• Rx: bowel meds, fluids, mob, fiber-rich diet (fruits, veg), avoid narcotics

Genitourinary

• Diuresis (2nd to fluid re-mobilization)• Difficulty voiding (due to postioning)• UTI’s• Calculus formation (10-15%),

hypercalciuria (esp SCI, Fxs)

• Rx: mob, fluids, upright positioning, d/c catheters

Skin

• Pressure ulcers– Risks: positioning, decreased tissue mass, poor skin

care/incontinence, shear– Sites: sacrum, heels, ischium, occiput, trochanter

• Rx: prevention! turning/positioning/seating, inspection (hands-on), skin hygiene

• Edema – may predispose to cellulitis• Subcutaneous bursitis (due to pressure)

– Rx: NSAID, steroid injection)

Endocrine

• Impaired glucose tolerance – hyperinsulinemia– Muscles develop insulin resistance

• Altered regulation of Parathyroid, Thyroid, adrenal, pituitary, growth hormones, androgens and plasma renin activity

• Altered circadian rhythm • Altered temperature and sweating response

Metabolic

• Urinary loss of:– Nitrogen – (begins day 5-6, peaks at 2 weeks)– Calcium – (begins day 2-3, peaks at 4-6 weeks)– Phosphorus

– Reversible post mobilization

Neurological

• Compression neuropathies – Ulnar (at the elbow)– Peroneal (fibular head)

• Decreased coordination / balance

• Decreased visual acuity

Psychological

• Sensory deprivation (“ICU psychosis”)– decreased attention span, awareness,

coordination, increased

• Depression, labiality, anxiety

• Sleep disturbance

• Increased auditory threshold

• Decreased pain threshold

Summary of Preventative Treatments

• Early mobilization• Strengthening• ROM• Maintain skin integrity• DVT prophylaxis• Pain management• Psychological assessment / treatment• Aggressive Respiratory management• B/B assessment & care