mobilization and exercise: physiologic basis for assessment, evaluation, and training

mobilization and exercise can help with what?

enhance oxygen transport

optimize function

what is mobilization?

therapeutic and prescriptive application of low workload activity

what are goals of mobilization?

improve or maintain oxygen transport

perform in the upright position when possible to receive benefits of gravitational stress

what is physical activity?

bodily movement produced by muscle contraction that increases energy expenditure substantially over the resting state; not generally structured or goal oriented

what is exercise?

a form of PA that is planned, structured, and repetitive

typically requires at least moderate physical exertion, such that RR and HR are noticeably accelerated, especially when performed to develop or maintained fitness

what does exercise create?

physiological adaptation; contributes to health and fitness improvements

what is training?

systematic application of progressive exercise stimulus to elicit specific physiological, functional, or skill-based goals

what does training involve and require?

long term planning and goals

requires consistency and progression for effectiveness

what is functional fitness?

an individual's ability to perform work required for their day to day instrumental, work, and leisure tasks

exercise tests can serve as _________

standardized outcome measures

describe using exercise as an assessment tool

repeated at set intervals to measure change from baseline

PTs should make certain testing ceiling isn't reache too easily

performed in tandem with physiologic measurement

selection of exercise tests should be __________

individualized based on patient based on patient needs and goals

acutely ill patients may be _______

hypermetabolic

mobilization/exercise increase what load?

metabolic load; load may already be elevated b/c of the current illness/treatment

PTs should ensure a ________ when prescribing exercise in acutely ill patients

safety margin

what are considerations for oxygen transport and metabolic demand of patients?

be mindful of cumulative effect of multiple interventions

patients with reduced O2 transport capacity are especially at risk

what factors contribute to increased metabolic demand and oxygen consumption in patient populations?

pathophysiological factors

intervention related factors

psychosocial factors

miscellaneous

what does cellular respiration depend on?

the integrity of the cardiopulmonary unit (combining CHO and fats with O2 to make ATP

when does the safety margin decrease?

during hypermetabolic state when individuals have reduced O2 transport capacity

how can aerobic capacity be increased?

high intensity exercise and aerobic exercise

what happens with increases in anaerobic threshold?

allows individuals with severely compromised aerobic systems to produce ATP longer through anaerobic mechanisms

what must patients be able to manage in regard to cellular energetics and exercise?

pH changes with anaerobic training

requires adequate kidney, CV and pulmonary function

when will acid begin to accumulate?

around 55% VO2max

what does optimal O2 transport depend on?

integrity of each step in the O2 transport pathway and the interdependency of these steps

what determines the impairment of O2 transport?

the # of steps of the O2 transport pathway affected by pathology and severity

what must the O2 transport system by exposed to in order to maximize capacity of the steps of the O2 transport pathway?

gravitational stress

exercise stress

what is the importance of gravitational and exercise stress?

both enhance the biochemical, physical, and mechanical efficiency of the steps in the O2 transport pathway and the patient's capacity to respond rapidly to these changes in the physical environment

prescription of mobilization and exercise should be based on what?

clinical presentation, functional needs, exercise test(s), patient goals, and prior level of function

________ tend to be safer for the population with pathology or limitations

submaximal tests

what are some challenges with prescription in acutely ill patients?

amount of time patients spend recumbent (in bed) and restricted mobility (due to physical impairments and environmental barriers)

______ is implicated in age-related physiological changes

oxidative stress

what is an oxidative stressor contributing to aging?

disuse deconditioning (worse when combined with smoking and western-type diet)

describe physical decline associated with aging and lack of PA

when functional capacity is maximized, the individual has better physiological reserve to deal with illness

exercise induced physiological and health advantages are lost after cessation of exercise

restricted mobility in older adults is associated with clinical depression

evidence supports need for sustained PA and exercise throughout life to derive functional and health benefits

what is prehabilitation?

PA and exercise prior to surgery/hospital admission to speed recovery, minimize hospital stay, reduce complications, and decrease time to return to activities

what should be used by PTs as post-operative preventative measures?

bolsters, adjustable beds, supportive chairs to return patients to physiologic positions as soon as possible

what are preventative effects of exercise?

aim for exercise dose that will maintain patient's conditioning level and prevent deterioration

upright position is the primary means of countering orthostatic changes associated with recumbency

true or false: recumbent exercise can be a substitute for gravitational stress associated with upright position

false

what are physiological effects of bed rest?

bedrest adversely affects most organ system by means of down-regulation of the oxygen transport system

all systems seem to be adversely affected by bed rest

there is a direct relationship between how sick the patient is and what?

the amount of time spent confined in bed

bed rest deconditioning is associated with what?

recumbency and restricted mobility

what declines fast with bed rest, CV and pulmonary function or musculoskeletal function?

CV and pulmonary function

what are different bed rest consequences?

fluid volume redistribution

muscular inactivity

altered distribution of body weight and pressure

aerobic deconditioning

what is a primary effect of mobilization and exercise on the CV and pulmonary systems?

enhanced mucociliary transport and airway clearance

frequent changes in body position augment airway clearance and minimize the pool and stagnation of bronchial secretions

what does CV deconditioning with bed rest result from?

loss of fluid volume and pressure regulating mechanisms, loss of plasma volume, and diuresis

hematocrit is increased and risk for DVT and thromboemboli increases

what are pulmonary sequelae of recumbency?

reduced lung volumes and capacities (especially FRC, RV, and FEV)

reduction of FRC from decrease in thoracic volume and increase in thoracic blood volume, both leading to pulmonary venous engorgement

what do increased closing volumes contribute to?

arterial desaturation and subsequent complications

what blood vessels dilated with bed rest?

vessels in muscle and splanchnic circulation

what happens to blood vessels with prolonged bed rest?

may impact ability to constrict

pooling in blood in the extremities when the patient assumes the upright position may cause patients to feel lightheaded or dizzy and may faint - orthostatic hypotension and resting tachycardia

describe musculoskeletal effects associated with bed rest

muscle weakness leading to discoordination, balance issues, poor posture

muscle stiffness and soreness

disuse osteoporosis and bone demineralization

skin breakdown

what muscle fibers atrophyt first?

type I fibers

what renal changes are associated with bed rest?

diuresis - increases renal load, may be problematic if renal disease is present

electrolyte imbalances: arrhythmias, muscle cramping, confusion, etc

what neuro changes are associated with bed rest?

blunted baroreceptor responses form, slow electrical activity in the brain, emotional and behavioral changes, sleep disturbance, AMS, diminished sympathetic activity

what metabolic changes are associated with bed rest?

glucose intolerance, reduced insulin sensitivity, increased calcium exertion, increased nitrogen excretion (muscle loss)

what immunological changes are associated with bed rest?

reduced cytokines and antibodies, reduced lymph flow

what are alternatives to best rest?

redesigned furniture or beds

lifting and transfer devices

tilt tables

what are acute pulmonary effects of mobilization and exercise?

increased regional ventilation, perfusion, and diffusion

increased zone 2

increased tidal volume

altered breathing frequency

increased minute ventilation

increased efficiency of respiratory mechanics

decreased airflow resistance

increased flow rates

increased strength and quality of a cough

increased mucociliary transport and airway clearance

increased distribution and function pulmonary immune factors

what are acute cardiovascular effects of mobilization and exercise?

hemodynamic effects

increased venous return, stroke volume, heart rate, cardiac output

increased myocardial contractility

increased coronary perfusion

increased circulating blood volume

increased chest tube drainage

peripheral circulatory effects

decreased peripheral vascular resistance

increased peripheral blood flow

increased peripheral tissue oxygen extraction

what is prescribing exercise and mobilization based on?

patient history, history of current illness and patient stability, assessment (chart review and physical exam), lab results, diagnostic test results, imaging, patient goals, prior level of function, baseline performance

what are mobilization stimuli for acutely ill patients?

ambulation

cycle ergometry (UE and LE)

activities of daily living

standing

transferring

dangling

cycle ergometry in bed (LE)

turning in bed

bed exercises

what is involved with preparation for mobilization?

patient should be physically prepared

patient's medication schedule should be reviewed

any equipment should be noted and positioned appropriately

move procedures and techniques should be discussed with team before implementation

what are physiological reactions to appropriate mobilization intensity?

optimal tidal volume (Vt)

increased RR

increased airflow rates

enhanced mucociliary transport

cough stimulation