INTRO TO TREATMENT Flashcards
CARDIORESPIRATORY PHYSIO: def & roles
D: area of physiotherapy that specializes in prevention, rehabilitation & compensation of clients with diseases & injuries in heart & lungs
ROLE: exercising or practice ventilation matching to perfusion
OPTIMIZE VENTILATION & OPTIMIZE PERFUSION
RESPI SYSTEM: 3 ≠ pats & component of each
1) Extra-thoracic airway: nasal & paranasal sinuses also
2) Intra-thoracic airway: - trachea
- main bronchi
- lobar bronchi
- segmental bronchi
- bronchiole
- respiratory bronchiole
Cartilages keep open of trachea, main bronchi, lobar bronchi & segmental bronchi
Smooth muscles keep open bronchiole & respiratory bronchiole
Trachea, main bronchi, lobar bronchi, segmental bronchi & bronchiole move air
Respiratory bronchiole is respiratory zone
3) Alveoli
MUCOCILIARY ACTIVITY, mucus & rheology def
Mucociliary activity
Function of mucociliary clearance system = remove foreign substances & particles
Mucus
= non-homogeneous, viscoelastic fluid containing glycoproteins, proteins & lipids in watery matrix
Rheology:
= capacity to undergo flow & deformation in response to forces applied to it
3 ≠ cases of impairment alveolar
Case 1:
Absent of blood flow in alveoli leading to functional dead space
=> change in positioning can help
Case 2:
Blood flow passes through alveoli & there is diffusion barrier
=> positive pressure can help
Case 3:
Blood flow passes through alveoli but this alveoli is non ventilated => positioning, inspiratory techniques & positive pressure can help
Ventilation/perfusion: description, definition of shunt
= matching of these 2 expressed as ratio of alveolar ventilation to perfusion
V/Q~1
VE = F x VT / VE = 10 x 500 mL/VE = 5000 mL Q = HR x SV/ Q = 70 x 70 mL / Q = 4900 mL V/Q = 5000/4900 = 1,02
Pathological mismatch due to high or low ratio
- High ratio : alveoli ventilated but perfusion impaired
- Low ratio : lung perfused but not adequately ventilated
=> SHUNT = fraction of cardiac output not exposed to gas exchange
Small shunt normal (bronchial circulation mingles with pulmonary venous drainage = venous admixture = 5%)
LUNG SECRETION & insufficient humidity
Insufficient humidity
- Increases mucus production (is dehydrated) - Slow down cilia mvt
- Increases airway irritability / infections
Lung secretion
- Never work with gravity
- Give optimal condition to mucocilia => cilia hydrated - Airway must be collapses & clear
Humidifying effects of nose breathing on inspiration (left) & expiration
Mucous velocity with ≠ ages & conditions
≠ pressures
- Alveolar pressure PA: pressure of air inside lung alveoli
- Pleural pressure Pip: force acting to inflate lung within thorax.
Always negative - Transpulmonary pressure TPP: pressure difference between pleural space & alveolar space. Often positive
- Transthoracic pressure TTP: pressure across entire respiratory system. Often positive
- Transrespiratory pressure TRP: total pressure difference across airways, lungs & chest wall. Often positive
- Equivalent pressure point EPP: When airway pressure has dropped to level where it equals intrapleural pressure during forced expiration
- Dynamic airway compression: results when intrapleural pressure equals or exceeds alveolar pressure, which causes dynamic collapsing of lung airways. Mechanical compression of lungs
Compliance: def & description
= willingness of lungs to distend
- Pressure–volume (compliance) curve indicating reduced compliance at either extreme of lung volume. Symbols represent alveolar size at ≠ volumes
V, lung volume
P, pressure (work to expand lung
Defence: component, description
COUGH
1) Deep inspiration to near total lung capacity 2) Snapping shut of glottis
3) Short pause to allow distribution of air past secretions
4) Sharp contraction of expiratory muscles to create intrathoracic pressures of at least 100mmHg
5) Sudden opening of glottis, exploding trapped gas outwards at up to 800km/h
If cough => compression of lung & airway => secretion goes up into extra-thoracic airway
- Accompanied by violent swings in pleural pressure - Dynamic airway compression
• Initiated in trachea
• Extended peripherally as lung volume decreases
- Airways normally reopen with subsequent deep breath
- Cough inhibited by PAIN
- Less efficient if :
• Obstructive airway disease (Severe stage) • Poor expiratory flow
• Airway collapsus
• Neurological disease
• If glottis bypassed by intubation or tracheostomy
Gravity: description
- Gravity & weight of lung act on ventilation by increasing pleural pressure at base (making it less negative) & thus reducing alveolar volume
- Lowest part of lung in relation to gravity called dependent region
To treat alveoli: - Do slow inspiration
- Position: affecting lung in depend zone (on bed)
3 ≠ cases of gravity
1) Effect of gravity on distribution of ventilation & perfusion (left), with position of alveoli on compliance curves (right). Upright lungs in healthy young non- obese person, showing slight downward ventilation gradient & strong downward perfusion gradient
2) In side-lying:
- Fresh gas arriving in lower lung provides greater contribution to gas exchange
- But upper lung more expanded : responds earlier to deep breathing exercises for increasing lung volume
Effect of gravity on distribution of ventilation & perfusion (left), with position of alveoli on compliance curves (right). Side-lying allows greater volume change in dependent lung due to pressure from abdominal contents stretching side of diaphragm. P, Pressure required to expand lung; V, lung volume.
3) Effect of gravity on distribution of ventilation & perfusion (left), with position of alveoli on compliance curves (right). (B) In supine, pressure from abdominal contents stretches dependent portion of diaphragm, compressing dependent alveoli but facilitating more efficient diaphragm contraction
Ventilation: minute ventilation, tidal volume, alveolar ventilation & normal values (VE, VT, RR & VA)
“We breathe to ventilate & ventilate to respire.”
Minute ventilation : amount of gas breathed per minute (tidal volume x respiratory rate RR)
Tidal volume : volume of air inhaled & exhaled at each breath
Alveolar ventilation : (tidal volume – physiological dead space) x RR
Healthy spontaneous breathing adult : - VE = 5-9 L
- VT = 450 – 600 mL
+ RR = 10-15 breaths/min
VA = 4200mL
Perfusion: def, description & 3 ≠ zones
- Lungs = awash with blood from dominant low-pressure pulmonary circulation (15 mmHg), which bathes surfaces of alveoli so that gas exchange can occur
- Pulmonary vasculature equivalent to 7000 kms of capillaries
- Effect of gravity on low-pressure pulmonary circulation = create perfusion gradient with more blood in dependent regions
- Perfusion gradient represented by zones:
ZONE I = in upper non dependent lung, where
alveolar pressure exceeds pulmonary arterial pressure (=> capillaries squashed)
ZONE II = in middle; during diastole alveolar pressure exceeds arterial pressure
ZONE III = in dependent lung, where arterial & venous pressure exceeds alveolar pressure
Collateral Channels definition
- Unimportant in normal lungs : less efficient (airflow resistance 50x greater!)
- In emphysema, collateral ventilation promotes more homogeneous ventilation
- Oscillations in VT & involuntary sighs every 5-10 mins prevent alveolar collapse
- Patients who are drowsy or sedated lose mechanism
Resistance: description
= force that must be overcome during breathing = pressure & flow change
Increase in total cross-section of airways as they divide, creating less frictional resistance as airflow becomes more laminar & streamlined
Left – both alveoli normal, but airway supplying alveolus B shows airflow obstruction, which causing frictional resistance to airflow
Right airways normal, but alveolus B shows reduced compliance caused by thickened alveolar–capillary membrane, increasing elastic resistance
