Introduction of CVP Flashcards
What vein is used to bypass a blockage during a CABG?
saphenous vein
What kind of prevention is it if the patient has the impairment and you are directly addressing the impairment?
Primary prevention
What kind of prevention is it when the PT addresses any other additional impairments or diseases?
Secondary prevention
formula for oxygen delivery (DO2)?
DO2 = arterial O2 x cardiac output
formula for oxygen consumption (VO2)?
VO2 = (arterial O2 - venous O2) x cardiac output
formula for oxygen extraction ratio (OER)?
OER = consumption/delivery = VO2/DO2
Oxygen transport is normally based on what?
demand of tissues
At rest, oxygen transport is how much greater than the actual demand?
3-4x
How much of the body’s oxygen is transported through hemoglobin?
98%
What is the primary mechanism for how we transport oxygen throughout the body?
Blood
Why is the balance between intravascular and extravascular fluid volume is important?
imbalance of electrolytes and water can affect the blood’s ability to transport oxygen which can impact organ function
What 3 things impacts delivery of oxygen from outside air to tissues?
1) atmospheric air
2) air quality
3) humidity
What effect does poor quality air have on the lungs?
it increases thickness of membrane in lungs making it more difficult to diffuse oxygen
How does nitrogen impact the lungs?
plays a role in keeping the alveoli open in the lungs
How does humidity impact the lungs?
humidity keeps up the mucus lining in the lungs – lack of humidity leads to erosion of the airways and possible infection from losing the mucus lining
Function of cilia?
catches debri and helps get it out
What does smoking do to cilia?
paralyzes cilia
small airways have more of what kind of muscle?
smooth muscle
large airways are ______ elastic?
less
Muscles of inspiration?
- external intercostals
- diaphragm
Muscles of expiration?
- internal intercostals
- abdominals
Function of the external intercostals during inspiration?
elevate the ribs and therefore increase the volume of the pleural cavities
Function of the diaphragm during inspiration?
depress the inferior wall of the thoracic cavity and, therefore, increase the volume of the pleural cavities
Function of the internal intercostals during expiration?
compress and lower the ribs and therefore decrease the volume of the pleural cavities
Function of the abdominals during expiration?
compress the abdominal cavity which elevates the abdominal organs and passively elevates the diaphragm and, therefore, decreases the volume of the pleural cavities
Expiration is normally passive or active?
passive
How is oxygen transferred from alveolar sacs to pulmonary circulation?
diffusion
What 5 things is diffusion based on?
1) surface area of alveolar capillary membrane
2) diffusing capacity of alveolar-capillary membrane
3) pulmonary capillary blood volume
4) ventilation/perfusion ratio
5) transit time of blood in alveolar capillary membrane
What is the optimal ventilation/perfusion ratio? (how much air you breathe out/how much blood is there)
0.8
Amount of oxygen that diffuses across alveolar-capillary membrane varies DIRECTLY with _______ and INVERSELY with ________.
Directly - size (surface area)
Indirectly - thickness
high or low perfusion at the apical end of the lungs?
low perfusion
high or low perfusion at the base of the lungs?
perfusion increased due to gravity
alveoli are expanded or compressed at the apical end of the lungs?
alveoli expand fully
alveoli are expanded or compressed at the base of the lungs?
compressed alveoli from enlarged vessels
Optimal area for ventilation perfusion is where?
in the middle of the lungs
Optimal function of the heart depends on what?
synchronized coupling of electrical conduction and mechanical contraction
What is preload?
the amount the ventricle stretches in able to hold the blood
What is afterload?
the amount of resistance needed to overcome by the left ventricle to get the blood to the body
Preload and afterload tells you what?
tells you how well your heart is functioning
What does oncotic pressure do?
pulls fluid in from the periphery into the blood vessel
What does hydrostatic pressure do?
pushes fluid out into the periphery from the blood vessel
What two pressures creates a fluid balance in the blood vessels?
hydrostatic and oncotic pressures
Amount of O2 extracted at rest?
23%
What is the rate of O2 extraction regulated by?
oxygen demand NOT oxygen availability
Is partial pressure higher in arterial blood or venous blood?
arterial blood
Why should partial pressures be higher in the arteries than the tissues?
so the oxygen pops off the hemoglobin and goes into the tissues
partially desaturated blood and CO2 are removed from the cells into what?
the venous circulation
9 steps of O2 Transport?
1) Inspired O2 and quality of ambient air
2) airways
3) lungs and chest wall
4) diffusion
5) perfusion
6) myocardial function
7) peripheral circulation
8) tissue extraction and use of O2
9) return of partially desaturated blood and CO2 to the lungs
Which step of oxygen transport would be affected during a myocardial infarction?
step 6: myocardial function
Which step of oxygen transport would be affected during pneumothorax from a stab wound?
step 3: lungs and chest wall
Which step of oxygen transport would be affected during asthma?
step 2: airways OR step 4: diffusion
Which step of oxygen transport would be affected during a pulmonary embolus?
step 5: perfusion
Which step of oxygen transport would be affected during hypertension?
step 7: peripheral circulation
Which step of oxygen transport would be affected during anemia?
step 8: tissue extraction and use of O2
Which step of oxygen transport would be affected during a deep vein thrombosis?
step 7: peripheral circulation
What 3 normal factors “shake up” oxygen transport?
activity, position, emotional stress
What has the greatest influence on O2 transport?
Gravity
How does restricted activity impacted CO, VO2, and OER?
lack of exercise decreases how well you are utilizing the oxygen you do have – decreases CO, VO2, and OER
Loss of gravitational stress causes what?
astronaut “puffy face and bird legs”
– loss of gravity allows for fluid to shift to thorax/head
External and internal signs of oxygen transport dysfunction?
External signs: - skin: pale, cyanotic, cold - speech: short of breath - diaphoresis Internal signs: - vital signs - respiratory patterns - hypoxia/low pulse oximetry - poor peripheral circulation -- decreased capillary refill ( > 3 sec)
