Blood and Gas Flashcards
Compliance
change in volume related to a change in pressure
pulmonory a. blood enters the artery, large diameter, thin-walled vessels=expansion
Pressures
RV-sys 25 dia 1
Ppa- sys 25 dia 8
LV- 100-120
Pulmonary artery pressure
Dia 8 mmhg in order to keep blood flow going. Pressure travel High to Low. Bronchioles capillary Dia 7mmhg.
Capillary pressure
Low hydrostatic pressure for absorbtion ~7
to return blood to LA ~1-5 (supine ~2mmHG)
If HIgh hydrostatic pressure, caps more permeable
Capillaries continuous flow
If low O2 in alvoel, caps constrict in order to obsorb
Avoid edema by constrict, they dont pemeate more
Blood volume
450mL total Respiratory 5%
70ml in caps
Shunt and Dams
How does blood get to oxygenated location?
Lungs regulate own blood flow. Alveolar O2 drops 70% ~70PavO2 by constrict of vessels near
Resistance moves blood to other capillary where O2 is higher
Zones of Flow
refers to the balance btwn the Pcap blood vs the Paveloi around capillary
Not geographic, different flow bc tall, gravity
Zone 1- contrict @Apex Pav»_space;Pcap, capillary stays closed. LOW blood flow
Zone 2- intermittent Pav high, pulsatile during systole and diastole
Zone 3- continuous flow.
Pcap >Pav
Zone interchangeable- in oder to profuse and
Eexercise effects
CO 6x fold
Lung will accommodate pressure, to mitigate edema
By interchangeable zones
inc capillary open
inc. flow rate through the alveolar capillaries b/c of inc surface are
inc. absorption
inc. the ventilatory rate of the alveoli,
diffusion capacity of the respiratory membrane’s 3x
Damming
LA is receiving blood from the pulmonary circuit,
IF LV fails to eject the blood CHF
have a backup of blood in the atrium
Closed circuit
Inc. Patrium will inc Pcap pressure. 1:1 ratio inc.
30mil Pulmonary edema
Daltons Law of Pressure
total pressure exerted on a container by a mixture of gases is equal to the sum of all the pressures of the individual gases.
Important dt atmospheric air is a mixture of gases.
21% of that 760 is the partial pressure of oxygen.
Flow= Pressure/Resistance
bigger the pressure differential between one set of a membrane and another,
the greater the rate of diffusion will be.
Henry’s Law Gases in solution
pressure, concentration of the gas in the solution and its solubility. move more easily in and out of a solution than others.
Factors- High to low press, High to low concentration, Solubility determines Rate Cross secitonal area Distance Weight of gas Temp.
alveolar membrane
as an air fluid interface, air comes in contact with water pressure differentials across that interface, determine which ways gases are moving and rate by partial pressures
alveolar basement membrane and endothelial cell of the capillary.,very thin at this point.
Alveolar Air vs Atmospheric
Nasal passage warms the hair, Other gases and O2 becomes vapor, adds to O2, helps dissolve in blood 47ml
Alveolar O2 less than atmospheric content
O2, CO2 constantly turning over low concentration
PO2 100mmHG not 160 bc of these factors
Gas exchanged in alveoli
O2 enters with inhale Diaphragm drops- for lung expansion O2 high in Pav >Pcap (deoxy) The pressure diff. will force O2 in blood O2 solubility poor Larger Pressure diff
CO2 similar, different pressures Soluble in mixture is fast (diff to measure) 20x vs O2 Back in alveoli (40-47) Exhaled
{Alveolar}
Factor for turn over
Ventaliatin rate
Diffusion/profuse of gas across membrane
Respiratory Unit
Bronchioles
Alveoli ducts
Sacs (many sacs)
Alveoli
Pathology affecting membrane
Pneumonia- aveloi fluid filld, difficult to absorb and diffuse
Emphysema-alveoli sacs destroyed
Diffusion capacity respiratory membrane
gas that will diffuse through the membrane each minute for a partial pressure difference of 1 millimeter of mercury.
230mL of O2/min diffuse
ventilation profusion ratio,
relationship between the ventilation of the alveoli
and the blood flow in the capillaries.
VAQ
0= no ventilation, no gas exchange, no blood flow
2.5 times the ideal
that represents a physiologic dead space,
more ventilation than there is profusion.
PpAV
determined by the rate
at which the alveoli are ventilated and the rate of transfer of gases across the membrane.
Some well ventilated
Some better blood flow
Shunt
blood that leaves the heart and comes back without exchanging gases is considered shunted, i
blood that’s poorly oxygenated coming to the left atrium
from the pulmonary circuit would be considered shunted blood.
Bronchial blood that feeds lungs
want arterial blood
to have a greater oxygen content than venous blood.
physiologic dead space
an alveolus where there is oxygen but no blood supply, and all of the oxygen in the dead space part of the respiratory tract is considered wasted
preparation of title volume
top of the lungs, where there is air but less blood flow.
bottom of the lungs, a physiologic shunt, where there’s more blood flow but less air.
Emphezema- damage alveoi sacs no blood flow VAQ 0
DVT
pulmonary embolism travel for LE to Lung Risk-surgeries, trauma, catheters who clot, lower extremity stasis, long distance air travel 1/1000 AA M=W(less)
S/S: chest pain, or thoracic pain, upper abdominal pain, syncope,
hemoptysis, SOB, painful breathing, sudden onset of wheezing, a new cardiac arrhythmia, or any other unexplained symptom
hypertensive, chest x-ray, atelectasis that might look like pneumonia, friction rub #1 tachypneic (90%)
Classic triad: #1dyspnea, difficulty
or painful breathing, 2- chest pain, 3- hemotpsis
