Oxygen Transport Flashcards
goals of cardiopulmonary PT
reverse / mitigate insults to 02 transport
reduce need for med interventions
components of 02 transport
tissue, heart, airway/lungs
how is blood carried
plasma, or combined w hemoglobin (98%)
how many 02 molecules can hemoglobin transport
4
cooperative binding
hemoglobin affinity for 02 increases as is saturation increases
hemoglobin alternated by
P02
(dec in PH
increase in temp, Pc02, DPG)
what do these factors do to hemoglobin
decrease affinity , release more 02 to mm
Bohr effect
curve shifts right (increase in 02 unloading)
what makes less 02 rerelease, altering hemoglobin
inc PH
dec temp Pc02 DPG
if less 02 released which way curve
left
why big drop in pressure from 150 to 103 mmHg
pa02 is a balance between two forces
addition to 02 from ventilation
removal of 02 by blood flow
8 steps in 02 cascade
inspire 02 airawwys lungs diffuse perfuse myocardial funciton peripheral circumstances tissue extraction
inspire 02 effected by
geography (air quality)
altered CNS, efferent pathways
chronic irruption of lungs leads to
allergies, inflammation reactions
airway narrowing caused by
edema mucus lesions objects
obstructed airways ___ run compliance and airway resistance
increase
how is gas exchange compromised
time constraints
perfect lug would have what
equal alveolar ventilation and cardiac output
why can’t we have perfect lungs
gravity
are bases or top of lungs more perfused
base
starling effect (myocardial function )
blood to heart determined amount ejected
cardiac output determined by
aortic pressure needed to get over peripheral resistance
what regulated SBP ( peripheral circulation)
arterials
limiting factors to tissue extraction
quality / quantity of mitochondria
electron transport chain
myoglobin
how to diagnose 02 transport limitations
determine steps in pathway
prioritize importance of steps in pathway
what can PT help
based on these, apply interventions
threats to 02 transport in lungs
ineffective breathing pattern
airways clearnace
lung fluid
chest wall
threats to 02 transport in blood
anemia
threats to 02 by gas exchange
pulmonary edema
body position
threats to 02 transport via mm
weak
fatigue
neuro mm disease
upper ab surgery
threats to 02 via heart
dec venous return/ CO
conduction / mech defect
abnormal after load
threats to 02 via systemic hemodynamics
BP
volume deficit/ excess
threats to 02 vis tissue perfusion
impaired CO
low 02 in blood
internveiton heir achy to manage 02 transport limitations
mobilization/exericse body posiion breathing controsl coughing maneouvers energy conservation ROM psotural drainage manual technique suction
why alveolar graph lower than ventricular
dead space in alveolar
does respiratory system limit exercise
generally no its overbuilt for 02/co2 transport
in highly trained, yes limits (can’t adapt to exercise)
Exercise induced arterial hypoxemia
venitilation / perfusion mismatching
arterio-venous shunting
(elite male endurance)
arterial 02 desaturation 3-4% below resting
hypoventilation
alveolar ventilation below the rate needed to maintain blood gas levels
inadequate compensatory hyperventilation
PaCo2 > 35mmHg
another names for inadequate hyperventilatory compensation
alveolar hypoventilation
mechanisms for inadequate hyper ventilatory compensation
blunted drive to breathe (reduce chemrsensitivity)
technical constraints (expiratory limitations)
Removal of EFL via He02 breathing _____ VE, ____ PaC02, ____ pa02
increase
reduce
increase
mechanisms for EIAH
perfusion mismatch (Va/Q)
arterio venous shunts
pulmonary cap disequilibrium
inflow > outflow does what to Ca02
increase
inflow < outflow does what to Ca02
decrease
VaQ high is
inflow > outflow
Va/Q low is
inflow < outflow
types of arterio venous shunts
extra and intra pulmonary
extra pulmonary shunt
deoxygenated blood bypasses lungs to left atrium
What does extra pulmonary shunt do to Pa02, sa02, ca02
decrease
does extra pulmonary shunt contribute to EIAH
unlikely
intra pulmonary shunt
deoxy blood through lungs
doesn’t participate in pulmonary gas exhange
dilutes arterial blood
whats intra pulmonary shunt do to pa02, sa02 ca02
decrease
do intra pulmonary shunts affect gas exchange during exercise
minor role in exercise gas exchange
determiants of alveolar cap diffusion disequilirbuim during exercise
decreased transit time of RBC in pulmonary caps
increased distance for diffusion
diffusion limitations
Blood gas barrier
function of blood gas barrier
pulmonary gas diffusion
withstand high cap wall stress with exercise
thin, strong
Physiological consequences of EIAH
dec Pa02, sa02, 02 delivery
fatigue
whens threshold of EIAH to influence exercise performance
when sa02 decreases 3-4% below resting
