lecture final Flashcards
What is the normal value for CaO2 and the equation for it
20 vol%
(1.34xHbxSaO2) + (PaO2x0.003)
what is the normal value for CvO2 and the equation for it
15vol%
(1.34xHbxSvO2)+(PvO2x0.003)
what is PAO2 normal value and the equation for it
100mmHg
[(Pb-H2O)xFiO2]-(PaCO2x1.25) PaO2 cannot be higher than PAO2
what is the equation for Qs/Qt
CcO2-CaO2/CcO2-CvO2
how do you find BH%
44mmHg - content/ saturated capacity x 100
where is the SA node and how many BPM
the SA node is located in the upper right atrium and produces 60-100 BPM
where is the AV node and how many BPM
the AV node is located in the lower portion of the right atrium and produces 40-60 BPM
what takes over when the SA and AV node fails and how many BPM
the pacemaker cells, bundle of His, and Purkinje fibers take over and produce 20-40 BPM
what is Hypercapnia
High CO2 levels in the blood resulting in increased depth of breathing w/ or w/o increased frequency
what is tachycardia
rapid HR >100 BPM
what is diffusion
process of gas molecules passively moving from an area of high concentrations to low concentrations
what is a true shunt
cardiac output that enters the left side of the heart w/o exchanging gases w/ alveolar gases. perfusion w/o ventilation (causes severe hypoxemia and cannot be helped with/ oxygen therapy)
what is deadspace
the volume of inspired air that does not reach the alveoli in the conducting zones. * ventilation w/o perfusion* (causes hypercapnia and can be helped with oxygen therapy)
what are the normal PaO2 values
80-100 mmHg
what are the normal values for PvO2
35-45 mmHg
Know the different ranges for hypoxemia
PaO2: 60-79 mild hypoxemia
PaO2: 40-59 moderate hypoxemia
PaO2: <40 severe hypoxemia
know the different ranges for hypoxemia with oxygen therapy
PaO2: <60 uncorrected hypoxemia
PaO2: 60-100 corrected hypoxemia
PaO2: >100 is overcorrected hypoxemia
what is anatomic deadspace
the volume of gas that only makes it to the conducting airways (nose to terminal bronchioles) no gas exchange occurs (1ml/lb of BW)
what is physiologic deadspace
sum of anatomic deadspace and alveolar deadspace
what is alveolar deadspace
oxygen that makes it to the alveoli but does not participate in gas exchange
given PFT values to be able to determine diagnosis of normal obstructive or restrictive
FEV1/FVC=FVC1% OVER 70% may be restrictive or normal under 70% will be obstructive
less than 80% FVC is abnormal <80% is restrictive >80% normal
what are the characteristics of the pore of kohn
small holes in intra-alveolar septa, permit gas movement between adjacent alveoli.
Formed by movement of macrophages, death of epithelial cells due to disease, and normal degeneration of cells due to aging.
Zone 1
least gravity dependent, up by the apex. Alveolar pressure is greater than arterial and venous pressure.
Zone 2
Middle part of the lobe, arterial pressure is greater than alveolar pressure but alveolar pressure is greater than venous pressure
Zone 3
Base of the lobe, most gravity dependent. Arterial pressure and venous pressure are greater than alveolar pressure.
understand the changes in intrapleural pressure in normal upright lungs
- intrapleural pressure is negative at all tines, without negative pressure the lungs would collapse.
- actual volume changes during inspiration is least in the upper lung
- natural intrpleural pressure gradient exist from the upper lung to the lower.
what are the anatomic differences between the right and the left mainstream bronchus
right: 25 degrees and is shorter/wider than left
Left: is 40-60 degree angle
what are the concentrations of atmospheric gases
PO2: 21%
PN2: 78%
1% other gases
atmospheric pressure:760 mmHG
water vapor: 47 mmHg
what happens to FiO2 and PO2 when you go up or down in elevation
PO2 will change and FiO2 will always remain the same
what are the muscles of inspiration
- external intercostal muscles
- scalene muscles
- sternocleidomastoid
- pectoral major
- trapezius
is inhalation/exhalation active or passive
first 30% of exhalation is effort dependent last 70% is not
Inspiration is active
expiration is passive
what is transthoracic pressure
difference between alveolar pressure and body surface pressure
Ptt= Palv-Pbs
what is trans-pulmonary pressure
difference between alveolar pressure and pleural pressure
Ptp=Palv-Ppl
what is transairway pressure
difference between mouth and alveolar pressure
Pta=Pm-Palv
how does hemoglobin work and its normal O2 binding capacity
4 heme groups, each group combine with 1 oxygen molecul. (if all 4 heme groups bound to O2= 100% saturation, 3= 75% saturation) they consist of 2 alpha and 2 beta chains
male: 14-16 g%
female: 12-15g%
what is scoliosis
spine is curved from side to side (s curve)
what is lordosis
inward curve of lumbar and cervical vertebral column
kyphosis
round back or hunch over, curvature of the thoracic
kyphoscoliosis
combo of scoliosis and kyphosis
if bronchial tube size increases or decreases what happens to driving pressure/flow
- flow is proportional to change in pressure while radius is inversely proportional to length and gas viscosity
- decrease radius by 1/2= decrease in flow of 1/16 of original
- decrease radius by 16%= decrease in flow by 1/2
- pressure will increase with decrease in radius
- decreasing radius by 1/2 increases pressure bye 16x to keep flow constant
- decrease radius by 16%= pressure must increase 2x for flow to remain constant.
where is pulmonary surfactant produced
type II pneumocytes are the primary source of pulmonary surfactant
what are the 7 functions of pulmonary surfactant
- decrease inflation pressure
- improve lung compliance
- provide alveolar stability
- decrease work of breathing
- enhance alveolar fluid clearance
- enhances foreign particle clearance
- serves as protective layer for cell surfaces
what effects surfactant/surface tensions size
the DPPC molecule causes surface tension to decrease w/ decreased alveolar size.
as alveolar size increases, surfactant thins out across the alveoli.
what is cheyne-stokes breathing
10-30 seconds of apnea followed by a gradual increase in volume and frequency, followed by another gradual decrease with another period of apnea. (heart failure)
what is biot’s breathing
short episodes of rapid deep respirations followed by 10-30 seconds of apnea (neurological injury and meningitis)
what kussmauls breathing
Increased RR and depth of breathing. Resulting in decrease in PACO2 (ketoacidosis and renal failure)
what are the four lung volumes in order
- inspiratory reserve volume (IRV)
- tidal volume (Vt)
- expiratory reserve volume (ERV)
- Residual volume (RV)
What are the four lung capacities and there corresponding volumes
- inspiratory capacity (IC) - (IRV,VT)
- Function residual capacity (FRC)- (ERV,RV)
- Vital capacity (VC)- (IRV,VT,ERV)
- Total lung capacity (TLC)- (IC, FRC) or (IRV,VT,ERV,RV)
Define ficks law of diffusion
- gas diffusion is directly proportional to the difference in partial pressure of the gas across the membrane
- gas diffusion is inversely proportional to membrane thickness
- gas diffusion is directly proportional to the diffusion constant of the gas
- surface area when decreased, results in decreased diffusion of gases, causes collapsed alveoli and increased alveolar fluid
- P1-P2 when decreased results in decreased diffusion causing decreased altitude, alveolar hypoventilation
- thickness of the A-C membrane when increased results in decreased diffusion and causes alveolar fibrosis and alveolar edema
what is a time constant and its equation
time constant- is the time necessary to inflate a particulate lung region to 60% of its potential filling capacity
TC=Raw x Cl
long time constant/ short time constant
long time constant- increased lung compliance and/or increased airway resistance
short time constant- decreased lung compliance and/or decreased airway resistance
the effects of increased airway resistance or decreased lung compliance
- when lung compliance decreases, so does tidal volume and time constant, but RR increases
- When airway resistance increases, so does tidal volume and time constant but RR decreases (allowing more time for filling)
ventilatory pattern definition and normal values
ventilatory pattern- RR and VT
normal; VT= 500ml and RR=15breaths per min
VE= RR x VT 15x.500=7.5L
what does stimulation of the baroreceptor reflex cause
- located in the walls of the carotid arteries/aorta
- short term regulator for BP
3.Responds instantly to BP changes and the medulla with increase sympathetic activity - If changes last more than a few days they accept it as a new normal
What is ventricular after load and what determines it
Ventricular after load- the force against which the ventricles must work to pump blood
determined by;
1. volume and viscosity of blood ejected
2. peripheral vascular resistance
3. total cross-sectional area of the vascular bed into which the blood is ejected
4. arterial BP reflects after load
Ventricular preload
Ventricular preload- the degree of myocardial fiber stretch prior to ventricular contraction
Increased stretch= increased strength of contraction
hypoxemic hypoxia
increased altitude, suffocation, drug overdose, lung disease, and neurological injury
stagnant (circulatory) hypoxia
cardiac arrest and shock
anemic hypoxia
anemia, blood loss, and carbon monoxide poisoning
histotoxic hypoxia
cyanide poisoning
alveolar minute volume (VAmin)
VAmin: tidal volume- deadspace x RR answer will be in liters
Recall normal diaphragmatic excursions
at rest: excursion is 1.5 cm, pressure change is 3-6 cmH2O
deep breath or exercise: excursion is 6-10 cm pressure may drop 50 Pb
Correctly interpret ABGs
PH: acidotic <7.35-7.45 >alkalotic
PaCO2: alkalemia < 35-45 >acidotic respiratory
HCO3: acidemia < 22-28 > alkalemia metabolism
alveolar air equation for O2- PaO2 [(Pb-H2O) x FiO2] - (PaCO2 x 1.25)
acute vs. chronic for ABGS
Acute- only one of the PaCO2 or HCO3 will be abnormal
Chronic- one will be acidotic the other will be alkalotic as they attempt to compensate
Factors that shift the oxyhemoglobin dissociation curve left and unloading of oxygen
Left shift: loading at the lungs, decreased unloading at the tissue
left shift with increased PH, decreased PCO2, and decreased temp
Factors that shift the oxyhemoglobin dissociation curve right and unloading of oxygen
Right shift: decreased loading at the lungs, increased unloading at the tissues.
right shift with decreased PH, increased PCO2, and increased temp
recall normal inspiration to exhalation ratio
I:E - 1:2
3 phases- inspiratory, expiratory, and pause phase
how gas movement occurs at the level of the alveoli
diffusion- area of high concentration to move to areas of low concentration. Directly related to surface area and pressure gradient.
normal CO2 production
200 ml/min of CO2 produced and 250 ml of O2 is consumed
normal SaO2
97% measure of the proportion of available Hb that is carrying O2
normal value for stroke volume
40-80 mL volume of blood ejected from the ventricle during each contraction
normal CaO2
20vol% bound to Hb and dissolved in plasma
normal CvO2
15vol% bound to Hb and dissolved in plasma
normal value DO2
1000 ml O2/min CaO2xCO
delivery of O2 to the tissues
normal value for CO
5 L/min
HR x SV
total volume of blood discharged from the ventricles per min
normal value for O2ER
0.25 amount of O2 extracted by peripheral tissues divided by the amount of O2 delivered
normal value for VO2
250 mL/min
the amount of O2 consumed per min
restrictive disorders, anatomy, pathophysiology, and PFT measurements effected
anatomy- non-airways/ gas regions (thoracic pump, lung parenchyma)
Breathing phase difficulty- inspiration
pathophysiology- decreased lung or thoracic compliance
PFT measurement effected- volumes
formula for compliance
Cl= triangle v/ triangle P
formula for resistance
Raw= triangle p (cmH2O)/ V (L/sec)
formula for elastance
triangle p/ triangle v
time constant
TC= Raw x Cl
what factors clinically modify clinical application of ficks law
- partial pressure
- alveolar surface area
- AC membrane T
Normal ranges of PaO2, PaCO2, PvO2, and PvCO2
PaO2: 80-100mmHg
PaCO2: 35-35 mmHg
PvO2: 35-45 mmHg
PvCO2: 42-48 mmHg
normal values for PAO2, PvO2, PaCO2, PvCO2, DO2, O2ER, QS/QT, VO2
PAO2: 100mmHg
PvO2: 40mmHg
PaCO2: 44mmHg
PvCO2: 46mmHg
DO2: 1000ml O2/min
O2ER: 0.25
QS/QT: normal <10%
VO2: 250 ml/min
equation for CcO2
(1.34xHb)+(PAO2x0.003)
VD/VT full equations
VD/VT ratio= PaCO2-PeCO2/ PaCO2
VD physiologic= VD/VT ratio x VT
VD alveolar= VD physiologic- VD anatomic (weight)
VAmin equation
(VT- VD anatomic) x RR
QS/QT equation
CcO2-CaO2/ Cco2- CvO2
BH and RH equation
BH= 44- content/sat capacity x 100
RH= content/ saturated capacity x 100
where is the pulmonary artery located and what else carries deoxygenated blood
the pulmonary artery is located in the right ventricle and carries deoxygenated blood, just like the veins do.
in posterior view the lung extends to what rib?
the 11th rib
where is intrapleural pressure more negative
at the apex
with increased PcO2 what happens to PVR
PVR Increases
what happens to PVR with a drop in PaO2
PVR will increase
what happens to PVR if PH drops
PVR will increase
where is perfusion better in the lungs
perfusion is better at the base of the lungs
what will acute hypoventilation show on an ABG
it will show an increase in PaCO2 and a decrease in PH
what happens to the time to fill when compliance is decreased
it will take less time to fill, and there will be a short time constant
increase RR, decrease Tidal volume
in metabolic acidosis with compensation what will the patient have to do
hyperventilate
what are the two conditions with increased CO2 levels in the blood
hypercapnia and hypercarbia
what happens to PO2 in increased altitudes
PO2 decreases
what describes gas movement at gas exchange units
molecular diffusion
two factors that effect ventricular after load
blood volume and PVR
what causes a decrease in PVR
recruitment and distention
stroke volume is determined by what
ventricular preload
ventricular afterload
myocardial contractility
what happens to driving pressure when a bronchial tube is reduced by 1/2
the driving pressure will increase 16x the original
upon inspiration alveolar size increases what happens to the surface tension and the surfactant
surface tension will increase but surfactant will decrease to alveolar surface area
ficks law is proportional and inversely proportional to what
- proportional to partial pressure of gas across membrane
- inversely proportional to membrane thickness
- directly proportional to the diffusion constant of a gas
when airway resistance increases what happens to ventilatory rate and tidal volume
vent rate decreases and tidal volume increases
what is 4800 ml in liters
4.8 L
know what the shunt percentages mean
0-10%- normal shunt 10-20%- not clinically significant
20-30%- signs of intrapulmonary disease
>30%- life threatening
formula for CcO2
(1.34xHb)+(PAO2 x 0.003)
what will happen to flow if you decrease radius size by 1/2
it will decrease flow to 1/16 of original
what will happen to flow if you decrease radius size by 16%
decreases flow by 1/2
what happens to driving pressure if you decrease radius by 1/2
driving pressure will have to increase by 16x to keep flow constant
what happens to driving pressure if you decrease radius by 16%
driving pressure must increase 2x for flow to remain constant
where is the nasopharynx located
Nasopharynx- end of nasal cavity to the base of soft palate, posterior to nasal cavity and superior to soft palate.
where is the oropharynx located
Oropharynx- base of soft palate to base of the tongue
where is the laryngopharynx located
laryngopharynx- base of tongue to esophageal opening