Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
186 Cards in this Set
- Front
- Back
|
Def. of cardiac output
|
the amount of blood pumped out of the left ventricle in 1 minute.
|
|
|
What is the formula for cardiac output?
|
HR x SV
|
|
|
Def. of stroke volume
|
amount of blood ejected from the left ventricle with each contraction.
|
|
|
Normal SV for adults
|
60-130 mL/beat
|
|
|
Normal C.O
|
4-8L/min at rest
|
|
|
What is the average C.O for an adult?
|
5L/min
|
|
|
C.O varies with
|
-age
-sex (10% higher in men) -body size -blood viscosity (hematocrit) -tissue demand for O2 |
|
|
Normal heart not stimulated by autonomic nervous system:
|
10 to 13L/min
-2x that amount when stimulated by sympathetic nervous system. |
|
|
Athlete's heart
|
enlarges 50% and capable of pumpling 35L/min
|
|
|
Heart plays a passive role in:
|
C.O and pumps whatever blood is returned to it
|
|
|
Failing
|
when diseased or damaged heart can no longer pump the amount of blood returned to it.
|
|
|
Venous return
|
amount of blood returing to the right atria each minute.
|
|
|
Normal venous return
|
the same as C.O 4-8L/min
|
|
|
What vital organs receive the greatest amount of blood flow in resting state because of higher metabolic needs?
|
muscles, liver and kidneys
|
|
|
Venous return increases with?
|
peripheral vasodilation
|
|
|
Venous return decreases with?
|
vasoconstriction
|
|
|
decrease in O2 to tissues occurs with?
|
high altitudes, CO or cyanide poisoning
|
|
|
Muscle fibers of the precapillary sphincters and metarterioles in the capillary beds are controlled by the concentration of:
|
O2, CO2, and H+, electrolytes, and other humoral substances
|
|
|
decrease in O2 and an increase in H+ and CO2 at tissues levels equals:
|
vasodilation
|
|
|
hypoxia
|
vasoconstriction, shunts greatest amount of blood flow to oxygenated alveoli (best O2)
|
|
|
Approximately 64% of total blood volume is:
|
venous system
|
|
|
20 to 25% of total blood volume can be lost w/out:
|
alter. circulatory function and pressures
|
|
|
Heart fails
|
CNS decrease blood flow to liver, kidneys, and other body areas to maintain perfusion to the most vital organs (heart and brain)
|
|
|
Formula for cardiac index:
|
C.O/BSA
|
|
|
Normal CI is:
|
2.5 to 4.0 L/min/m2
|
|
|
CI measurement allows a standardized interpretation of:
|
cardiac function
|
|
|
At what age is CI the highest?
|
10yrs and it decreases w/age to approx 2.4L/min/m2 at age 80.
|
|
|
Def. of cardiac work:
|
a measurement of the energy spent ejecting blood from the ventricles against aortic and pulmonary artery pressures.
-it correlates well with the amount of O2 needed by the heart. |
|
|
Normally the cardiac work is much higher for the:
|
left ventricle
-must eject against the MAP, which is about 6x the MPAP. |
|
|
Cardiac work index
|
measures the work per min per square meter of each ventricle and is calculated using the following:
LCWI=CIxMAPx0.0136=3.4-4.2 RCWI=CIxMPAPx0.0136=0.4-0.66 |
|
|
Ventricular stroke work
|
a measure of myocardial work per contraction
|
|
|
Formula for ventricular stroke work
|
SV x pressure across vascular bed
|
|
|
Ventricular volume
|
estimated by measuring end diastolic pressure
|
|
|
Normal LVSWI
|
43-61 g/min/m2/beat
|
|
|
Normal RVSWI
|
7-12 g/min/m2/beat
|
|
|
End diastolic volume
|
the amount of blood in the ventricle at the end of filling (diastole)
|
|
|
Ejection fraction
|
the fraction of end diastolic volume ejected with each systole
|
|
|
Normal EF
|
65% to 70% drops with cardiac failure
|
|
|
Formula for EF
|
SV/EDV
|
|
|
EF decreases as
|
cardiac function decreases
|
|
|
EF of 30%
|
pt. exercies tolerance is limited because of hearts inability to maintain an adequate cardiac output
|
|
|
SV is determined by three factors:
|
preload, afterload, and contractility
|
|
|
Bradycardia
|
increase SV
|
|
|
Tachycardia
|
decrease C.O at rates of 120-130 (180)
increase O2 consumption |
|
|
Preload
|
created by end diastolic vol.
-the greater the stretch on the myocardium prior to contraction the greater the subsequent contraction will be. |
|
|
Whe preload is too low:
|
SV and CO will drop
-too much stretch on the heart will also reduce SV |
|
|
Starlings law of the heart
|
the greater the stretch on the resting ventricule, the greater the strength of the contraction w/in physiologic limits.
|
|
|
The stiffer the left ventricle
|
the higher the preload needs to be to obtain an adequate SV
|
|
|
Reduced ventricular compliance is caused by:
|
-MI
-shock -pericardial effusions -PEEP -postivive inotropic drugs |
|
|
pump overstretched
|
no longer able to eject all of its blood efficiently and C.O begins to fall
|
|
|
diastole
|
atrioventricular valves are open (tricuspid and mitral)
|
|
|
central venous pressure
|
filling pressure for Rt heart is Rt atrial pressure
|
|
|
pulmonary capillary wedge pressure
|
filling pressure for Lt heart is Lt atrial pressure
|
|
|
pressure is the result of;
|
vol., space, adn compliance of the chamber the vol. is entering
|
|
|
factors that increase ventricular compliance
|
-relief of ischemia
-vasodilator drugs -cardiomyopathies |
|
|
3 main factors affecting amount of blood returned to heart
|
-chanes in circulating blood vol
-changes in the distribution of the blood vol -atrial contraction |
|
|
spontaneous inspiration
|
lowers intrapleural pressures; improves venous return and CO
|
|
|
Positive pressure breaths
|
increase intrapleural pressures and reduce venous return and CO
|
|
|
2 components of afterload
|
peripheral vascular resistance
tension in the ventricular wall |
|
|
as afterload increases
|
so does O2 demand of the heart
|
|
|
decreasing afterload with vasodilators may help improve:
|
SV but can cause BP to drop if the blood volume is low
|
|
|
SVR
|
is a measure of resistance to blood flow through the systemic circulation
|
|
|
SVR increases with:
|
peripheral vasoconstriction and occurs with hypertension and use of vasoconstrictors
|
|
|
PVR
|
a measure of pulmonary vascular resistance and increases with pulmonary vasoconstriction as seen in hyposemia and acidosis
|
|
|
Contractility
|
a measure of myocardial contraction strength
|
|
|
Contractility determined by
|
-amount of stretch on ventricule prior to contraction
-inotropic state of the heart |
|
|
Contractility is reduced with:
|
hypoxia, acidosis, electrolyte abnormalities, and MI
|
|
|
Acute cardiac tamponade
|
the sudden accumulation of fluid or blood w/in the pericardial space
|
|
|
Acute MI
|
necrosis of the myocardial tissue due to the lack of blood supply to myocardium
|
|
|
paradoxical pulse
|
a drop in BP during inspiration of more than 10mm Hg
|
|
|
decreasing afterload with vasodilators may help improve:
|
SV but can cause BP to drop if the blood volume is low
|
|
|
decreasing afterload with vasodilators may help improve:
|
SV but can cause BP to drop if the blood volume is low
|
|
|
SVR
|
is a measure of resistance to blood flow through the systemic circulation
|
|
|
SVR
|
is a measure of resistance to blood flow through the systemic circulation
|
|
|
SVR increases with:
|
peripheral vasoconstriction and occurs with hypertension and use of vasoconstrictors
|
|
|
SVR increases with:
|
peripheral vasoconstriction and occurs with hypertension and use of vasoconstrictors
|
|
|
PVR
|
a measure of pulmonary vascular resistance and increases with pulmonary vasoconstriction as seen in hyposemia and acidosis
|
|
|
PVR
|
a measure of pulmonary vascular resistance and increases with pulmonary vasoconstriction as seen in hyposemia and acidosis
|
|
|
Contractility
|
a measure of myocardial contraction strength
|
|
|
Contractility
|
a measure of myocardial contraction strength
|
|
|
Contractility determined by
|
-amount of stretch on ventricule prior to contraction
-inotropic state of the heart |
|
|
Contractility determined by
|
-amount of stretch on ventricule prior to contraction
-inotropic state of the heart |
|
|
Contractility is reduced with:
|
hypoxia, acidosis, electrolyte abnormalities, and MI
|
|
|
Contractility is reduced with:
|
hypoxia, acidosis, electrolyte abnormalities, and MI
|
|
|
Acute cardiac tamponade
|
the sudden accumulation of fluid or blood w/in the pericardial space
|
|
|
Acute cardiac tamponade
|
the sudden accumulation of fluid or blood w/in the pericardial space
|
|
|
Acute MI
|
necrosis of the myocardial tissue due to the lack of blood supply to myocardium
|
|
|
Acute MI
|
necrosis of the myocardial tissue due to the lack of blood supply to myocardium
|
|
|
paradoxical pulse
|
a drop in BP during inspiration of more than 10mm Hg
|
|
|
paradoxical pulse
|
a drop in BP during inspiration of more than 10mm Hg
|
|
|
chest wall compliance decreases while lung compliance increases what disease am I?
|
COPD
|
|
|
raise intrathoracic pressure and decreased venous return:
|
-tension pneumo
-valsalva maneuver -breath holding in children -prolonged bouts of coughing -PPV |
|
|
atrail contraction
|
approx 30% of total C.O by leading the ventrile at the end of diastole
|
|
|
a cause of higher C.O
|
anemia
|
|
|
elevated systemic vascular resistance caused by vasoconstriction:
|
cold, inadequate perfusion, HTN, and drugs
|
|
|
drugs that cause vasoconstriction:
|
-norepinephrine (Levophed)
-methoxamine (Vasoxyl) -epinephrine (Adrenalin) |
|
|
Vasodilators:
|
-nitroprusside
-phentolamine (Regitine) -chlorppromazine (Thorazine) |
|
|
sympathetic nerve stimulation drugs
|
-norepinephrine
-catecholamines |
|
|
inotropic drugs
|
+calcium, digitalis, epi, norepi, dopamine, dobutamine, amtinone, isoproterenol, caffeine
-beta blockers, barbiturates, antiarrhythmic agents (procainamide adn quinidine) |
|
|
physiologic depressants
|
-decrease calcium
-increase in K+ and Na- |
|
|
Formula for CPP
|
diastolic BP - PCWP
|
|
|
variables used to describe ventricular performance and pumping efficiency:
|
-EF
-cardiac work -stroke work |
|
|
most common technique for measuring C.O in the ICU:
|
-thermodilution
-Fick method -echocardiography -transthoracic bioimpedance -radionuclide imaging |
|
|
Norm ESV
|
50-60 mL
|
|
|
Norm CPP
|
60-80 mm Hg
|
|
|
Norm RCWI
|
0.4-0.66 kg/min/m2
|
|
|
RVSWI
|
7.9-9.7 g/min/m2/beat
|
|
|
PVRI
|
225-325 dynes
|
|
|
SVRI
|
1970-2400 dynes
|
|
|
SI
|
30-50 ml/m2
|
|
|
EDV
|
120-180 ml/beat
|
|
|
RPP
|
<12,000 mm Hg
|
|
|
LCWI
|
3.4-4.2 kg/min/m2
|
|
|
LVSWI
|
50-62 g/min/m2/beat
|
|
|
PVR
|
<2 units or 110-250 dynes
|
|
|
SVR
|
15-20 units or 900-1400 dynes
|
|
|
transtracheal ultrasound
|
attached to the end of the ET tube adn aimed at the descending aorta
|
|
|
transesophageal ultrasound
|
placed in the esophagus adn aimed at descending aorta
|
|
|
intravascular ultrasound
|
is placed on the distal endo of a pulmonary artery catheter
|
|
|
hemodynamic monitoring is performed to evaluate:
|
-intravascular fluid vol
-cardiac function -vascular function -identify sudden changes in the pt's hemodynamic status |
|
|
Norm BP
|
120/80
|
|
|
Norm MAP
|
80-100
|
|
|
CVP
|
<6
|
|
|
PAP
|
20-30/6-15
|
|
|
PCWP
|
4-12 mm Hg
|
|
|
LVP
|
100-140/0-5mm Hg
|
|
|
RAP
|
2-6mm Hg
|
|
|
RVP
|
20-30/0-5mm Hg
|
|
|
RVEDP
|
2-6mm Hg
|
|
|
MPAP
|
10-20mm Hg
|
|
|
LAP
|
4-12 mm Hg
|
|
|
LVEDP
|
5-12 mm Hg
|
|
|
indications for placement of arterial catheter
|
-significant hemodynamic instability
-frequent draws |
|
|
CAP monitoring
|
-severe hypotension (shock)
-severe HTN -unstable respiratory failure |
|
|
Catheter usually placed in:
|
-radial (more common)
-ulnar -brachial -axillary -femoral artery |
|
|
Seldinger techinque
|
use a needle to penetrate the artery, and a soft tipped guidewire is then threaded through the needle into the artery. Next needle is removed, leaving the guidewire in place, Finally, the arterial catheter is advanced over the guidewire into position and the guidewire is removed, leaving the catheter in place
|
|
|
approx 70% of coronary artery perfusion occurs during the
|
diastolic phase, coronary artery perfusion may be compromiese if the diastolic pressure falls below 50mm Hg
|
|
|
RVAPW
|
0-300mm Hg
|
|
|
HTN
|
>160/90
|
|
|
hypotension
|
<90/60
|
|
|
arterial pressure waveforms
|
should have a clear upstroke on the left
-dicrotic notch on the downstroke on the right -dicrotic notch represents aortic valve closure |
|
|
hypotension is caused by:
|
-low blood volume
-poor cardiac function -low vascular resistance |
|
|
HTN caused by
|
-excessive contraction of the Lt ventricle
-vasoconstriction -admin. of vasopressors -sympathetic stimulation(fear or stress) |
|
|
pulse pressure
|
difference between systolic and diastolic pressures
|
|
|
Ischemia
|
occurs with embolism, thrombus, or arterial spasm
-can result in tissue necrosis if not recognized rapidly |
|
|
hemorrhage
|
occurs if line becomes disconnected or if stopcock left open
|
|
|
indications for monitoring CVP
|
-assess circulating blood vol and filling pressures of heart
-assess Rt ventricular function -pt w/major surgery or trauma -pts with pulmonary edema benefit from CVP monitoring |
|
|
most popular CVP catheter is:
|
7 French with a triple lumen
|
|
|
decrease in BP
|
-hypovolemia (fluid/blood loss)
-cardiac failure and shock (MI) -vasodilation (sepsis) |
|
|
BP increases with
|
-improve circulatory vol & function
-sympathetic stimulation (fear, meds) -vasoconstriction -admin of vasopressors |
|
|
Formula for MAP
|
1/3pulse pressure + diastolic pressure
or systolic pressure +(diastolic pressure x2) ------------------------------------------ 3 |
|
|
the triple lumen on the CVP catheter allows for infusion of:
|
medications
port for blood samples |
|
|
common sites for placement of CVP are:
|
-subclavian
-internal jugular -femoral veins |
|
|
most popular placement for CVP
|
internal jugular because it's a straight shot
|
|
|
CVP waveforms reflect pressure changes in:
|
Rt atrium
|
|
|
transducer system
|
-need to be hooked up to monitor
-more accurate adn provides a waveform |
|
|
water monometer
|
-reported in cm H2O
-inexpensive -easy to use -not sure if get waveform |
|
|
causes of increased CVP
|
-fluid overload
-Rt/Lt heart failure -pulmonary HTN -tricuspid valve stenosis -pulmonary embolism -increased venous return |
|
|
causes of decreased CVP
|
-reduced circulating blood vol
-vasodilation (reducing venous return) -leaks in the pressure system -spontaneous inspiration |
|
|
complication of CVP monitoring during placement
|
-bleeding
-pneumo (higher with subclavian) |
|
|
Complications of CVP monitoring over time
|
-infection (main)
-embolus -air embolus (keep stopcock uncapped) |
|
|
pulmonary artery pressure monitoring
|
developed to allow better evaluation of left ventricular function
-balloon tipped catheter |
|
|
PA allows assessment of:
|
-Lt ventricular filling pressure
-pulmonary vascular resistance -arteriovenous oxygen difference -mixed venous oxygen levels |
|
|
indications for PA pressure monitoring
|
-severe cardiogenic pulmonary edema
-pts w/ARDS who are hemodynamically unstable -pts w/major thoracic surgery -pts w/septic or severe cardiogenic shock |
|
|
most common sites for insertion of PA
|
-subclavian
-internal jugular veins |
|
|
PA systolic pressure
|
20-30mm Hg
-increases with high pulmonary vascular resistance -decreases with poor Rt heart function and pulmonary vasodilation |
|
|
PA diastolic pressure
|
8-15mm Hg
-normally reflect Lt heart filling pressures |
|
|
wedge pressure
|
4-12mm Hg
-elevates w/Lt heart failure or mitral stenosis -decreases with hypovolemia |
|
|
complications of PA monitoring
|
-during cannulation, hemothorax, pneumo, and damage to blood vessels
-dysrhythmias as passes through heart -infection, thrombus, embolism, bleeding, and hematoma -pulonary infarction possible |
|
|
Henry Plummer
|
endoscopy
|
|
|
first application of flexible fiberoptics to the field of endoscopy was in:
|
1957 when technology was initially applied to gastroscopes
|
|
|
1969 Sigeto Akeda of japan brought the first:
|
bronchoscope (visual of airways)
|
|
|
modern rigid bronchoscopes have valves that allow:
|
-flow of general anesthesia and O2
-pathway for suctioning and removal of foreign bodies -passage for biopsy |
|
|
what % of current bronchosocpies are performed using a flexible fiberoptic scope?
|
90%
|
|
|
indications for bronchoscopy
|
-diagnostic (most common)
-therapeutic |
|
|
most common diagnostic indication is abnormality on chest roentgenogram:
|
-infiltrates
-atelectasis -mass |
|
|
standard flexible bronch has an external diameter of:
|
5.3mm and total length of 605mm
|
|
|
complications of bronch
|
mortality <0.01%
|
|
|
contraindicated bronch if pt has a history of
|
bleeding problems
|
|
|
possible problems that occur with bronch:
|
-bleeding
-pneumo -infection |
|
|
nostril is numbed with
|
Xylocaine
|
|
|
for safety during a bronch personnel wear:
|
gown, mask, goggles, and gloves during the procedure
|
|
|
RT assist bronchoscopist with selection and insertion of:
|
-2% and 4% Xylocaine
-brushes to obtain cells and abnormal tissues -biopsy forceps -needle aspiration apparatus |
|
|
monitor pt's vital signs every
|
5 min
|
|
|
complete charting to include:
|
-notes of procedure
-indications -medications -specimens collected -test requested -note any complications and postoperative impression |
|
|
Rigid scopes give better access to
|
large airways and are best to remove aspirated large foreign bodies
|
