Hemodynamics Flashcards
1
Q
MAP is…
A
the measure of the average arterial perfusion pressure, which determines blood flow to the tissues
2
Q
MAP equation
A
[2(DBP) + SBP] / 3
3
Q
MAP normal range
A
70-105 mmHg
4
Q
CVP is…
A
volume in the right side of the heart, when the tricuspid valve is open; reflects the filling pressures in the right ventricle
5
Q
guide for overall fluid balance
A
CVP
6
Q
CVP normal range
A
2 - 5 mmHg
7
Q
CO is…
A
the measurement of the amt of blood ejected by the ventricles EACH MINUTE. it reflects pump efficiency and is a determinant of tissue perfusion
8
Q
CO equation
A
HR x SV = CO
9
Q
CO normal range
A
4 - 8 L/min
10
Q
CI is…
A
the measurement of the cardiac output adjusted for body size. it is a more precise measurement of pump efficiency than CO
11
Q
CI equation
A
CI = CO / BSA (body surface area)
12
Q
CI normal range
A
2.5 - 4.0 L/min
13
Q
SV is…
A
represents the volume of blood ejected from the ventricle with EACH CONTRACTION
14
Q
SV is influenced by
A
preload, afterload, and contractility
15
Q
SV equation
A
SV = CO / HR
16
Q
SV normal range
A
60-80 ml/beat (60-70)
17
Q
SVR is ..
A
a measurement of the left ventricular afterload.
18
Q
SVR equation
A
(MAP - CVP) / (CO x 80)
19
Q
SVR normal range
A
900-1400 dynes/sec/cm-5
20
Q
a diseased valve and resitance in the systemic arterial circulation (increases/decreases) SVR
A
increase
21
Q
PVR is
A
measurement of right ventricular afterload
22
Q
PVR equation
A
(PAM - PCWP) / (CO x 80)
23
Q
PVR normal range
A
100-250 dynes/sec/cm-5
24
Q
EF is..
A
a measurement of the ratio fo the amt of blood ejected from the LV to the amt of blood remaining in the ventricle at the end of diastole.
25
indirect measurement of contractility
EF
26
EF equation
SV / (EDV x 100)
27
EDV is...
the amt of blood available for ejection at the end of diastole
28
EF normal range
60% or greater
29
EDV normal range
100-160 ml/m2
30
SBP normal range
90-130 mHg
31
DBP normal range
60-90 mmHg
32
normal HR
60-100
33
normal RR
10-25
34
normal SaO2
92-100%
35
what causes low CO?
shock,
hypovolemia,
low O2 delivery
36
what causes high CO?
increased volume given
improved contractility
volume replenished
37
what causes high CVP?
```
hypervolemia
R/L HF
RV failure
pulmonic valve stenosis
pulmonary HTN
tamponade
tricuspid valve dz
RV infarct
```
38
what causes low CVP?
hypovolemia (poor venous return to R. heart)
sepsis (vasodilation)
vasodilation/decreased venous return
39
what causes high RR?
hypercapneic
septic
hypoxic
40
what causes low temp?
sepsis
| impaired immune response
41
what causes high MAP?
peripheral vasoconstriction
42
what causes low MAP?
hypoperfusion
43
what happens if afterload is high?
ventricle dose not empty
low CO
low SV
44
what happens if afterload is low?
weak contraction
low CO
low SBP
45
what happens if preload is high?
overstretch
| impedes contraction
46
what happens if preload is low?
not enough volume to make muscle stretch and push volume through the heart
47
what is SvO2?
whether the heart and lungs effort to supply O2 to the tissues is sufficient to meet the tissue's O2 demands. (Is CO adequate?)
48
what causes high SvO2?
high O2 supple (high CO from inotropic drugs, IABP, afterload reduction, early septic shock)
high O2 sat
High hemoglobin (blood transfusion)
low O2 demand (hypothermia, fever reduction, late sepsis, paralysis, pain relief, anesthesia)
PAWP balloon inflated
wedged deflated balloon in cap bed
49
what causes low SvO2
low O2 supply -- low CO -- heart failyre, hypovolemia, dysrhythmias, cardiac depressants (beta blockers)
low O2 sats -- resp failure, pulomnary infiltrates, suctioning, vent disconnected, low Hemoglobin (anemia or hemorrhage)
high O2 consumption: hyperthermia, seizures, shivering, pain, high work of breathing, high metabolic rate, exercise, agitation
50
estimate of L vent afterload
SVR
51
estimate of R ventricular afterload
PVR
52
what causes high SVR?
```
aortic stenosis
periph vasoconstriction (hypothermia--warm pt, hypovolemia)
```
53
what causes low SVR?
vasodilation or shock (septic, neurogenic, anaphylactic)
54
what causes high PVR?
pulm HTN
| increased afterload of R vent
55
what causes low PVR?
decreased afterload of R vent (Right HF, hypovolemia)
56
what increases CI?
hyperthyroidism
low SVR
fever
increased O2 demand
57
what decreases CI
```
LV failure
acidosis
increased SVR
hemorrhage
hypovolemia
tamponade
```
58
PAOP normal range
5-12 mmHg
59
what increases PAOP>
```
LV failure
mitral valve dz
increased SVR
hypervolemia
tamponade
```
60
what decreases PAOP?
hypovolemia
| severe vasodilation
61
if the trandsucer is too high, what kind of reading will you get?
falsely low reading
62
if the transducer is too low, what kind of reading will you get?
falsely high reading
63
if the pt is above the level of the transducer, what kind of reading will you get?
falsely high reading
64
if the pt is below the level of the transducer, what kind of reading will you get?
falsely low reading
65
what pressure should the bag be set to?
300 mmHg
66
can you give meds through an A-line?
NO! not through arteries, only through veins
67
indications for intraarterial BP monitoring?
unstable cardiac pt; hx of HTV, hx of low BP
titrating meds to BP
for any major medical or surgical condition that compromises CO, tissue perfusion, or fluid volume status
68
sites for a-lines
radial artery
femoral artery
brachial artery
69
highest point of a-line waveform?
systole -- when blood ejected from left ventricle
70
lowest point of a-line waveform?
diastole
71
what is the dicrotic notch?
closure of the aortic valve -- diastole is about to begin
72
if communication from the artery to the transducer is interrupted, what kind of waveform will be produced?
dampened
73
causes for a dampened waveform?
kink in line or clot
74
an narrow upward systolic peak that produces a falsey high systolic reading?
underdampened waveform ; overshoot or fling
75
what is CVP measuring?
filling pressure of the RIGHT side of the heart
76
sites for CVP monitoring?
subclavian -- preferred
IJ -- most common
femoral -- easiest but cant bend at hip
77
after inserting CVP, what should you do next?
check breath sounds -- pneumothroax
| and get CXR -- tip in SVC
78
what is normal CVP?
2-5 mmHg
79
what measures the preload of the right side of the heart? (right atrial pressure)
CVP
80
what measure the amount of volume in the heart at the end of diastole?
CVP
81
what are indications for monitoring CVP?
HF
fluid overload
dehydration
bleeding out
82
what do we use to check fluid volume status?
CVP
83
what is the volume of blood in the left ventricle at the end of diastole?
preload
84
what affects preload?
venous return to heart
total blood volume
atrial kick
85
does the heart failure pt have (too much/too little) preload?
too much
86
does the hypovolemic pt have (too much/too little) preload?
too little
87
what is used to measure preload?
PAOP
88
tx for an air embolus?
100 O2
| left lateral trendelenburg position
89
what is an excellent ealry warning system for pt who is bleeding, vasodilating, receiving diuretics or being rewarmed after cardiac surgery?
CVP monitoring
90
which falls first, CVP or MAP?
CVP
91
if pt has high BP, will they have low or high CVP?
high
92
if pt is fluid overloaded, what will CVP be?
high CVP
93
if a pt is dehydrated, what will CVP be?
low CVP
94
if pt has blood loss, what will CVP be?
low CVP
95
if pt is bleeding, what will CVP be?
low
96
what does the swanz ganz measure?
PAP
97
what measures left atrial pressure?
CVP
98
what measures right atrial pressure?
PAOP
99
the output in one minute?
CO
100
if the pump is weak, what will CO be?
low
101
if the BP is high, what will CO be?
low bc more difficult for the heart to pump against
102
if the CVP is low, what will the CO be?
low -- low fluid
103
amount of blood ejected with EACH BEAT?
SV
104
what mesures preload of right side of heart?
CVP
105
what measure preload of left side of heart?
PAOP
106
in heart failure pts, preload is...
increased
107
in fluid overload pts.. preload is..
increased
108
in hypervolemic pts.. preload is...
increased
109
in a dehydrated pt.. preload is...
decreased
110
normal PAOP
5-12 mmHg
111
what the LV has to pump against to get blodo from the heart all the way around body and back to heart
SVR
112
what RV has to pump against to get through lungs
PVR
113
if afterload is increased, the workload of the heart is..
increased
114
vasoconstriction causes afterload to
increase (increases SVR)
115
hypertension causes afterload to
increase
116
aortic stenosis causes afterload to
increase
117
the lower the SVR, the __________ the CO
higher
118
conditions that increase SVR?
HTN
| vasoconstriction
119
conditions that decrease SVR?
vasodilation
120
factors that affect contractility
```
preload
afterload: increasing afterload makes it more difficult to contract
myocardial oxygenation
electrolyte balance
positive or negative inotropic meds
functional myocardium
```
121
if HR is fast can the heart adequately fill? how does this affect CO?
NO, so CO decreases
all increasing the O2 requirement to the heart, but cant get it bc not getting O2 out
122
what hemodynamics does the PAC (swans ganz) measure?
CVP, PVR, SVR
123
normal DO2 (delivery of O2 to tissues)
900-1100 ml/min
124
normal VO2 (oxygen consumption)
200-300 ml/min
| 1/4
125
how can O2 delivery be improved?
```
vasodilate pt if high afterload
sedate
give them oxygen
give them blood bc H&H is low
improve the "pump"
```
126
what is SvO2?
mixed venous oxygen saturation
127
what is normal SvO2?
65-75%
128
if anemic or hypoxic, SVO2 will be
decreased
129
how do we measure SVO2?
swanz ganz
130
if SOB and stresses, what will happen to SVO2?
decrease
131
if HR is increased (fever, infection), what will SVO2 be
decreased
132
if oxygen consumption is increased, what will SVO2 be?
decreased
133
if shivering or seizureing, SVO2 will be
decreased
134
what if pt is afebrile and sedated? what else can make SVO2 decrease?
delivery problem (instead of consumption)-- so is preload low? is afterload high? is heart bad?
135
sedation and anesthesia.. what will SVO2 be?
high
136
hypothermia.. what will SVO2 be?
high
137
sepsis.. what will SVO2 be
high -- tissue cant use the oxygen
