hemodynamic monitoring Flashcards
(82 cards)
1
Q
3 aspects of hemodynamic monitoring
A
- arterial pressure
- central venous pressure
- central venous O2 sat (ScvO2)
2
Q
principles of invasive monitoring nurses can:
A
- assess cardiac function
- circulating blood vol status
- physiological responses to medical and nursing interventions
3
Q
invasive catheters 2
A
dependent on pressures
- ART line
- CVC
4
Q
flush solution
A
NS
sometime heparin solution but can cause HIT
5
Q
pressure bag
A
manual inflate to 300mmHg to ensure that blood from tubing doesnt go back up the tubing of pressure system
6
Q
pressure tubing set
A
- is non-compliant to produce accurate reading
- allows continuous flow rate of 3ml/hr (under pressure)
- has fast flush device - allows bolus and flushes to clear blood during set up or to obtain blood sample
- typical- has 3 way stopclocks. one for blood sample, the other for zeroing
7
Q
transducer
A
- senses BP in artery or vein
- BP transducer is translated into electrical signal to monitor
- also provides tracing (waveform) = BP and used for ECG monitoring
8
Q
ECG
A
Electrocardiogram
9
Q
why do you calibrate equipment? 2
A
to ensure accuracy of 2 baseline measurements
1. calibrate to atmospheric pressure “zeroing”
- determine the phlebostatic axis for transducer height placement “leveling the transducer”
10
Q
leveling the transducer
A
- aligning the transducer with level of atrium
- line up air filled interface with the LEFT atrium to correct for changes in hydrostatic pressure in blood vessels above or below level of heart
- a carpenters level can be used to ensure phleb axis reference point
- if change in position, must do again
- if transducer is too high = false low BP reading
11
Q
phlebostatic Axis
A
physical reference point on chest 4th intercoastal space to mid- axillary along with mid- anterior/posterior
- aprox level of atria
- can be pole mounted or arm mounted
- transducer must always be leveled to the phlebostatic axis
12
Q
if the transducer is below the phleb axis…
A
we can think of it as the fluid in the system exerting extra weight on the transducer with reads as pressure inaccurate high readings
13
Q
why do we calibrate equip?
A
to insure accuracy and 2 baseline measurements are needed
14
Q
what is calibrating system to atmospheric pressure
A
zeroing
15
Q
zeroing transducer
A
calibrate to atmospheric pressure
- 3 way stopcock nearest transducer is turned to open to air and close to PT and flush system
- monitor adjusts to zero (instead of atmospheric pressure which is 760mmHg)
- zero provides baseline
16
Q
leveling step-by-step
A
- PT supine with HOB 0-60 degrees. doc HOB for reference
- locate the phlebostatic axis
- 4th intercost space
- axilla midline btwn anterior and posterior where X is - place carpenter level btwn phlebo axis and air filled interface (air reference stop cock) of transducer
- move transducer up/down IV pole until air-filled interface is centered
17
Q
why do you position PT supine and reference HOB
A
to ensure accuracy of the readings
18
Q
why locate the phlebo axis?
A
physical point of level of transducer reduces the effect of hydrostatic forces on transducer
ensures consistency of readings
19
Q
why place carpenters level and move transducer up/down?
A
to ensure transducer air reference stopcock is leveled with the level of the right atrium
20
Q
when will you see a flat waveform on the monitor
A
when you open the stopcock to air
21
Q
why do you open to air?
A
the monitor can use atmospheric pressure as reference
22
Q
steps to zeroing
A
- open stopcock to air- see flat waveform
- push and release zero button
- turn stopcock back to monitoring position and observe waveform
“open to PT, off to air”
23
Q
where is the phlebo axis
A
level of the R atrium
24
Q
what if the transducer is below the phlebo axis?
A
inaccurate high reading
25
when we level the phlebo axis, we level the?
transducer
26
to prime and flush the pressure line we?
pull the fast flush device
27
what is the purpose of zeroing the transducer
allows the monitor to set zero for atmospheric pressure
28
how is the numeric value of the hemodynamic pressure transferred to the bedside monitor
catheter, fluid sensation, transducer, electrical signal, cable, monitor, display
29
arterial BP monitoring
- provides accurate continuous monitoring, waveform for visualizing systolic and diastolic pressures and arterial access for blood sampling
- involves cannulation of major preiph artery
30
nursing responsibility for ART line
- accuracy of monitor system
- troubleshooting
- apply knowledge obtained from monitor
-monitor, integrity of lines, set up system, accuracy of values of and waveform, alarm limits,
31
the transducer on a hemodynamic monitoring system is leveled to the PT's phlebostatic axis. which is located where?
1. level of the right atrium
| 2. 4th intercostal space mid-axillary
32
when does the transducer need to be zeroed
1. whenever there is a disconnection between the transducer and monitor
2. in order to obtain accurate readings
3. to negate the effects of atmospheric pressure
33
you notice your PT's arterial pressure waveform has a steep upstroke, an obvious dicrotic notch and a trough. you would?
consider this normal
34
the hemodynamic assess framwork is? 3
1. is part of the O2 supply and demand framework
2. focuses primarily on heart rate and the determinants of CO
3. incorporates data from hemodynamic monitoring systems
NOT- isolation to direct PT assessment
35
why do we use the radial artery for ART line?
easy access and low risk bc of collateral circulation
36
ART BP and cuff BP can be what difference
5-10mmHG
37
ART BP is related to?
and also affected by?
CO!
and SNS and compensatory mechanisms of periph vasoconstriction
38
BP within normal limits does not necessary indicate?
adequate CO
39
when we interpret BP and MAP we need to consider:
1. normal BP and MAP
2. previous
3. current interventions (meds)
4. other hemodynamic assess interventions
5. underlying patho
40
when we look at waveform, we look at:
1. upstroke
2. dicrotic notch
3. down stroke
also look at ECG (heart beat)
41
what does the waveform look like on poorly perfused beat?
the waveform is smaller
42
when the ART and ECG waveforms change?
mainly when the ECG wave changes
the electomechanical event in the heart has changed , which alters the ventrical contraction = decreased SV or blood ejected
43
decreased SV =
decreased CO
44
PVC
premature ventricular contraction
from poor perfusion or non=perfused beat
45
what is it called if the transducer is oversensitive?
overshooting, fling, underdampened
46
what does overshooting waveform look like?
sharper upstroke of normal ART waveform
47
what do you do if you notice a sharper upstroke on ART wave?
do fast flush square waveform test.
will show multiple oscuilltations after pulling the fast flush instead of just two
48
what is it called when transducer is undersensitive?
dampened waveform
every pulse/flow will not be sensed by cath tip
BP 80/50 (norm 120/80)
49
what happens to the waveform if dampened?
sharp upstroke becomes lost and and occasionaly notch becomes lost.
50
what is the first thing you do if you notice dampened?
assess PT, then square waveform
51
how do you know the ART waveform is demonstrating decreased CO?
amongst regular waveforms, smaller ones would be visible
52
what would be the possibility of blood backing up the ART line from site? 3
1. tubing disconnect
2. pressure bag deflated
3. inadequate flush solution
53
if you see flat line on ART monitor you? 3
1. ABC
2. check site
3. check tubing
54
risks associated with invasive ART monitor
1. infection
2. decreased tissue perfusion
3. embolus d/t thrombus at catheter tip
4. hemorrhage
55
blood sample for CVC
| for ART?
CVC- use stopcock and use trow away sample
ART- has no stopcock and has VAMP which reduced blood exposure
56
after removal of ART line, how long do youput pressure?
5-10 min
57
CVC monitor reflects
volume of blood at right ventricular end diastolic pressure or right sided preload
direct communicates R atrium
58
where do you place CVC for monitoring
1. IJ ** (internal first then external if not)- bld flow is higher
2. subclavian
3. bracial when not moitoring?
59
when do you use CVP : 3
when PT has significant alteration in fluid vol
1. hypovolemia- hemorrhage
2. hypervolemia- fluid overload
3. require rapid diuresis
60
you can use the square waveform test with a CVC to test?
1. as guide in fluid vol replacement
2. and assess impact of diuresis
- watch CVP go from 10 to normal level (2-6) then can stop diuretic therapy
61
when do you use subclavian vein?
if longer than 5 days needed
62
2 major risks with CVC insertion
1. pneumothorax - if misplaced puncture lung pleura
| 2. dysrrhythmias - if too far it tickles atrium
63
CVP normal value?
2-6
64
where do you read the CVP waveform?
at end-expiraton
65
where can you read the CVP waveform? 2
1. the monitor
| 2. manual from the print out strip
66
why do you look at CVP at end-expiration?
it eliminates the influence of intrathoracic pressure during ventilation
at end-expire, the intrathoracic pressure approximates atmospheric pressure and
CVP readings are less likely to be influenced by pulmonary pressures that may be generated in the ventilation cycle.
67
PT position for CVP measurements
supine flat or supine HOB 0-60
68
how can CVP indicate right sided preload
during diastole, R atrium and vent equilibriate
69
in order to have accurate CVP results, intrathoracic pressures must be at a minimum at:
end of expire
70
2 primary causes of complications of CVC insertion
1. pneumothorax
| 2. dysrrhthmias
71
key indications for CVP monitoring?
hypo or hypervolemia monitoring
72
what is ScvO2? and what is the normal value?
central venous catheter oxygen saturation
norm- 60-80%
73
what percent of oxygenated blood bound to HgB returns back to heart?
65-75%
74
what does ScvO2 reflect?
O2 supply and demand balance to brain and upper body
measured in central lines in superior vena cava
75
what would it mean is ScvO2 = 58%
that O2 supply is not meeting O2 demand
76
if a PT has a temp of 39.5 what would you anticipate the ScvO2 to be?
below 60 %
77
if your PT has a SaO2 of 84% on 60% FiO2, what do you anticipate the ScvO2 to be?
below 60%
78
increased preload on the heart can be describes as?
decreased force of diastole, leaving extra blood in the chamber
79
what influencing factors might alter a PTs HR?
- pain
- anxious
- temp
- hypovolemia/ hypotension = altered baroreceptor input into vasomotor center in medulla = tachycardia
- meds (BB)
80
definition of preload:
influenced by?
vol of blood inthe ventricles at the end of diastole
by: venous return and total circulating vol
81
what does a PT need if they have decreased vent compliance?
increased vent pressure and volume to support less stretch
82
definition afterload
what is the primary determinant?
resistance or load against which the ventricles have to pump to eject blood and produce cardiac output
primary = tone or vessel diameter
