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hemodynamics

Terms in this set (53)

what 4 things need to be present for a hemodynamic monitoring system to function?
-system needs pressure
- high pressure tubing
-continuous flush of 3ml/hr to keep patent
- transducer
what does a transducer do?
converts pressure to an electrical signal
what does transducer need to sit?
at the phlebostatic axis - 4th intercostal at midaxillary line
how do you zero a transducer
turn stopcock off to pt, open to air and hit "zero" to zero to atmospheric pressure
why would you use PA hemodynamic monitoring?
-to evaluate cardiac function
- to evaluate pulmonary pressures
where do you place a PA cath?
subclavian
femoral
jugular
what are complications of PA cath?
infection/sepsis
air emboli or thrombus
heart muscle perforation
dysrhythmias
pneumothorax
what does CVP indicate?
right ventricular end diastolic pressure (R vent preload)
what is normal CVP?
2-8 mmHg
why do you want to measure venous pressure?
to get idea of:
-the capacity of the vascular system
-blood volume
-pumping action of the heart
what is considered the central venous system?
superior vena cava
inferior vena cava
right atrium
why might CVP be elevated?
-hypervolemia
- right CHF
- tricuspid regurgitation
- pericardial tamponade
why might CVP be reduced?
hypovolemia
what does systolic PAP indicate?
right ventricular pressure during systole
what is normal systolic PAP value?
20-30mmHg
what does diastolic PAP indicate?
pressure in pulmonary artery during diasole
- aortic and pulmonic valves closed
what is normal diastolic PAP value?
10-15mmHg
why might you have elevated PAP?
-pulmonary disease
-pulmonary embolism
-COPD
-pulmonary HTN
-pulmonary edema
-L vent failure
why might you have reduced PAP?
hypovolemia
what does the PAWP indicate?
L ventricle end diastolic pressure (preload in L vent)
how much air is inflated to achieve a PAWP?
1-1.5mL
what does the catheter measure when getting a PAWP measurement?
the pressure in the pulmonary venous system, which is equalizes to the L heart chamber pressures
what is normal PAWP?
8-12mmHg
what is PAWP directly related to?
diastolic fiber stretch, aka LV filling pressure
why would you have an increased PAWP?
-L vent heart failure
-increased LAP or pulmonary pressure
-mitral valve stenosis
-mitral valve regurgitation
- PEEP
-CPAP
why would you have a reduced PAWP?
hypovolemia
when will you see an onset of pulmonary congestion (PAWP level)?
PAWP = 18-20
when will you see moderate pulmonary congestion (PAWP level)?
PAWP = 20-25
when will you see severe pulmonary congestion (PAWP level)?
PAWP = 25-30
when will you see pulmonary edema (PAWP level)?
PAWP = >30
how is CO measured with a PA cath?
using thermodilution technique
steps of getting a CO reading
1. room temp NS or D5W injected into proximal port
2. bead at tip of cath detects temp change when reaches pulm artery
3. CO displayed on monitor - need 3 similar waveforms
what is a normal CO?
4-8L/min
what is cardiac index?
CO/body surface area
what is a normal cardiac index?
2.5-4L/min/m2
where is a arterial line inserted?
-radial
-femoral
-brachial
- pedal
what needs to be performed before inserting art line in radial artery?
allen's test
what is art line post insertion care?
suture line in place
sterile dressing
calibrate
complications of art line?
-hematoma
-infection
-decreased blood flow to extremity
-thrombus
-emboli
-blood loss
why would you use an art line?
-monitor for instant changes in BP
-more accurate BP readings than non-invasive
-access to obtain ABGs/blood draws
what will a normal art line wave form have?
dicrotic notch
what will a overdamped art line reading give you?
decreased BP readings
what will an underdamped art line give you?
increased BP readings
how do you fix an underdamped waveform?
-remove extra stopcocks/tubing from a line
why might you have an underdamped waveform (physiologically)?
artherosclerosis
HTN
fever
aortic regurgitation
how do you fix an overdamped waveform?
-flush catheter
-make sure no air bubbles
- make sure all connections are tight
why might you have an overdamped waveform (physiologically)
vasodilation
sepsis
shock states
what part of PA cath measures CO?
thermistor lumen
5 parameters measured by PA cath
-CVP
-PAP
-PAWP
-CO/CI
-PVR/SVR
when would you use a PA cath?
-pt post MI
-monitor fluid status - hypovolemic shock
-post open-heart surgery pt
why would you use a PA cath in a pt diagnosed with MI?
-to evaluate fluid status
-to evaluate cardiac funtion
what does dicrotic notch in a-line represent?
closure of aortic valve
what do you monitor for on patient with art line?
neurovascular status distal of art-line
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