ICU 2B Flashcards
3 important factors when measuring haemodynamics
- accuracy
- interpretation + knowledge
- a correct response to the reading
Equipment needed
Transducer
Amplifier
Monitor / Recorder
Transducer
Converts fluid waves into electrical
signals
Amplifier
Increases the size of the electrical signal
Monitor / Recorder
Displays the signal and saves
data
Calibration of Equipment
Leveling
Zeroing
Leveling
Transducer at the level of
right atrium (phlebostatic
axis = 4th intercostal space
mid axilla)
Zeroing
• Atmospheric pressure
Complications
The most common complication is infection, hence the importance of ANTT.
Micro-organisms can migrate down the transducer line and rest at the insertion
site causing swelling (phlebitis), redness or pus; thus causing trauma to the
artery, possibly its collapse, and increasing the risk of sepsis.
Other complications include:
- Arterial wall puncture/Haematoma/Thrombosis
- Disconnection/haemorrhage/sanguination
- Sepsis
- Vascular insufficiency
- Arterial spasm
Arterial Line reflects the patients BP
MAP = mean arterial pressure (somewhere between 60-85mmHg)
Central Venous Pressure generally reflects the patient’s fluid status
CVP = 3 – 8 mm Hg
• Low CVP = hypovolaemia or ↓ venous return
• High CVP = overhydration, or ↑ venous return (right-sided heart
failure)
Central Venous Catheters
Measures the pressures in the right atrium.
• Used to assess right ventricular function and
venous blood return to heart.
CVP / Right Atrial Pressures
Reflection of right
ventricular filling pressures (preload)
• Increased CVP = fluid overload
• Decreased CVP = hypovolaemia
Triple Lumen CVC
Proximal port
Medial port
Distal port
hole closest to point of entry (18g, white)
18g (blue)
furthest away from entry point (used for CVP measurement, 16g –generally brown)
Nursing Implications
• Check unit policy (usually requires competency)
• Sterile dressing changes
• Tubing, caps and fluid bag changes as per policy
• Flush lumens; never tie off !
• Unused should be saline locked (not heparin)
• Withdraw blood before injection (to ensure
patency and to avoid pushing clot into patient).
Complications
- Local infection à sepsis
- Air embolism
- Pneumothorax/ haemothorax
- Blocked / clotted off
- Cardiac arrhythmias
- Damage to vein or adjacent structures
- Haemorrhage
The pulmonary artery catheter (PAC)
is a balloon
tipped thermo dilution catheter, that is inserted via
a large vein and floated into the pulmonary artery.
It is used to obtain haemodynamic measurements
which together with clinical observations indicate
how efficiently the heart is functioning.
Indications for a PAC
- To assess cardiovascular status: CCF, complicated MI, cardiac
tamponade, monitoring post cardiac bypass graft surgery - Shock (all types)
- Assessment of pulmonary status: Acute respiratory failure,
pulmonary hypertension, pulmonary oedema - To assess fluid status and requirements: burns, sepsis
- Major systems dysfunction
Nursing Implications
• Check patient position
• spontaneous ventilation - record end inspiration
• positive ventilation - record end expiration
• dysrhythmias
• dampened trace
• kink or knot
• Beware of spontaneous wedge (balloon inflates
and gets stuck)
Nursing Management of Pressure Lines
• Don’t become complacent …….these lines carry
potential fatal consequences for the patient if they
are not managed correctly
• Observe all sites for infection
• Don’t ever inject into an artery - could mean
amputation!
• Ensure NO air gets in the lines (not even a tiny bit!)
• Secure all lines and label correctly
