- HAEMODYNAMIC MONITORING - Flashcards
Purpose of Invasive Arterial Blood Pressure (ABP)
ABP facilitates continuous blood pressure monitoring and allows access for frequent arterial blood sampling
Arterial line Insertion sites (5)
- radial artery - femoral artery - brachial artery - dorsalis pedis artery - umbilical (neonates)
Indications for an arterial line (5)
- Uncontrolled hypertension - hypovolaemia - shock of all aetiology - vasoactive drugs/inotropes (e.g. aramine, adrenaline, dobutamine) - frequent blood sampling without venepuncture
Contraindications for an arterial line (5)
- absent pulse - full thickness burns - inadequate circulation - Buergers disease - Raynauds syndrome
Define and give the purpose of the Allens test
The Allens test is performed by manually occluding both radial and ulnar arteries through palpation. When the had turns white (poor perfusion) the ulnar artery is released and the hand should return to red (adequate perfusion). The Allens test determines the adequacy of the ulnar artery should the radial artery be occluded or damaged.
Nursing considerations for an arterial line (5)
- Maintain visibility of the insertion site and limb and perform 1/24ly neuromuscular obs - Perform manually blood pressure to ensure accuracy of 1st ABP - Zero the transducer at the beginning of each shift - Ensure the transducer is positioned at the phlebostatic axis to ensure accuracy of reading - Ensure medical officer performs Allens test prior to insertion of cannula
What is the atmospheric pressure (that must be zero’d)
760mmHg
Where is the phlebostatic axis?
Approximate reference point with the right atrium (4th intercostal space, mid-axilla/mid-thoracic line
What is the function of the transducer?
Converts the mechanical energy of the distension and recoil of the the vessels into an electrical signal displayed as a waveform on the monitor
What is the purpose of the pressure bag?
Inflated at 300mmHg will deliver approximately 3-5mls/hr to prevent back flow of blood and to maintain line patency
Define Central Venous Pressure
CVP is a measurement of is the blood pressure in the venae cavae, near the right atrium of the heart. CVP reflects the amount of blood returning to the heart and the ability of the heart to pump the blood back into the arterial system. It is used as a guide for overall fluid balance.
What is a normal CVP
0-8mmHg/2-8mmHg
List the insertion site for a CVC (3)
- Jugular vein (internal or external) - Subclavian vein - Femoral vein
Indications for a CVC (7)
- monitor fluid status through CVP - administer large amounts of fluid - administer fluids/medications rapidly - administering irritating meds - difficulty obtaining other access - long-term access - administering TPN
Contraindications for a CVC (9)
- obstructed vein (e.g. clot) - stenosis of the vein - severe coagulopathy - respiratory failure with high FiO2 - contaminated site - traumatised site (e.g. #clavical and subclavian vein) - full thickness burns - uncooperative awake pt - raised ICP
Nursing considerations for a CVC (5)
- Position pt supine or at 30 degrees - Place the transducer at the phlebostatic axis to ensure accurate CVP - Document pt position when CVP was taken and ensure same position for future measurements - Maintain patency of all CVC lumens with 8hrly flushes - Check CVC position on CXR prior to commencing infusions
What does the peak curvature of the arterial waveform represent (1)
Peak systolic pressure - aortic valve opens and blood is forced into the aorta
What does the diacrotic notch of the diacritic arch on an arterial waveform represent? (2)
Closure of the aortic valve
What does the anacrotic limb of an arterial waveform represent? (3)
This represents diastolic pressure - relaxation and vessel recoil
What does the anacrotic notch of the anacrotic limb in an arterial waveform represent?
The represents the opening of the aortic valve proceeding ventricular systole
What does the “a wave” of a CVP waveform represent?
atrial contraction
What does the “c wave” of a CVP waveform represent ?
bulging of the tricuspid valve into the atrium during ventricular filling
What does the “x decent” of a CVP waveform represent?
atrial relaxation
What does the “v wave” of a CVP waveform represent?
atrial filling
What does the “y decent” of a CVP waveform represent?
atrioventricular valve opening and the ventricles filling
Identify patient positioning for each of the insertion site options
Jugular (internal or external) - right side preferred - head turned slightly away from sight of venepuncture - Supine and Trendelenburg position (10-15 degrees feet above head) Subclavian - Supine, arm abducted, head neutural - Right side preferred - Trendelenburg position (10-15 degrees feet above head) Femoral - Supine flat position
List the equipment needed for CVC insertion
The insertion kit Sutures on a curved needle A needle driver Local anaesthetic Sterile saline Tinted alcohol-based chlorhexidine for skin antisepsis Transparent adhesive dressing Adhesive dressing Sterile gauze swabs Alcohol-based handrub Two pairs of sterile gloves A sterile gown Cap, mask, and protective eyewear
List the functions of each lumen in a multi-lumen CVC
distal for drawing blood and CVP measurements
medial for TPN
proximal for IV infusions
List the trouble shooting for a CVC when there is difficulty zeroing or reaching baseline on waveform (6)
- check all equipment, connections,taps and lines
- ensure all infusions running are switched off to infusions
- ensure there is adequate pressure in the pressure bag
- ensure the waveform is correctly labelled on the monitor
- check line for bubbles and blood clots - ensure all roller clamps are open
List the troubleshooting of a CVC when you are getting a false high reading (5)
- check the position of the catheter by checking the measurement markings on the catheter - check positioning at previous readings, previous position of the transducer and position on chest x-ray - re-zero waveform - remover any kinks, air bubbles, clots -if patient is on NIV take into account the PEEP
List the troubleshooting of a CVC that you are unable to asperate from (4)
- DO NOT FLUSH - lie the patient down flat if tolerated with CVC line down - check patient side for kinks - inform MO and consider replacing CVC if lumen is blocked
What is the normal value for pH on an ABG?
7.35-7.45
What is the normal value for HCO3- on an ABG?
22-26mmol/L
What is the normal value of pCO2 in an ABG?
35-45mmHg
What is the normal value of paO2 in an ABG?
75-100mmHg
What is the normal value of lactate in an ABG?
0.5-2.0 mmol/L
List the complications of an Arterial line (5)
Haemorrhage Emboli Infection Inadvertent drug administration Ischemia
