Invasive Arterial BP Flashcards
Purpose of the Invasive arterial BP monitoring
beat to beat monitoring of BP
Allow for multiple ABG measurements
Monitoring of CO and SV when unable to place Pulmonary catheter
2 Contraindications for A line
Smaller end arteries with inadequate collateral blood flow
Suspected vascular insufficiency
Possible complications of A-line
Hematoma Thrombosis with distal ischemia Catheter embolism Pseudoaneurysm Systemic infection
Factors that increase risk for complications
Multiple attempts
High dose vasopressor
Large bore catheters
Best practice for A-line to prevent complications
2 interventions helpful
Continuous saline infusion 2-6ml /hr
flexible guidewire
Monitor pulse ox on the same side of the A-line
When should femoral A-line be discontinued?
within 5 days
When should A-line placed in sites other than femoral be D/C
Should not be changed on discontinued within 7 days
What does the Allen test check
Integrity of the ulnar collateral circulation
Steps to perform the allen test?
Ask the patient make a fist
Occlude both radial and ulnar arteries while patient
Relaxes blanched hand
Release pressure on the ulnar artery and flushing of the hand should occur within 5 seconds
What indicates insufficient collateral circulation
Flushing after > 10 seconds
If no flushing after 10 seconds
Test is NEGATIVE, DO NOT CANNULATE RADIAL ARTERY
If flushing occur within 5 seconds
Test is POSiTiVE, may cannulate radial artery
A-line Radial site and accuracy and one disadvantage
Radial site most commonly used, not accurate as it is distal from the heart.
Arterial line site that may lead to peripheral neuropathy
Radial
A-line Site more tortuous in its path
Ulnar
A-line Site allows patient mobility and comfort
Axllary
A-line site associated with Brachial Plexopathy?
Axillary
What is the implications of more centrally located catheters?
Risk of cerebral air or emboli with vigorous retrograde flushing
Associated with a less distorted waveform than more peripheral vessels , more prone to kinking
Brachial
A-line largest artery
Femoral
What is the site that more closely resemble the AORTIC pressure than peripheral sites such as the radial artery
Femoral
What is the Seldinger technique?
The use of the Guidewire-assisted cannulation
Position of the arm during radial a line insertion
Slight dorsiflexion
Steps to insert radial a-line
artery is palpated
Skin prepared with antiseptic
Local anesthetics for patient comfort and reduction of vasospasm
Needle and catheter introduced in vessel
Proximal occlusion ->tubing connected –>sterile dsg
The “fast flush” test is a method used at the
bedside to determine
the natural frequency and damping characteristics of the
transducing system.
The transducer is placed at the level of the
RIGHT ATRIUM
For beach chair or sitting position, transducer of a-line is commonly placed at the
Tragus of the ear to approximate the circle of willis and therefore cerebral pressure.
Before initiating therapy, the transducer system should be
examined quickly and the patency of
the arterial cannula verified.
2 conditions in which a line contraindicated
Reynaud phenomenon Thromboangiitis obliterans (Buerger disease),
Fidelity of the transducer system is better when the
tubing are stiff
mass of the fluid is small
the number of stopcocks is limited,
connecting tubing is not excessive
Underdamped pressure system will
Overestimate BP by 15-30mmHg
Overdamped pressure system will
Underestimate BP
Critically ill newborn infants, the________ represents a
convenient site for catheterization in order to measure arterial blood pressure and for blood sampling for laboratory values.
umbilical artery
Should not be attempted in efforts to restore function to an apparently occluded indwelling arterial catheter. It is
best to __________
High-pressure flushing
Clear the line by hand with a small syringe, using the minimum pressure and volume necessary, as even small-volume flushes (0.5 to 1 mL)
Small volume flushes even 0.5-1ml injected into the radial arteries of small infants using automated pressurizing
systems may cause
retrograde flow into the cerebral vessels
In arterial line monitoring, the slope of the upstroke indicates
Contractility
In arterial line monitoring, the slope of the downstroke indicates
Peripheral vascular resistance
Peripheral compared to central arterial waveform: arterial upstroke
STEEPER
Higher systolic peak peripheral vs central
Peripheral
Later dicrotic notch peripheral vs central
Peripheral
- Usually the primary source of hand blood flow
Ulnar artery
Brachial artery cannulation Danger! –
median nerve
Femoral A-line
Must be careful to be below inguinal ligament
